diff --git a/lib/cli/Arguments.php b/lib/cli/Arguments.php
index 298d1a0..c6e41de 100644
--- a/lib/cli/Arguments.php
+++ b/lib/cli/Arguments.php
@@ -19,14 +19,23 @@
 
 /**
  * Parses command line arguments.
+ *
+ * @implements \ArrayAccess<string, mixed>
  */
 class Arguments implements \ArrayAccess {
+	/** @var array<string, array<string, mixed>> */
 	protected $_flags = array();
+	/** @var array<string, array<string, mixed>> */
 	protected $_options = array();
+	/** @var bool */
 	protected $_strict = false;
+	/** @var array<int, string> */
 	protected $_input = array();
+	/** @var array<int, string> */
 	protected $_invalid = array();
+	/** @var array<string, mixed>|null */
 	protected $_parsed;
+	/** @var Lexer|null */
 	protected $_lexer;
 
 	/**
@@ -36,37 +45,50 @@ class Arguments implements \ArrayAccess {
 	 *
 	 * `'help'` is `true` by default, `'strict'` is false by default.
 	 *
-	 * @param  array  $options  An array of options for this parser.
+	 * @param  array<string, mixed>  $options  An array of options for this parser.
 	 */
 	public function __construct($options = array()) {
 		$options += array(
 			'strict' => false,
-			'input'  => array_slice($_SERVER['argv'], 1)
+			'input'  => isset( $_SERVER['argv'] ) && is_array( $_SERVER['argv'] ) ? array_slice( $_SERVER['argv'], 1 ) : array(),
 		);
 
-		$this->_input = $options['input'];
-		$this->setStrict($options['strict']);
+		$input = $options['input'];
+		if ( ! is_array( $input ) ) {
+			$input = array();
+		}
+		$this->_input = array_map( function( $item ) { return is_scalar( $item ) ? (string) $item : ''; }, $input );
+		$this->setStrict( ! empty( $options['strict'] ) );
 
-		if (isset($options['flags'])) {
-			$this->addFlags($options['flags']);
+		if ( isset( $options['flags'] ) && is_array( $options['flags'] ) ) {
+			/** @var array<string, array<string, mixed>|string> $flags */
+			$flags = $options['flags'];
+			$this->addFlags( $flags );
 		}
-		if (isset($options['options'])) {
-			$this->addOptions($options['options']);
+		if ( isset( $options['options'] ) && is_array( $options['options'] ) ) {
+			/** @var array<string, array<string, mixed>|string> $opts */
+			$opts = $options['options'];
+			$this->addOptions( $opts );
 		}
 	}
 
 	/**
 	 * Get the list of arguments found by the defined definitions.
 	 *
-	 * @return array
+	 * @return array<string, mixed>
 	 */
 	public function getArguments() {
 		if (!isset($this->_parsed)) {
 			$this->parse();
 		}
-		return $this->_parsed;
+		return $this->_parsed ?? [];
 	}
 
+	/**
+	 * Get the help screen.
+	 *
+	 * @return HelpScreen
+	 */
 	public function getHelpScreen() {
 		return new HelpScreen($this);
 	}
@@ -77,7 +99,11 @@ public function getHelpScreen() {
 	 * @return string
 	 */
 	public function asJSON() {
-		return json_encode($this->_parsed);
+		$json = json_encode( $this->_parsed );
+		if ( false === $json ) {
+			throw new \RuntimeException( 'Failed to encode arguments as JSON' );
+		}
+		return $json;
 	}
 
 	/**
@@ -92,7 +118,11 @@ public function offsetExists($offset) {
 			$offset = $offset->key;
 		}
 
-		return array_key_exists($offset, $this->_parsed);
+		if ( ! is_string( $offset ) && ! is_int( $offset ) ) {
+			return false;
+		}
+
+		return array_key_exists($offset, $this->_parsed ?? []);
 	}
 
 	/**
@@ -107,9 +137,15 @@ public function offsetGet($offset) {
 			$offset = $offset->key;
 		}
 
+		if ( ! is_string( $offset ) && ! is_int( $offset ) ) {
+			return null;
+		}
+
 		if (isset($this->_parsed[$offset])) {
 			return $this->_parsed[$offset];
 		}
+
+		return null;
 	}
 
 	/**
@@ -124,6 +160,11 @@ public function offsetSet($offset, $value) {
 			$offset = $offset->key;
 		}
 
+		if ( ! is_string( $offset ) && ! is_int( $offset ) ) {
+			return;
+		}
+
+		$offset = (string) $offset;
 		$this->_parsed[$offset] = $value;
 	}
 
@@ -138,6 +179,10 @@ public function offsetUnset($offset) {
 			$offset = $offset->key;
 		}
 
+		if ( ! is_string( $offset ) && ! is_int( $offset ) ) {
+			return;
+		}
+
 		unset($this->_parsed[$offset]);
 	}
 
@@ -145,7 +190,7 @@ public function offsetUnset($offset) {
 	 * Adds a flag (boolean argument) to the argument list.
 	 *
 	 * @param mixed  $flag  A string representing the flag, or an array of strings.
-	 * @param array  $settings  An array of settings for this flag.
+	 * @param array<string, mixed>|string  $settings  An array of settings for this flag.
 	 * @setting string  description  A description to be shown in --help.
 	 * @setting bool    default  The default value for this flag.
 	 * @setting bool    stackable  Whether the flag is repeatable to increase the value.
@@ -160,6 +205,11 @@ public function addFlag($flag, $settings = array()) {
 			$settings['aliases'] = $flag;
 			$flag = array_shift($settings['aliases']);
 		}
+		if ( is_scalar( $flag ) ) {
+			$flag = (string) $flag;
+		} else {
+			$flag = '';
+		}
 		if (isset($this->_flags[$flag])) {
 			$this->_warn('flag already exists: ' . $flag);
 			return $this;
@@ -181,7 +231,7 @@ public function addFlag($flag, $settings = array()) {
 	 * primary flag character, and the values should be the settings array
 	 * used by {addFlag}.
 	 *
-	 * @param array  $flags  An array of flags to add
+	 * @param array<string, array<string, mixed>|string>  $flags  An array of flags to add
 	 * @return $this
 	 */
 	public function addFlags($flags) {
@@ -201,7 +251,7 @@ public function addFlags($flags) {
 	 * Adds an option (string argument) to the argument list.
 	 *
 	 * @param mixed  $option  A string representing the option, or an array of strings.
-	 * @param array  $settings  An array of settings for this option.
+	 * @param array<string, mixed>|string  $settings  An array of settings for this option.
 	 * @setting string  description  A description to be shown in --help.
 	 * @setting bool    default  The default value for this option.
 	 * @setting array   aliases  Other ways to trigger this option.
@@ -215,6 +265,11 @@ public function addOption($option, $settings = array()) {
 			$settings['aliases'] = $option;
 			$option = array_shift($settings['aliases']);
 		}
+		if ( is_scalar( $option ) ) {
+			$option = (string) $option;
+		} else {
+			$option = '';
+		}
 		if (isset($this->_options[$option])) {
 			$this->_warn('option already exists: ' . $option);
 			return $this;
@@ -235,7 +290,7 @@ public function addOption($option, $settings = array()) {
 	 * primary option string, and the values should be the settings array
 	 * used by {addOption}.
 	 *
-	 * @param array  $options  An array of options to add
+	 * @param array<string, array<string, mixed>|string>  $options  An array of options to add
 	 * @return $this
 	 */
 	public function addOptions($options) {
@@ -269,7 +324,7 @@ public function setStrict($strict) {
 	/**
 	 * Get the list of invalid arguments the parser found.
 	 *
-	 * @return array
+	 * @return array<int, string>
 	 */
 	public function getInvalidArguments() {
 		return $this->_invalid;
@@ -280,12 +335,16 @@ public function getInvalidArguments() {
 	 *
 	 * @param mixed  $flag  Either a string representing the flag or an
 	 *                      cli\arguments\Argument object.
-	 * @return array
+	 * @return array<string, mixed>|null
 	 */
 	public function getFlag($flag) {
 		if ($flag instanceOf Argument) {
 			$obj  = $flag;
-			$flag = $flag->value;
+			$flag = $flag->value();
+		}
+
+		if ( ! is_string( $flag ) && ! is_int( $flag ) ) {
+			return null;
 		}
 
 		if (isset($this->_flags[$flag])) {
@@ -302,12 +361,24 @@ public function getFlag($flag) {
 				return $settings;
 			}
 		}
+
+		return null;
 	}
 
+	/**
+	 * Get all flags.
+	 *
+	 * @return array<string, array<string, mixed>>
+	 */
 	public function getFlags() {
 		return $this->_flags;
 	}
 
+	/**
+	 * Check if there are any flags defined.
+	 *
+	 * @return bool
+	 */
 	public function hasFlags() {
 		return !empty($this->_flags);
 	}
@@ -341,12 +412,16 @@ public function isStackable($flag) {
 	 *
 	 * @param mixed  $option Either a string representing the option or an
 	 *                       cli\arguments\Argument object.
-	 * @return array
+	 * @return array<string, mixed>|null
 	 */
 	public function getOption($option) {
 		if ($option instanceOf Argument) {
 			$obj = $option;
-			$option = $option->value;
+			$option = $option->value();
+		}
+
+		if ( ! is_string( $option ) && ! is_int( $option ) ) {
+			return null;
 		}
 
 		if (isset($this->_options[$option])) {
@@ -362,12 +437,24 @@ public function getOption($option) {
 				return $settings;
 			}
 		}
+
+		return null;
 	}
 
+	/**
+	 * Get all options.
+	 *
+	 * @return array<string, array<string, mixed>>
+	 */
 	public function getOptions() {
 		return $this->_options;
 	}
 
+	/**
+	 * Check if there are any options defined.
+	 *
+	 * @return bool
+	 */
 	public function hasOptions() {
 		return !empty($this->_options);
 	}
@@ -388,7 +475,7 @@ public function isOption($argument) {
 	 * will use either the first long name given or the first name in the list
 	 * if a long name is not given.
 	 *
-	 * @return array
+	 * @return void
 	 * @throws arguments\InvalidArguments
 	 */
 	public function parse() {
@@ -398,15 +485,21 @@ public function parse() {
 
 		$this->_applyDefaults();
 
-		foreach ($this->_lexer as $argument) {
-			if ($this->_parseFlag($argument)) {
-				continue;
-			}
-			if ($this->_parseOption($argument)) {
-				continue;
-			}
+		if ($this->_lexer) {
+			foreach ($this->_lexer as $argument) {
+				if (null === $argument) {
+					continue;
+				}
+				if ($this->_parseFlag($argument)) {
+					continue;
+				}
+				if ($this->_parseOption($argument)) {
+					continue;
+				}
 
-			array_push($this->_invalid, $argument->raw);
+				$raw = $argument->raw();
+				array_push($this->_invalid, is_scalar($raw) ? (string) $raw : '');
+			}
 		}
 
 		if ($this->_strict && !empty($this->_invalid)) {
@@ -418,6 +511,8 @@ public function parse() {
 	 * This applies the default values, if any, of all of the
 	 * flags and options, so that if there is a default value
 	 * it will be available.
+	 *
+	 * @return void
 	 */
 	private function _applyDefaults() {
 		foreach($this->_flags as $flag => $settings) {
@@ -432,10 +527,22 @@ private function _applyDefaults() {
 		}
 	}
 
+	/**
+	 * Warn about something.
+	 *
+	 * @param string $message
+	 * @return void
+	 */
 	private function _warn($message) {
 		trigger_error('[' . __CLASS__ .'] ' . $message, E_USER_WARNING);
 	}
 
+	/**
+	 * Parse a flag.
+	 *
+	 * @param Argument $argument
+	 * @return bool
+	 */
 	private function _parseFlag($argument) {
 		if (!$this->isFlag($argument)) {
 			return false;
@@ -446,7 +553,8 @@ private function _parseFlag($argument) {
 				$this[$argument->key] = 0;
 			}
 
-			$this[$argument->key] += 1;
+			$current = $this[$argument->key];
+			$this[$argument->key] = (is_int($current) ? $current : 0) + 1;
 		} else {
 			$this[$argument->key] = true;
 		}
@@ -454,11 +562,19 @@ private function _parseFlag($argument) {
 		return true;
 	}
 
+	/**
+	 * Parse an option.
+	 *
+	 * @param Argument $option
+	 * @return bool
+	 */
 	private function _parseOption($option) {
 		if (!$this->isOption($option)) {
 			return false;
 		}
 
+		assert(null !== $this->_lexer);
+
 		// Peak ahead to make sure we get a value.
 		if ($this->_lexer->end() || !$this->_lexer->peek->isValue) {
 			$optionSettings = $this->getOption($option->key);
@@ -477,13 +593,20 @@ private function _parseOption($option) {
 		// Store as array and join to string after looping for values
 		$values = array();
 
+		$this->_lexer->next();
+
 		// Loop until we find a flag in peak-ahead
-		foreach ($this->_lexer as $value) {
-			array_push($values, $value->raw);
+		while ( $this->_lexer->valid() ) {
+			$value = $this->_lexer->current();
+			if ( null === $value ) {
+				break;
+			}
+			array_push( $values, $value->raw );
 
