From faea6f55cfee0b261aec9517d474425089c5cf2b Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@gmail.com>
Date: Fri, 12 Jul 2024 16:13:16 -0700
Subject: [PATCH 1/4] Add --builtin-only flag to module migrator

Also fixes some built-in functions that weren't being migrated.
---
 CHANGELOG.md                                  | 10 ++++
 lib/src/migration_visitor.dart                |  2 +-
 lib/src/migrators/calc_interpolation.dart     |  9 ++-
 lib/src/migrators/division.dart               |  9 +--
 lib/src/migrators/module.dart                 | 58 ++++++++++++++-----
 .../migrators/module/built_in_functions.dart  |  4 ++
 lib/src/migrators/namespace.dart              | 10 ++--
 lib/src/migrators/strict_unary.dart           |  7 ++-
 pubspec.yaml                                  |  4 +-
 .../built_in_functions/builtin_only.hrx       | 19 ++++++
 10 files changed, 96 insertions(+), 36 deletions(-)
 create mode 100644 test/migrators/module/built_in_functions/builtin_only.hrx

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f2a876b..3474e5d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
+## 2.1.0
+
+### Module Migrator
+
+* Add a new `--builtin-only` flag, which migrates global functions to their
+  `sass:` module equivalents, while leaving `@import` rules unchanged.
+
+* Fix bug where some functions (`opacity`, `is-bracketed`, and
+  `selector-extend`) would not be migrated.
+
 ## 2.0.3
 
 ### Module Migrator
diff --git a/lib/src/migration_visitor.dart b/lib/src/migration_visitor.dart
index d13de19..53ae6d7 100644
--- a/lib/src/migration_visitor.dart
+++ b/lib/src/migration_visitor.dart
@@ -66,7 +66,7 @@ abstract class MigrationVisitor extends ScopedAstVisitor {
   /// syntax, in which case this returns an empty string.
   String get semicolon => currentUrl.path.endsWith('.sass') ? "" : ";";
 
-  MigrationVisitor(this.importCache, this.migrateDependencies);
+  MigrationVisitor(this.importCache, {required this.migrateDependencies});
 
   /// Runs a new migration on [stylesheet] (and its dependencies, if
   /// [migrateDependencies] is true) and returns a map of migrated contents.
diff --git a/lib/src/migrators/calc_interpolation.dart b/lib/src/migrators/calc_interpolation.dart
index d72891b..a28fe98 100644
--- a/lib/src/migrators/calc_interpolation.dart
+++ b/lib/src/migrators/calc_interpolation.dart
@@ -19,8 +19,8 @@ class CalculationInterpolationMigrator extends Migrator {
   @override
   Map<Uri, String> migrateFile(
       ImportCache importCache, Stylesheet stylesheet, Importer importer) {
-    var visitor =
-        _CalculationInterpolationVisitor(importCache, migrateDependencies);
+    var visitor = _CalculationInterpolationVisitor(importCache,
+        migrateDependencies: migrateDependencies);
     var result = visitor.run(stylesheet, importer);
     missingDependencies.addAll(visitor.missingDependencies);
     return result;
@@ -28,9 +28,8 @@ class CalculationInterpolationMigrator extends Migrator {
 }
 
 class _CalculationInterpolationVisitor extends MigrationVisitor {
-  _CalculationInterpolationVisitor(
-      ImportCache importCache, bool migrateDependencies)
-      : super(importCache, migrateDependencies);
+  _CalculationInterpolationVisitor(super.importCache,
+      {required super.migrateDependencies});
 
   @override
   void visitFunctionExpression(FunctionExpression node) {
diff --git a/lib/src/migrators/division.dart b/lib/src/migrators/division.dart
index 39827e8..1f8a90b 100644
--- a/lib/src/migrators/division.dart
+++ b/lib/src/migrators/division.dart
@@ -66,7 +66,8 @@ More info: https://sass-lang.com/d/slash-div""";
   Map<Uri, String> migrateFile(
       ImportCache importCache, Stylesheet stylesheet, Importer importer) {
     var visitor = _DivisionMigrationVisitor(
-        importCache, isPessimistic, useMultiplication, migrateDependencies);
+        importCache, isPessimistic, useMultiplication,
+        migrateDependencies: migrateDependencies);
     var result = visitor.run(stylesheet, importer);
     missingDependencies.addAll(visitor.missingDependencies);
     return result;
@@ -80,9 +81,9 @@ class _DivisionMigrationVisitor extends MigrationVisitor {
   final bool isPessimistic;
   final bool useMultiplication;
 
-  _DivisionMigrationVisitor(ImportCache importCache, this.isPessimistic,
-      this.useMultiplication, bool migrateDependencies)
-      : super(importCache, migrateDependencies);
+  _DivisionMigrationVisitor(
+      super.importCache, this.isPessimistic, this.useMultiplication,
+      {required super.migrateDependencies});
 
