MDL-75282 editor_tiny: Always use Tiny for @tiny tests

This is a subsequent part of MDL-75886 relating to the introduction of
TinyMCE.

Part of MDL-75966

lib/editor/tiny/tests/behat/behat_editor_tiny.php

@@ -0,0 +1,67 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * TinyMCE custom steps definitions.
+ *
+ * @package    editor_tiny
+ * @category   test
+ * @copyright  2022 Andrew Lyons <andrew@nicols.co.uk>
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+use Behat\Behat\Hook\Scope\BeforeScenarioScope;
+
+// NOTE: no MOODLE_INTERNAL test here, this file may be required by behat before including /config.php.
+require_once(__DIR__ . '/../../../../behat/behat_base.php');
+
+/**
+ * TinyMCE custom behat step definitions.
+ *
+ * @package    editor_tiny
+ * @category   test
+ * @copyright  2022 Andrew Lyons <andrew@nicols.co.uk>
+ */
+class behat_editor_tiny extends behat_base {
+    /**
+     * Set Tiny as default editor before executing Tiny tests.
+     *
+     * This step is required to ensure that TinyMCE is set as the current default editor as it may
+     * not always be the default editor.
+     *
+     * Any Scenario, or Feature, which has the `editor_tiny` tag, or any `tiny_*` tag will have
+     * this step executed before the Scenario.
+     *
+     * @BeforeScenario
+     * @param BeforeScenarioScope $scope The Behat Scope
+     */
+    public function set_default_editor_flag(BeforeScenarioScope $scope): void {
+        // This only applies to a scenario which matches the editor_tiny, or an tiny subplugin.
+        $callback = function (string $tag): bool {
+            return $tag === 'editor_tiny' || substr($tag, 0, 5) === 'tiny_';
+        };
+
+        if (!self::scope_tags_match($scope, $callback)) {
+            // This scope does not require TinyMCE. Exit now.
+            return;
+        }
+
+        // TinyMCE is a JavaScript editor so require JS here.
+        $this->require_javascript();
+
+        $this->execute('behat_general::the_default_editor_is_set_to', ['tiny']);
+    }
+}