-			if (!$this->_lexer->end() && !$this->_lexer->peek->isValue) {
+			if ( ! $this->_lexer->end() && ! $this->_lexer->peek->isValue ) {
 				break;
 			}
+			$this->_lexer->next();
 		}
 
 		$this[$option->key] = join(' ', $values);
diff --git a/lib/cli/Colors.php b/lib/cli/Colors.php
index bba9f40..fb9e071 100644
--- a/lib/cli/Colors.php
+++ b/lib/cli/Colors.php
@@ -18,6 +18,7 @@
  * Reference: http://graphcomp.com/info/specs/ansi_col.html#colors
  */
 class Colors {
+	/** @var array<string, array<string, int>> */
 	static protected $_colors = array(
 		'color' => array(
 			'black'   => 30,
@@ -48,14 +49,28 @@ class Colors {
 			'white'   => 47
 		)
 	);
+	/** @var bool|null */
 	static protected $_enabled = null;
 
+	/** @var array<string, array<string, string>> */
 	static protected $_string_cache = array();
 
+	/**
+	 * Enable colorized output.
+	 *
+	 * @param bool $force Force enable.
+	 * @return void
+	 */
 	static public function enable($force = true) {
 		self::$_enabled = $force === true ? true : null;
 	}
 
+	/**
+	 * Disable colorized output.
+	 *
+	 * @param bool $force Force disable.
+	 * @return void
+	 */
 	static public function disable($force = true) {
 		self::$_enabled = $force === true ? false : null;
 	}
@@ -64,6 +79,9 @@ static public function disable($force = true) {
 	 * Check if we should colorize output based on local flags and shell type.
 	 *
 	 * Only check the shell type if `Colors::$_enabled` is null and `$colored` is null.
+	 *
+	 * @param bool|null $colored Force enable or disable the colorized output.
+	 * @return bool
 	 */
 	static public function shouldColorize($colored = null) {
 		return self::$_enabled === true ||
@@ -75,8 +93,8 @@ static public function shouldColorize($colored = null) {
 	/**
 	 * Set the color.
 	 *
-	 * @param string  $color  The name of the color or style to set.
-     * @return string
+	 * @param string|array<string, string|int>  $color  The name of the color or style to set, or an array of options.
+	 * @return string
 	 */
 	static public function color($color) {
 		if (!is_array($color)) {
@@ -171,6 +189,7 @@ static public function decolorize( $string, $keep = 0 ) {
 	 * @param string $passed The original string before colorization.
 	 * @param string $colorized The string after running through self::colorize.
 	 * @param string $deprecated Optional. Not used. Default null.
+	 * @return void
 	 */
 	static public function cacheString( $passed, $colorized, $deprecated = null ) {
 		self::$_string_cache[md5($passed)] = array(
@@ -225,7 +244,7 @@ static public function pad( $string, $length, $pre_colorized = false, $encoding
 	/**
 	 * Get the color mapping array.
 	 *
-	 * @return array Array of color tokens mapped to colors and styles.
+	 * @return array<string, array<string, string|int>> Array of color tokens mapped to colors and styles.
 	 */
 	static public function getColors() {
 		return array(
@@ -268,7 +287,7 @@ static public function getColors() {
 	/**
 	 * Get the cached string values.
 	 *
-	 * @return array The cached string values.
+	 * @return array<string, array<string, string>> The cached string values.
 	 */
 	static public function getStringCache() {
 		return self::$_string_cache;
@@ -276,6 +295,8 @@ static public function getStringCache() {
 
 	/**
 	 * Clear the string cache.
+	 *
+	 * @return void
 	 */
 	static public function clearStringCache() {
 		self::$_string_cache = array();
@@ -305,7 +326,7 @@ static public function getResetCode() {
 	 * @param string      $string   The string to wrap (with ANSI codes).
 	 * @param int         $width    The maximum display width per line.
 	 * @param string|bool $encoding Optional. The encoding of the string. Default false.
-	 * @return array Array of wrapped string segments.
+	 * @return array<int, string> Array of wrapped string segments.
 	 */
 	static public function wrapPreColorized( $string, $width, $encoding = false ) {
 		$wrapped = array();
@@ -319,6 +340,10 @@ static public function wrapPreColorized( $string, $width, $encoding = false ) {
 		// Split the string into parts: ANSI codes and text
 		$parts = preg_split( $ansi_pattern, $string, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
 		
+		if ( false === $parts ) {
+			$parts = array( $string );
+		}
+
 		foreach ( $parts as $part ) {
 			// Check if this part is an ANSI code
 			if ( preg_match( $ansi_pattern, $part ) ) {
@@ -340,6 +365,7 @@ static public function wrapPreColorized( $string, $width, $encoding = false ) {
 				
 				while ( $offset < $text_length ) {
 					$char = \cli\safe_substr( $part, $offset, 1, false, $encoding );
+					assert( is_string( $char ) );
 					$char_width = \cli\strwidth( $char, $encoding );
 					
 					// Check if adding this character would exceed the width
diff --git a/lib/cli/Memoize.php b/lib/cli/Memoize.php
index cedbc19..b08a619 100644
--- a/lib/cli/Memoize.php
+++ b/lib/cli/Memoize.php
@@ -13,8 +13,15 @@
 namespace cli;
 
 abstract class Memoize {
+	/** @var array<string, mixed> */
 	protected $_memoCache = array();
 
+	/**
+	 * Magic getter to retrieve memoized properties.
+	 *
+	 * @param string $name Property name.
+	 * @return mixed
+	 */
 	public function __get($name) {
 		if (isset($this->_memoCache[$name])) {
 			return $this->_memoCache[$name];
@@ -29,11 +36,16 @@ public function __get($name) {
 			return ($this->_memoCache[$name] = null);
 		}
 
-		$method = array($this, $name);
-		($this->_memoCache[$name] = call_user_func($method));
+		($this->_memoCache[$name] = $this->$name());
 		return $this->_memoCache[$name];
 	}
 
+	/**
+	 * Unmemoize a property or all properties.
+	 *
+	 * @param string|bool $name Property name to unmemoize, or true to unmemoize all.
+	 * @return void
+	 */
 	protected function _unmemo($name) {
 		if ($name === true) {
 			$this->_memoCache = array();
diff --git a/lib/cli/Notify.php b/lib/cli/Notify.php
index beaa0b3..e5a6271 100644
--- a/lib/cli/Notify.php
+++ b/lib/cli/Notify.php
@@ -24,14 +24,23 @@
  * of characters to indicate progress is being made.
  */
 abstract class Notify {
+	/** @var int */
 	protected $_current = 0;
+	/** @var bool */
 	protected $_first = true;
+	/** @var int */
 	protected $_interval;
+	/** @var string */
 	protected $_message;
+	/** @var int|null */
 	protected $_start;
+	/** @var float|null */
 	protected $_timer;
+	/** @var float|int|null */
 	protected $_tick;
+	/** @var int */
 	protected $_iteration = 0;
+	/** @var float|int */
 	protected $_speed = 0;
 
 	/**
@@ -52,11 +61,14 @@ public function __construct($msg, $interval = 100) {
 	 * @abstract
 	 * @param boolean  $finish
 	 * @see cli\Notify::tick()
+	 * @return void
 	 */
 	abstract public function display($finish = false);
 
 	/**
 	 * Reset the notifier state so the same instance can be used in multiple loops.
+	 *
+	 * @return void
 	 */
 	public function reset() {
 		$this->_current = 0;
@@ -109,7 +121,7 @@ public function speed() {
 			$this->_speed = ($this->_current / $this->_iteration) / $span;
 		}
 
-		return $this->_speed;
+		return (int) $this->_speed;
 	}
 
 	/**
@@ -120,7 +132,7 @@ public function speed() {
 	 * @return string  The formatted time span.
 	 */
 	public function formatTime($time) {
-		return floor($time / 60) . ':' . str_pad($time % 60, 2, 0, STR_PAD_LEFT);
+		return sprintf('%02d:%02d', (int)floor($time / 60), $time % 60);
 	}
 
 	/**
@@ -128,6 +140,7 @@ public function formatTime($time) {
 	 * no longer needed.
 	 *
 	 * @see cli\Notify::display()
+	 * @return void
 	 */
 	public function finish() {
 		Streams::out("\r");
@@ -140,6 +153,7 @@ public function finish() {
 	 * the ticker is incremented by 1.
 	 *
 	 * @param int  $increment  The amount to increment by.
+	 * @return void
 	 */
 	public function increment($increment = 1) {
 		$this->_current += $increment;
@@ -174,6 +188,7 @@ public function shouldUpdate() {
 	 * @see cli\Notify::increment()
 	 * @see cli\Notify::shouldUpdate()
 	 * @see cli\Notify::display()
+	 * @return void
 	 */
 	public function tick($increment = 1) {
 		$this->increment($increment);
diff --git a/lib/cli/Progress.php b/lib/cli/Progress.php
index a18c0a4..cd6b4ba 100644
--- a/lib/cli/Progress.php
+++ b/lib/cli/Progress.php
@@ -20,6 +20,7 @@
  * @see cli\Notify
  */
 abstract class Progress extends \cli\Notify {
+	/** @var int */
 	protected $_total = 0;
 
 	/**
@@ -40,6 +41,7 @@ public function __construct($msg, $total, $interval = 100) {
 	 *
 	 * @param int  $total  The total number of times this indicator should be `tick`ed.
 	 * @throws \InvalidArgumentException  Thrown if the `$total` is less than 0.
+	 * @return void
 	 */
 	public function setTotal($total) {
 		$this->_total = (int)$total;
@@ -51,6 +53,9 @@ public function setTotal($total) {
 
 	/**
 	 * Reset the progress state so the same instance can be used in multiple loops.
+	 *
+	 * @param int|null $total Optional new total.
+	 * @return void
 	 */
 	public function reset($total = null) {
 		parent::reset();
@@ -97,12 +102,14 @@ public function estimated() {
 		}
 
 		$estimated = round($this->_total / $speed);
-		return $estimated;
+		return (int)$estimated;
 	}
 
 	/**
 	 * Forces the current tick count to the total ticks given at instantiation
 	 * time before passing on to `cli\Notify::finish()`.
+	 *
+	 * @return void
 	 */
 	public function finish() {
 		$this->_current = $this->_total;
@@ -114,6 +121,7 @@ public function finish() {
 	 * the ticker is incremented by 1.
 	 *
 	 * @param int  $increment  The amount to increment by.
+	 * @return void
 	 */
 	public function increment($increment = 1) {
 		$this->_current = min($this->_total, $this->_current + $increment);
diff --git a/lib/cli/Shell.php b/lib/cli/Shell.php
index 9afb257..a3bb95d 100755
--- a/lib/cli/Shell.php
+++ b/lib/cli/Shell.php
@@ -50,7 +50,7 @@ static public function columns() {
 					}
 				} else {
 					$size = exec( '/usr/bin/env stty size 2>/dev/null' );
-					if ( '' !== $size && preg_match( '/[0-9]+ ([0-9]+)/', $size, $matches ) ) {
+					if ( $size && preg_match( '/[0-9]+ ([0-9]+)/', $size, $matches ) ) {
 						$columns = (int) $matches[1];
 					}
 					if ( ! $columns ) {
@@ -99,7 +99,9 @@ static public function isPiped() {
 
 	/**
 	 * Uses `stty` to hide input/output completely.
+	 *
 	 * @param boolean $hidden Will hide/show the next data. Defaults to true.
+	 * @return void
 	 */
 	static public function hide($hidden = true) {
 		system( 'stty ' . ( $hidden? '-echo' : 'echo' ) );
diff --git a/lib/cli/Streams.php b/lib/cli/Streams.php
index 71b454f..22a22e5 100755
--- a/lib/cli/Streams.php
+++ b/lib/cli/Streams.php
@@ -4,20 +4,36 @@
 
 class Streams {
 
+	/** @var resource */
 	protected static $out = STDOUT;
+	/** @var resource */
 	protected static $in = STDIN;
+	/** @var resource */
 	protected static $err = STDERR;
 
+	/**
+	 * Call a method on this class.
+	 *
+	 * @param string $func The method name.
+	 * @param array<int, mixed> $args The arguments.
+	 * @return mixed
+	 */
 	static function _call( $func, $args ) {
-		$method = __CLASS__ . '::' . $func;
+		$method = array( __CLASS__, $func );
+		assert( is_callable( $method ) );
 		return call_user_func_array( $method, $args );
 	}
 
-	static public function isTty() {
-		if ( function_exists('stream_isatty') ) {
-			return stream_isatty(static::$out);
+	/**
+	 * Check if the stream is a TTY.
+	 *
+	 * @return bool
+	 */
+	public static function isTty() {
+		if ( function_exists( 'stream_isatty' ) ) {
+			return stream_isatty( static::$out );
 		} else {
-			return (function_exists('posix_isatty') && posix_isatty(static::$out));
+			return ( function_exists( 'posix_isatty' ) && posix_isatty( static::$out ) );
 		}
 	}
 