   /// True when division is allowed by the context the current node is in.
   var _isDivisionAllowed = false;
diff --git a/lib/src/migrators/module.dart b/lib/src/migrators/module.dart
index e1afbf8..e15b2aa 100644
--- a/lib/src/migrators/module.dart
+++ b/lib/src/migrators/module.dart
@@ -32,6 +32,8 @@ class ModuleMigrator extends Migrator {
 
   @override
   final argParser = ArgParser()
+    ..addFlag('builtin-only',
+        help: 'Migrates global functions without migrating @import.')
     ..addMultiOption('remove-prefix',
         abbr: 'p',
         help: 'Removes PREFIX from all migrated member names.\n'
@@ -77,6 +79,13 @@ class ModuleMigrator extends Migrator {
   Map<Uri, String> migrateFile(
       ImportCache importCache, Stylesheet stylesheet, Importer importer) {
     var forwards = {for (var arg in argResults!['forward']) ForwardType(arg)};
+    var builtInOnly = argResults!['builtin-only'] as bool;
+    if (builtInOnly &&
+        (argResults!.wasParsed('forward') ||
+            argResults!.wasParsed('remove-prefix'))) {
+      throw MigrationException('--forward and --remove-prefix may not be '
+          'passed with --builtin-only.');
+    }
     if (forwards.contains(ForwardType.prefixed) &&
         !argResults!.wasParsed('remove-prefix')) {
       throw MigrationException(
@@ -85,8 +94,10 @@ class ModuleMigrator extends Migrator {
     }
 
     var references = References(importCache, stylesheet, importer);
-    var visitor = _ModuleMigrationVisitor(importCache, references,
-        globalResults!['load-path'] as List<String>, migrateDependencies,
+    var visitor = _ModuleMigrationVisitor(
+        importCache, references, globalResults!['load-path'] as List<String>,
+        migrateDependencies: migrateDependencies,
+        builtInOnly: builtInOnly,
         prefixesToRemove: (argResults!['remove-prefix'] as List<String>)
             .map((prefix) => prefix.replaceAll('_', '-')),
         forwards: forwards);
@@ -186,9 +197,6 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// main migration pass is used.
   final References references;
 
-  /// Cache used to load stylesheets.
-  final ImportCache importCache;
-
   /// List of paths that stylesheets can be loaded from.
   final List<String> loadPaths;
 
@@ -199,6 +207,9 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// The values of the --forward flag.
   final Set<ForwardType> forwards;
 
+  /// Whether to migrate only global functions, leaving `@import` rules as-is.
+  final bool builtInOnly;
+
   /// Constructs a new module migration visitor.
   ///
   /// [importCache] must be the same one used by [references].
@@ -210,22 +221,25 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// the module migrator will filter out the dependencies' migration results.
   ///
   /// This converts the OS-specific relative [loadPaths] to absolute URL paths.
-  _ModuleMigrationVisitor(this.importCache, this.references,
-      List<String> loadPaths, bool migrateDependencies,
-      {Iterable<String> prefixesToRemove = const [], this.forwards = const {}})
+  _ModuleMigrationVisitor(
+      super.importCache, this.references, List<String> loadPaths,
+      {required super.migrateDependencies,
+      required this.builtInOnly,
+      Iterable<String> prefixesToRemove = const [],
+      this.forwards = const {}})
       : loadPaths = List.unmodifiable(
             loadPaths.map((path) => p.toUri(p.absolute(path)).path)),
-        prefixesToRemove = UnmodifiableSetView(prefixesToRemove.toSet()),
-        super(importCache, migrateDependencies);
+        prefixesToRemove = UnmodifiableSetView(prefixesToRemove.toSet());
 
   /// Checks which global declarations need to be renamed, then runs the
   /// migrator.
   @override
   Map<Uri, String> run(Stylesheet stylesheet, Importer importer) {
-    references.globalDeclarations.forEach(_renameDeclaration);
+    if (!builtInOnly) references.globalDeclarations.forEach(_renameDeclaration);
     var migrated = super.run(stylesheet, importer);
 
-    if (forwards.contains(ForwardType.importOnly) || _needsImportOnly) {
+    if (!builtInOnly &&
+        (forwards.contains(ForwardType.importOnly) || _needsImportOnly)) {
       var url = stylesheet.span.sourceUrl!;
       var importOnlyUrl = getImportOnlyUrl(url);
       var results = _generateImportOnly(url, importOnlyUrl);
@@ -597,7 +611,8 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// Adds a namespace to any function call that requires it.
   @override
   void visitFunctionExpression(FunctionExpression node) {
-    if (node.namespace != null) {
+    if (node.namespace != null ||
+        (builtInOnly && references.sources[node] is! BuiltInSource)) {
       super.visitFunctionExpression(node);
       return;
     }
@@ -613,7 +628,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
       });
     }
 
