Add a fromImport fields to CanonicalizeRequest and FileImportRequest (#…

…61)

See sass/sass#3055
See webpack-contrib/sass-loader#905

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 1.0.0-beta.9
+
+* Added `CanonicalizeRequest.fromImport` and `FileImportRequest.fromImport`
+  fields to allow importers to correctly handle import-only files.
+
 ## 1.0.0-beta.8
 
 * Added fields to support requesting and sending formatted errors and logs.

embedded_sass.proto

@@ -432,6 +432,16 @@ message OutboundMessage {
     // each importer in order until one returns something other than `null`.
     // That is the result of the import.
     string url = 4;
+
+    /// Whether this request comes from an `@import` rule.
+    ///
+    /// When evaluating `@import` rules, URLs should canonicalize to an
+    /// [import-only file] if one exists for the URL being canonicalized.
+    /// Otherwise, canonicalization should be identical for `@import` and `@use`
+    /// rules.
+    ///
+    /// [import-only file]: https://sass-lang.com/documentation/at-rules/import#import-only-files
+    bool fromImport = 5;
   }
 
   // A request for a custom importer to load the contents of a stylesheet.
@@ -468,6 +478,16 @@ message OutboundMessage {
 
     // The (non-canonicalized) URL of the import.
     string url = 4;
+
+    /// Whether this request comes from an `@import` rule.
+    ///
+    /// When evaluating `@import` rules, filesystem importers should load an
+    /// [import-only file] if one exists for the URL being canonicalized.
+    /// Otherwise, canonicalization should be identical for `@import` and `@use`
+    /// rules.
+    ///
+    /// [import-only file]: https://sass-lang.com/documentation/at-rules/import#import-only-files
+    bool fromImport = 5;
   }
 
   // A request to invoke a custom Sass function and return its result.