@@ -27,36 +43,37 @@ static public function isTty() {
 	 * then each key in the array will be the placeholder name. Placeholders are of the
 	 * format {:key}.
 	 *
-	 * @param string   $msg  The message to render.
-	 * @param mixed    ...   Either scalar arguments or a single array argument.
+	 * @param string  $msg  The message to render.
+	 * @param mixed   ...$args Either scalar arguments or a single array argument.
 	 * @return string  The rendered string.
 	 */
-	public static function render( $msg ) {
-		$args = func_get_args();
-
+	public static function render( $msg, ...$args ) {
 		// No string replacement is needed
-		if( count( $args ) == 1 || ( is_string( $args[1] ) && '' === $args[1] ) ) {
+		if ( empty( $args ) || ( is_string( $args[0] ) && '' === $args[0] ) ) {
 			return Colors::shouldColorize() ? Colors::colorize( $msg ) : $msg;
 		}
 
 		// If the first argument is not an array just pass to sprintf
-		if( !is_array( $args[1] ) ) {
+		if ( ! is_array( $args[0] ) ) {
 			// Normalize color tokens before sprintf: colorize or strip them so no raw %tokens reach sprintf
 			if ( Colors::shouldColorize() ) {
-				$args[0] = Colors::colorize( $args[0] );
+				$msg = Colors::colorize( $msg );
 			} else {
-				$args[0] = Colors::decolorize( $args[0] );
+				$msg = Colors::decolorize( $msg );
 			}
 
 			// Escape percent characters for sprintf
-			$args[0] = preg_replace('/(%([^\w]|$))/', "%$1", $args[0]);
+			$msg = (string) preg_replace( '/(%([^\w]|$))/', '%$1', $msg );
 
-			return call_user_func_array( 'sprintf', $args );
+			$sprintf_args = array_merge( array( $msg ), $args );
+			/** @var string $rendered */
+			$rendered = call_user_func_array( 'sprintf', $sprintf_args );
+			return $rendered;
 		}
 
 		// Here we do named replacement so formatting strings are more understandable
-		foreach( $args[1] as $key => $value ) {
-			$msg = str_replace( '{:' . $key . '}', $value, $msg );
+		foreach ( $args[0] as $key => $value ) {
+			$msg = str_replace( '{:' . $key . '}', is_scalar( $value ) ? (string) $value : '', $msg );
 		}
 		return Colors::shouldColorize() ? Colors::colorize( $msg ) : $msg;
 	}
@@ -66,24 +83,26 @@ public static function render( $msg ) {
 	 * through `sprintf` before output.
 	 *
 	 * @param string  $msg  The message to output in `printf` format.
-	 * @param mixed   ...   Either scalar arguments or a single array argument.
+	 * @param mixed   ...$args Either scalar arguments or a single array argument.
 	 * @return void
 	 * @see \cli\render()
 	 */
-	public static function out( $msg ) {
-		fwrite( static::$out, self::_call( 'render', func_get_args() ) );
+	public static function out( $msg, ...$args ) {
+		$rendered = self::_call( 'render', func_get_args() );
+		fwrite( static::$out, is_scalar( $rendered ) ? (string) $rendered : '' );
 	}
 
 	/**
 	 * Pads `$msg` to the width of the shell before passing to `cli\out`.
 	 *
 	 * @param string  $msg  The message to pad and pass on.
-	 * @param mixed   ...   Either scalar arguments or a single array argument.
+	 * @param mixed   ...$args Either scalar arguments or a single array argument.
 	 * @return void
 	 * @see cli\out()
 	 */
-	public static function out_padded( $msg ) {
-		$msg = self::_call( 'render', func_get_args() );
+	public static function out_padded( $msg, ...$args ) {
+		$rendered = self::_call( 'render', func_get_args() );
+		$msg      = is_scalar( $rendered ) ? (string) $rendered : '';
 		self::out( str_pad( $msg, \cli\Shell::columns() ) );
 	}
 
@@ -91,12 +110,14 @@ public static function out_padded( $msg ) {
 	 * Prints a message to `STDOUT` with a newline appended. See `\cli\out` for
 	 * more documentation.
 	 *
+	 * @param string $msg The message to print.
+	 * @return void
 	 * @see cli\out()
 	 */
 	public static function line( $msg = '' ) {
 		// func_get_args is empty if no args are passed even with the default above.
-		$args = array_merge( func_get_args(), array( '' ) );
-		$args[0] .= "\n";
+		$args    = array_merge( func_get_args(), array( '' ) );
+		$args[0] = ( is_scalar( $args[0] ) ? (string) $args[0] : '' ) . "\n";
 
 		self::_call( 'out', $args );
 	}
@@ -107,14 +128,15 @@ public static function line( $msg = '' ) {
 	 *
 	 * @param string  $msg  The message to output in `printf` format. With no string,
 	 *                      a newline is printed.
-	 * @param mixed   ...   Either scalar arguments or a single array argument.
+	 * @param mixed   ...$args Either scalar arguments or a single array argument.
 	 * @return void
 	 */
-	public static function err( $msg = '' ) {
+	public static function err( $msg = '', ...$args ) {
 		// func_get_args is empty if no args are passed even with the default above.
-		$args = array_merge( func_get_args(), array( '' ) );
-		$args[0] .= "\n";
-		fwrite( static::$err, self::_call( 'render', $args ) );
+		$args     = array_merge( func_get_args(), array( '' ) );
+		$args[0]  = ( is_scalar( $args[0] ) ? (string) $args[0] : '' ) . "\n";
+		$rendered = self::_call( 'render', $args );
+		fwrite( static::$err, is_scalar( $rendered ) ? (string) $rendered : '' );
 	}
 
 	/**
@@ -129,10 +151,11 @@ public static function err( $msg = '' ) {
 	 * @throws \Exception  Thrown if ctrl-D (EOT) is sent as input.
 	 */
 	public static function input( $format = null, $hide = false ) {
-		if ( $hide )
+		if ( $hide ) {
 			Shell::hide();
+		}
 
-		if( $format ) {
+		if ( $format ) {
 			fscanf( static::$in, $format . "\n", $line );
 		} else {
 			$line = fgets( static::$in );
@@ -143,11 +166,11 @@ public static function input( $format = null, $hide = false ) {
 			echo "\n";
 		}
 
-		if( $line === false ) {
+		if ( $line === false ) {
 			throw new \Exception( 'Caught ^D during input' );
 		}
 
-		return trim( $line );
+		return trim( (string) $line );
 	}
 
 	/**
@@ -163,18 +186,20 @@ public static function input( $format = null, $hide = false ) {
 	 * @see cli\input()
 	 */
 	public static function prompt( $question, $default = false, $marker = ': ', $hide = false ) {
-		if( $default && strpos( $question, '[' ) === false ) {
+		if ( $default && strpos( $question, '[' ) === false ) {
 			$question .= ' [' . $default . ']';
 		}
 
-		while( true ) {
+		while ( true ) {
 			self::out( $question . $marker );
 			$line = self::input( null, $hide );
 
-			if ( trim( $line ) !== '' )
+			if ( trim( $line ) !== '' ) {
 				return $line;
-			if( $default !== false )
-				return $default;
+			}
+			if ( $default !== false ) {
+				return (string) $default;
+			}
 		}
 	}
 
@@ -184,27 +209,31 @@ public static function prompt( $question, $default = false, $marker = ': ', $hid
 	 *
 	 * @param string  $question  The question to ask the user.
 	 * @param string  $choice    A string of characters allowed as a response. Case is ignored.
-	 * @param string  $default   The default choice. NULL if a default is not allowed.
+	 * @param string|null $default   The default choice. NULL if a default is not allowed.
 	 * @return string  The users choice.
 	 * @see cli\prompt()
 	 */
 	public static function choose( $question, $choice = 'yn', $default = 'n' ) {
-		if( !is_string( $choice ) ) {
+		if ( ! is_string( $choice ) ) {
 			$choice = join( '', $choice );
 		}
 
 		// Make every choice character lowercase except the default
-		$choice = str_ireplace( $default, strtoupper( $default ), strtolower( $choice ) );
+		if ( null !== $default ) {
+			$choice = str_ireplace( $default, strtoupper( $default ), strtolower( $choice ) );
+		} else {
+			$choice = strtolower( $choice );
+		}
 		// Separate each choice with a forward-slash
-		$choices = trim( join( '/', preg_split( '//', $choice ) ), '/' );
+		$choices = trim( join( '/', str_split( $choice ) ), '/' );
 
-		while( true ) {
-			$line = self::prompt( sprintf( '%s? [%s]', $question, $choices ), $default, '' );
+		while ( true ) {
+			$line = self::prompt( sprintf( '%s? [%s]', $question, $choices ), $default ?? false, '' );
 
-			if( stripos( $choice, $line ) !== false ) {
+			if ( stripos( $choice, $line ) !== false ) {
 				return strtolower( $line );
 			}
-			if( !empty( $default ) ) {
+			if ( ! empty( $default ) ) {
 				return strtolower( $default );
 			}
 		}
@@ -215,8 +244,8 @@ public static function choose( $question, $choice = 'yn', $default = 'n' ) {
 	 * choose an option. The array must be a single dimension with either strings
 	 * or objects with a `__toString()` method.
 	 *
-	 * @param array   $items    The list of items the user can choose from.
-	 * @param string  $default  The index of the default item.
+	 * @param array<int|string, mixed>   $items    The list of items the user can choose from.
+	 * @param string|null  $default  The index of the default item.
 	 * @param string  $title    The message displayed to the user when prompted.
 	 * @return string  The index of the chosen item.
 	 * @see cli\line()
@@ -226,29 +255,42 @@ public static function choose( $question, $choice = 'yn', $default = 'n' ) {
 	public static function menu( $items, $default = null, $title = 'Choose an item' ) {
 		$map = array_values( $items );
 
-		if( $default && strpos( $title, '[' ) === false && isset( $items[$default] ) ) {
-			$title .= ' [' . $items[$default] . ']';
+		if ( $default && strpos( $title, '[' ) === false && isset( $items[ $default ] ) ) {
+			$default_item = $items[ $default ];
+			$default_str  = '';
+			if ( is_scalar( $default_item ) ) {
+				$default_str = (string) $default_item;
+			} elseif ( is_object( $default_item ) && method_exists( $default_item, '__toString' ) ) {
+				$default_str = (string) $default_item;
+			}
+			$title .= ' [' . $default_str . ']';
 		}
 
-		foreach( $map as $idx => $item ) {
-			self::line( '  %d. %s', $idx + 1, (string)$item );
+		foreach ( $map as $idx => $item ) {
+			$item_str = '';
+			if ( is_scalar( $item ) ) {
+				$item_str = (string) $item;
+			} elseif ( is_object( $item ) && method_exists( $item, '__toString' ) ) {
+				$item_str = (string) $item;
+			}
+			self::line( '  %d. %s', $idx + 1, $item_str );
 		}
 		self::line();
 
-		while( true ) {
+		while ( true ) {
 			fwrite( static::$out, sprintf( '%s: ', $title ) );
 			$line = self::input();
 
-			if( is_numeric( $line ) ) {
-				$line--;
-				if( isset( $map[$line] ) ) {
-					return array_search( $map[$line], $items );
+			if ( is_numeric( $line ) ) {
+				--$line;
+				if ( isset( $map[ $line ] ) ) {
+					return (string) array_search( $map[ $line ], $items );
 				}
 
-				if( $line < 0 || $line >= count( $map ) ) {
+				if ( $line < 0 || $line >= count( $map ) ) {
 					self::err( 'Invalid menu selection: out of range' );
 				}
-			} else if( isset( $default ) ) {
+			} elseif ( isset( $default ) ) {
 				return $default;
 			}
 		}
@@ -271,15 +313,16 @@ public static function menu( $items, $default = null, $title = 'Choose an item'
 	 * @throws \Exception Thrown if $stream is not a resource of the 'stream' type.
 	 */
 	public static function setStream( $whichStream, $stream ) {
-		if( !is_resource( $stream ) || get_resource_type( $stream ) !== 'stream' ) {
+		if ( ! is_resource( $stream ) || get_resource_type( $stream ) !== 'stream' ) {
 			throw new \Exception( 'Invalid resource type!' );
 		}
-		if( property_exists( __CLASS__, $whichStream ) ) {
+		if ( property_exists( __CLASS__, $whichStream ) ) {
 			static::${$whichStream} = $stream;
 		}
-		register_shutdown_function( function() use ($stream) {
-			fclose( $stream );
-		} );
+		register_shutdown_function(
+			function () use ( $stream ) {
+				fclose( $stream );
+			}
+		);
 	}
-
 }
diff --git a/lib/cli/Table.php b/lib/cli/Table.php
index 8ae90aa..770de06 100644
--- a/lib/cli/Table.php
+++ b/lib/cli/Table.php
@@ -23,17 +23,23 @@
  * The `Table` class is used to display data in a tabular format.
  */
 class Table {
+	/** @var \cli\table\Renderer */
 	protected $_renderer;
+	/** @var array<int, string> */
 	protected $_headers = array();
+	/** @var array<int, string> */
 	protected $_footers = array();
+	/** @var array<int, int> */
 	protected $_width = array();
+	/** @var array<int, array<int, string>> */
 	protected $_rows = array();
+	/** @var array<string, int>|array<int, int> */
 	protected $_alignments = array();
 