-    if (node.name == "get-function") {
+    if (node.name == "get-function" && !builtInOnly) {
       var declaration = references.getFunctionReferences[node];
       if (declaration != null) {
         _unreferencable.check(declaration, node);
@@ -776,7 +791,12 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
         }
       }
       if (ruleUrl != null) {
-        if (_useAllowed) {
+        if (builtInOnly) {
+          _upstreamStylesheets.add(currentUrl);
+          if (migrateDependencies) visitDependency(ruleUrl, import.span);
+          _upstreamStylesheets.remove(currentUrl);
+          return;
+        } else if (_useAllowed) {
           migratedRules.addAll(_migrateImportToRules(ruleUrl, import.span));
         } else {
           migratedRules.add(_migrateImportToLoadCss(ruleUrl, import.span)
@@ -1071,6 +1091,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
     _useAllowed = false;
     super.visitIncludeRule(node);
     if (node.namespace != null) return;
+    if (builtInOnly && references.sources[node] is! BuiltInSource) return;
 
     var declaration = references.mixins[node];
     if (declaration == null) {
@@ -1089,7 +1110,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   @override
   void visitMixinRule(MixinRule node) {
     _useAllowed = false;
-    _renameReference(nameSpan(node), MemberDeclaration(node));
+    if (!builtInOnly) _renameReference(nameSpan(node), MemberDeclaration(node));
     super.visitMixinRule(node);
   }
 
@@ -1119,6 +1140,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   @override
   void visitVariableExpression(VariableExpression node) {
     if (node.namespace != null) return;
+    if (builtInOnly && references.sources[node] is! BuiltInSource) return;
     var declaration = references.variables[node];
     if (declaration == null) {
       // TODO(jathak): Error here as part of fixing #182.
@@ -1145,6 +1167,10 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// renaming or namespacing if necessary.
   @override
   void visitVariableDeclaration(VariableDeclaration node) {
+    if (builtInOnly) {
+      super.visitVariableDeclaration(node);
+      return;
+    }
     var declaration = MemberDeclaration(node);
     var defaultDeclaration =
         references.defaultVariableDeclarations[declaration];
diff --git a/lib/src/migrators/module/built_in_functions.dart b/lib/src/migrators/module/built_in_functions.dart
index 72aaf00..b17917c 100644
--- a/lib/src/migrators/module/built_in_functions.dart
+++ b/lib/src/migrators/module/built_in_functions.dart
@@ -22,6 +22,7 @@ const builtInFunctionModules = {
   "complement": "color",
   "invert": "color",
   "alpha": "color",
+  "opacity": "color",
   "opacify": "color",
   "fade-in": "color",
   "transparentize": "color",
@@ -43,6 +44,7 @@ const builtInFunctionModules = {
   "is-superselector": "selector",
   "simple-selectors": "selector",
   "selector-parse": "selector",
+  "selector-extend": "selector",
   "percentage": "math",
   "round": "math",
   "ceil": "math",
@@ -62,6 +64,7 @@ const builtInFunctionModules = {
   "zip": "list",
   "index": "list",
   "list-separator": "list",
+  "is-bracketed": "list",
   "feature-exists": "meta",
   "variable-exists": "meta",
   "global-variable-exists": "meta",
@@ -100,6 +103,7 @@ const builtInFunctionNameChanges = {
   "selector-replace": "replace",
   "selector-unify": "unify",
   "selector-parse": "parse",
+  "selector-extend": "extend",
   "unitless": "is-unitless",
   "comparable": "compatible",
   "list-separator": "separator",
diff --git a/lib/src/migrators/namespace.dart b/lib/src/migrators/namespace.dart
index 39c1efd..3ffc21d 100644
--- a/lib/src/migrators/namespace.dart
+++ b/lib/src/migrators/namespace.dart
@@ -38,8 +38,9 @@ class NamespaceMigrator extends Migrator {
     var renamer = Renamer<UseRule>(argResults!['rename'].join('\n'),
         {'': ((rule) => rule.namespace!), 'url': (rule) => rule.url.toString()},
         sourceUrl: '--rename');
-    var visitor = _NamespaceMigrationVisitor(renamer,
-        argResults!['force'] as bool, importCache, migrateDependencies);
+    var visitor = _NamespaceMigrationVisitor(
+        renamer, argResults!['force'] as bool, importCache,
+        migrateDependencies: migrateDependencies);
     var result = visitor.run(stylesheet, importer);
     missingDependencies.addAll(visitor.missingDependencies);
     return result;
@@ -62,9 +63,8 @@ class _NamespaceMigrationVisitor extends MigrationVisitor {
       assertInStylesheet(__usedNamespaces, '_usedNamespaces');
   Set<String>? __usedNamespaces;
 
