detectMappingType example

                if (null === $bundle) {
                    throw new \InvalidArgumentException(sprintf('Bundle "%s" does not exist or it is not enabled.', $mappingName));
                }

                $mappingConfig = $this->getMappingDriverBundleConfigDefaults($mappingConfig, $bundle, $container, $bundleMetadata['path']);
                if (!$mappingConfig) {
                    continue;
                }
            } elseif (!$mappingConfig['type']) {
                $mappingConfig['type'] = $this->detectMappingType($mappingConfig['dir'], $container);
            }

            $this->assertValidMappingConfiguration($mappingConfig, $objectManager['name']);
            $this->setMappingDriverConfig($mappingConfig, $mappingName);
            $this->setMappingDriverAlias($mappingConfig, $mappingName);
        }
    }

    /** * Register the alias for this mapping driver. * * Aliases can be used in the Query languages of all the Doctrine object managers to simplify writing tasks. * * @return void */