 	/**
 	 * Cached map of valid alignment constants.
 	 *
-	 * @var array|null
+	 * @var array<string|int, int>|null
 	 */
 	private static $_valid_alignments_map = null;
 
@@ -49,50 +55,65 @@ class Table {
 	 *     table are used as the header values.
 	 *  3. Pass nothing and use `setHeaders()` and `addRow()` or `setRows()`.
 	 *
-	 * @param array  $headers    Headers used in this table. Optional.
-	 * @param array  $rows       The rows of data for this table. Optional.
-	 * @param array  $footers    Footers used in this table. Optional.
-	 * @param array  $alignments Column alignments. Optional.
+	 * @param array<mixed>  $headers    Headers used in this table. Optional.
+	 * @param array<mixed>  $rows       The rows of data for this table. Optional.
+	 * @param array<mixed>  $footers    Footers used in this table. Optional.
+	 * @param array<mixed>  $alignments Column alignments. Optional.
 	 */
-	public function __construct(array $headers = array(), array $rows = array(), array $footers = array(), array $alignments = array()) {
-		if (!empty($headers)) {
+	public function __construct( array $headers = array(), array $rows = array(), array $footers = array(), array $alignments = array() ) {
+		$safe_strval = function ( $v ) {
+			return ( is_scalar( $v ) || ( is_object( $v ) && method_exists( $v, '__toString' ) ) ) ? (string) $v : '';
+		};
+
+		if ( ! empty( $headers ) ) {
 			// If all the rows is given in $headers we use the keys from the
 			// first row for the header values
-			if ($rows === array()) {
-				$rows = $headers;
-				$keys = array_keys(array_shift($headers));
-				$headers = array();
+			if ( $rows === array() ) {
+				$rows      = $headers;
+				$first_row = array_shift( $headers );
+				$keys      = is_array( $first_row ) ? array_keys( $first_row ) : array();
+				$headers   = array_map( $safe_strval, $keys );
+			} else {
+				$headers = array_map( $safe_strval, $headers );
+			}
 
-				foreach ($keys as $header) {
-					$headers[$header] = $header;
+			$this->setHeaders( $headers );
+
+			$safe_rows = array();
+			foreach ( $rows as $row ) {
+				if ( is_array( $row ) ) {
+					$safe_rows[] = array_map( $safe_strval, $row );
 				}
 			}
-
-			$this->setHeaders($headers);
-			$this->setRows($rows);
+			$this->setRows( $safe_rows );
 		}
 
-		if (!empty($footers)) {
-			$this->setFooters($footers);
+		if ( ! empty( $footers ) ) {
+			$this->setFooters( array_map( $safe_strval, $footers ) );
 		}
 
-		if (!empty($alignments)) {
-			$this->setAlignments($alignments);
+		if ( ! empty( $alignments ) ) {
+			/** @var array<string, int>|array<int, int> $alignments */
+			$this->setAlignments( $alignments );
 		}
 
-		if (Shell::isPiped()) {
-			$this->setRenderer(new Tabular());
+		if ( Shell::isPiped() ) {
+			$this->setRenderer( new Tabular() );
 		} else {
-			$this->setRenderer(new Ascii());
+			$this->setRenderer( new Ascii() );
 		}
 	}
 
-	public function resetTable()
-	{
-		$this->_headers = array();
-		$this->_width = array();
-		$this->_rows = array();
-		$this->_footers = array();
+	/**
+	 * Reset the table state.
+	 *
+	 * @return $this
+	 */
+	public function resetTable() {
+		$this->_headers    = array();
+		$this->_width      = array();
+		$this->_rows       = array();
+		$this->_footers    = array();
 		$this->_alignments = array();
 		return $this;
 	}
@@ -102,8 +123,7 @@ public function resetTable()
 	 *
 	 * @return $this
 	 */
-	public function resetRows()
-	{
+	public function resetRows() {
 		$this->_rows = array();
 		return $this;
 	}
@@ -115,22 +135,23 @@ public function resetRows()
 	 * @see   table\Renderer
 	 * @see   table\Ascii
 	 * @see   table\Tabular
+	 * @return void
 	 */
-	public function setRenderer(Renderer $renderer) {
+	public function setRenderer( Renderer $renderer ) {
 		$this->_renderer = $renderer;
 	}
 
 	/**
 	 * Loops through the row and sets the maximum width for each column.
 	 *
-	 * @param array  $row  The table row.
-     * @return array $row
+	 * @param array<int, string>  $row  The table row.
+	 * @return array<int, string> $row
 	 */
-	protected function checkRow(array $row) {
-		foreach ($row as $column => $str) {
+	protected function checkRow( array $row ) {
+		foreach ( $row as $column => $str ) {
 			$width = Colors::width( $str, $this->isAsciiPreColorized( $column ) );
-			if (!isset($this->_width[$column]) || $width > $this->_width[$column]) {
-				$this->_width[$column] = $width;
+			if ( ! isset( $this->_width[ $column ] ) || $width > $this->_width[ $column ] ) {
+				$this->_width[ $column ] = $width;
 			}
 		}
 
@@ -146,9 +167,10 @@ protected function checkRow(array $row) {
 	 * @uses cli\Shell::isPiped() Determine what format to output
 	 *
 	 * @see cli\Table::renderRow()
+	 * @return void
 	 */
 	public function display() {
-		foreach( $this->getDisplayLines() as $line ) {
+		foreach ( $this->getDisplayLines() as $line ) {
 			Streams::line( $line );
 		}
 	}
@@ -159,23 +181,24 @@ public function display() {
 	 * This method is useful for adding rows incrementally to an already-rendered table.
 	 * It will display the row with side borders and a bottom border (if using Ascii renderer).
 	 *
-	 * @param array $row The row data to display.
+	 * @param array<int, string> $row The row data to display.
+	 * @return void
 	 */
-	public function displayRow(array $row) {
+	public function displayRow( array $row ) {
 		// Update widths if this row has wider content
-		$row = $this->checkRow($row);
-		
+		$row = $this->checkRow( $row );
+
 		// Recalculate widths for the renderer
-		$this->_renderer->setWidths($this->_width, false);
-		
-		$rendered_row = $this->_renderer->row($row);
-		$row_lines = explode( PHP_EOL, $rendered_row );
+		$this->_renderer->setWidths( $this->_width, false );
+
+		$rendered_row = $this->_renderer->row( $row );
+		$row_lines    = explode( PHP_EOL, $rendered_row );
 		foreach ( $row_lines as $line ) {
 			Streams::line( $line );
 		}
-		
+
 		$border = $this->_renderer->border();
-		if (isset($border)) {
+		if ( isset( $border ) ) {
 			Streams::line( $border );
 		}
 	}
@@ -186,37 +209,37 @@ public function displayRow(array $row) {
 	 * @see cli\Table::display()
 	 * @see cli\Table::renderRow()
 	 *
-	 * @return array
+	 * @return array<int, string>
 	 */
 	public function getDisplayLines() {
-		$this->_renderer->setWidths($this->_width, $fallback = true);
-		$this->_renderer->setHeaders($this->_headers);
-		$this->_renderer->setAlignments($this->_alignments);
+		$this->_renderer->setWidths( $this->_width, $fallback = true );
+		$this->_renderer->setHeaders( $this->_headers );
+		$this->_renderer->setAlignments( $this->_alignments );
 		$border = $this->_renderer->border();
 
 		$out = array();
-		if (isset($border)) {
+		if ( isset( $border ) ) {
 			$out[] = $border;
 		}
-		$out[] = $this->_renderer->row($this->_headers);
-		if (isset($border)) {
+		$out[] = $this->_renderer->row( $this->_headers );
+		if ( isset( $border ) ) {
 			$out[] = $border;
 		}
 
-		foreach ($this->_rows as $row) {
-			$row = $this->_renderer->row($row);
+		foreach ( $this->_rows as $row ) {
+			$row = $this->_renderer->row( $row );
 			$row = explode( PHP_EOL, $row );
 			$out = array_merge( $out, $row );
 		}
 
 		// Only add final border if there are rows
-		if (!empty($this->_rows) && isset($border)) {
+		if ( ! empty( $this->_rows ) && isset( $border ) ) {
 			$out[] = $border;
 		}
 
-		if ($this->_footers) {
-			$out[] = $this->_renderer->row($this->_footers);
-			if (isset($border)) {
+		if ( $this->_footers ) {
+			$out[] = $this->_renderer->row( $this->_footers );
+			if ( isset( $border ) ) {
 				$out[] = $border;
 			}
 		}
@@ -227,42 +250,49 @@ public function getDisplayLines() {
 	 * Sort the table by a column. Must be called before `cli\Table::display()`.
 	 *
 	 * @param int  $column  The index of the column to sort by.
+	 * @return void
 	 */
-	public function sort($column) {
-		if (!isset($this->_headers[$column])) {
-			trigger_error('No column with index ' . $column, E_USER_NOTICE);
+	public function sort( $column ) {
+		if ( ! isset( $this->_headers[ $column ] ) ) {
+			trigger_error( 'No column with index ' . $column, E_USER_NOTICE );
 			return;
 		}
 
-		usort($this->_rows, function($a, $b) use ($column) {
-			return strcmp($a[$column], $b[$column]);
-		});
+		usort(
+			$this->_rows,
+			function ( $a, $b ) use ( $column ) {
+				return strcmp( $a[ $column ], $b[ $column ] );
+			}
+		);
 	}
 
 	/**
 	 * Set the headers of the table.
 	 *
-	 * @param array  $headers  An array of strings containing column header names.
+	 * @param array<int, string>  $headers  An array of strings containing column header names.
+	 * @return void
 	 */
-	public function setHeaders(array $headers) {
-		$this->_headers = $this->checkRow($headers);
+	public function setHeaders( array $headers ) {
+		$this->_headers = $this->checkRow( $headers );
 	}
 
 	/**
 	 * Set the footers of the table.
 	 *
-	 * @param array  $footers  An array of strings containing column footers names.
+	 * @param array<int, string>  $footers  An array of strings containing column footers names.
+	 * @return void
 	 */
-	public function setFooters(array $footers) {
-		$this->_footers = $this->checkRow($footers);
+	public function setFooters( array $footers ) {
+		$this->_footers = $this->checkRow( $footers );
 	}
 
 	/**
 	 * Set the alignments of the table.
 	 *
-	 * @param array  $alignments  An array of alignment constants keyed by column name.
+	 * @param array<string, int>|array<int, int>  $alignments  An array of alignment constants keyed by column name or index.
+	 * @return void
 	 */
-	public function setAlignments(array $alignments) {
+	public function setAlignments( array $alignments ) {
 		// Initialize the cached valid alignments map on first use
 		if ( null === self::$_valid_alignments_map ) {
 			self::$_valid_alignments_map = array_flip( array( Column::ALIGN_LEFT, Column::ALIGN_RIGHT, Column::ALIGN_CENTER ) );
@@ -284,35 +314,43 @@ public function setAlignments(array $alignments) {
 	/**
 	 * Add a row to the table.
 	 *
-	 * @param array  $row  The row data.
+	 * @param array<int, string>  $row  The row data.
 	 * @see cli\Table::checkRow()
+	 * @return void
 	 */
-	public function addRow(array $row) {
-		$this->_rows[] = $this->checkRow($row);
+	public function addRow( array $row ) {
+		$this->_rows[] = $this->checkRow( $row );
 	}
 
 	/**
 	 * Clears all previous rows and adds the given rows.
 	 *
-	 * @param array  $rows  A 2-dimensional array of row data.
+	 * @param array<int, array<int, string>>  $rows  A 2-dimensional array of row data.
 	 * @see cli\Table::addRow()
+	 * @return void
 	 */
-	public function setRows(array $rows) {
+	public function setRows( array $rows ) {
 		$this->_rows = array();
-		foreach ($rows as $row) {
-			$this->addRow($row);
+		foreach ( $rows as $row ) {
+			$this->addRow( $row );
 		}
 	}
 
+	/**
+	 * Count the number of rows in the table.
+	 *
+	 * @return int
+	 */
 	public function countRows() {
-		return count($this->_rows);
+		return count( $this->_rows );
 	}
 