-  _NamespaceMigrationVisitor(this.renamer, this.forceRename,
-      ImportCache importCache, bool migrateDependencies)
-      : super(importCache, migrateDependencies);
+  _NamespaceMigrationVisitor(this.renamer, this.forceRename, super.importCache,
+      {required super.migrateDependencies});
 
   @override
   void visitStylesheet(Stylesheet node) {
diff --git a/lib/src/migrators/strict_unary.dart b/lib/src/migrators/strict_unary.dart
index 2dc73a0..0d426dd 100644
--- a/lib/src/migrators/strict_unary.dart
+++ b/lib/src/migrators/strict_unary.dart
@@ -19,7 +19,8 @@ class StrictUnaryMigrator extends Migrator {
   @override
   Map<Uri, String> migrateFile(
       ImportCache importCache, Stylesheet stylesheet, Importer importer) {
-    var visitor = _UnaryMigrationVisitor(importCache, migrateDependencies);
+    var visitor = _UnaryMigrationVisitor(importCache,
+        migrateDependencies: migrateDependencies);
     var result = visitor.run(stylesheet, importer);
     missingDependencies.addAll(visitor.missingDependencies);
     return result;
@@ -27,8 +28,8 @@ class StrictUnaryMigrator extends Migrator {
 }
 
 class _UnaryMigrationVisitor extends MigrationVisitor {
-  _UnaryMigrationVisitor(ImportCache importCache, bool migrateDependencies)
-      : super(importCache, migrateDependencies);
+  _UnaryMigrationVisitor(super.importCache,
+      {required super.migrateDependencies});
 
   @override
   void visitBinaryOperationExpression(BinaryOperationExpression node) {
diff --git a/pubspec.yaml b/pubspec.yaml
index df61c11..07e3b2f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: sass_migrator
-version: 2.0.3
+version: 2.1.0
 description: A tool for running migrations on Sass files
 homepage: https://github.com/sass/migrator
 
@@ -17,7 +17,7 @@ dependencies:
   node_interop: ^2.0.2
   node_io: ^2.3.0
   path: ^1.8.0
-  sass_api: ^9.2.7
+  sass_api: ^10.4.8
   source_span: ^1.8.1
   stack_trace: ^1.10.0
   string_scanner: ^1.1.0
diff --git a/test/migrators/module/built_in_functions/builtin_only.hrx b/test/migrators/module/built_in_functions/builtin_only.hrx
new file mode 100644
index 0000000..f1af697
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only.hrx
@@ -0,0 +1,19 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@import "library";
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+$red: red;
+$blue: blue;
+
+<==> output/entrypoint.scss
+@use "sass:color";
+@import "library";
+a {
+  color: color.mix($red, $blue);
+}

From 988a53f37898aad8cec37cbcf8199d06be52c6c6 Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@gmail.com>
Date: Wed, 17 Jul 2024 13:32:33 -0700
Subject: [PATCH 2/4] Fix broken calc_interpolation test

---
 .../calc_interpolation/calc_remove_interpolation.hrx   | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/migrators/calc_interpolation/calc_remove_interpolation.hrx b/test/migrators/calc_interpolation/calc_remove_interpolation.hrx
index 0e0767b..ef28802 100644
--- a/test/migrators/calc_interpolation/calc_remove_interpolation.hrx
+++ b/test/migrators/calc_interpolation/calc_remove_interpolation.hrx
@@ -8,8 +8,8 @@ $d: 5;
 .a { .b: calc($b * #{$c + 1}); }
 
 // More than one interpolations
-.a { 
-    .b: calc($b - #{$c + 1} + #{$d}); 
+.a {
+    .b: calc($b - #{$c + 1} + #{$d});
     .c: calc(100% - #{$TABLE_TITLE + 2px});
 }
 
@@ -35,9 +35,9 @@ $d: 5;
 .a { .b: calc($b * ($c + 1)); }
 
 // More than one interpolations
-.a { 
-    .b: calc($b - ($c + 1) + $d); 
-    .c: calc(100% - ($TABLE-TITLE + 2px));
+.a {
+    .b: calc($b - ($c + 1) + $d);
+    .c: calc(100% - ($TABLE_TITLE + 2px));
 }
 
 // Nested

From ddbf9d60e3991d97bff1466fb3608859596bcf5d Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@gmail.com>
Date: Wed, 9 Oct 2024 11:25:18 -0700
Subject: [PATCH 3/4] Add more tests; fix issue with null namespace use

