Add support for .length on strings

Author: theodorejb

README.md

@@ -8,7 +8,7 @@ possible to swap out Mustache for Handlebars and continue using the same templat
 ## Features
 
 * Supports all Handlebars syntax and language features, including expressions, subexpressions, helpers,
-partials, hooks, `@data` variables, whitespace control, and `.length` on arrays.
+partials, hooks, `@data` variables, whitespace control, and `.length` on arrays and strings.
 * Templates are parsed using [PHP Handlebars Parser](https://github.com/devtheorem/php-handlebars-parser),
 which implements the same lexical analysis and AST grammar specification as Handlebars.js.
 * Tested against the [Handlebars.js spec](https://github.com/jbboehr/handlebars-spec)

src/Runtime.php

@@ -143,15 +143,17 @@ public static function nullCheck(mixed $base, string $key): mixed
     }
 
     /**
-     * Terminal .length lookup: returns count() for arrays (since PHP arrays have no native .length
-     * property), an explicit 'length' key if present, or null for non-array bases.
-     * When $strict is true, throws for any non-array base, mirroring HBS.js strict-mode behavior.
+     * Terminal .length lookup: returns an explicit 'length' key if present, and otherwise
+     * count() for arrays and strlen() for strings, since PHP doesn't have native .length properties.
      */
     public static function lookupLength(mixed $base, bool $strict = false): mixed
     {
         if (is_array($base)) {
             return array_key_exists('length', $base) ? $base['length'] : count($base);
         }
+        if (is_string($base)) {
+            return strlen($base);
+        }
         return $strict ? self::strictLookup($base, 'length') : null;
     }
 

tests/ErrorTest.php

@@ -83,12 +83,6 @@ public static function renderErrorProvider(): array
                 'data' => ['foo' => false],
                 'expected' => '"length" not defined in false',
             ],
-            'strict mode .length on string' => [
-                'template' => '{{foo.length}}',
-                'options' => new Options(strict: true),
-                'data' => ['foo' => 'hello'],
-                'expected' => '"length" not defined in "hello"',
-            ],
             'strict mode .length on integer' => [
                 'template' => '{{foo.length}}',
                 'options' => new Options(strict: true),

tests/RegressionTest.php

@@ -61,7 +61,7 @@ public function testLog(): void
     #[DataProvider("ifElseProvider")]
     #[DataProvider("sectionProvider")]
     #[DataProvider("contextProvider")]
-    #[DataProvider("arrayLengthProvider")]
+    #[DataProvider("lengthProvider")]
     #[DataProvider("dataClosuresProvider")]
     #[DataProvider("missingDataProvider")]
     #[DataProvider("syntaxProvider")]
@@ -2238,7 +2238,7 @@ public static function contextProvider(): array
     }
 
     /** @return array<string, RegIssue> */
-    public static function arrayLengthProvider(): array
+    public static function lengthProvider(): array
     {
         return [
             'LNC#216 - {{array.length}} evaluation support - empty array' => [
@@ -2276,6 +2276,28 @@ public static function arrayLengthProvider(): array
                 'data' => ['foo' => ['length' => fn() => 'testing']],
                 'expected' => 'testing',
             ],
+            'string length' => [
+                'template' => '{{foo.length}}',
+                'data' => ['foo' => 'hello'],
+                'expected' => '5',
+            ],
+            'string length - empty string' => [
+                'template' => '{{foo.length}}',
+                'data' => ['foo' => ''],
+                'expected' => '0',
+            ],
+            'string length - strict mode' => [
+                'template' => '{{foo.length}}',
+                'options' => new Options(strict: true),
+                'data' => ['foo' => 'hello'],
+                'expected' => '5',
+            ],
+            'string length - strict mode empty string' => [
+                'template' => '{{foo.length}}',
+                'options' => new Options(strict: true),
+                'data' => ['foo' => ''],
+                'expected' => '0',
+            ],
         ];
     }