From 6129adfa28d5e5b6dec74e5ef5a1018f688bd38b Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Fri, 8 Sep 2023 16:07:56 -0700
Subject: [PATCH 01/10] Avoid relying on buggy import order in the legacy
 importer (#245)

Historically, the legacy importer shim has strongly assumed that all
calls to `canonicalize()` would doubled: once as a URL resolved
relative to the current importer, and again as a URL passed to the
importers list. However, this relies on buggy, non-spec-compliant
behavior in Dart Sass: absolute URLs should never be passed to the
current importer, only to the global list of importers.

This change avoids relying on that behavior by instead disambiguating
relative loads using a custom URL protocol prefix. All canonical URLs
passed to Dart Sass now have the prefix `legacy-importer-` added to
the beginning. This allows us to disambiguate relative loads, and
ignore them for non-`file:` URLs, since relative loads and _only_
relative loads will have schemes beginning with `legacy-importer-`.

To avoid regressing the developer experience, we then strip these
prefixes from all URLs before they're passed to any developer-facing
APIs or displayed to the user.
---
 lib/src/compile.ts         | 62 +++++++++++++++++++++++++++----------
 lib/src/legacy/importer.ts | 63 +++++++++++++++++++-------------------
 lib/src/legacy/index.ts    | 55 ++++++++++++++++++---------------
 lib/src/legacy/utils.ts    | 59 +++++++++++++++++++++++++++++++++++
 4 files changed, 167 insertions(+), 72 deletions(-)
 create mode 100644 lib/src/legacy/utils.ts

diff --git a/lib/src/compile.ts b/lib/src/compile.ts
index c60cbf57..96d3a0a2 100644
--- a/lib/src/compile.ts
+++ b/lib/src/compile.ts
@@ -18,11 +18,32 @@ import {MessageTransformer} from './message-transformer';
 import {PacketTransformer} from './packet-transformer';
 import {SyncEmbeddedCompiler} from './sync-compiler';
 import {deprotofySourceSpan} from './deprotofy-span';
-import {legacyImporterProtocol} from './legacy/importer';
+import {
+  removeLegacyImporter,
+  removeLegacyImporterFromSpan,
+  legacyImporterProtocol,
+} from './legacy/utils';
+
+/// Allow the legacy API to pass in an option signaling to the modern API that
+/// it's being run in legacy mode.
+///
+/// This is not intended for API users to pass in, and may be broken without
+/// warning in the future.
+type OptionsWithLegacy<sync extends 'sync' | 'async'> = Options<sync> & {
+  legacy?: boolean;
+};
+
+/// Allow the legacy API to pass in an option signaling to the modern API that
+/// it's being run in legacy mode.
+///
+/// This is not intended for API users to pass in, and may be broken without
+/// warning in the future.
+type StringOptionsWithLegacy<sync extends 'sync' | 'async'> =
+  StringOptions<sync> & {legacy?: boolean};
 
 export function compile(
   path: string,
-  options?: Options<'sync'>
+  options?: OptionsWithLegacy<'sync'>
 ): CompileResult {
   const importers = new ImporterRegistry(options);
   return compileRequestSync(
@@ -34,7 +55,7 @@ export function compile(
 
 export function compileString(
   source: string,
-  options?: StringOptions<'sync'>
+  options?: StringOptionsWithLegacy<'sync'>
 ): CompileResult {
   const importers = new ImporterRegistry(options);
   return compileRequestSync(
@@ -46,7 +67,7 @@ export function compileString(
 
 export function compileAsync(
   path: string,
-  options?: Options<'async'>
+  options?: OptionsWithLegacy<'async'>
 ): Promise<CompileResult> {
   const importers = new ImporterRegistry(options);
   return compileRequestAsync(
@@ -58,7 +79,7 @@ export function compileAsync(
 
 export function compileStringAsync(
   source: string,
-  options?: StringOptions<'async'>
+  options?: StringOptionsWithLegacy<'async'>
 ): Promise<CompileResult> {
   const importers = new ImporterRegistry(options);
   return compileRequestAsync(
@@ -151,7 +172,7 @@ function newCompileRequest(
 async function compileRequestAsync(
   request: proto.InboundMessage_CompileRequest,
   importers: ImporterRegistry<'async'>,
-  options?: Options<'async'>
+  options?: OptionsWithLegacy<'async'> & {legacy?: boolean}
 ): Promise<CompileResult> {
   const functions = new FunctionRegistry(options?.functions);
   const embeddedCompiler = new AsyncEmbeddedCompiler();
@@ -197,7 +218,7 @@ async function compileRequestAsync(
 function compileRequestSync(
   request: proto.InboundMessage_CompileRequest,
   importers: ImporterRegistry<'sync'>,
-  options?: Options<'sync'>
+  options?: OptionsWithLegacy<'sync'>
 ): CompileResult {
   const functions = new FunctionRegistry(options?.functions);
   const embeddedCompiler = new SyncEmbeddedCompiler();
@@ -272,16 +293,23 @@ function createDispatcher<sync extends 'sync' | 'async'>(
 
 /** Handles a log event according to `options`. */
 function handleLogEvent(
-  options: Options<'sync' | 'async'> | undefined,
+  options: OptionsWithLegacy<'sync' | 'async'> | undefined,
   event: proto.OutboundMessage_LogEvent
 ): void {
+  let span = event.span ? deprotofySourceSpan(event.span) : null;
+  if (span && options?.legacy) span = removeLegacyImporterFromSpan(span);
+  let message = event.message;
+  if (options?.legacy) message = removeLegacyImporter(message);
+  let formatted = event.formatted;
+  if (options?.legacy) formatted = removeLegacyImporter(formatted);
+
   if (event.type === proto.LogEventType.DEBUG) {
     if (options?.logger?.debug) {
-      options.logger.debug(event.message, {
-        span: deprotofySourceSpan(event.span!),
+      options.logger.debug(message, {
+        span: span!,
       });
     } else {
-      console.error(event.formatted);
+      console.error(formatted);
     }
   } else {
     if (options?.logger?.warn) {
@@ -289,16 +317,16 @@ function handleLogEvent(
         {
           deprecation: event.type === proto.LogEventType.DEPRECATION_WARNING,
         };
-
-      const spanProto = event.span;
-      if (spanProto) params.span = deprotofySourceSpan(spanProto);
+      if (span) params.span = span;
 
       const stack = event.stackTrace;
-      if (stack) params.stack = stack;
+      if (stack) {
+        params.stack = options?.legacy ? removeLegacyImporter(stack) : stack;
+      }
 
-      options.logger.warn(event.message, params);
+      options.logger.warn(message, params);
     } else {
-      console.error(event.formatted);
+      console.error(formatted);
     }
   }
 }
diff --git a/lib/src/legacy/importer.ts b/lib/src/legacy/importer.ts
index 149c55cf..791cfc12 100644
--- a/lib/src/legacy/importer.ts
+++ b/lib/src/legacy/importer.ts
@@ -3,7 +3,6 @@
 // https://opensource.org/licenses/MIT.
 