---
 lib/src/migrators/module.dart                 |  6 ++--
 lib/src/migrators/module/references.dart      | 12 ++++++--
 .../basic.hrx}                                |  0
 .../builtin_only/local_shadow.hrx             | 20 +++++++++++++
 .../builtin_only/migrate_deps.hrx             | 24 +++++++++++++++
 .../builtin_only/module_already_exists.hrx    | 20 +++++++++++++
 .../builtin_only/multiple_imports.hrx         | 29 +++++++++++++++++++
 .../builtin_only/partially_migrated.hrx       | 19 ++++++++++++
 .../builtin_only/shadowed_by_import.hrx       | 20 +++++++++++++
 .../builtin_only/shadowed_by_use.hrx          | 22 ++++++++++++++
 .../built_in_functions/shadowed_by_use.hrx    | 24 +++++++++++++++
 .../partial_migration/use_null_namespace.hrx  | 20 +++++++++++++
 12 files changed, 211 insertions(+), 5 deletions(-)
 rename test/migrators/module/built_in_functions/{builtin_only.hrx => builtin_only/basic.hrx} (100%)
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx
 create mode 100644 test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx
 create mode 100644 test/migrators/module/built_in_functions/shadowed_by_use.hrx
 create mode 100644 test/migrators/module/partial_migration/use_null_namespace.hrx

diff --git a/lib/src/migrators/module.dart b/lib/src/migrators/module.dart
index e15b2aa..26eb154 100644
--- a/lib/src/migrators/module.dart
+++ b/lib/src/migrators/module.dart
@@ -611,8 +611,10 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
   /// Adds a namespace to any function call that requires it.
   @override
   void visitFunctionExpression(FunctionExpression node) {
+    var source = references.sources[node];
     if (node.namespace != null ||
-        (builtInOnly && references.sources[node] is! BuiltInSource)) {
+        source is UseSource ||
+        builtInOnly && source is! BuiltInSource) {
       super.visitFunctionExpression(node);
       return;
     }
@@ -795,7 +797,6 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
           _upstreamStylesheets.add(currentUrl);
           if (migrateDependencies) visitDependency(ruleUrl, import.span);
           _upstreamStylesheets.remove(currentUrl);
-          return;
         } else if (_useAllowed) {
           migratedRules.addAll(_migrateImportToRules(ruleUrl, import.span));
         } else {
@@ -804,6 +805,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
         }
       }
     }
+    if (builtInOnly) return;
 
     rulesText = migratedRules.join('$semicolon\n$indent');
     if (rulesText.isEmpty) {
diff --git a/lib/src/migrators/module/references.dart b/lib/src/migrators/module/references.dart
index c65d293..1f3619e 100644
--- a/lib/src/migrators/module/references.dart
+++ b/lib/src/migrators/module/references.dart
@@ -383,13 +383,19 @@ class _ReferenceVisitor extends ScopedAstVisitor {
   void visitUseRule(UseRule node) {
     super.visitUseRule(node);
     var namespace = node.namespace;
-    if (namespace == null) return;
     if (node.url.scheme == 'sass') {
-      _namespaces[namespace] = node.url;
+      if (namespace != null) _namespaces[namespace] = node.url;
       return;
     }
     var canonicalUrl = _loadUseOrForward(node.url, node);
-    _namespaces[namespace] = canonicalUrl;
+    if (namespace != null) {
+      _namespaces[namespace] = canonicalUrl;
+    } else {
+      var moduleScope = _moduleScopes[canonicalUrl]!;
+      currentScope.variables.addAll(moduleScope.variables);
+      currentScope.mixins.addAll(moduleScope.mixins);
+      currentScope.functions.addAll(moduleScope.functions);
+    }
 
