Symfony\Component\DependencyInjection\Tests\ContainerBuilderTest::testAliases PHP Method

    public function testAliases()
    {
        $builder = new ContainerBuilder();
        $builder->register('foo', 'stdClass');
        $builder->setAlias('bar', 'foo');
        $this->assertTrue($builder->hasAlias('bar'), '->hasAlias() returns true if the alias exists');
        $this->assertFalse($builder->hasAlias('foobar'), '->hasAlias() returns false if the alias does not exist');
        $this->assertEquals('foo', (string) $builder->getAlias('bar'), '->getAlias() returns the aliased service');
        $this->assertTrue($builder->has('bar'), '->setAlias() defines a new service');
        $this->assertTrue($builder->get('bar') === $builder->get('foo'), '->setAlias() creates a service that is an alias to another one');

        try {
            $builder->setAlias('foobar', 'foobar');
            $this->fail('->setAlias() throws an InvalidArgumentException if the alias references itself');
        } catch (\InvalidArgumentException $e) {
            $this->assertEquals('An alias can not reference itself, got a circular reference on "foobar".', $e->getMessage(), '->setAlias() throws an InvalidArgumentException if the alias references itself');
        }

        try {
            $builder->getAlias('foobar');
            $this->fail('->getAlias() throws an InvalidArgumentException if the alias does not exist');
        } catch (\InvalidArgumentException $e) {
            $this->assertEquals('The service alias "foobar" does not exist.', $e->getMessage(), '->getAlias() throws an InvalidArgumentException if the alias does not exist');
        }
    }