*
* @param array $registryData
* @param string $moduleName
+ * @param string[] $handled Internal parameter for recursion. (Optional)
* @return array
+ * @throws ResourceLoaderCircularDependencyError
*/
- protected static function getImplicitDependencies( array $registryData, $moduleName ) {
+ protected static function getImplicitDependencies(
+ array $registryData,
+ $moduleName,
+ array $handled = []
+ ) {
static $dependencyCache = [];
- // The list of implicit dependencies won't be altered, so we can
- // cache them without having to worry.
+ // No modules will be added or changed server-side after this point,
+ // so we can safely cache parts of the tree for re-use.
if ( !isset( $dependencyCache[$moduleName] ) ) {
if ( !isset( $registryData[$moduleName] ) ) {
- // Dependencies may not exist
- $dependencyCache[$moduleName] = [];
+ // Unknown module names are allowed here, this is only an optimisation.
+ // Checks for illegal and unknown dependencies happen as PHPUnit structure tests,
+ // and also client-side at run-time.
+ $flat = [];
} else {
$data = $registryData[$moduleName];
- $dependencyCache[$moduleName] = $data['dependencies'];
+ $flat = $data['dependencies'];
+ // Prevent recursion
+ $handled[] = $moduleName;
foreach ( $data['dependencies'] as $dependency ) {
- // Recursively get the dependencies of the dependencies
- $dependencyCache[$moduleName] = array_merge(
- $dependencyCache[$moduleName],
- self::getImplicitDependencies( $registryData, $dependency )
- );
+ if ( in_array( $dependency, $handled, true ) ) {
+ // If we encounter a circular dependency, then stop the optimiser and leave the
+ // original dependencies array unmodified. Circular dependencies are not
+ // supported in ResourceLoader. Awareness of them exists here so that we can
+ // optimise the registry when it isn't broken, and otherwise transport the
+ // registry unchanged. The client will handle this further.
+ throw new ResourceLoaderCircularDependencyError();
+ } else {
+ // Recursively add the dependencies of the dependencies
+ $flat = array_merge(
+ $flat,
+ self::getImplicitDependencies( $registryData, $dependency, $handled )
+ );
+ }
}
}
+
+ $dependencyCache[$moduleName] = $flat;
}
return $dependencyCache[$moduleName];
public static function compileUnresolvedDependencies( array &$registryData ) {
foreach ( $registryData as $name => &$data ) {
$dependencies = $data['dependencies'];
- foreach ( $data['dependencies'] as $dependency ) {
- $implicitDependencies = self::getImplicitDependencies( $registryData, $dependency );
- $dependencies = array_diff( $dependencies, $implicitDependencies );
+ try {
+ foreach ( $data['dependencies'] as $dependency ) {
+ $implicitDependencies = self::getImplicitDependencies( $registryData, $dependency );
+ $dependencies = array_diff( $dependencies, $implicitDependencies );
+ }
+ } catch ( ResourceLoaderCircularDependencyError $err ) {
+ // Leave unchanged
+ $dependencies = $data['dependencies'];
}
+
// Rebuild keys
$data['dependencies'] = array_values( $dependencies );
}