 import {strict as assert} from 'assert';
-import {pathToFileURL, URL as NodeURL} from 'url';
 import * as fs from 'fs';
 import * as p from 'path';
 import * as util from 'util';
@@ -26,6 +25,12 @@ import {
   LegacyPluginThis,
   LegacySyncImporter,
 } from '../vendor/sass';
+import {
+  pathToLegacyFileUrl,
+  legacyFileUrlToPath,
+  legacyImporterProtocol,
+  legacyImporterProtocolPrefix,
+} from './utils';
 
 /**
  * A special URL protocol we use to signal when a stylesheet has finished
@@ -36,9 +41,9 @@ import {
 export const endOfLoadProtocol = 'sass-embedded-legacy-load-done:';
 
 /**
- * The URL protocol to use for URLs canonicalized using `LegacyImporterWrapper`.
+ * The `file:` URL protocol with [legacyImporterProtocolPrefix] at the beginning.
  */
-export const legacyImporterProtocol = 'legacy-importer:';
+export const legacyImporterFileProtocol = 'legacy-importer-file:';
 
 // A count of `endOfLoadProtocol` imports that have been generated. Each one
 // must be a different URL to ensure that the importer results aren't cached.
@@ -68,11 +73,6 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
   // `this.callbacks`, if it returned one.
   private lastContents: string | undefined;
 
-  // Whether we're expecting the next call to `canonicalize()` to be a relative
-  // load. The legacy importer API doesn't handle these loads in the same way as
-  // the modern API, so we always return `null` in this case.
-  private expectingRelativeLoad = true;
-
   constructor(
     private readonly self: LegacyPluginThis,
     private readonly callbacks: Array<LegacyImporter<sync>>,
@@ -90,14 +90,23 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
   ): PromiseOr<URL | null, sync> {
     if (url.startsWith(endOfLoadProtocol)) return new URL(url);
 
-    // Since there's only ever one modern importer in legacy mode, we can be
-    // sure that all normal loads are preceded by exactly one relative load.
-    if (this.expectingRelativeLoad) {
-      if (url.startsWith('file:')) {
+    if (
+      url.startsWith(legacyImporterProtocolPrefix) ||
+      url.startsWith(legacyImporterProtocol)
+    ) {
+      // A load starts with `legacyImporterProtocolPrefix` if and only if it's a
+      // relative load for the current importer rather than an absolute load.
+      // For the most part, we want to ignore these, but for `file:` URLs
+      // specifically we want to resolve them on the filesystem to ensure
+      // locality.
+      const urlWithoutPrefix = url.substring(
+        legacyImporterProtocolPrefix.length
+      );
+      if (urlWithoutPrefix.startsWith('file:')) {
         let resolved: string | null = null;
 
         try {
-          const path = fileUrlToPathCrossPlatform(url);
+          const path = fileUrlToPathCrossPlatform(urlWithoutPrefix);
           resolved = resolvePath(path, options.fromImport);
         } catch (error: unknown) {
           if (
@@ -119,16 +128,11 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
 
         if (resolved !== null) {
           this.prev.push({url: resolved, path: true});
-          return pathToFileURL(resolved);
+          return pathToLegacyFileUrl(resolved);
         }
       }
 
-      this.expectingRelativeLoad = false;
       return null;
-    } else if (!url.startsWith('file:')) {
-      // We'll only search for another relative import when the URL isn't
-      // absolute.
-      this.expectingRelativeLoad = true;
     }
 
     const prev = this.prev[this.prev.length - 1];
@@ -153,14 +157,14 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
                 encodeURI((result as {file: string}).file)
             );
           } else if (/^[A-Za-z+.-]+:/.test(url)) {
-            return new URL(url);
+            return new URL(`${legacyImporterProtocolPrefix}${url}`);
           } else {
             return new URL(legacyImporterProtocol + encodeURI(url));
           }
         } else {
           if (p.isAbsolute(result.file)) {
             const resolved = resolvePath(result.file, options.fromImport);
-            return resolved ? pathToFileURL(resolved) : null;
+            return resolved ? pathToLegacyFileUrl(resolved) : null;
           }
 
           const prefixes = [...this.loadPaths, '.'];
@@ -171,16 +175,16 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
               p.join(prefix, result.file),
               options.fromImport
             );
-            if (resolved !== null) return pathToFileURL(resolved);
+            if (resolved !== null) return pathToLegacyFileUrl(resolved);
           }
           return null;
         }
       }),
       result => {
         if (result !== null) {
-          const path = result.protocol === 'file:';
+          const path = result.protocol === legacyImporterFileProtocol;
           this.prev.push({
-            url: path ? fileUrlToPathCrossPlatform(result as NodeURL) : url,
+            url: path ? legacyFileUrlToPath(result) : url,
             path,
           });
           return result;
@@ -190,7 +194,7 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
               p.join(loadPath, url),
               options.fromImport
             );
-            if (resolved !== null) return pathToFileURL(resolved);
+            if (resolved !== null) return pathToLegacyFileUrl(resolved);
           }
           return null;
         }
@@ -208,7 +212,7 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
       };
     }
 
-    if (canonicalUrl.protocol === 'file:') {
+    if (canonicalUrl.protocol === legacyImporterFileProtocol) {
       const syntax = canonicalUrl.pathname.endsWith('.sass')
         ? 'indented'
         : canonicalUrl.pathname.endsWith('.css')
@@ -217,10 +221,7 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
 
       let contents =
         this.lastContents ??
-        fs.readFileSync(
-          fileUrlToPathCrossPlatform(canonicalUrl as NodeURL),
-          'utf-8'
-        );
+        fs.readFileSync(legacyFileUrlToPath(canonicalUrl), 'utf-8');
       this.lastContents = undefined;
       if (syntax === 'scss') {
         contents += this.endOfLoadImport;
@@ -311,7 +312,7 @@ export class LegacyImporterWrapper<sync extends 'sync' | 'async'>
   // The `@import` statement to inject after the contents of files to ensure
   // that we know when a load has completed so we can pass the correct `prev`
   // argument to callbacks.
-  private get endOfLoadImport() {
+  private get endOfLoadImport(): string {
     return `\n;@import "${endOfLoadProtocol}${endOfLoadCount++}";`;
   }
 }
diff --git a/lib/src/legacy/index.ts b/lib/src/legacy/index.ts
index 1631a534..8cc381e7 100644
--- a/lib/src/legacy/index.ts
+++ b/lib/src/legacy/index.ts
@@ -4,7 +4,7 @@
 
 import * as fs from 'fs';
 import * as p from 'path';
-import {URL, pathToFileURL} from 'url';
+import {pathToFileURL, URL} from 'url';
 
 import {Exception} from '../exception';
 import {
@@ -33,11 +33,13 @@ import {
   StringOptions,
 } from '../vendor/sass';
 import {wrapFunction} from './value/wrap';
+import {endOfLoadProtocol, LegacyImporterWrapper} from './importer';
 import {
-  endOfLoadProtocol,
   legacyImporterProtocol,
-  LegacyImporterWrapper,
-} from './importer';
+  pathToLegacyFileUrl,
+  removeLegacyImporter,
+  removeLegacyImporterFromSpan,
+} from './utils';
 
 export function render(
   options: LegacyOptions<'async'>,
@@ -74,8 +76,8 @@ export function renderSync(options: LegacyOptions<'sync'>): LegacyResult {
   }
 }
 