     // `_moduleSources[canonicalUrl]` is set in `_loadUseOrForward`.
     var moduleSources = _moduleSources[canonicalUrl]!;
diff --git a/test/migrators/module/built_in_functions/builtin_only.hrx b/test/migrators/module/built_in_functions/builtin_only/basic.hrx
similarity index 100%
rename from test/migrators/module/built_in_functions/builtin_only.hrx
rename to test/migrators/module/built_in_functions/builtin_only/basic.hrx
diff --git a/test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx b/test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx
new file mode 100644
index 0000000..7b62b0f
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx
@@ -0,0 +1,20 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@import "library";
+
+@function mix($a, $b) {
+  @return $a;
+}
+
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+$red: red;
+$blue: blue;
+
+<==> log.txt
+Nothing to migrate!
diff --git a/test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx b/test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx
new file mode 100644
index 0000000..0c2d538
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx
@@ -0,0 +1,24 @@
+<==> arguments
+--builtin-only --migrate-deps
+
+<==> input/entrypoint.scss
+@import "library";
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+$red: invert(red);
+$blue: invert(blue);
+
+<==> output/entrypoint.scss
+@use "sass:color";
+@import "library";
+a {
+  color: color.mix($red, $blue);
+}
+
+<==> output/_library.scss
+@use "sass:color";
+$red: color.invert(red);
+$blue: color.invert(blue);
diff --git a/test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx b/test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx
new file mode 100644
index 0000000..f08a2fc
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx
@@ -0,0 +1,20 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@use "sass:color";
+@import "library";
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+$red: red;
+$blue: blue;
+
+<==> output/entrypoint.scss
+@use "sass:color";
+@import "library";
+a {
+  color: color.mix($red, $blue);
+}
diff --git a/test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx b/test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx
new file mode 100644
index 0000000..6a68114
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx
@@ -0,0 +1,29 @@
+<==> arguments
+--builtin-only --migrate-deps
+
+<==> input/entrypoint.scss
+@import "a", "b";
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_a.scss
+$red: invert(red);
+
+<==> input/_b.scss
+$blue: invert(blue);
+
+<==> output/entrypoint.scss
+@use "sass:color";
+@import "a", "b";
+a {
+  color: color.mix($red, $blue);
+}
+
+<==> output/_a.scss
+@use "sass:color";
+$red: color.invert(red);
+
+<==> output/_b.scss
+@use "sass:color";
+$blue: color.invert(blue);
diff --git a/test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx b/test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx
new file mode 100644
index 0000000..0e60b37
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx
@@ -0,0 +1,19 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@use "sass:math";
+@import "library";
+a {
+  b: round(math.sqrt($c));
+}
+
+<==> input/_library.scss
+$c: 7;
+
+<==> output/entrypoint.scss
+@use "sass:math";
+@import "library";
+a {
+  b: math.round(math.sqrt($c));
+}
diff --git a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx b/test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx
new file mode 100644
index 0000000..493f55c
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx
@@ -0,0 +1,20 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@import "library";
+
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+$red: red;
+$blue: blue;
+
+@function mix($a, $b) {
+  @return $a;
+}
+
+<==> log.txt
+Nothing to migrate!
diff --git a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx b/test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx
new file mode 100644
index 0000000..7ff1441
--- /dev/null
+++ b/test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx
@@ -0,0 +1,22 @@
+<==> arguments
+--builtin-only
+
+<==> input/entrypoint.scss
+@use "library" as *;
+@import "colors";
+
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+@function mix($a, $b) {
+  @return $a;
+}
+
+<==> input/_colors.scss
+$red: red;
+$blue: blue;
+
+<==> log.txt
+Nothing to migrate!
diff --git a/test/migrators/module/built_in_functions/shadowed_by_use.hrx b/test/migrators/module/built_in_functions/shadowed_by_use.hrx
new file mode 100644
index 0000000..908770b
--- /dev/null
+++ b/test/migrators/module/built_in_functions/shadowed_by_use.hrx
@@ -0,0 +1,24 @@
+<==> input/entrypoint.scss
+@use "library" as *;
+@import "colors";
+
+a {
+  color: mix($red, $blue);
+}
+
+<==> input/_library.scss
+@function mix($a, $b) {
+  @return $a;
+}
+
+<==> input/_colors.scss
+$red: red;
+$blue: blue;
+
+<==> output/entrypoint.scss
+@use "library" as *;
+@use "colors";
+
+a {
+  color: mix(colors.$red, colors.$blue);
+}
diff --git a/test/migrators/module/partial_migration/use_null_namespace.hrx b/test/migrators/module/partial_migration/use_null_namespace.hrx
new file mode 100644
index 0000000..1bd44a6
--- /dev/null
+++ b/test/migrators/module/partial_migration/use_null_namespace.hrx
@@ -0,0 +1,20 @@
+<==> input/entrypoint.scss
+@use "library" as *;
+
+a {
+  @include test(fn($x));
+}
+
+<==> input/_library.scss
+@mixin test($arg) {
+  b: $arg;
+}
+
+@function fn($arg) {
+  @return $arg;
+}
+
+$x: red;
+
+<==> log.txt
+Nothing to migrate!

From 9fe3c661daea5a0a00058f188fa086f19bf66150 Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@gmail.com>
Date: Thu, 10 Oct 2024 10:41:53 -0700
Subject: [PATCH 4/4] Code review

---
 CHANGELOG.md                                  |  2 +-
 lib/src/migrators/module.dart                 | 21 ++++++++++------
 .../{builtin_only => built_in_only}/basic.hrx |  2 +-
 .../built_in_only/get_function.hrx            | 25 +++++++++++++++++++
 .../local_shadow.hrx                          |  2 +-
 .../migrate_deps.hrx                          |  2 +-
 .../module_already_exists.hrx                 |  2 +-
 .../multiple_imports.hrx                      |  2 +-
 .../partially_migrated.hrx                    |  2 +-
 .../shadowed_by_import.hrx                    |  2 +-
 .../shadowed_by_use.hrx                       |  2 +-
 .../module/built_in_functions/namespacing.hrx |  2 ++
 12 files changed, 49 insertions(+), 17 deletions(-)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/basic.hrx (94%)
 create mode 100644 test/migrators/module/built_in_functions/built_in_only/get_function.hrx
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/local_shadow.hrx (93%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/migrate_deps.hrx (92%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/module_already_exists.hrx (94%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/multiple_imports.hrx (92%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/partially_migrated.hrx (93%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/shadowed_by_import.hrx (93%)
 rename test/migrators/module/built_in_functions/{builtin_only => built_in_only}/shadowed_by_use.hrx (94%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2392b8b..1dacf10 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 
 ### Module Migrator
 
