Add Behat test for experimental checks from addon

tests/behat/features/plugin-check.feature

@@ -490,10 +490,12 @@ Feature: Test that the WP-CLI command works.
        */
 
       $text = 'I am bad'; // This should trigger the error.
+
+      $string = 'This is experimental string.';
       """
     And I run the WP-CLI command `plugin activate foo-sample`
 
-    # The two checks from pcp-addon should be available.
+    # The two stable checks from pcp-addon should be available.
     When I run the WP-CLI command `plugin list-checks --fields=slug,category,stability --format=csv`
     Then STDOUT should contain:
       """
@@ -503,6 +505,17 @@ Feature: Test that the WP-CLI command works.
       """
       example_runtime,new_category,stable
       """
+    And STDOUT should not contain:
+      """
+      example_experimental,new_category,experimental
+      """
+
+    # Experimental checks from pcp-addon should be available.
+    When I run the WP-CLI command `plugin list-checks --fields=slug,category,stability --format=csv --include-experimental`
+    Then STDOUT should contain:
+      """
+      example_experimental,new_category,experimental
+      """
 
     # The new check category should therefore also be available.
     When I run the WP-CLI command `plugin list-check-categories --fields=slug,name --format=csv`
@@ -525,6 +538,13 @@ Feature: Test that the WP-CLI command works.
       prohibited_text_detected,ERROR
       """
 
+    # Running experimental checks, including the one from pcp-addon
+    When I run the WP-CLI command `plugin check foo-sample --fields=code,type --format=csv --include-experimental`
+    Then STDOUT should contain:
+      """
+      experimental_text_detected,ERROR
+      """
+
     # Running only the check from pcp-addon
     When I run the WP-CLI command `plugin check foo-sample --checks=example_static --fields=code,type --format=csv`
     Then STDOUT should contain:

tests/behat/testdata/pcp-addon/Example_Experimental_Check.php

@@ -0,0 +1,41 @@
+<?php
+
+use WordPress\Plugin_Check\Checker\Check_Result;
+use WordPress\Plugin_Check\Checker\Checks\Abstract_File_Check;
+use WordPress\Plugin_Check\Traits\Amend_Check_Result;
+use WordPress\Plugin_Check\Traits\Experimental_Check;
+
+class Example_Experimental_Check extends Abstract_File_Check {
+
+	use Amend_Check_Result;
+	use Experimental_Check;
+
+	public function get_categories() {
+		return array( 'new_category' );
+	}
+
+	protected function check_files( Check_Result $result, array $files ) {
+		$php_files = self::filter_files_by_extension( $files, 'php' );
+		$file      = self::file_preg_match( '#experimental#', $php_files );
+		if ( $file ) {
+			$this->add_result_error_for_file(
+				$result,
+				__( 'Experimental text found.', 'pcp-addon' ),
+				'experimental_text_detected',
+				$file,
+				0,
+				0,
+				'',
+				7
+			);
+		}
+	}
+
+	public function get_description(): string {
+		return '';
+	}
+
+	public function get_documentation_url(): string {
+		return '';
+	}
+}

tests/behat/testdata/pcp-addon/pcp-addon.php

@@ -23,12 +23,14 @@ function ( array $categories ) {
 	function ( array $checks ) {
 		require_once plugin_dir_path( __FILE__ ) . 'Example_Static_Check.php';
 		require_once plugin_dir_path( __FILE__ ) . 'Example_Runtime_Check.php';
+		require_once plugin_dir_path( __FILE__ ) . 'Example_Experimental_Check.php';
 
 		return array_merge(
 			$checks,
 			array(
-				'example_static'  => new Example_Static_Check(),
-				'example_runtime' => new Example_Runtime_Check(),
+				'example_static'       => new Example_Static_Check(),
+				'example_runtime'      => new Example_Runtime_Check(),
+				'example_experimental' => new Example_Experimental_Check(),
 			)
 		);
 	}