-// Does some initial adjustments of `options` to make it easier to convert pass
-// to the new API.
+// Does some initial adjustments of `options` to make it easier to pass to the
+// new API.
 function adjustOptions<sync extends 'sync' | 'async'>(
   options: LegacyOptions<sync>
 ): LegacyOptions<sync> {
@@ -119,7 +121,7 @@ function isStringOptions<sync extends 'sync' | 'async'>(
 function convertOptions<sync extends 'sync' | 'async'>(
   options: LegacyOptions<sync>,
   sync: SyncBoolean<sync>
-): Options<sync> {
+): Options<sync> & {legacy: true} {
   if (
     'outputStyle' in options &&
     options.outputStyle !== 'compressed' &&
@@ -165,6 +167,7 @@ function convertOptions<sync extends 'sync' | 'async'>(
     verbose: options.verbose,
     charset: options.charset,
     logger: options.logger,
+    legacy: true,
   };
 }
 
@@ -172,13 +175,15 @@ function convertOptions<sync extends 'sync' | 'async'>(
 function convertStringOptions<sync extends 'sync' | 'async'>(
   options: LegacyStringOptions<sync>,
   sync: SyncBoolean<sync>
-): StringOptions<sync> {
+): StringOptions<sync> & {legacy: true} {
   const modernOptions = convertOptions(options, sync);
 
   return {
     ...modernOptions,
     url: options.file
-      ? pathToFileURL(options.file)
+      ? options.importer
+        ? pathToLegacyFileUrl(options.file)
+        : pathToFileURL(options.file)
       : new URL(legacyImporterProtocol),
     importer: modernOptions.importers ? modernOptions.importers[0] : undefined,
     syntax: options.indentedSyntax ? 'indented' : 'scss',
@@ -256,12 +261,11 @@ function newLegacyResult(
     sourceMap.sources = sourceMap.sources
       .filter(source => !source.startsWith(endOfLoadProtocol))
       .map(source => {
+        source = removeLegacyImporter(source);
         if (source.startsWith('file://')) {
           return pathToUrlString(
             p.relative(sourceMapDir, fileUrlToPathCrossPlatform(source))
           );
-        } else if (source.startsWith(legacyImporterProtocol)) {
-          return source.substring(legacyImporterProtocol.length);
         } else if (source.startsWith('data:')) {
           return 'stdin';
         } else {
@@ -299,13 +303,14 @@ function newLegacyResult(
       includedFiles: result.loadedUrls
         .filter(url => url.protocol !== endOfLoadProtocol)
         .map(url => {
-          if (url.protocol === 'file:') {
-            return fileUrlToPathCrossPlatform(url as URL);
-          } else if (url.protocol === legacyImporterProtocol) {
+          if (url.protocol === legacyImporterProtocol) {
             return decodeURI(url.pathname);
-          } else {
-            return url.toString();
           }
+
+          const urlString = removeLegacyImporter(url.toString());
+          return urlString.startsWith('file:')
+            ? fileUrlToPathCrossPlatform(urlString)
+            : urlString;
         }),
     },
   };
@@ -321,25 +326,27 @@ function newLegacyException(error: Error): LegacyException {
     });
   }
 
+  const span = error.span ? removeLegacyImporterFromSpan(error.span) : null;
   let file: string;
-  if (!error.span?.url) {
+  if (!span?.url) {
     file = 'stdin';
-  } else if (error.span.url.protocol === 'file:') {
+  } else if (span.url.protocol === 'file:') {
     // We have to cast to Node's URL type here because the specified type is the
     // standard URL type which is slightly less featureful. `fileURLToPath()`
     // does work with standard URL objects in practice, but we know that we
     // generate Node URLs here regardless.
-    file = fileUrlToPathCrossPlatform(error.span.url as URL);
+    file = fileUrlToPathCrossPlatform(span.url as URL);
   } else {
-    file = error.span.url.toString();
+    file = span.url.toString();
   }
 
+  const errorString = removeLegacyImporter(error.toString());
   return Object.assign(new Error(), {
     status: 1,
-    message: error.toString().replace(/^Error: /, ''),
-    formatted: error.toString(),
-    toString: () => error.toString(),
-    stack: error.stack,
+    message: errorString.replace(/^Error: /, ''),
+    formatted: errorString,
+    toString: () => errorString,
+    stack: error.stack ? removeLegacyImporter(error.stack) : undefined,
     line: isNullOrUndefined(error.span?.start.line)
       ? undefined
       : error.span!.start.line + 1,
diff --git a/lib/src/legacy/utils.ts b/lib/src/legacy/utils.ts
new file mode 100644
index 00000000..05ffe42b
--- /dev/null
+++ b/lib/src/legacy/utils.ts
@@ -0,0 +1,59 @@
+// Copyright 2023 Google Inc. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import {strict as assert} from 'assert';
+import {pathToFileURL} from 'url';
+
+import {fileUrlToPathCrossPlatform} from '../utils';
+import {SourceSpan} from '../vendor/sass';
+import {legacyImporterFileProtocol} from './importer';
+
+/**
+ * The URL protocol to use for URLs canonicalized using `LegacyImporterWrapper`.
+ */
+export const legacyImporterProtocol = 'legacy-importer:';
+
+/**
+ * The prefix for absolute URLs canonicalized using `LegacyImporterWrapper`.
+ *
+ * This is used to distinguish imports resolved relative to URLs returned by a
+ * legacy importer from manually-specified absolute URLs.
+ */
+export const legacyImporterProtocolPrefix = 'legacy-importer-';
+
+/// A regular expression that matches legacy importer protocol syntax that
+/// should be removed from human-readable messages.
+const removeLegacyImporterRegExp = new RegExp(
+  `${legacyImporterProtocol}|${legacyImporterProtocolPrefix}`,
+  'g'
+);
+
+/// Returns `string` with all instances of legacy importer syntax removed.
+export function removeLegacyImporter(string: string): string {
+  return string.replace(removeLegacyImporterRegExp, '');
+}
+
+/// Returns a copy of [span] with the URL updated to remove legacy importer
+/// syntax.
+export function removeLegacyImporterFromSpan(span: SourceSpan): SourceSpan {
+  if (!span.url) return span;
+  return {...span, url: new URL(removeLegacyImporter(span.url.toString()))};
+}
+
+/// Converts [path] to a `file:` URL and adds the [legacyImporterProtocolPrefix]
+/// to the beginning so we can distinguish it from manually-specified absolute
+/// `file:` URLs.
+export function pathToLegacyFileUrl(path: string): URL {
+  return new URL(`${legacyImporterProtocolPrefix}${pathToFileURL(path)}`);
+}
+
+/// Converts a `file:` URL with [legacyImporterProtocolPrefix] to the filesystem
+/// path which it represents.
+export function legacyFileUrlToPath(url: URL): string {
+  assert.equal(url.protocol, legacyImporterFileProtocol);
+  const originalUrl = url
+    .toString()
+    .substring(legacyImporterProtocolPrefix.length);
+  return fileUrlToPathCrossPlatform(originalUrl);
+}