-* Add a new `--builtin-only` flag, which migrates global functions to their
+* Add a new `--built-in-only` flag, which migrates global functions to their
   `sass:` module equivalents, while leaving `@import` rules unchanged.
 
 * Fix bug where some functions (`opacity`, `is-bracketed`, and
diff --git a/lib/src/migrators/module.dart b/lib/src/migrators/module.dart
index 26eb154..ba623ec 100644
--- a/lib/src/migrators/module.dart
+++ b/lib/src/migrators/module.dart
@@ -32,7 +32,7 @@ class ModuleMigrator extends Migrator {
 
   @override
   final argParser = ArgParser()
-    ..addFlag('builtin-only',
+    ..addFlag('built-in-only',
         help: 'Migrates global functions without migrating @import.')
     ..addMultiOption('remove-prefix',
         abbr: 'p',
@@ -79,12 +79,12 @@ class ModuleMigrator extends Migrator {
   Map<Uri, String> migrateFile(
       ImportCache importCache, Stylesheet stylesheet, Importer importer) {
     var forwards = {for (var arg in argResults!['forward']) ForwardType(arg)};
-    var builtInOnly = argResults!['builtin-only'] as bool;
+    var builtInOnly = argResults!['built-in-only'] as bool;
     if (builtInOnly &&
         (argResults!.wasParsed('forward') ||
             argResults!.wasParsed('remove-prefix'))) {
       throw MigrationException('--forward and --remove-prefix may not be '
-          'passed with --builtin-only.');
+          'passed with --built-in-only.');
     }
     if (forwards.contains(ForwardType.prefixed) &&
         !argResults!.wasParsed('remove-prefix')) {
@@ -630,7 +630,7 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
       });
     }
 
-    if (node.name == "get-function" && !builtInOnly) {
+    if (node.name == "get-function") {
       var declaration = references.getFunctionReferences[node];
       if (declaration != null) {
         _unreferencable.check(declaration, node);
@@ -648,12 +648,15 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
       // Warn for get-function calls without a static name.
       var nameArg =
           node.arguments.named['name'] ?? node.arguments.positional.first;
-      if (nameArg is! StringExpression || nameArg.text.asPlain == null) {
+      if ((nameArg is! StringExpression || nameArg.text.asPlain == null) &&
+          !builtInOnly) {
         emitWarning(
             "get-function call may require \$module parameter", nameArg.span);
         return;
       }
 
+      if (builtInOnly && declaration != null) return;
+
       _patchNamespaceForFunction(node, declaration, (namespace) {
         var beforeParen = node.span.end.offset - 1;
         addPatch(Patch(node.span.file.span(beforeParen, beforeParen),
@@ -794,9 +797,11 @@ class _ModuleMigrationVisitor extends MigrationVisitor {
       }
       if (ruleUrl != null) {
         if (builtInOnly) {
-          _upstreamStylesheets.add(currentUrl);
-          if (migrateDependencies) visitDependency(ruleUrl, import.span);
-          _upstreamStylesheets.remove(currentUrl);
+          if (migrateDependencies) {
+            _upstreamStylesheets.add(currentUrl);
+            visitDependency(ruleUrl, import.span);
+            _upstreamStylesheets.remove(currentUrl);
+          }
         } else if (_useAllowed) {
           migratedRules.addAll(_migrateImportToRules(ruleUrl, import.span));
         } else {
diff --git a/test/migrators/module/built_in_functions/builtin_only/basic.hrx b/test/migrators/module/built_in_functions/built_in_only/basic.hrx
similarity index 94%
rename from test/migrators/module/built_in_functions/builtin_only/basic.hrx
rename to test/migrators/module/built_in_functions/built_in_only/basic.hrx
index f1af697..7ae2ad6 100644
--- a/test/migrators/module/built_in_functions/builtin_only/basic.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/basic.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @import "library";
diff --git a/test/migrators/module/built_in_functions/built_in_only/get_function.hrx b/test/migrators/module/built_in_functions/built_in_only/get_function.hrx
new file mode 100644
index 0000000..62d9546
--- /dev/null
+++ b/test/migrators/module/built_in_functions/built_in_only/get_function.hrx
@@ -0,0 +1,25 @@
+<==> arguments
+--built-in-only
+
+<==> input/entrypoint.scss
+@import "library";
+
+a {
+  b: call(get-function(mix), red, blue);
+  c: call(get-function(fn), green);
+}
+
+<==> input/_library.scss
+@function fn($x) {
+  @return $x;
+}
+
+<==> output/entrypoint.scss
+@use "sass:color";
+@use "sass:meta";
+@import "library";
+
+a {
+  b: meta.call(meta.get-function(mix, $module: "color"), red, blue);
+  c: meta.call(meta.get-function(fn), green);
+}
diff --git a/test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx b/test/migrators/module/built_in_functions/built_in_only/local_shadow.hrx
similarity index 93%
rename from test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx
rename to test/migrators/module/built_in_functions/built_in_only/local_shadow.hrx
index 7b62b0f..d417c2d 100644
--- a/test/migrators/module/built_in_functions/builtin_only/local_shadow.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/local_shadow.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @import "library";
diff --git a/test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx b/test/migrators/module/built_in_functions/built_in_only/migrate_deps.hrx
similarity index 92%
rename from test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx
rename to test/migrators/module/built_in_functions/built_in_only/migrate_deps.hrx
index 0c2d538..7a53fa2 100644
--- a/test/migrators/module/built_in_functions/builtin_only/migrate_deps.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/migrate_deps.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only --migrate-deps
+--built-in-only --migrate-deps
 
