diff --git a/lib/src/migrators/module.dart b/lib/src/migrators/module.dart index 76d15131..44b1928a 100644 --- a/lib/src/migrators/module.dart +++ b/lib/src/migrators/module.dart @@ -200,6 +200,19 @@ class _ModuleMigrationVisitor extends MigrationVisitor { /// The values of the --forward flag. final Set forwards; + // Maps direct and indirect dependencies to prevent any potential loops. + final Map _dependencies = {}; + + void _addDependency(Uri source, Uri importedPath) { + if (_dependencies.containsKey(importedPath) && _dependencies[importedPath] == source) { + // Throw an error indicating a potential loop. + var sourceUrl = _absoluteUrlToDependency(source); + var importedPathUrl = _absoluteUrlToDependency(importedPath); + throw MigrationException('Dependency loop detected: ${sourceUrl.item1} -> ${importedPathUrl.item1}'); + } + _dependencies[source] = importedPath; + } + /// Constructs a new module migration visitor. /// /// [importCache] must be the same one used by [references]. @@ -1239,6 +1252,13 @@ class _ModuleMigrationVisitor extends MigrationVisitor { var url = declaration.sourceUrl; if (url == currentUrl) return null; + // Trace dependencies for loop detection. + try { + _addDependency(currentUrl, url); + } on Exception catch (e) { + throw MigrationSourceSpanException(e.toString(), declaration.member.span); + } + // If we can load [declaration] from a library entrypoint URL, do so. Choose // the shortest one if there are multiple options. var libraryUrls = references.libraries[declaration]; diff --git a/test/migrators/module/namespace_references/loop_error.hrx b/test/migrators/module/namespace_references/loop_error.hrx new file mode 100644 index 00000000..5895d3ff --- /dev/null +++ b/test/migrators/module/namespace_references/loop_error.hrx @@ -0,0 +1,21 @@ +<==> arguments +--migrate-deps + +<==> input/entrypoint.scss +@import "ejemplo"; +$var: $value; + +<==> input/_ejemplo.scss +$value: blue; +a { + color: $var; +} + +<==> error.txt +Error: Error: Dependency loop detected: entrypoint -> ejemplo + , +1 | $value: blue; + | ^^^^^^^^^^^^ + ' + _ejemplo.scss 1:1 root stylesheet +Migration failed!