Add PHP 8.0 named parameters support

docs/usage/using-wp-mock.md

@@ -74,6 +74,16 @@ For example, the invocation below will set the expectation that the `get_permali
 WP_Mock::userFunction('get_permalink')->once()->with(42)->andReturn('https://example.com/foo');
 ```
 
+To mock functions that are called using named parameters, e.g. `get_permalink(post: 42)`, you must pass the arguments as an associative array:
+
+```php
+WP_Mock::userFunction('get_permalink', [
+    'args' => [
+        'post' => '42',
+    ],
+])->once()->andReturn('https://example.com/foo');
+```
+
 ## Using expectations in arguments
 
 You can also pass an associative array of arguments to the second parameter of `WP_Mock::userFunction()` to set expectations about the function's arguments, the number of times it should be called, and what it should return.

php/WP_Mock/Functions.php

@@ -97,7 +97,8 @@ public function flush(): void
      */
     public function register(string $function, array $args = [])
     {
-        $this->generateFunction($function);
+        $functionArgs = isset($args['args']) && is_array($args['args']) ? $args['args'] : [];
+        $this->generateFunction($function, $functionArgs);
 
         if (empty($this->mockedFunctions[$function])) {
             /** @phpstan-ignore-next-line */
@@ -138,7 +139,10 @@ protected function setUpMock($mock, string $functionName, array $args = [])
 
         // set the expected arguments the function should be called with
         if (isset($args['args'])) {
-            $this->setExpectedArgs($expectation, $args['args']);
+            $this->setExpectedArgs(
+                $expectation,
+                is_array($args['args']) ? array_values($args['args']): $args['args']
+            );
         }
 
         // set the expected return value based on a passed argument or return values for each call in order
@@ -272,25 +276,27 @@ protected function setExpectedReturn(&$expectation, $return)
      * The declared function is namespace-aware.
      *
      * @param string $functionName function name
+     * @param array<int|string, mixed> $functionArgs function arguments
      * @return void
      * @throws InvalidArgumentException
      */
-    protected function generateFunction(string $functionName): void
+    protected function generateFunction(string $functionName, array $functionArgs = []): void
     {
         $functionName = $this->sanitizeFunctionName($functionName);
 
         $this->validateFunctionName($functionName);
 
-        $this->createFunction($functionName) or $this->replaceFunction($functionName);
+        $this->createFunction($functionName, $functionArgs) or $this->replaceFunction($functionName);
     }
 
     /**
      * Creates a function using eval.
      *
      * @param string $functionName function name
+     * @param array<int|string, mixed> $functionArgs function arguments, required only when calling mocked functions using named parameters
      * @return bool true if this function created the mock, false otherwise
      */
-    protected function createFunction(string $functionName): bool
+    protected function createFunction(string $functionName, array $functionArgs = []): bool
     {
         if (in_array($functionName, self::$userMockedFunctions, true)) {
             return true;
@@ -304,9 +310,19 @@ protected function createFunction(string $functionName): bool
         $name = array_pop($parts);
         $namespace = empty($parts) ? '' : 'namespace '.implode('\\', $parts).';'.PHP_EOL;
 
+        $functionNamedParameters = '';
+
+        $has_named_parameters = array_reduce( array_keys($functionArgs), function ($carry, $arg) {
+            return $carry && !is_int($arg);
+        }, true);
+
+        if($has_named_parameters){
+            $functionNamedParameters = implode(', ', array_map(fn($name) => '$' . $name, array_keys($functionArgs)));
+        }
+
         $declaration = <<<EOF
 $namespace
-function $name() {
+function $name($functionNamedParameters) {
 	return \\WP_Mock\\Functions\\Handler::handleFunction('$functionName', func_get_args());
 }
 EOF;

tests/Integration/WP_MockTest.php

@@ -335,4 +335,36 @@ public function testCanExpectHooksNotAdded() : void
 
         $this->assertConditionsMet();
     }
+
+    /**
+     * Fix "Error : Unknown named parameter $transient" when passing named parameters in the argument list.
+     *
+     * @covers \WP_Mock::userFunction()
+     * @see WP_Mock\Functions::createFunction()
+     *
+     * @throws Exception
+     */
+    public function testCanMockNamedParameters(): void {
+
+        if(!version_compare(PHP_VERSION, '8.0', '>=')) {
+            $this->markTestSkipped('PHP 8.0 required for named parameters.');
+        }
+
+        WP_Mock::userFunction('get_transient', [
+            'times'  => 1,
+            'args'   => [
+                'transient' => 'my-transient-name',
+            ],
+            'return' => 'the-mocked-transient-value',
+        ]);
+
+        // Without this, tests fail on PHP 7.4.
+        // PHP Fatal error:  Uncaught ParseError: syntax error, unexpected ':', expecting ')' in :362
+        $hidePhp8CodeFromOlderVersions = <<<'PHP'
+        return get_transient(transient: 'my-transient-name');
+        PHP;
+
+        /** @phpstan-ignore-next-line function "exists" */
+        $this->assertEquals('the-mocked-transient-value', eval($hidePhp8CodeFromOlderVersions));
+    }
 }