From f7509e60f8a73fb2ab653c3c5430bc7845e02f52 Mon Sep 17 00:00:00 2001
From: Sass Bot <sass.bot.beep.boop@gmail.com>
Date: Thu, 14 Sep 2023 00:56:46 +0000
Subject: [PATCH 02/10] Update Dart Sass version and release

---
 CHANGELOG.md                  | 40 +++++++++++++++++++++++++++++++++++
 npm/darwin-arm64/package.json |  2 +-
 npm/darwin-x64/package.json   |  2 +-
 npm/linux-arm/package.json    |  2 +-
 npm/linux-arm64/package.json  |  2 +-
 npm/linux-ia32/package.json   |  2 +-
 npm/linux-x64/package.json    |  2 +-
 npm/win32-ia32/package.json   |  2 +-
 npm/win32-x64/package.json    |  2 +-
 package.json                  | 20 +++++++++---------
 10 files changed, 58 insertions(+), 18 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 49739cdc..e828616a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,43 @@
+## 1.67.0
+
+* All functions defined in CSS Values and Units 4 are now once again parsed as
+  calculation objects: `round()`, `mod()`, `rem()`, `sin()`, `cos()`, `tan()`,
+  `asin()`, `acos()`, `atan()`, `atan2()`, `pow()`, `sqrt()`, `hypot()`,
+  `log()`, `exp()`, `abs()`, and `sign()`.
+
+  Unlike in 1.65.0, function calls are _not_ locked into being parsed as
+  calculations or plain Sass functions at parse-time. This means that
+  user-defined functions will take precedence over CSS calculations of the same
+  name. Although the function names `calc()` and `clamp()` are still forbidden,
+  users may continue to freely define functions whose names overlap with other
+  CSS calculations (including `abs()`, `min()`, `max()`, and `round()` whose
+  names overlap with global Sass functions).
+
+* As a consequence of the change in calculation parsing described above,
+  calculation functions containing interpolation are now parsed more strictly
+  than before. However, all interpolations that would have produced valid CSS
+  will continue to work, so this is not considered a breaking change.
+
+* Interpolations in calculation functions that aren't used in a position that
+  could also have a normal calculation value are now deprecated. For example,
+  `calc(1px #{"+ 2px"})` is deprecated, but `calc(1px + #{"2px"})` is still
+  allowed. This deprecation is named `calc-interp`. See [the Sass website] for
+  more information.
+
+  [the Sass website]: https://sass-lang.com/d/calc-interp
+
+* **Potentially breaking bug fix**: The importer used to load a given file is no
+  longer used to load absolute URLs that appear in that file. This was
+  unintented behavior that contradicted the Sass specification. Absolute URLs
+  will now correctly be loaded only from the global importer list. This applies
+  to the modern JS API, the Dart API, and the embedded protocol.
+
+### Embedded Sass
+
+* Substantially improve the embedded compiler's performance when compiling many
+  files or files that require many importer or function call round-trips with
+  the embedded host.
+
 ## 1.66.1
 
 ### JS API
diff --git a/npm/darwin-arm64/package.json b/npm/darwin-arm64/package.json
index ef47479c..7ef98f92 100644
--- a/npm/darwin-arm64/package.json
+++ b/npm/darwin-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-arm64",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The darwin-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/darwin-x64/package.json b/npm/darwin-x64/package.json
index 3cae9643..bb0761b6 100644
--- a/npm/darwin-x64/package.json
+++ b/npm/darwin-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-x64",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The darwin-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm/package.json b/npm/linux-arm/package.json
index 34901cc4..72b4db15 100644
--- a/npm/linux-arm/package.json
+++ b/npm/linux-arm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The linux-arm binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm64/package.json b/npm/linux-arm64/package.json
index 2ebc4d2c..1e6ad6d3 100644
--- a/npm/linux-arm64/package.json
+++ b/npm/linux-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm64",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The linux-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-ia32/package.json b/npm/linux-ia32/package.json
index 31dbdf95..6bd14ee9 100644
--- a/npm/linux-ia32/package.json
+++ b/npm/linux-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-ia32",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The linux-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-x64/package.json b/npm/linux-x64/package.json
index 64020198..bc2b1ada 100644
--- a/npm/linux-x64/package.json
+++ b/npm/linux-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-x64",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The linux-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-ia32/package.json b/npm/win32-ia32/package.json
index 77d85e2e..89cf8f7f 100644
--- a/npm/win32-ia32/package.json
+++ b/npm/win32-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-ia32",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The win32-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-x64/package.json b/npm/win32-x64/package.json
index ebdbaa90..bfc2df01 100644
--- a/npm/win32-x64/package.json
+++ b/npm/win32-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-x64",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "description": "The win32-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/package.json b/package.json
index b6d9cbac..b10ab871 100644
--- a/package.json
+++ b/package.json
@@ -1,8 +1,8 @@
 {
   "name": "sass-embedded",
-  "version": "1.66.1",
+  "version": "1.67.0",
   "protocol-version": "2.1.0",
-  "compiler-version": "1.66.1",
+  "compiler-version": "1.67.0",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
@@ -31,14 +31,14 @@
     "test": "jest"
   },
   "optionalDependencies": {
-    "sass-embedded-darwin-arm64": "1.66.1",
-    "sass-embedded-darwin-x64": "1.66.1",
-    "sass-embedded-linux-arm": "1.66.1",
-    "sass-embedded-linux-arm64": "1.66.1",
-    "sass-embedded-linux-ia32": "1.66.1",
-    "sass-embedded-linux-x64": "1.66.1",
-    "sass-embedded-win32-ia32": "1.66.1",
-    "sass-embedded-win32-x64": "1.66.1"
+    "sass-embedded-darwin-arm64": "1.67.0",
+    "sass-embedded-darwin-x64": "1.67.0",
+    "sass-embedded-linux-arm": "1.67.0",
+    "sass-embedded-linux-arm64": "1.67.0",
+    "sass-embedded-linux-ia32": "1.67.0",
+    "sass-embedded-linux-x64": "1.67.0",
+    "sass-embedded-win32-ia32": "1.67.0",
+    "sass-embedded-win32-x64": "1.67.0"
   },
   "dependencies": {
     "@bufbuild/protobuf": "^1.0.0",

