Fix one more orphan import-only bug (#180)

CHANGELOG.md

@@ -1,3 +1,10 @@
+## 1.3.7
+
+### Module Migrator
+
+* Fix a crash in a rare edge case involving orphan import-only files and
+  multiple load paths.
+
 ## 1.3.6
 
 ### Module Migrator

lib/src/migrators/module.dart

@@ -766,7 +766,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
     for (var import in dynamicImports) {
       var ruleUrl = import.url;
       var tuple = importCache.canonicalize(Uri.parse(ruleUrl),
-          baseImporter: importer, forImport: true);
+          baseImporter: importer, baseUrl: currentUrl, forImport: true);
       var canonicalImport = tuple?.item2;
       if (references.orphanImportOnlyFiles.containsKey(canonicalImport)) {
         ruleUrl = null;

pubspec.yaml

@@ -1,5 +1,5 @@
 name: sass_migrator
-version: 1.3.6
+version: 1.3.7
 description: A tool for running migrations on Sass files
 author: Jennifer Thakar <[email protected]>
 homepage: https://github.com/sass/migrator

test/migrators/module/partial_migration/changed_path/load_paths.hrx

@@ -0,0 +1,36 @@
+<==> arguments
+--migrate-deps --load-path load-path --load-path .
+
+<==> README.md
+This test is for a combination of edge cases where an orphan import-only file
+available through two load paths, one of which is the directory the migrator
+is being run from.
+
+This is a regression test for a bug where References and _ModuleMigrationVisitor
+disagreed about which import-only file to use, resulting in a crash.
+
+<==> input/entrypoint/in/a/subdirectory.scss
+@import "old";
+
+a {
+  color: $lib-variable;
+}
+
+<==> input/load-path/_old.import.scss
+@forward "new" as lib-*;
+
+<==> input/_new.scss
+$variable: green;
+
+<==> input/_old.import.scss
+@forward "wrong";
+
+<==> input/_wrong.scss
+$lib-variable: blue;
+
+<==> output/entrypoint/in/a/subdirectory.scss
+@use "new";
+
+a {
+  color: new.$variable;
+}