[ExpressionLanguage] Add enum expression function

Author: alexandre-daubois

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+6.3
+---
+
+ * Add `enum` expression function
+
 6.2
 ---
 

ExpressionLanguage.php

@@ -138,6 +138,19 @@ public function registerProvider(ExpressionFunctionProviderInterface $provider)
     protected function registerFunctions()
     {
         $this->addFunction(ExpressionFunction::fromPhp('constant'));
+
+        $this->addFunction(new ExpressionFunction('enum',
+            static fn ($str): string => sprintf("(\constant(\$v = (%s))) instanceof \UnitEnum ? \constant(\$v) : throw new \TypeError(\sprintf('The string \"%%s\" is not the name of a valid enum case.', \$v))", $str),
+            static function ($arguments, $str): \UnitEnum {
+                $value = \constant($str);
+
+                if (!$value instanceof \UnitEnum) {
+                    throw new \TypeError(sprintf('The string "%s" is not the name of a valid enum case.', $str));
+                }
+
+                return $value;
+            }
+        ));
     }
 
     private function getLexer(): Lexer

Tests/ExpressionLanguageTest.php

@@ -18,6 +18,8 @@
 use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
 use Symfony\Component\ExpressionLanguage\ParsedExpression;
 use Symfony\Component\ExpressionLanguage\SyntaxError;
+use Symfony\Component\ExpressionLanguage\Tests\Fixtures\FooBackedEnum;
+use Symfony\Component\ExpressionLanguage\Tests\Fixtures\FooEnum;
 use Symfony\Component\ExpressionLanguage\Tests\Fixtures\TestProvider;
 
 class ExpressionLanguageTest extends TestCase
@@ -78,6 +80,53 @@ public function testConstantFunction()
         $this->assertEquals('\constant("PHP_VERSION")', $expressionLanguage->compile('constant("PHP_VERSION")'));
     }
 
+    public function testEnumFunctionWithConstantThrows()
+    {
+        $this->expectException(\TypeError::class);
+        $this->expectExceptionMessage('The string "PHP_VERSION" is not the name of a valid enum case.');
+        $expressionLanguage = new ExpressionLanguage();
+        $expressionLanguage->evaluate('enum("PHP_VERSION")');
+    }
+
+    public function testCompiledEnumFunctionWithConstantThrows()
+    {
+        $this->expectException(\TypeError::class);
+        $this->expectExceptionMessage('The string "PHP_VERSION" is not the name of a valid enum case.');
+        $expressionLanguage = new ExpressionLanguage();
+        eval($expressionLanguage->compile('enum("PHP_VERSION")').';');
+    }
+
+    public function testEnumFunction()
+    {
+        $expressionLanguage = new ExpressionLanguage();
+        $this->assertSame(FooEnum::Foo, $expressionLanguage->evaluate('enum("Symfony\\\\Component\\\\ExpressionLanguage\\\\Tests\\\\Fixtures\\\\FooEnum::Foo")'));
+    }
+
+    public function testCompiledEnumFunction()
+    {
+        $result = null;
+        $expressionLanguage = new ExpressionLanguage();
+        eval(sprintf('$result = %s;', $expressionLanguage->compile('enum("Symfony\\\\Component\\\\ExpressionLanguage\\\\Tests\\\\Fixtures\\\\FooEnum::Foo")')));
+
+        $this->assertSame(FooEnum::Foo, $result);
+    }
+
+    public function testBackedEnumFunction()
+    {
+        $expressionLanguage = new ExpressionLanguage();
+        $this->assertSame(FooBackedEnum::Bar, $expressionLanguage->evaluate('enum("Symfony\\\\Component\\\\ExpressionLanguage\\\\Tests\\\\Fixtures\\\\FooBackedEnum::Bar")'));
+        $this->assertSame('Foo', $expressionLanguage->evaluate('enum("Symfony\\\\Component\\\\ExpressionLanguage\\\\Tests\\\\Fixtures\\\\FooBackedEnum::Bar").value'));
+    }
+
+    public function testCompiledEnumFunctionWithBackedEnum()
+    {
+        $result = null;
+        $expressionLanguage = new ExpressionLanguage();
+        eval(sprintf('$result = %s;', $expressionLanguage->compile('enum("Symfony\\\\Component\\\\ExpressionLanguage\\\\Tests\\\\Fixtures\\\\FooBackedEnum::Bar")')));
+
+        $this->assertSame(FooBackedEnum::Bar, $result);
+    }
+
     public function testProviders()
     {
         $expressionLanguage = new ExpressionLanguage(null, [new TestProvider()]);

Tests/Fixtures/FooBackedEnum.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\ExpressionLanguage\Tests\Fixtures;
+
+enum FooBackedEnum: string
+{
+    case Bar = 'Foo';
+}

Tests/Fixtures/FooEnum.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Symfony\Component\ExpressionLanguage\Tests\Fixtures;
+
+enum FooEnum
+{
+    case Foo;
+}