From ffa994740223a570cc91ff0befc5cfadf3730f59 Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Mon, 18 Sep 2023 13:50:16 -0700
Subject: [PATCH 03/10] Properly include and export TypeScript types (#248)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

We need to copy the entrypoing typings file, as described in [the
TypeScript docs]:

> It’s important to note that the CommonJS entrypoint and the ES
> module entrypoint each needs its own declaration file, even if the
> contents are the same between them. Every declaration file is
> interpreted either as a CommonJS module or as an ES module, based on
> its file extension and the `"type"` field of the `package.json`, and
> this detected module kind must match the module kind that Node will
> detect for the corresponding JavaScript file for type checking to be
> correct. Attempting to use a single `.d.ts` file to type both an ES
> module entrypoint and a CommonJS entrypoint will cause TypeScript to
> think only one of those entrypoints exists, causing compiler errors
> for users of the package.

[the TypeScript docs]: https://www.typescriptlang.org/docs/handbook/esm-node.html

Closes #247
---
 package.json | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index b10ab871..6ae77ad2 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded",
-  "version": "1.67.0",
+  "version": "1.67.1-dev",
   "protocol-version": "2.1.0",
   "compiler-version": "1.67.0",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
@@ -8,7 +8,11 @@
   "author": "Google Inc.",
   "license": "MIT",
   "exports": {
-    "import": "./dist/lib/index.mjs",
+    "import": {
+      "types": "./dist/lib/index.m.d.ts",
+      "default": "./dist/lib/index.mjs"
+    },
+    "types": "./dist/lib/index.d.ts",
     "default": "./dist/lib/index.js"
   },
   "main": "dist/lib/index.js",
@@ -25,7 +29,7 @@
     "check:gts": "gts check",
     "check:tsc": "tsc --noEmit",
     "clean": "gts clean",
-    "compile": "tsc && cp lib/index.mjs dist/lib/index.mjs",
+    "compile": "tsc && cp lib/index.mjs dist/lib/index.mjs && cp -r lib/src/vendor/sass/ dist/lib/src/vendor/sass && cp dist/lib/src/vendor/sass/index.d.ts dist/lib/src/vendor/sass/index.m.d.ts",
     "fix": "gts fix",
     "prepublishOnly": "npm run clean && ts-node ./tool/prepare-release.ts",
     "test": "jest"

From 8e7a23aee8319d6eaf5f2cc84f7f9f04f46962a4 Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Mon, 18 Sep 2023 16:00:22 -0700
Subject: [PATCH 04/10] Pass the containing URL to importers under some
 circumstances (#246)

Closes #3247
---
 lib/src/importer-registry.ts | 18 ++++++++++++++----
 tool/get-language-repo.ts    |  2 +-
 tool/utils.ts                | 16 ++++++++++++----
 3 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/lib/src/importer-registry.ts b/lib/src/importer-registry.ts
index 7b734940..a3d825e0 100644
--- a/lib/src/importer-registry.ts
+++ b/lib/src/importer-registry.ts
@@ -45,7 +45,7 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
   register(
     importer: Importer<sync> | FileImporter<sync>
   ): proto.InboundMessage_CompileRequest_Importer {
-    const response = new proto.InboundMessage_CompileRequest_Importer();
+    const message = new proto.InboundMessage_CompileRequest_Importer();
     if ('canonicalize' in importer) {
       if ('findFileUrl' in importer) {
         throw new Error(
@@ -54,14 +54,18 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
         );
       }
 
-      response.importer = {case: 'importerId', value: this.id};
+      message.importer = {case: 'importerId', value: this.id};
+      message.nonCanonicalScheme =
+        typeof importer.nonCanonicalScheme === 'string'
+          ? [importer.nonCanonicalScheme]
+          : importer.nonCanonicalScheme ?? [];
       this.importersById.set(this.id, importer);
     } else {
-      response.importer = {case: 'fileImporterId', value: this.id};
+      message.importer = {case: 'fileImporterId', value: this.id};
       this.fileImportersById.set(this.id, importer);
     }
     this.id += 1;
-    return response;
+    return message;
   }
 
   /** Handles a canonicalization request. */
@@ -78,6 +82,9 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
         return thenOr(
           importer.canonicalize(request.url, {
             fromImport: request.fromImport,
+            containingUrl: request.containingUrl
+              ? new URL(request.containingUrl)
+              : null,
           }),
           url =>
             new proto.InboundMessage_CanonicalizeResponse({
@@ -157,6 +164,9 @@ export class ImporterRegistry<sync extends 'sync' | 'async'> {
         return thenOr(
           importer.findFileUrl(request.url, {
             fromImport: request.fromImport,
+            containingUrl: request.containingUrl
+              ? new URL(request.containingUrl)
+              : null,
           }),
           url => {
             if (!url) return new proto.InboundMessage_FileImportResponse();
diff --git a/tool/get-language-repo.ts b/tool/get-language-repo.ts
index 83a264b8..cd8da97c 100644
--- a/tool/get-language-repo.ts
+++ b/tool/get-language-repo.ts
@@ -32,7 +32,7 @@ export async function getLanguageRepo(
   // Workaround for https://github.com/shelljs/shelljs/issues/198
   // This file is a symlink which gets messed up by `shell.cp` (called from
   // `utils.link`) on Windows.
-  shell.rm('build/sass/spec/README.md');
+  if (process.platform === 'win32') shell.rm('build/sass/spec/README.md');
 
   await utils.link('build/sass/js-api-doc', p.join(outPath, 'sass'));
 
diff --git a/tool/utils.ts b/tool/utils.ts
index 3e4a343c..9dc1af5a 100644
--- a/tool/utils.ts
+++ b/tool/utils.ts
@@ -2,7 +2,7 @@
 // MIT-style license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
-import {promises as fs, existsSync} from 'fs';
+import {promises as fs, existsSync, lstatSync} from 'fs';
 import * as p from 'path';
 import * as shell from 'shelljs';
 
@@ -17,13 +17,21 @@ export function fetchRepo(options: {
   outPath: string;
   ref: string;
 }): void {
-  if (!existsSync(p.join(options.outPath, options.repo))) {
+  const path = p.join(options.outPath, options.repo);
+  if (lstatSync(path).isSymbolicLink() && existsSync(p.join(path, '.git'))) {
+    throw (
+      `${path} is a symlink to a git repo, not overwriting.\n` +
+      `Run "rm ${path}" and try again.`
+    );
+  }
+
+  if (!existsSync(path)) {
     console.log(`Cloning ${options.repo} into ${options.outPath}.`);
     shell.exec(
       `git clone \
       --depth=1 \
       https://github.com/sass/${options.repo} \
-      ${p.join(options.outPath, options.repo)}`,
+      ${path}`,
       {silent: true}
     );
   }
@@ -35,7 +43,7 @@ export function fetchRepo(options: {
     `git fetch --depth=1 origin ${options.ref} && git reset --hard FETCH_HEAD`,
     {
       silent: true,
-      cwd: p.join(options.outPath, options.repo),
+      cwd: path,
     }
   );
 }