 <==> input/entrypoint.scss
 @import "library";
diff --git a/test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx b/test/migrators/module/built_in_functions/built_in_only/module_already_exists.hrx
similarity index 94%
rename from test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx
rename to test/migrators/module/built_in_functions/built_in_only/module_already_exists.hrx
index f08a2fc..c03c437 100644
--- a/test/migrators/module/built_in_functions/builtin_only/module_already_exists.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/module_already_exists.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @use "sass:color";
diff --git a/test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx b/test/migrators/module/built_in_functions/built_in_only/multiple_imports.hrx
similarity index 92%
rename from test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx
rename to test/migrators/module/built_in_functions/built_in_only/multiple_imports.hrx
index 6a68114..49c91a2 100644
--- a/test/migrators/module/built_in_functions/builtin_only/multiple_imports.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/multiple_imports.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only --migrate-deps
+--built-in-only --migrate-deps
 
 <==> input/entrypoint.scss
 @import "a", "b";
diff --git a/test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx b/test/migrators/module/built_in_functions/built_in_only/partially_migrated.hrx
similarity index 93%
rename from test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx
rename to test/migrators/module/built_in_functions/built_in_only/partially_migrated.hrx
index 0e60b37..12162c7 100644
--- a/test/migrators/module/built_in_functions/builtin_only/partially_migrated.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/partially_migrated.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @use "sass:math";
diff --git a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx b/test/migrators/module/built_in_functions/built_in_only/shadowed_by_import.hrx
similarity index 93%
rename from test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx
rename to test/migrators/module/built_in_functions/built_in_only/shadowed_by_import.hrx
index 493f55c..266f60a 100644
--- a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_import.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/shadowed_by_import.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @import "library";
diff --git a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx b/test/migrators/module/built_in_functions/built_in_only/shadowed_by_use.hrx
similarity index 94%
rename from test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx
rename to test/migrators/module/built_in_functions/built_in_only/shadowed_by_use.hrx
index 7ff1441..3038439 100644
--- a/test/migrators/module/built_in_functions/builtin_only/shadowed_by_use.hrx
+++ b/test/migrators/module/built_in_functions/built_in_only/shadowed_by_use.hrx
@@ -1,5 +1,5 @@
 <==> arguments
---builtin-only
+--built-in-only
 
 <==> input/entrypoint.scss
 @use "library" as *;
diff --git a/test/migrators/module/built_in_functions/namespacing.hrx b/test/migrators/module/built_in_functions/namespacing.hrx
index 7cf86d4..5904584 100644
--- a/test/migrators/module/built_in_functions/namespacing.hrx
+++ b/test/migrators/module/built_in_functions/namespacing.hrx
@@ -2,6 +2,7 @@
 $a: mix(red, blue);
 $b: str-length("hello");
 $c: scale-color(blue, $lightness: -10%);
+$d: call(get-function(mix), red, blue);
 
 @function fn($args...) {
   @return keywords($args);
@@ -14,6 +15,7 @@ $c: scale-color(blue, $lightness: -10%);
 $a: color.mix(red, blue);
 $b: string.length("hello");
 $c: color.scale(blue, $lightness: -10%);
+$d: meta.call(meta.get-function(mix, $module: "color"), red, blue);
 
 @function fn($args...) {
   @return meta.keywords($args);