 	/**
 	 * Set whether items in an Ascii table are pre-colorized.
 	 *
-	 * @param bool|array $precolorized A boolean to set all columns in the table as pre-colorized, or an array of booleans keyed by column index (number) to set individual columns as pre-colorized.
+	 * @param bool|array<int, bool> $pre_colorized A boolean to set all columns in the table as pre-colorized, or an array of booleans keyed by column index (number) to set individual columns as pre-colorized.
 	 * @see cli\Ascii::setPreColorized()
+	 * @return void
 	 */
 	public function setAsciiPreColorized( $pre_colorized ) {
 		if ( $this->_renderer instanceof Ascii ) {
@@ -324,8 +362,9 @@ public function setAsciiPreColorized( $pre_colorized ) {
 	 * Set the wrapping mode for table cells.
 	 *
 	 * @param string $mode One of: 'wrap' (default - wrap at character boundaries),
-	 *                     'word-wrap' (wrap at word boundaries), or 'truncate' (truncate with ellipsis).
+	 *                     'word-wrap' (word boundaries), or 'truncate' (truncate with ellipsis).
 	 * @see cli\Ascii::setWrappingMode()
+	 * @return void
 	 */
 	public function setWrappingMode( $mode ) {
 		if ( $this->_renderer instanceof Ascii ) {
diff --git a/lib/cli/Tree.php b/lib/cli/Tree.php
index 7570902..b1df849 100644
--- a/lib/cli/Tree.php
+++ b/lib/cli/Tree.php
@@ -17,7 +17,9 @@
  */
 class Tree {
 
+    /** @var \cli\tree\Renderer */
     protected $_renderer;
+    /** @var array<mixed> */
     protected $_data = array();
 
     /**
@@ -27,6 +29,7 @@ class Tree {
      * @see   tree\Renderer
      * @see   tree\Ascii
      * @see   tree\Markdown
+     * @return void
      */
     public function setRenderer(tree\Renderer $renderer) {
         $this->_renderer = $renderer;
@@ -41,7 +44,8 @@ public function setRenderer(tree\Renderer $renderer) {
      *         ],
      *         'Thing',
      *     ]
-     * @param array $data
+     * @param array<mixed> $data
+     * @return void
      */
     public function setData(array $data)
     {
@@ -60,6 +64,8 @@ public function render()
 
     /**
      * Display the rendered tree
+     *
+     * @return void
      */
     public function display()
     {
diff --git a/lib/cli/arguments/Argument.php b/lib/cli/arguments/Argument.php
index 9bc01f9..7ab070b 100644
--- a/lib/cli/arguments/Argument.php
+++ b/lib/cli/arguments/Argument.php
@@ -16,16 +16,26 @@
 
 /**
  * Represents an Argument or a value and provides several helpers related to parsing an argument list.
+ *
+ * @property-read bool $isLong
+ * @property-read bool $isShort
+ * @property-read bool $isArgument
+ * @property-read bool $canExplode
+ * @property-read array<int, string> $exploded
+ * @property-read string $raw
+ * @property-read bool $isValue
  */
 class Argument extends Memoize {
 	/**
 	 * The canonical name of this argument, used for aliasing.
 	 *
-	 * @param string
+	 * @var string
 	 */
 	public $key;
 
+	/** @var string */
 	private $_argument;
+	/** @var string */
 	private $_raw;
 
 	/**
@@ -121,7 +131,7 @@ public function canExplode() {
 	 * Returns all but the first character of the argument, removing them from the
 	 * objects representation at the same time.
 	 *
-	 * @return array
+	 * @return array<int, string>
 	 */
 	public function exploded() {
 		$exploded = array();
@@ -130,7 +140,7 @@ public function exploded() {
 			array_push($exploded, $this->_argument[$i - 1]);
 		}
 
-		$this->_argument = array_pop($exploded);
+		$this->_argument = (string) array_pop($exploded);
 		$this->_raw      = '-' . $this->_argument;
 		return $exploded;
 	}
diff --git a/lib/cli/arguments/HelpScreen.php b/lib/cli/arguments/HelpScreen.php
index f800788..ed4b7b3 100644
--- a/lib/cli/arguments/HelpScreen.php
+++ b/lib/cli/arguments/HelpScreen.php
@@ -18,105 +18,161 @@
  * Arguments help screen renderer
  */
 class HelpScreen {
+	/** @var array<string, array<string, mixed>> */
 	protected $_flags = array();
+	/** @var int */
 	protected $_flagMax = 0;
+	/** @var array<string, array<string, mixed>> */
 	protected $_options = array();
+	/** @var int */
 	protected $_optionMax = 0;
 
-	public function __construct(Arguments $arguments) {
-		$this->setArguments($arguments);
+	/**
+	 * @param Arguments $arguments
+	 */
+	public function __construct( Arguments $arguments ) {
+		$this->setArguments( $arguments );
 	}
 
+	/**
+	 * @return string
+	 */
 	public function __toString() {
 		return $this->render();
 	}
 
-	public function setArguments(Arguments $arguments) {
-		$this->consumeArgumentFlags($arguments);
-		$this->consumeArgumentOptions($arguments);
+	/**
+	 * @param Arguments $arguments
+	 * @return void
+	 */
+	public function setArguments( Arguments $arguments ) {
+		$this->consumeArgumentFlags( $arguments );
+		$this->consumeArgumentOptions( $arguments );
 	}
 
-	public function consumeArgumentFlags(Arguments $arguments) {
-		$data = $this->_consume($arguments->getFlags());
+	/**
+	 * @param Arguments $arguments
+	 * @return void
+	 */
+	public function consumeArgumentFlags( Arguments $arguments ) {
+		$data = $this->_consume( $arguments->getFlags() );
 
-		$this->_flags = $data[0];
+		$this->_flags   = $data[0];
 		$this->_flagMax = $data[1];
 	}
 
-	public function consumeArgumentOptions(Arguments $arguments) {
-		$data = $this->_consume($arguments->getOptions());
+		/**
+	 * @param Arguments $arguments
+	 * @return void
+	 */
+	public function consumeArgumentOptions( Arguments $arguments ) {
+		$data = $this->_consume( $arguments->getOptions() );
 
-		$this->_options = $data[0];
+		$this->_options   = $data[0];
 		$this->_optionMax = $data[1];
 	}
 
+	/**
+	 * @return string
+	 */
 	public function render() {
 		$help = array();
 
-		array_push($help, $this->_renderFlags());
-		array_push($help, $this->_renderOptions());
+		array_push( $help, $this->_renderFlags() );
+		array_push( $help, $this->_renderOptions() );
 
-		return join("\n\n", $help);
+		return join( "\n\n", $help );
 	}
 
+	/**
+	 * @return string|null
+	 */
 	private function _renderFlags() {
-		if (empty($this->_flags)) {
+		if ( empty( $this->_flags ) ) {
 			return null;
 		}
 
-		return "Flags\n" . $this->_renderScreen($this->_flags, $this->_flagMax);
+		return "Flags\n" . $this->_renderScreen( $this->_flags, $this->_flagMax );
 	}
 
+	/**
+	 * @return string|null
+	 */
 	private function _renderOptions() {
-		if (empty($this->_options)) {
+		if ( empty( $this->_options ) ) {
 			return null;
 		}
 
-		return "Options\n" . $this->_renderScreen($this->_options, $this->_optionMax);
+		return "Options\n" . $this->_renderScreen( $this->_options, $this->_optionMax );
 	}
 
-	private function _renderScreen($options, $max) {
+	/**
+	 * @param array<string, array<string, mixed>> $options
+	 * @param int $max
+	 * @return string
+	 */
+	private function _renderScreen( $options, $max ) {
 		$help = array();
-		foreach ($options as $option => $settings) {
-			$formatted = '  ' . str_pad($option, $max);
+		foreach ( $options as $option => $settings ) {
+			$formatted = '  ' . str_pad( $option, $max );
 
-			$dlen = 80 - 4 - $max;
+			$dlen          = max( 1, 80 - 4 - $max );
+			$settings_desc = $settings['description'];
+			$desc_str      = ( is_scalar( $settings_desc ) || ( is_object( $settings_desc ) && method_exists( $settings_desc, '__toString' ) ) ) ? (string) $settings_desc : '';
 
-			$description = str_split($settings['description'], $dlen);
-			$formatted.= '  ' . array_shift($description);
+			$description = array();
+			if ( '' !== $desc_str ) {
+				$description = str_split( $desc_str, $dlen );
+			}
 
-			if ($settings['default']) {
-				$formatted .= ' [default: ' . $settings['default'] . ']';
+			if ( empty( $description ) ) {
+				$description = array( '' );
 			}
 
-			$pad = str_repeat(' ', $max + 3);
-			while ($desc = array_shift($description)) {
+			$formatted .= '  ' . array_shift( $description );
+
+			if ( ! empty( $settings['default'] ) ) {
+				$default_val = $settings['default'];
+				$default_str = ( is_scalar( $default_val ) || ( is_object( $default_val ) && method_exists( $default_val, '__toString' ) ) ) ? (string) $default_val : '';
+				if ( '' !== $default_str ) {
+					$formatted .= ' [default: ' . $default_str . ']';
+				}
+			}
+
+			$pad = str_repeat( ' ', $max + 3 );
+			while ( $desc = array_shift( $description ) ) {
 				$formatted .= "\n{$pad}{$desc}";
 			}
 
-			array_push($help, $formatted);
+			array_push( $help, $formatted );
 		}
 
-		return join("\n", $help);
+		return join( "\n", $help );
 	}
 
-	private function _consume($options) {
+	/**
+	 * @param array<string, array<string, mixed>> $options
+	 * @return array{0: array<string, array<string, mixed>>, 1: int}
+	 */
+	private function _consume( $options ) {
 		$max = 0;
 		$out = array();
 
-		foreach ($options as $option => $settings) {
-			$names = array('--' . $option);
+		foreach ( $options as $option => $settings ) {
+			$names = array( '--' . $option );
 
-			foreach ($settings['aliases'] as $alias) {
-				array_push($names, '-' . $alias);
+			$aliases = $settings['aliases'];
+			if ( is_array( $aliases ) ) {
+				foreach ( $aliases as $alias ) {
+					array_push( $names, '-' . ( is_scalar( $alias ) ? (string) $alias : '' ) );
+				}
 			}
 
-			$names = join(', ', $names);
-			$max = max(strlen($names), $max);
-			$out[$names] = $settings;
+			$names         = join( ', ', $names );
+			$max           = max( strlen( $names ), $max );
+			$out[ $names ] = $settings;
 		}
 
-		return array($out, $max);
+		return array( $out, $max );
 	}
 }
-
diff --git a/lib/cli/arguments/InvalidArguments.php b/lib/cli/arguments/InvalidArguments.php
index 633c8c6..5a0b315 100644
--- a/lib/cli/arguments/InvalidArguments.php
+++ b/lib/cli/arguments/InvalidArguments.php
@@ -16,10 +16,11 @@
  * Thrown when undefined arguments are detected in strict mode.
  */
 class InvalidArguments extends \InvalidArgumentException {
+	/** @var array<int, string> */
 	protected $arguments;
 
 	/**
-	 * @param array  $arguments  A list of arguments that do not fit the profile.
+	 * @param array<int, string>  $arguments  A list of arguments that do not fit the profile.
 	 */
 	public function __construct(array $arguments) {
 		$this->arguments = $arguments;
@@ -29,12 +30,15 @@ public function __construct(array $arguments) {
 	/**
 	 * Get the arguments that caused the exception.
 	 *
-	 * @return array
+	 * @return array<int, string>
 	 */
 	public function getArguments() {
 		return $this->arguments;
 	}
 
+	/**
+	 * @return string
+	 */
 	private function _generateMessage() {
 		return 'unknown argument' .
 			(count($this->arguments) > 1 ? 's' : '') .
diff --git a/lib/cli/arguments/Lexer.php b/lib/cli/arguments/Lexer.php
index 3fb054b..381e3a6 100644
--- a/lib/cli/arguments/Lexer.php
+++ b/lib/cli/arguments/Lexer.php
@@ -14,15 +14,25 @@
 
 use cli\Memoize;
 
+/**
+ * @property-read Argument $peek
+ *
+ * @implements \Iterator<int, Argument|null>
+ */
 class Lexer extends Memoize implements \Iterator {
+	/** @var Argument|null */
 	private $_item;
+	/** @var array<int, string> */
 	private $_items = array();
+	/** @var int */
 	private $_index = 0;
+	/** @var int */
 	private $_length = 0;
+	/** @var bool */
 	private $_first = true;
 
 	/**
-	 * @param array  $items  A list of strings to process as tokens.
+	 * @param array<int, string>  $items  A list of strings to process as tokens.
 	 */
 	public function __construct(array $items) {
 		$this->_items = $items;
@@ -32,7 +42,7 @@ public function __construct(array $items) {
 	/**
 	 * The current token.
 	 *
-	 * @return string
+	 * @return Argument|null
 	 */
 	#[\ReturnTypeWillChange]
 	public function current() {
@@ -95,9 +105,11 @@ public function valid() {
 	 * Push an element to the front of the stack.
 	 *
 	 * @param mixed  $item  The value to set
+	 * @return void
 	 */
 	public function unshift($item) {
-		array_unshift($this->_items, $item);
+		$item_str = (is_scalar($item) || (is_object($item) && method_exists($item, '__toString'))) ? (string)$item : '';
+		array_unshift($this->_items, $item_str);
 		$this->_length += 1;
 	}
 
@@ -110,16 +122,23 @@ public function end() {
 		return ($this->_index + 1) == $this->_length;
 	}
 
