class TwigDeprecationsTest

class TwigDeprecationsTest extends KernelTestBase {
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    protected static $modules = [
        'system',
        'theme_test',
    ];
    
    /**
     * Test deprecating variables at definition in hook_theme().
     */
    public function testHookThemeDeprecations() : void {
        $element = [
            '#theme' => 'theme_test_deprecations_hook_theme',
            '#foo' => 'foo',
            '#bar' => 'bar',
        ];
        // Both 'foo' and 'bar' are deprecated in theme_test_hook_theme(),
        // but 'bar' is not used in theme-test-deprecations-hook-theme.html.twig.
        $this->expectDeprecation($this->getDeprecationMessage('foo'));
        $this->assertEquals('foo', $this->container
            ->get('renderer')
            ->renderRoot($element));
    }
    
    /**
     * Test theme_test_deprecations_preprocess renders without deprecations.
     */
    public function testThemeTestDeprecations() : void {
        $this->assertRendered('foo|set_var|bar', []);
    }
    
    /**
     * Test deprecation of undefined variable triggers no error.
     */
    public function testUndefinedDeprecation() : void {
        $preprocess = [
            'deprecations' => [
                'undefined' => $this->getDeprecationMessage('undefined'),
            ],
        ];
        $this->assertRendered('foo|set_var|bar', $preprocess);
    }
    
    /**
     * Test deprecation of single variable triggers error.
     */
    public function testSingleDeprecation() : void {
        $preprocess = [
            'deprecations' => [
                'foo' => $this->getDeprecationMessage('foo'),
            ],
        ];
        $this->expectDeprecation($this->getDeprecationMessage('foo'));
        $this->assertRendered('foo|set_var|bar', $preprocess);
    }
    
    /**
     * Test deprecation of empty variable triggers error.
     */
    public function testEmptyDeprecation() : void {
        $preprocess = [
            'foo' => '',
            'deprecations' => [
                'foo' => $this->getDeprecationMessage('foo'),
            ],
        ];
        $this->expectDeprecation($this->getDeprecationMessage('foo'));
        $this->assertRendered('|set_var|bar', $preprocess);
    }
    
    /**
     * Test deprecation of multiple variables triggers errors.
     */
    public function testMultipleDeprecations() : void {
        $preprocess = [
            'deprecations' => [
                'foo' => $this->getDeprecationMessage('foo'),
                'bar' => $this->getDeprecationMessage('bar'),
            ],
        ];
        $this->expectDeprecation($this->getDeprecationMessage('foo'));
        $this->expectDeprecation($this->getDeprecationMessage('bar'));
        $this->assertRendered('foo|set_var|bar', $preprocess);
    }
    
    /**
     * Test deprecation of variables assigned inside template triggers no error.
     */
    public function testAssignedVariableDeprecation() : void {
        $preprocess = [
            'contents' => [
                'content',
            ],
            'deprecations' => [
                'set_var' => $this->getDeprecationMessage('set_var'),
                'for_var' => $this->getDeprecationMessage('for_var'),
            ],
        ];
        $this->assertRendered('foo|set_var|content|bar', $preprocess);
    }
    
    /**
     * Test deprecation of variables in parent does not leak to child.
     */
    public function testParentVariableDeprecation() : void {
        // 'foo' is used before the child template is processed, so this test
        // shows that processing the child does not lead to parent usage being
        // forgotten.
        // 'gaz' is used in the child template but only deprecated in the parent
        // template, so no deprecation error is triggered for it.
        $preprocess = [
            'contents' => [
                'child' => [
                    '#theme' => 'theme_test_deprecations_child',
                    '#foo' => 'foo-child',
                    '#bar' => 'bar-child',
                    '#gaz' => 'gaz-child',
                ],
            ],
            'deprecations' => [
                'foo' => $this->getDeprecationMessage('foo'),
                'gaz' => $this->getDeprecationMessage('gaz'),
            ],
        ];
        $this->assertRendered('foo|set_var|foo-child|gaz-child|bar', $preprocess);
    }
    
    /**
     * Assert that 'theme_test_deprecations_preprocess' renders expected text.
     *
     * @param string $expected
     *   The expected text.
     * @param array $preprocess
     *   An array to merge in theme_test_deprecations_preprocess_preprocess().
     */
    protected function assertRendered($expected, array $preprocess) : void {
        \Drupal::state()->set('theme_test.theme_test_deprecations_preprocess', $preprocess);
        $element = [
            '#theme' => 'theme_test_deprecations_preprocess',
            '#foo' => 'foo',
            '#bar' => 'bar',
            '#gaz' => 'gaz',
            '#set_var' => 'overridden',
        ];
        $this->assertEquals($expected, $this->container
            ->get('renderer')
            ->renderRoot($element));
    }
    
    /**
     * Get an example deprecation message for a named variable.
     */
    protected function getDeprecationMessage($variable) : string {
        return "'{$variable}' is deprecated in drupal:X.0.0 and is removed from drupal:Y.0.0. Use 'new_{$variable}' instead. See https://www.example.com.";
    }

}