From af816d094111b22a52c7fb8a1b86e0c905184364 Mon Sep 17 00:00:00 2001
From: Jennifer Thakar <jathak@google.com>
Date: Wed, 2 Jun 2021 14:52:17 -0700
Subject: [PATCH] Fix bug in --update with built-in modules (#1338)

Fixes #1335.
---
 CHANGELOG.md                           |  3 +++
 lib/src/visitor/find_dependencies.dart |  9 +++++----
 pubspec.yaml                           |  2 +-
 test/cli/shared/update.dart            | 11 +++++++++++
 4 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5e169bad..f69bd3ec8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## 1.34.1
 
+* Fix a bug where `--update` would always compile any file that depends on a
+  built-in module.
+
 * Fix the URL for the `@-moz-document` deprecation message.
 
 * Fix a bug with `@for` loops nested inside property declarations.
diff --git a/lib/src/visitor/find_dependencies.dart b/lib/src/visitor/find_dependencies.dart
index 80a876fa5..64bd2095a 100644
--- a/lib/src/visitor/find_dependencies.dart
+++ b/lib/src/visitor/find_dependencies.dart
@@ -10,12 +10,13 @@ import 'recursive_statement.dart';
 /// Returns two lists of dependencies for [stylesheet].
 ///
 /// The first is a list of URLs from all `@use` and `@forward` rules in
-/// [stylesheet]. The second is a list of all imports in [stylesheet].
+/// [stylesheet] (excluding built-in modules). The second is a list of all
+/// imports in [stylesheet].
 Tuple2<List<Uri>, List<Uri>> findDependencies(Stylesheet stylesheet) =>
     _FindDependenciesVisitor().run(stylesheet);
 
 /// A visitor that traverses a stylesheet and records, all `@import`, `@use`,
-/// and `@forward` rules it contains.
+/// and `@forward` rules (excluding built-in modules) it contains.
 class _FindDependenciesVisitor extends RecursiveStatementVisitor {
   final _usesAndForwards = <Uri>[];
   final _imports = <Uri>[];
@@ -35,11 +36,11 @@ class _FindDependenciesVisitor extends RecursiveStatementVisitor {
   void visitSupportsCondition(SupportsCondition condition) {}
 
   void visitUseRule(UseRule node) {
-    _usesAndForwards.add(node.url);
+    if (node.url.scheme != 'sass') _usesAndForwards.add(node.url);
   }
 
   void visitForwardRule(ForwardRule node) {
-    _usesAndForwards.add(node.url);
+    if (node.url.scheme != 'sass') _usesAndForwards.add(node.url);
   }
 
   void visitImportRule(ImportRule node) {
diff --git a/pubspec.yaml b/pubspec.yaml
index 197eddbbb..f27aad41c 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: sass
-version: 1.34.1-dev
+version: 1.34.1
 description: A Sass implementation in Dart.
 author: Sass Team
 homepage: https://github.com/sass/dart-sass
diff --git a/test/cli/shared/update.dart b/test/cli/shared/update.dart
index 3453f12ec..fb45398c9 100644
--- a/test/cli/shared/update.dart
+++ b/test/cli/shared/update.dart
@@ -183,6 +183,17 @@ void sharedTests(Future<TestProcess> runSass(Iterable<String> arguments)) {
 
       await d.file("dir/test.css", "a {b: c}").validate();
     });
+
+    test("that uses a built-in module", () async {
+      await d.file("test.scss", "@use 'sass:math'; a {b: c}").create();
+      await d.file("out.css", "x {y: z}").create();
+
+      var sass = await update(["test.scss:out.css"]);
+      expect(sass.stdout, emitsDone);
+      await sass.shouldExit(0);
+
+      await d.file("out.css", "x {y: z}").validate();
+    });
   });
 
   group("updates a CSS file", () {