+	/**
+	 * @return void
+	 */
 	private function _shift() {
-		$this->_item = new Argument(array_shift($this->_items));
+		$shifted = array_shift($this->_items);
+		$this->_item = null !== $shifted ? new Argument($shifted) : null;
 		$this->_index += 1;
 		$this->_explode();
 		$this->_unmemo('peek');
 	}
 
+	/**
+	 * @return void
+	 */
 	private function _explode() {
-		if (!$this->_item->canExplode) {
-			return false;
+		if (null === $this->_item || !$this->_item->canExplode) {
+			return;
 		}
 
 		foreach ($this->_item->exploded as $piece) {
diff --git a/lib/cli/cli.php b/lib/cli/cli.php
index ccc2b51..b86eaa6 100755
--- a/lib/cli/cli.php
+++ b/lib/cli/cli.php
@@ -19,12 +19,12 @@
  * then each key in the array will be the placeholder name. Placeholders are of the
  * format {:key}.
  *
- * @param string   $msg  The message to render.
- * @param mixed    ...   Either scalar arguments or a single array argument.
+ * @param string  $msg  The message to render.
+ * @param mixed   ...$args Either scalar arguments or a single array argument.
  * @return string  The rendered string.
  */
-function render( $msg ) {
-	return Streams::_call( 'render', func_get_args() );
+function render( $msg, ...$args ) {
+	return Streams::render( $msg, ...$args );
 }
 
 /**
@@ -32,11 +32,11 @@ function render( $msg ) {
  * through `sprintf` before output.
  *
  * @param string  $msg  The message to output in `printf` format.
- * @param mixed   ...   Either scalar arguments or a single array argument.
+ * @param mixed   ...$args Either scalar arguments or a single array argument.
  * @return void
  * @see \cli\render()
  */
-function out( $msg ) {
+function out( $msg, ...$args ) {
 	Streams::_call( 'out', func_get_args() );
 }
 
@@ -44,11 +44,11 @@ function out( $msg ) {
  * Pads `$msg` to the width of the shell before passing to `cli\out`.
  *
  * @param string  $msg  The message to pad and pass on.
- * @param mixed   ...   Either scalar arguments or a single array argument.
+ * @param mixed   ...$args Either scalar arguments or a single array argument.
  * @return void
  * @see cli\out()
  */
-function out_padded( $msg ) {
+function out_padded( $msg, ...$args ) {
 	Streams::_call( 'out_padded', func_get_args() );
 }
 
@@ -56,6 +56,8 @@ function out_padded( $msg ) {
  * Prints a message to `STDOUT` with a newline appended. See `\cli\out` for
  * more documentation.
  *
+ * @param string $msg Message to print.
+ * @return void
  * @see cli\out()
  */
 function line( $msg = '' ) {
@@ -68,10 +70,10 @@ function line( $msg = '' ) {
  *
  * @param string  $msg  The message to output in `printf` format. With no string,
  *                      a newline is printed.
- * @param mixed   ...   Either scalar arguments or a single array argument.
+ * @param mixed   ...$args Either scalar arguments or a single array argument.
  * @return void
  */
-function err( $msg = '' ) {
+function err( $msg = '', ...$args ) {
 	Streams::_call( 'err', func_get_args() );
 }
 
@@ -140,7 +142,7 @@ function confirm( $question, $default = false ) {
  * choose an option. The array must be a single dimension with either strings
  * or objects with a `__toString()` method.
  *
- * @param array  $items   The list of items the user can choose from.
+ * @param array<int|string, mixed>  $items   The list of items the user can choose from.
  * @param string $default The index of the default item.
  * @param string $title   The message displayed to the user when prompted.
  * @return string  The index of the chosen item.
@@ -162,10 +164,10 @@ function menu( $items, $default = null, $title = 'Choose an item' ) {
  */
 function safe_strlen( $str, $encoding = false ) {
 	// Allow for selective testings - "1" bit set tests grapheme_strlen(), "2" preg_match_all( '/\X/u' ), "4" mb_strlen(), "other" strlen().
-	$test_safe_strlen = getenv( 'PHP_CLI_TOOLS_TEST_SAFE_STRLEN' );
+	$test_safe_strlen = (int) getenv( 'PHP_CLI_TOOLS_TEST_SAFE_STRLEN' );
 
-	// Assume UTF-8 if no encoding given - `grapheme_strlen()` will return null if given non-UTF-8 string.
-	if ( ( ! $encoding || 'UTF-8' === $encoding ) && can_use_icu() && null !== ( $length = grapheme_strlen( $str ) ) ) {
+	// Assume UTF-8 if no encoding given - `grapheme_strlen()` will return false on failure.
+	if ( ( ! $encoding || 'UTF-8' === $encoding ) && can_use_icu() && is_int( $length = grapheme_strlen( $str ) ) ) {
 		if ( ! $test_safe_strlen || ( $test_safe_strlen & 1 ) ) {
 			return $length;
 		}
@@ -181,10 +183,12 @@ function safe_strlen( $str, $encoding = false ) {
 		if ( ! $encoding ) {
 			$encoding = mb_detect_encoding( $str, null, true /*strict*/ );
 		}
-		$length = $encoding ? mb_strlen( $str, $encoding ) : mb_strlen( $str ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
+		$length = is_string( $encoding ) ? mb_strlen( $str, $encoding ) : mb_strlen( $str ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
 		if ( 'UTF-8' === $encoding ) {
 			// Subtract combining characters.
-			$length -= preg_match_all( get_unicode_regexs( 'm' ), $str, $dummy /*needed for PHP 5.3*/ );
+			$m_regex = get_unicode_regexs( 'm' );
+			assert( is_string( $m_regex ) );
+			$length -= preg_match_all( $m_regex, $str, $dummy /*needed for PHP 5.3*/ );
 		}
 		if ( ! $test_safe_strlen || ( $test_safe_strlen & 4 ) ) {
 			return $length;
@@ -215,6 +219,8 @@ function safe_substr( $str, $start, $length = false, $is_width = false, $encodin
 	// Normalize `$length` when not specified - PHP 5.3 substr takes false as full length, PHP > 5.3 takes null.
 	if ( null === $length || false === $length ) {
 		$length = $safe_strlen;
+	} else {
+		$length = (int) $length;
 	}
 	// Normalize `$start` - various methods treat this differently.
 	if ( $start > $safe_strlen ) {
@@ -225,7 +231,7 @@ function safe_substr( $str, $start, $length = false, $is_width = false, $encodin
 	}
 
 	// Allow for selective testings - "1" bit set tests grapheme_substr(), "2" preg_split( '/\X/' ), "4" mb_substr(), "8" substr().
-	$test_safe_substr = getenv( 'PHP_CLI_TOOLS_TEST_SAFE_SUBSTR' );
+	$test_safe_substr = (int) getenv( 'PHP_CLI_TOOLS_TEST_SAFE_SUBSTR' );
 
 	// Assume UTF-8 if no encoding given - `grapheme_substr()` will return false (not null like `grapheme_strlen()`) if given non-UTF-8 string.
 	if ( ( ! $encoding || 'UTF-8' === $encoding ) && can_use_icu() && false !== ( $try = grapheme_substr( $str, $start, $length ) ) ) {
@@ -248,7 +254,7 @@ function safe_substr( $str, $start, $length = false, $is_width = false, $encodin
 			$encoding = mb_detect_encoding( $str, null, true /*strict*/ );
 		}
 		// Bug: not adjusting for combining chars.
-		$try = $encoding ? mb_substr( $str, $start, $length, $encoding ) : mb_substr( $str, $start, $length ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
+		$try = is_string( $encoding ) ? mb_substr( $str, $start, $length, $encoding ) : mb_substr( $str, $start, $length ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
 		if ( 'UTF-8' === $encoding && $is_width ) {
 			$try = _safe_substr_eaw( $try, $length );
 		}
@@ -262,11 +268,14 @@ function safe_substr( $str, $start, $length = false, $is_width = false, $encodin
 /**
  * Internal function used by `safe_substr()` to adjust for East Asian double-width chars.
  *
+ * @param string $str
+ * @param int $length
  * @return string
  */
 function _safe_substr_eaw( $str, $length ) {
 	// Set the East Asian Width regex.
 	$eaw_regex = get_unicode_regexs( 'eaw' );
+	assert( is_string( $eaw_regex ) );
 
 	// If there's any East Asian double-width chars...
 	if ( preg_match( $eaw_regex, $str ) ) {
@@ -279,6 +288,9 @@ function _safe_substr_eaw( $str, $length ) {
 		} else {
 			// Explode string into an array of UTF-8 chars. Based on core `_mb_substr()` in "wp-includes/compat.php".
 			$chars = preg_split( '/([\x00-\x7f\xc2-\xf4][^\x00-\x7f\xc2-\xf4]*)/', $str, $length + 1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
+			if ( false === $chars ) {
+				$chars = array( $str );
+			}
 			$cnt = min( count( $chars ), $length );
 			$width = $length;
 
@@ -322,10 +334,12 @@ function strwidth( $string, $encoding = false ) {
 	$string = (string) $string;
 	
 	// Set the East Asian Width and Mark regexs.
-	list( $eaw_regex, $m_regex ) = get_unicode_regexs();
+	$regexs = get_unicode_regexs();
+	assert( is_array( $regexs ) );
+	list( $eaw_regex, $m_regex ) = $regexs;
 
 	// Allow for selective testings - "1" bit set tests grapheme_strlen(), "2" preg_match_all( '/\X/u' ), "4" mb_strwidth(), "other" safe_strlen().
-	$test_strwidth = getenv( 'PHP_CLI_TOOLS_TEST_STRWIDTH' );
+	$test_strwidth = (int) getenv( 'PHP_CLI_TOOLS_TEST_STRWIDTH' );
 
 	// Assume UTF-8 if no encoding given - `grapheme_strlen()` will return null if given non-UTF-8 string.
 	if ( ( ! $encoding || 'UTF-8' === $encoding ) && can_use_icu() && null !== ( $width = grapheme_strlen( $string ) ) ) {
@@ -344,7 +358,7 @@ function strwidth( $string, $encoding = false ) {
 		if ( ! $encoding ) {
 			$encoding = mb_detect_encoding( $string, null, true /*strict*/ );
 		}
-		$width = $encoding ? mb_strwidth( $string, $encoding ) : mb_strwidth( $string ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
+		$width = is_string( $encoding ) ? mb_strwidth( $string, $encoding ) : mb_strwidth( $string ); // mbstring funcs can fail if given `$encoding` arg that evals to false.
 		if ( 'UTF-8' === $encoding ) {
 			// Subtract combining characters.
 			$width -= preg_match_all( $m_regex, $string, $dummy /*needed for PHP 5.3*/ );
@@ -393,8 +407,8 @@ function can_use_pcre_x() {
 /**
  * Get the regexs generated from Unicode data.
  *
- * @param string $idx Optional. Return a specific regex only. Default null.
- * @return array|string  Returns keyed array if not given $idx or $idx doesn't exist, otherwise the specific regex string.
+ * @param string|null $idx Optional. Return a specific regex only. Default null.
+ * @return array<int, string>|string  Returns keyed array if not given $idx or $idx doesn't exist, otherwise the specific regex string.
  */
 function get_unicode_regexs( $idx = null ) {
 	static $eaw_regex; // East Asian Width regex. Characters that count as 2 characters as they're "wide" or "fullwidth". See http://www.unicode.org/reports/tr11/tr11-19.html
diff --git a/lib/cli/notify/Dots.php b/lib/cli/notify/Dots.php
index e3a5159..2d00de2 100644
--- a/lib/cli/notify/Dots.php
+++ b/lib/cli/notify/Dots.php
@@ -19,9 +19,12 @@
  * A Notifier that displays a string of periods.
  */
 class Dots extends Notify {
+	/** @var int */
 	protected $_dots;
+	/** @var string */
 	protected $_format = '{:msg}{:dots}  ({:elapsed}, {:speed}/s)';
-	protected $_iteration;
+	/** @var int */
+	protected $_iteration = 0;
 
 	/**
 	 * Instantiates a Notification object.
@@ -46,6 +49,7 @@ public function __construct($msg, $dots = 3, $interval = 100) {
 	 *
 	 * @param boolean  $finish  `true` if this was called from
 	 *                          `cli\Notify::finish()`, `false` otherwise.
+	 * @return void
 	 * @see cli\out_padded()
 	 * @see cli\Notify::formatTime()
 	 * @see cli\Notify::speed()
diff --git a/lib/cli/notify/Spinner.php b/lib/cli/notify/Spinner.php
index 8da7890..80f5faf 100644
--- a/lib/cli/notify/Spinner.php
+++ b/lib/cli/notify/Spinner.php
@@ -19,8 +19,11 @@
  * The `Spinner` Notifier displays an ASCII spinner.
  */
 class Spinner extends Notify {
+	/** @var string */
 	protected $_chars = '-\|/';
+	/** @var string */
 	protected $_format = '{:msg} {:char}  ({:elapsed}, {:speed}/s)';
+	/** @var int */
 	protected $_iteration = 0;
 
