Plugins and Themes: Add filters to validation functions.

It is now possible to add additional validation requirements for themes and plugins besides the built in core checks.

Developed in #1812 and #10361.

Props kraftbj, mukesh27, jorbin, joedolson.
Fixes #54381.


git-svn-id: https://develop.svn.wordpress.org/trunk@60995 602fd350-edb4-49c9-b593-d223f7449a82

Author: aaronjorbin

src/wp-admin/includes/plugin.php

@@ -1247,7 +1247,20 @@ function validate_plugin_requirements( $plugin ) {
 		);
 	}
 
-	return true;
+	/**
+	 * Filters the plugin requirement validation response.
+	 *
+	 * If a plugin fails due to a Core-provided validation (incompatible WP, PHP versions), this
+	 * filter will not fire. A WP_Error response will already be returned.
+	 *
+	 * This filter is intended to add additional validation steps by site administrators.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param bool|WP_Error $met_requirements True if the plugin meets requirements, WP_Error if not.
+	 * @param string $plugin Path to the plugin file relative to the plugins directory.
+	 */
+	return apply_filters( 'validate_plugin_requirements', true, $plugin );
 }
 
 /**

src/wp-includes/theme.php

@@ -1002,7 +1002,20 @@ function validate_theme_requirements( $stylesheet ) {
 		);
 	}
 
-	return true;
+	/**
+	 * Filters the theme requirement validation response.
+	 *
+	 * If a theme fails due to a Core-provided validation (incompatible WP, PHP versions), this
+	 * filter will not fire. A WP_Error response will already be returned.
+	 *
+	 * This filter is intended to add additional validation steps by site administrators.
+	 *
+	 * @since 6.9.0
+	 *
+	 * @param bool|WP_Error $met_requirements True if the theme meets requirements, WP_Error if not.
+	 * @param string $stylesheet Directory name for the theme.
+	 */
+	return apply_filters( 'validate_theme_requirements', true, $stylesheet );
 }
 
 /**

tests/phpunit/tests/theme.php

@@ -1529,4 +1529,54 @@ public function test_switch_to_blog_uses_original_template_path() {
 
 		$this->assertSame( $template_path, $new_template_path, 'Switching blogs switches the template path' );
 	}
+
+	/**
+	 * Verify the validate_theme_requirements theme responds as expected for twentyten.
+	 *
+	 * @ticket 54381
+	 */
+	public function test_validate_theme_requirements_filter_default() {
+		// Default expectation since twentyten has the least strict requirements.
+		$this->assertTrue( validate_theme_requirements( 'twentyten' ) );
+	}
+
+	/**
+	 * Verify that a filtered failure of validate_theme_requirements returns WP_Error
+	 *
+	 * @ticket 54381
+	 */
+	public function test_validate_theme_requirements_filter_error() {
+		// Adds an extra requirement that always fails.
+		add_filter(
+			'validate_theme_requirements',
+			function () {
+				return new WP_Error( 'theme_test_failed_requirement' );
+			}
+		);
+
+		$this->assertInstanceOf( 'WP_Error', validate_theme_requirements( 'twentyten' ) );
+	}
+
+	/**
+	 * Verify that the theme is passed through to the validate_theme_requirements filter by selectively erroring.
+	 *
+	 * @ticket 54381
+	 */
+	public function test_validate_theme_requirements_filter_selective_failure() {
+		// Adds an extra requirement only for a particular theme.
+		add_filter(
+			'validate_theme_requirements',
+			function ( $met_requirements, $stylesheet ) {
+				if ( 'twentytwenty' === $stylesheet ) {
+					return new WP_Error( 'theme_test_failed_requirement' );
+				}
+				return $met_requirements;
+			},
+			10,
+			2
+		);
+
+		$this->assertTrue( validate_theme_requirements( 'twentyten' ) );
+		$this->assertInstanceOf( 'WP_Error', validate_theme_requirements( 'twentytwenty' ) );
+	}
 }