From 37acf72ec0d5f39203c92dfcd9af2e8aee02a852 Mon Sep 17 00:00:00 2001
From: Sass Bot <sass.bot.beep.boop@gmail.com>
Date: Thu, 21 Sep 2023 01:14:40 +0000
Subject: [PATCH 05/10] Update Dart Sass version and release

---
 CHANGELOG.md                  | 56 +++++++++++++++++++++++++++--------
 npm/darwin-arm64/package.json |  2 +-
 npm/darwin-x64/package.json   |  2 +-
 npm/linux-arm/package.json    |  2 +-
 npm/linux-arm64/package.json  |  2 +-
 npm/linux-ia32/package.json   |  2 +-
 npm/linux-x64/package.json    |  2 +-
 npm/win32-ia32/package.json   |  2 +-
 npm/win32-x64/package.json    |  2 +-
 package.json                  | 20 ++++++-------
 10 files changed, 62 insertions(+), 30 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e828616a..e56a37ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,40 @@
+## 1.68.0
+
+* Fix the source spans associated with the `abs-percent` deprecation.
+
+### JS API
+
+* Non-filesystem importers can now set the `nonCanonicalScheme` field, which
+  declares that one or more URL schemes (without `:`) will never be used for
+  URLs returned by the `canonicalize()` method.
+
+* Add a `containingUrl` field to the `canonicalize()` and `findFileUrl()`
+  methods of importers, which is set to the canonical URL of the stylesheet that
+  contains the current load. For filesystem importers, this is always set; for
+  other importers, it's set only if the current load has no URL scheme, or if
+  its URL scheme is declared as non-canonical by the importer.
+
+### Dart API
+
+* Add `AsyncImporter.isNonCanonicalScheme`, which importers (async or sync) can
+  use to indicate that a certain URL scheme will never be used for URLs returned
+  by the `canonicalize()` method.
+
+* Add `AsyncImporter.containingUrl`, which is set during calls to the
+  `canonicalize()` method to the canonical URL of the stylesheet that contains
+  the current load. This is set only if the current load has no URL scheme, or
+  if its URL scheme is declared as non-canonical by the importer.
+
+### Embedded Sass
+
+* The `CalculationValue.interpolation` field is deprecated and will be removed
+  in a future version. It will no longer be set by the compiler, and if the host
+  sets it it will be treated as equivalent to `CalculationValue.string` except
+  that `"("` and `")"` will be added to the beginning and end of the string
+  values.
+
+* Properly include TypeScript types in the `sass-embedded` package.
+
 ## 1.67.0
 
 * All functions defined in CSS Values and Units 4 are now once again parsed as
@@ -13,18 +50,13 @@
   CSS calculations (including `abs()`, `min()`, `max()`, and `round()` whose
   names overlap with global Sass functions).
 
-* As a consequence of the change in calculation parsing described above,
-  calculation functions containing interpolation are now parsed more strictly
-  than before. However, all interpolations that would have produced valid CSS
-  will continue to work, so this is not considered a breaking change.
-
-* Interpolations in calculation functions that aren't used in a position that
-  could also have a normal calculation value are now deprecated. For example,
-  `calc(1px #{"+ 2px"})` is deprecated, but `calc(1px + #{"2px"})` is still
-  allowed. This deprecation is named `calc-interp`. See [the Sass website] for
-  more information.
-
-  [the Sass website]: https://sass-lang.com/d/calc-interp
+* **Breaking change**: As a consequence of the change in calculation parsing
+  described above, calculation functions containing interpolation are now parsed
+  more strictly than before. However, _almost_ all interpolations that would
+  have produced valid CSS will continue to work. The only exception is
+  `#{$variable}%` which is not valid in Sass and is no longer valid in
+  calculations. Instead of this, either use `$variable` directly and ensure it
+  already has the `%` unit, or write `($variable * 1%)`.
 
 * **Potentially breaking bug fix**: The importer used to load a given file is no
   longer used to load absolute URLs that appear in that file. This was
diff --git a/npm/darwin-arm64/package.json b/npm/darwin-arm64/package.json
index 7ef98f92..2bd3811a 100644
--- a/npm/darwin-arm64/package.json
+++ b/npm/darwin-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-arm64",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The darwin-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/darwin-x64/package.json b/npm/darwin-x64/package.json
index bb0761b6..08d5ca1c 100644
--- a/npm/darwin-x64/package.json
+++ b/npm/darwin-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-darwin-x64",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The darwin-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm/package.json b/npm/linux-arm/package.json
index 72b4db15..cdd33f03 100644
--- a/npm/linux-arm/package.json
+++ b/npm/linux-arm/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The linux-arm binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-arm64/package.json b/npm/linux-arm64/package.json
index 1e6ad6d3..4719d518 100644
--- a/npm/linux-arm64/package.json
+++ b/npm/linux-arm64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-arm64",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The linux-arm64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-ia32/package.json b/npm/linux-ia32/package.json
index 6bd14ee9..8d48cf15 100644
--- a/npm/linux-ia32/package.json
+++ b/npm/linux-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-ia32",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The linux-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/linux-x64/package.json b/npm/linux-x64/package.json
index bc2b1ada..4bc67f55 100644
--- a/npm/linux-x64/package.json
+++ b/npm/linux-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-linux-x64",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The linux-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-ia32/package.json b/npm/win32-ia32/package.json
index 89cf8f7f..4137c236 100644
--- a/npm/win32-ia32/package.json
+++ b/npm/win32-ia32/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-ia32",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The win32-ia32 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/npm/win32-x64/package.json b/npm/win32-x64/package.json
index bfc2df01..062fbdc1 100644
--- a/npm/win32-x64/package.json
+++ b/npm/win32-x64/package.json
@@ -1,6 +1,6 @@
 {
   "name": "sass-embedded-win32-x64",
-  "version": "1.67.0",
+  "version": "1.68.0",
   "description": "The win32-x64 binary for sass-embedded",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
diff --git a/package.json b/package.json
index 6ae77ad2..587af699 100644
--- a/package.json
+++ b/package.json
@@ -1,8 +1,8 @@
 {
   "name": "sass-embedded",
-  "version": "1.67.1-dev",
+  "version": "1.68.0",
   "protocol-version": "2.1.0",
-  "compiler-version": "1.67.0",
+  "compiler-version": "1.68.0",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
   "repository": "sass/embedded-host-node",
   "author": "Google Inc.",
@@ -35,14 +35,14 @@
     "test": "jest"
   },
   "optionalDependencies": {
-    "sass-embedded-darwin-arm64": "1.67.0",
-    "sass-embedded-darwin-x64": "1.67.0",
-    "sass-embedded-linux-arm": "1.67.0",
-    "sass-embedded-linux-arm64": "1.67.0",
-    "sass-embedded-linux-ia32": "1.67.0",
-    "sass-embedded-linux-x64": "1.67.0",
-    "sass-embedded-win32-ia32": "1.67.0",
-    "sass-embedded-win32-x64": "1.67.0"
+    "sass-embedded-darwin-arm64": "1.68.0",
+    "sass-embedded-darwin-x64": "1.68.0",
+    "sass-embedded-linux-arm": "1.68.0",
+    "sass-embedded-linux-arm64": "1.68.0",
+    "sass-embedded-linux-ia32": "1.68.0",
+    "sass-embedded-linux-x64": "1.68.0",
+    "sass-embedded-win32-ia32": "1.68.0",
+    "sass-embedded-win32-x64": "1.68.0"
   },
   "dependencies": {
     "@bufbuild/protobuf": "^1.0.0",