 	/**
@@ -29,6 +32,7 @@ class Spinner extends Notify {
 	 *
 	 * @param boolean  $finish  `true` if this was called from
 	 *                          `cli\Notify::finish()`, `false` otherwise.
+	 * @return void
 	 * @see cli\out_padded()
 	 * @see cli\Notify::formatTime()
 	 * @see cli\Notify::speed()
diff --git a/lib/cli/progress/Bar.php b/lib/cli/progress/Bar.php
index 9c58f76..9fcf397 100644
--- a/lib/cli/progress/Bar.php
+++ b/lib/cli/progress/Bar.php
@@ -26,9 +26,13 @@
  *   ^MSG  PER% [=======================            ]  00:00 / 00:00$
  */
 class Bar extends Progress {
+	/** @var string */
 	protected $_bars = '=>';
+	/** @var string */
 	protected $_formatMessage = '{:msg}  {:percent}% [';
+	/** @var string */
 	protected $_formatTiming = '] {:elapsed} / {:estimated}';
+	/** @var string */
 	protected $_format = '{:msg}{:bar}{:timing}';
 
 	/**
@@ -61,6 +65,7 @@ public function __construct($msg, $total, $interval = 100, $formatMessage = null
 	 *
 	 * @param boolean  $finish  `true` if this was called from
 	 *                          `cli\Notify::finish()`, `false` otherwise.
+	 * @return void
 	 * @see cli\out()
 	 * @see cli\Notify::formatTime()
 	 * @see cli\Notify::elapsed()
@@ -71,7 +76,7 @@ public function __construct($msg, $total, $interval = 100, $formatMessage = null
 	public function display($finish = false) {
 		$_percent = $this->percent();
 
-		$percent = str_pad(floor($_percent * 100), 3);
+		$percent = str_pad((string)(int)floor($_percent * 100), 3);
 		$msg = $this->_message;
 		$current = $this->current();
 		$total = $this->total();
@@ -91,7 +96,7 @@ public function display($finish = false) {
 			$size = 0;
 		}
 
-		$bar = str_repeat($this->_bars[0], floor($_percent * $size)) . $this->_bars[1];
+		$bar = str_repeat($this->_bars[0], (int)floor($_percent * $size)) . $this->_bars[1];
 		// substr is needed to trim off the bar cap at 100%
 		$bar = substr(str_pad($bar, $size, ' '), 0, $size);
 
@@ -104,6 +109,7 @@ public function display($finish = false) {
 	 *
 	 * @param int    $increment The amount to increment by.
 	 * @param string $msg       The text to display next to the Notifier. (optional)
+	 * @return void
 	 * @see cli\Notify::tick()
 	 */
 	public function tick($increment = 1, $msg = null) {
diff --git a/lib/cli/table/Ascii.php b/lib/cli/table/Ascii.php
index fd20bc9..b71d5d4 100644
--- a/lib/cli/table/Ascii.php
+++ b/lib/cli/table/Ascii.php
@@ -34,27 +34,47 @@ class Ascii extends Renderer {
 	 */
 	private const ELLIPSIS_WIDTH = 3;
 
+	/**
+	 * @var array<string, string>
+	 */
 	protected $_characters = array(
 		'corner'  => '+',
 		'line'    => '-',
 		'border'  => '|',
 		'padding' => ' ',
 	);
+
+	/**
+	 * @var string|null
+	 */
 	protected $_border = null;
+
+	/**
+	 * @var int|null
+	 */
 	protected $_constraintWidth = null;
+
+	/**
+	 * @var bool|array<int, bool>
+	 */
 	protected $_pre_colorized = false;
+
+	/**
+	 * @var string
+	 */
 	protected $_wrapping_mode = 'wrap'; // 'wrap', 'word-wrap', or 'truncate'
 
 	/**
 	 * Set the widths of each column in the table.
 	 *
-	 * @param array  $widths    The widths of the columns.
-	 * @param bool   $fallback  Whether to use these values as fallback only.
+	 * @param array<int, int> $widths   The widths of the columns.
+	 * @param bool            $fallback Whether to use these values as fallback only.
+	 * @return void
 	 */
-	public function setWidths(array $widths, $fallback = false) {
-		if ($fallback) {
+	public function setWidths( array $widths, $fallback = false ) {
+		if ( $fallback ) {
 			foreach ( $this->_widths as $index => $value ) {
-			    $widths[$index] = $value;
+				$widths[ $index ] = $value;
 			}
 		}
 		$this->_widths = $widths;
@@ -62,18 +82,18 @@ public function setWidths(array $widths, $fallback = false) {
 		if ( is_null( $this->_constraintWidth ) ) {
 			$this->_constraintWidth = (int) Shell::columns();
 		}
-		$col_count = count( $widths );
-		$col_borders_count = $col_count ? ( ( $col_count - 1 ) * strlen( $this->_characters['border'] ) ) : 0;
+		$col_count           = count( $widths );
+		$col_borders_count   = $col_count ? ( ( $col_count - 1 ) * strlen( $this->_characters['border'] ) ) : 0;
 		$table_borders_count = strlen( $this->_characters['border'] ) * 2;
-		$col_padding_count = $col_count * strlen( $this->_characters['padding'] ) * 2;
-		$max_width = $this->_constraintWidth - $col_borders_count - $table_borders_count - $col_padding_count;
+		$col_padding_count   = $col_count * strlen( $this->_characters['padding'] ) * 2;
+		$max_width           = $this->_constraintWidth - $col_borders_count - $table_borders_count - $col_padding_count;
 
 		if ( $widths && $max_width && array_sum( $widths ) > $max_width ) {
 
-			$avg = floor( $max_width / count( $widths ) );
+			$avg           = (int) floor( $max_width / count( $widths ) );
 			$resize_widths = array();
-			$extra_width = 0;
-			foreach( $widths as $width ) {
+			$extra_width   = 0;
+			foreach ( $widths as $width ) {
 				if ( $width > $avg ) {
 					$resize_widths[] = $width;
 				} else {
@@ -82,8 +102,8 @@ public function setWidths(array $widths, $fallback = false) {
 			}
 
 			if ( ! empty( $resize_widths ) && $extra_width ) {
-				$avg_extra_width = floor( $extra_width / count( $resize_widths ) );
-				foreach( $widths as &$width ) {
+				$avg_extra_width = (int) floor( $extra_width / count( $resize_widths ) );
+				foreach ( $widths as &$width ) {
 					if ( in_array( $width, $resize_widths ) ) {
 						$width = $avg + $avg_extra_width;
 						array_shift( $resize_widths );
@@ -95,7 +115,6 @@ public function setWidths(array $widths, $fallback = false) {
 					}
 				}
 			}
-
 		}
 
 		$this->_widths = $widths;
@@ -107,6 +126,7 @@ public function setWidths(array $widths, $fallback = false) {
 	 * Set the constraint width for the table
 	 *
 	 * @param int $constraintWidth
+	 * @return void
 	 */
 	public function setConstraintWidth( $constraintWidth ) {
 		$this->_constraintWidth = $constraintWidth;
@@ -117,6 +137,7 @@ public function setConstraintWidth( $constraintWidth ) {
 	 *
 	 * @param string $mode One of: 'wrap' (default - wrap at character boundaries),
 	 *                     'word-wrap' (wrap at word boundaries), or 'truncate' (truncate with ellipsis).
+	 * @return void
 	 */
 	public function setWrappingMode( $mode ) {
 		if ( ! in_array( $mode, self::VALID_WRAPPING_MODES, true ) ) {
@@ -130,10 +151,11 @@ public function setWrappingMode( $mode ) {
 	 *
 	 * The keys `corner`, `line` and `border` are used in rendering.
 	 *
-	 * @param $characters  array  Characters used in rendering.
+	 * @param array<string, string> $characters Characters used in rendering.
+	 * @return void
 	 */
-	public function setCharacters(array $characters) {
-		$this->_characters = array_merge($this->_characters, $characters);
+	public function setCharacters( array $characters ) {
+		$this->_characters = array_merge( $this->_characters, $characters );
 	}
 
 	/**
@@ -143,10 +165,10 @@ public function setCharacters(array $characters) {
 	 * @return string  The table border.
 	 */
 	public function border() {
-		if (!isset($this->_border)) {
+		if ( ! isset( $this->_border ) ) {
 			$this->_border = $this->_characters['corner'];
-			foreach ($this->_widths as $width) {
-				$this->_border .= str_repeat($this->_characters['line'], $width + 2);
+			foreach ( $this->_widths as $width ) {
+				$this->_border .= str_repeat( $this->_characters['line'], $width + 2 );
 				$this->_border .= $this->_characters['corner'];
 			}
 		}
@@ -157,27 +179,31 @@ public function border() {
 	/**
 	 * Renders a row for output.
 	 *
-	 * @param array  $row  The table row.
-	 * @return string  The formatted table row.
+	 * @param array<int, mixed> $row The table row.
+	 * @return string The formatted table row.
 	 */
 	public function row( array $row ) {
 
 		$extra_row_count = 0;
+		$extra_rows      = [];
 
 		if ( count( $row ) > 0 ) {
 			$extra_rows = array_fill( 0, count( $row ), array() );
 
 			foreach ( $row as $col => $value ) {
-				$value              = $value ?: '';
+				$value              = ( is_scalar( $value ) || ( is_object( $value ) && method_exists( $value, '__toString' ) ) ) ? (string) $value : '';
 				$col_width          = $this->_widths[ $col ];
 				$encoding           = function_exists( 'mb_detect_encoding' ) ? mb_detect_encoding( $value, null, true /*strict*/ ) : false;
 				$original_val_width = Colors::width( $value, self::isPreColorized( $col ), $encoding );
 				if ( $col_width && ( $original_val_width > $col_width || strpos( $value, "\n" ) !== false ) ) {
 					$split_lines = preg_split( '/\r\n|\n/', $value );
+					if ( false === $split_lines ) {
+						$split_lines = array( $value );
+					}
 
 					$wrapped_lines = [];
 					foreach ( $split_lines as $line ) {
-						$line_wrapped = $this->wrapText( $line, $col_width, $encoding, self::isPreColorized( $col ) );
+						$line_wrapped  = $this->wrapText( $line, $col_width, $encoding, self::isPreColorized( $col ) );
 						$wrapped_lines = array_merge( $wrapped_lines, $line_wrapped );
 					}
 
@@ -190,34 +216,34 @@ public function row( array $row ) {
 			}
 		}
 
-		$row = array_map(array($this, 'padColumn'), $row, array_keys($row));
-		array_unshift($row, ''); // First border
-		array_push($row, ''); // Last border
+		$row = array_map( array( $this, 'padColumn' ), $row, array_keys( $row ) );
+		array_unshift( $row, '' ); // First border
+		array_push( $row, '' ); // Last border
 
-		$ret = join($this->_characters['border'], $row);
+		$ret = join( $this->_characters['border'], $row );
 		if ( $extra_row_count ) {
-			foreach( $extra_rows as $col => $col_values ) {
-				while( count( $col_values ) < $extra_row_count ) {
+			foreach ( $extra_rows as $col => $col_values ) {
+				while ( count( $col_values ) < $extra_row_count ) {
 					$col_values[] = '';
 				}
 			}
 
 			do {
 				$row_values = array();
-				$has_more = false;
-				foreach( $extra_rows as $col => &$col_values ) {
+				$has_more   = false;
+				foreach ( $extra_rows as $col => &$col_values ) {
 					$row_values[ $col ] = ! empty( $col_values ) ? array_shift( $col_values ) : '';
 					if ( count( $col_values ) ) {
 						$has_more = true;
 					}
 				}
 
-				$row_values = array_map(array($this, 'padColumn'), $row_values, array_keys($row_values));
-				array_unshift($row_values, ''); // First border
-				array_push($row_values, ''); // Last border
+				$row_values = array_map( array( $this, 'padColumn' ), $row_values, array_keys( $row_values ) );
+				array_unshift( $row_values, '' ); // First border
+				array_push( $row_values, '' ); // Last border
 
-				$ret .= PHP_EOL . join($this->_characters['border'], $row_values);
-			} while( $has_more );
+				$ret .= PHP_EOL . join( $this->_characters['border'], $row_values );
+			} while ( $has_more );
 		}
 		return $ret;
 	}
@@ -236,16 +262,24 @@ private function getColumnAlignment( $column ) {
 		return Column::ALIGN_LEFT;
 	}
 
-	private function padColumn($content, $column) {
+	/**
+	 * Pad a column value.
+	 *
+	 * @param string $content The column content.
+	 * @param int    $column  The column index.
+	 * @return string The padded column.
+	 */
+	private function padColumn( $content, $column ) {
 		$alignment = $this->getColumnAlignment( $column );
-		$content = str_replace( "\t", '    ', (string) $content );
+		$content   = str_replace( "\t", '    ', (string) $content );
 		return $this->_characters['padding'] . Colors::pad( $content, $this->_widths[ $column ], $this->isPreColorized( $column ), false, $alignment ) . $this->_characters['padding'];
 	}
 