From 1784d46bec6ddf05bdfc4695b4aef160f33b0b52 Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Thu, 28 Sep 2023 10:59:56 -0700
Subject: [PATCH 06/10] Update the embedded protocol versino (#251)

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 587af699..f71b4129 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "sass-embedded",
   "version": "1.68.0",
-  "protocol-version": "2.1.0",
+  "protocol-version": "2.2.0",
   "compiler-version": "1.68.0",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
   "repository": "sass/embedded-host-node",

From 6849715fcf9692be874cfb61bee33f730451136d Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Thu, 28 Sep 2023 13:02:40 -0700
Subject: [PATCH 07/10] Forbid LLM contributions (#250)

---
 CONTRIBUTING.md | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index e7c61af0..bcdbc8c7 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -3,6 +3,15 @@
 We'd love to accept your patches and contributions to this project. There are
 just a few small guidelines you need to follow.
 
+* [Contributor License Agreement](#contributor-license-agreement)
+* [Code Reviews](#code-reviews)
+* [Large Language Models](#large-language-models)
+* [Release Process](#release-process)
+* [Keeping in Sync With Other Packages](#keeping-in-sync-with-other-packages)
+  * [Local Development](#local-development)
+  * [Continuous Integration](#continuous-integration)
+  * [Release](#release)
+
 ## Contributor License Agreement
 
 Contributions to this project must be accompanied by a Contributor License
@@ -15,13 +24,24 @@ You generally only need to submit a CLA once, so if you've already submitted one
 (even if it was for a different project), you probably don't need to do it
 again.
 
-## Code reviews
+## Code Reviews
 
 All submissions, including submissions by project members, require review. We
 use GitHub pull requests for this purpose. Consult
 [GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
 information on using pull requests.
 
+## Large Language Models
+
+Do not submit any code or prose written or modified by large language models or
+"artificial intelligence" such as GitHub Copilot or ChatGPT to this project.
+These tools produce code that looks plausible, which means that not only is it
+likely to contain bugs those bugs are likely to be difficult to notice on
+review. In addition, because these models were trained indiscriminately and
+non-consensually on open-source code with a variety of licenses, it's not
+obvious that we have the moral or legal right to redistribute code they
+generate.
+
 ## Release process
 
 Because this package's version remains in lockstep with the current version of
@@ -36,7 +56,7 @@ such, manual commits should never:
 * Update the `package.json`'s `"compiler-version"` field to a non-`-dev` number.
   Changing it from non-`-dev` to dev when using a new feature is fine.
 
-# Keeping in Sync With Other Packages
+## Keeping in Sync With Other Packages
 
 The embedded host depends on several different components which come from
 different repositories:
@@ -51,7 +71,7 @@ different repositories:
 
 These dependencies are made available in different ways depending on context.
 
-## Local Development
+### Local Development
 
 When developing locally, you can download all of these dependencies by running
 `npm run init`. This provides the following options for `compiler` (for the
@@ -77,14 +97,14 @@ By default:
 * This uses the Dart Sass version from the latest revision on GitHub, unless the
   `--compiler-path` was passed in which case it uses that version of Dart Sass.
 
-## Continuous Integration
+### Continuous Integration
 
 CI tests also use `npm run init`, so they use the same defaults as local
 development. However, if the pull request description includes a link to a pull
 request for Dart Sass, the embedded protocol, or the JS API, this will check out
 that version and run tests against it instead.
 
-## Release
+### Release
 
 When this package is released to npm, it downloads the embedded protocol version
 that matches `protocol-version` in `package.json`. It downloads the latest JS

From 79ab0914f93fd15409f4ae778b8d4459512dd980 Mon Sep 17 00:00:00 2001
From: "dependabot[bot]" <49699333+dependabot[bot]@users.noreply.github.com>
Date: Mon, 2 Oct 2023 16:36:51 -0700
Subject: [PATCH 08/10] Bump minipass from 7.0.3 to 7.0.4 (#254)

Bumps [minipass](https://github.com/isaacs/minipass) from 7.0.3 to 7.0.4.
- [Changelog](https://github.com/isaacs/minipass/blob/main/CHANGELOG.md)
- [Commits](https://github.com/isaacs/minipass/compare/v7.0.3...v7.0.4)

---
updated-dependencies:
- dependency-name: minipass
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index f71b4129..1e88355f 100644
--- a/package.json
+++ b/package.json
@@ -68,7 +68,7 @@
     "extract-zip": "^2.0.1",
     "gts": "^5.0.0",
     "jest": "^29.4.1",
-    "minipass": "7.0.3",
+    "minipass": "7.0.4",
     "npm-run-all": "^4.1.5",
     "shelljs": "^0.8.4",
     "source-map-js": "^1.0.2",

From c9dee9b22e4e5619e86ee78c44c41fe83b5add55 Mon Sep 17 00:00:00 2001
From: Natalie Weizenbaum <nweiz@google.com>
Date: Thu, 5 Oct 2023 14:10:47 -0700
Subject: [PATCH 09/10] Fix new eslint issues (#255)