 	/**
 	 * Set whether items are pre-colorized.
 	 *
-	 * @param bool|array $colorized A boolean to set all columns in the table as pre-colorized, or an array of booleans keyed by column index (number) to set individual columns as pre-colorized.
+	 * @param bool|array<int, bool> $pre_colorized A boolean to set all columns in the table as pre-colorized, or an array of booleans keyed by column index (number) to set individual columns as pre-colorized.
+	 * @return void
 	 */
 	public function setPreColorized( $pre_colorized ) {
 		$this->_pre_colorized = $pre_colorized;
@@ -258,7 +292,7 @@ public function setPreColorized( $pre_colorized ) {
 	 * @param int         $width     The maximum width.
 	 * @param string|bool $encoding  The text encoding.
 	 * @param bool        $is_precolorized Whether the text is pre-colorized.
-	 * @return array Array of wrapped lines.
+	 * @return array<int, string> Array of wrapped lines.
 	 */
 	protected function wrapText( $text, $width, $encoding, $is_precolorized ) {
 		if ( ! $width ) {
@@ -276,11 +310,11 @@ protected function wrapText( $text, $width, $encoding, $is_precolorized ) {
 		if ( 'truncate' === $this->_wrapping_mode ) {
 			if ( $width <= self::ELLIPSIS_WIDTH ) {
 				// Not enough space for ellipsis, just truncate
-				return array( \cli\safe_substr( $text, 0, $width, true /*is_width*/, $encoding ) );
+				return array( (string) \cli\safe_substr( $text, 0, $width, true /*is_width*/, $encoding ) );
 			}
-			
+
 			// Truncate and add ellipsis
-			$truncated = \cli\safe_substr( $text, 0, $width - self::ELLIPSIS_WIDTH, true /*is_width*/, $encoding );
+			$truncated = (string) \cli\safe_substr( $text, 0, $width - self::ELLIPSIS_WIDTH, true /*is_width*/, $encoding );
 			return array( $truncated . self::ELLIPSIS );
 		}
 
@@ -291,23 +325,23 @@ protected function wrapText( $text, $width, $encoding, $is_precolorized ) {
 
 		// Default: character-boundary wrapping
 		$wrapped_lines = array();
-		$line = $text;
-		
+		$line          = $text;
+
 		// Use the new color-aware wrapping for pre-colorized content
 		if ( $is_precolorized ) {
 			$wrapped_lines = Colors::wrapPreColorized( $line, $width, $encoding );
 		} else {
 			// For non-colorized content, use character-boundary wrapping
 			do {
-				$wrapped_value = \cli\safe_substr( $line, 0, $width, true /*is_width*/, $encoding );
+				$wrapped_value = (string) \cli\safe_substr( $line, 0, $width, true /*is_width*/, $encoding );
 				$val_width     = Colors::width( $wrapped_value, $is_precolorized, $encoding );
 				if ( $val_width ) {
 					$wrapped_lines[] = $wrapped_value;
-					$line = \cli\safe_substr( $line, \cli\safe_strlen( $wrapped_value, $encoding ), null /*length*/, false /*is_width*/, $encoding );
+					$line            = (string) \cli\safe_substr( $line, \cli\safe_strlen( $wrapped_value, $encoding ), null /*length*/, false /*is_width*/, $encoding );
 				}
 			} while ( $line );
 		}
-		
+
 		return $wrapped_lines;
 	}
 
@@ -318,56 +352,59 @@ protected function wrapText( $text, $width, $encoding, $is_precolorized ) {
 	 * @param int         $width     The maximum width.
 	 * @param string|bool $encoding  The text encoding.
 	 * @param bool        $is_precolorized Whether the text is pre-colorized.
-	 * @return array Array of wrapped lines.
+	 * @return array<int, string> Array of wrapped lines.
 	 */
 	protected function wordWrap( $text, $width, $encoding, $is_precolorized ) {
-		$wrapped_lines = array();
-		$current_line = '';
+		$wrapped_lines      = array();
+		$current_line       = '';
 		$current_line_width = 0;
-		
+
 		// Split by spaces and hyphens while keeping the delimiters
 		$words = preg_split( '/(\s+|-)/u', $text, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
-		
+		if ( false === $words ) {
+			$words = array( $text );
+		}
+
 		foreach ( $words as $word ) {
 			$word_width = Colors::width( $word, $is_precolorized, $encoding );
-			
+
 			// If this word alone exceeds the width, we need to split it
 			if ( $word_width > $width ) {
 				// Flush current line if not empty
 				if ( $current_line !== '' ) {
-					$wrapped_lines[] = $current_line;
-					$current_line = '';
+					$wrapped_lines[]    = $current_line;
+					$current_line       = '';
 					$current_line_width = 0;
 				}
-				
+
 				// Split the long word at character boundaries
 				$remaining_word = $word;
 				while ( $remaining_word ) {
-					$chunk = \cli\safe_substr( $remaining_word, 0, $width, true /*is_width*/, $encoding );
+					$chunk           = (string) \cli\safe_substr( $remaining_word, 0, $width, true /*is_width*/, $encoding );
 					$wrapped_lines[] = $chunk;
-					$remaining_word = \cli\safe_substr( $remaining_word, \cli\safe_strlen( $chunk, $encoding ), null /*length*/, false /*is_width*/, $encoding );
+					$remaining_word  = (string) \cli\safe_substr( $remaining_word, \cli\safe_strlen( $chunk, $encoding ), null /*length*/, false /*is_width*/, $encoding );
 				}
 				continue;
 			}
-			
+
 			// Check if adding this word would exceed the width
 			if ( $current_line !== '' && $current_line_width + $word_width > $width ) {
 				// Start a new line
-				$wrapped_lines[] = $current_line;
-				$current_line = $word;
+				$wrapped_lines[]    = $current_line;
+				$current_line       = $word;
 				$current_line_width = $word_width;
 			} else {
 				// Add to current line
-				$current_line .= $word;
+				$current_line       .= $word;
 				$current_line_width += $word_width;
 			}
 		}
-		
+
 		// Add any remaining content
 		if ( $current_line !== '' ) {
 			$wrapped_lines[] = $current_line;
 		}
-		
+
 		return $wrapped_lines ?: array( '' );
 	}
 
diff --git a/lib/cli/table/Renderer.php b/lib/cli/table/Renderer.php
index 6bf6df7..10aa85a 100644
--- a/lib/cli/table/Renderer.php
+++ b/lib/cli/table/Renderer.php
@@ -16,10 +16,27 @@
  * Table renderers are used to change how a table is displayed.
  */
 abstract class Renderer {
+	/**
+	 * @var array<int, int>
+	 */
 	protected $_widths = array();
+
+	/**
+	 * @var array<string|int, int>
+	 */
 	protected $_alignments = array();
+
+	/**
+	 * @var array<int, string>
+	 */
 	protected $_headers = array();
 
+	/**
+	 * Constructor.
+	 *
+	 * @param array<int, int> $widths     Column widths.
+	 * @param array<string|int, int> $alignments Column alignments.
+	 */
 	public function __construct(array $widths = array(), array $alignments = array()) {
 		$this->setWidths($widths);
 		$this->setAlignments($alignments);
@@ -28,7 +45,8 @@ public function __construct(array $widths = array(), array $alignments = array()
 	/**
 	 * Set the alignments of each column in the table.
 	 *
-	 * @param array  $alignments  The alignments of the columns.
+	 * @param array<string|int, int> $alignments The alignments of the columns.
+	 * @return void
 	 */
 	public function setAlignments(array $alignments) {
 		$this->_alignments = $alignments;
@@ -37,7 +55,8 @@ public function setAlignments(array $alignments) {
 	/**
 	 * Set the headers of the table.
 	 *
-	 * @param array  $headers  The headers of the table.
+	 * @param array<int, string> $headers The headers of the table.
+	 * @return void
 	 */
 	public function setHeaders(array $headers) {
 		$this->_headers = $headers;
@@ -46,8 +65,9 @@ public function setHeaders(array $headers) {
 	/**
 	 * Set the widths of each column in the table.
 	 *
-	 * @param array  $widths    The widths of the columns.
-	 * @param bool   $fallback  Whether to use these values as fallback only.
+	 * @param array<int, int> $widths   The widths of the columns.
+	 * @param bool            $fallback Whether to use these values as fallback only.
+	 * @return void
 	 */
 	public function setWidths(array $widths, $fallback = false) {
 		if ($fallback) {
@@ -62,7 +82,7 @@ public function setWidths(array $widths, $fallback = false) {
 	 * Render a border for the top and bottom and separating the headers from the
 	 * table rows.
 	 *
-	 * @return string  The table border.
+	 * @return string|null  The table border.
 	 */
 	public function border() {
 		return null;
@@ -71,8 +91,8 @@ public function border() {
 	/**
 	 * Renders a row for output.
 	 *
-	 * @param array  $row  The table row.
-	 * @return string  The formatted table row.
+	 * @param array<int, mixed> $row The table row.
+	 * @return string The formatted table row.
 	 */
-	abstract public function row(array $row);
+	abstract public function row( array $row );
 }
diff --git a/lib/cli/table/Tabular.php b/lib/cli/table/Tabular.php
index 0675b4c..f373799 100644
--- a/lib/cli/table/Tabular.php
+++ b/lib/cli/table/Tabular.php
@@ -19,32 +19,40 @@ class Tabular extends Renderer {
 	/**
 	 * Renders a row for output.
 	 *
-	 * @param array  $row  The table row.
-	 * @return string  The formatted table row.
+	 * @param array<int, mixed> $row The table row.
+	 * @return string The formatted table row.
 	 */
 	public function row( array $row ) {
-		$rows   = [];
-		$output = '';
+		/** @var array<int, array<int, string>> $rows */
+		$rows        = [];
+		$output      = '';
+		$split_lines = [];
+		$col         = null;
 
 		foreach ( $row as $col => $value ) {
-			$value       = isset( $value ) ? (string) $value : '';
+			$value       = ( isset( $value ) && ( is_scalar( $value ) || ( is_object( $value ) && method_exists( $value, '__toString' ) ) ) ) ? (string) $value : '';
 			$value       = str_replace( "\t", '    ', $value );
 			$split_lines = preg_split( '/\r\n|\n/', $value );
+			if ( false === $split_lines ) {
+				$split_lines = array( $value );
+			}
 			// Keep anything before the first line break on the original line
 			$row[ $col ] = array_shift( $split_lines );
 		}
 
 		$rows[] = $row;
 
-		foreach ( $split_lines as $i => $line ) {
-			if ( ! isset( $rows[ $i + 1 ] ) ) {
-				$rows[ $i + 1 ] = array_fill_keys( array_keys( $row ), '' );
+		if ( null !== $col ) {
+			foreach ( $split_lines as $i => $line ) {
+				if ( ! isset( $rows[ $i + 1 ] ) ) {
+					$rows[ $i + 1 ] = array_fill_keys( array_keys( $row ), '' );
+				}
+				$rows[ $i + 1 ][ $col ] = $line;
 			}
-			$rows[ $i + 1 ][ $col ] = $line;
 		}
 
 		foreach ( $rows as $r ) {
-			$output .= implode( "\t", array_values( $r ) ) . PHP_EOL;
+			$output .= implode( "\t", $r ) . PHP_EOL;
 		}
 		return rtrim( $output, PHP_EOL );
 	}
diff --git a/lib/cli/tree/Ascii.php b/lib/cli/tree/Ascii.php
index 00edf38..a94a8ef 100644
--- a/lib/cli/tree/Ascii.php
+++ b/lib/cli/tree/Ascii.php
@@ -18,7 +18,7 @@
 class Ascii extends Renderer {
 
     /**
-     * @param array $tree
+     * @param array<int|string, mixed> $tree
      * @return string
      */
     public function render(array $tree)
diff --git a/lib/cli/tree/Markdown.php b/lib/cli/tree/Markdown.php
index ba1fd05..7f718f7 100644
--- a/lib/cli/tree/Markdown.php
+++ b/lib/cli/tree/Markdown.php
@@ -37,7 +37,7 @@ function __construct($padding = null)
     /**
      * Renders the tree
      *
-     * @param array $tree
+     * @param array<int|string, mixed> $tree
      * @param int $level Optional
      * @return string
      */
diff --git a/lib/cli/tree/Renderer.php b/lib/cli/tree/Renderer.php
index ff352bc..8348ffe 100644
--- a/lib/cli/tree/Renderer.php
+++ b/lib/cli/tree/Renderer.php
@@ -18,7 +18,7 @@
 abstract class Renderer {
 
     /**
-     * @param array $tree
+     * @param array<int|string, mixed> $tree
      * @return string|null
      */
     abstract public function render(array $tree);
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
new file mode 100644
index 0000000..4611d49
--- /dev/null
+++ b/phpstan.neon.dist
@@ -0,0 +1,9 @@
+parameters:
+  level: 9
+  paths:
+    - lib
+  scanDirectories:
+    - vendor/wp-cli/wp-cli/php
+  scanFiles:
+    - vendor/php-stubs/wordpress-stubs/wordpress-stubs.php
+  treatPhpDocTypesAsCertain: false