---
 lib/src/sync-process/index.ts    | 2 +-
 package.json                     | 2 +-
 tool/init.ts                     | 2 +-
 tool/prepare-optional-release.ts | 2 +-
 tool/prepare-release.ts          | 2 +-
 tool/utils.ts                    | 2 +-
 tsconfig.build.json              | 7 +++++++
 tsconfig.json                    | 9 ++++-----
 8 files changed, 17 insertions(+), 11 deletions(-)
 create mode 100644 tsconfig.build.json

diff --git a/lib/src/sync-process/index.ts b/lib/src/sync-process/index.ts
index 286ad346..426dbb1c 100644
--- a/lib/src/sync-process/index.ts
+++ b/lib/src/sync-process/index.ts
@@ -141,7 +141,7 @@ export class SyncProcess {
   /** Closes down the worker thread and the stdin stream. */
   private close(): void {
     this.port.close();
-    this.worker.terminate();
+    void this.worker.terminate();
     this.stdin.destroy();
   }
 }
diff --git a/package.json b/package.json
index 1e88355f..32bdafa6 100644
--- a/package.json
+++ b/package.json
@@ -29,7 +29,7 @@
     "check:gts": "gts check",
     "check:tsc": "tsc --noEmit",
     "clean": "gts clean",
-    "compile": "tsc && cp lib/index.mjs dist/lib/index.mjs && cp -r lib/src/vendor/sass/ dist/lib/src/vendor/sass && cp dist/lib/src/vendor/sass/index.d.ts dist/lib/src/vendor/sass/index.m.d.ts",
+    "compile": "tsc -p tsconfig.build.json && cp lib/index.mjs dist/lib/index.mjs && cp -r lib/src/vendor/sass/ dist/lib/src/vendor/sass && cp dist/lib/src/vendor/sass/index.d.ts dist/lib/src/vendor/sass/index.m.d.ts",
     "fix": "gts fix",
     "prepublishOnly": "npm run clean && ts-node ./tool/prepare-release.ts",
     "test": "jest"
diff --git a/tool/init.ts b/tool/init.ts
index cb50c12b..a178675f 100644
--- a/tool/init.ts
+++ b/tool/init.ts
@@ -36,7 +36,7 @@ const argv = yargs(process.argv.slice(2))
   })
   .parseSync();
 
-(async () => {
+void (async () => {
   try {
     const outPath = 'lib/src/vendor';
 
diff --git a/tool/prepare-optional-release.ts b/tool/prepare-optional-release.ts
index 9ad7cb68..36a42ba7 100644
--- a/tool/prepare-optional-release.ts
+++ b/tool/prepare-optional-release.ts
@@ -104,7 +104,7 @@ async function downloadRelease(options: {
   await fs.unlink(zippedAssetPath);
 }
 
-(async () => {
+void (async () => {
   try {
     const version = pkg['compiler-version'] as string;
     if (version.endsWith('-dev')) {
diff --git a/tool/prepare-release.ts b/tool/prepare-release.ts
index 8d4c08b4..30b49618 100644
--- a/tool/prepare-release.ts
+++ b/tool/prepare-release.ts
@@ -8,7 +8,7 @@ import * as shell from 'shelljs';
 import * as pkg from '../package.json';
 import {getLanguageRepo} from './get-language-repo';
 
-(async () => {
+void (async () => {
   try {
     await sanityCheckBeforeRelease();
 
diff --git a/tool/utils.ts b/tool/utils.ts
index 9dc1af5a..e0cc581e 100644
--- a/tool/utils.ts
+++ b/tool/utils.ts
@@ -18,7 +18,7 @@ export function fetchRepo(options: {
   ref: string;
 }): void {
   const path = p.join(options.outPath, options.repo);
-  if (lstatSync(path).isSymbolicLink() && existsSync(p.join(path, '.git'))) {
+  if (existsSync(p.join(path, '.git')) && lstatSync(path).isSymbolicLink()) {
     throw (
       `${path} is a symlink to a git repo, not overwriting.\n` +
       `Run "rm ${path}" and try again.`
diff --git a/tsconfig.build.json b/tsconfig.build.json
new file mode 100644
index 00000000..0673a92b
--- /dev/null
+++ b/tsconfig.build.json
@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.json",
+  "exclude": [
+    "lib/src/vendor/dart-sass/**",
+    "**/*.test.ts"
+  ]
+}
diff --git a/tsconfig.json b/tsconfig.json
index 693fadcb..c839cc1e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -11,11 +11,10 @@
     "lib": ["DOM"]
   },
   "include": [
+    "*.ts",
     "lib/**/*.ts",
-    "tool/*.ts"
+    "tool/**/*.ts",
+    "test/**/*.ts"
   ],
-  "exclude": [
-    "**/*.test.ts",
-    "lib/src/vendor/dart-sass/**"
-  ]
+  "exclude": ["lib/src/vendor/dart-sass/**"]
 }

From 9e354f020c0060880967ba2aa757b167f299a553 Mon Sep 17 00:00:00 2001
From: Connor Skees <39542938+connorskees@users.noreply.github.com>
Date: Thu, 5 Oct 2023 14:50:58 -0700
Subject: [PATCH 10/10] Add first class mixins (#253)

Co-authored-by: Natalie Weizenbaum <nweiz@google.com>
---
 CONTRIBUTING.md               |  9 +++++---
 lib/index.mjs                 |  5 +++++
 lib/index.ts                  |  1 +
 lib/src/protofier.ts          |  8 +++++++
 lib/src/value/index.ts        | 12 ++++++++++
 lib/src/value/mixin.ts        | 41 +++++++++++++++++++++++++++++++++++
 package.json                  |  2 +-
 tool/get-embedded-compiler.ts |  2 +-
 8 files changed, 75 insertions(+), 5 deletions(-)
 create mode 100644 lib/src/value/mixin.ts

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index bcdbc8c7..cc5fbeb4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -74,9 +74,9 @@ These dependencies are made available in different ways depending on context.
 ### Local Development
 
 When developing locally, you can download all of these dependencies by running
-`npm run init`. This provides the following options for `compiler` (for the
-embedded compiler), `protocol` (for the embedded protocol), and `api` (for the
-JS API):
+`npm install` and then `npm run init`. This provides the following options for
+`compiler` (for the embedded compiler), `protocol` (for the embedded protocol),
+and `api` (for the JS API):
 
 * `--<type>-path`: The local filesystem path of the package to use. This is
   useful when doing local development on both the host and its dependencies at
@@ -85,6 +85,9 @@ JS API):
 * `--<type>-ref`: A Git reference for the GitHub repository of the package to
   clone.
 
+If developing locally, you will need to specify both the compiler and language.
+For example: `npm run init -- --compiler-path=dart-sass --language-path=language`.
+
 By default:
 
 * This uses the version of the embedded protocol and compiler specified by
diff --git a/lib/index.mjs b/lib/index.mjs
index 374e98e9..ff94ed4e 100644
--- a/lib/index.mjs
+++ b/lib/index.mjs
@@ -13,6 +13,7 @@ export const SassBoolean = sass.SassBoolean;
 export const SassCalculation = sass.SassCalculation
 export const SassColor = sass.SassColor;
 export const SassFunction = sass.SassFunction;
+export const SassMixin = sass.SassMixin;
 export const SassList = sass.SassList;
 export const SassMap = sass.SassMap;
 export const SassNumber = sass.SassNumber;
@@ -95,6 +96,10 @@ export default {
     defaultExportDeprecation();
     return sass.SassFunction;
   },
+  get SassMixin() {
+    defaultExportDeprecation();
+    return sass.SassMixin;
+  },
   get SassList() {
     defaultExportDeprecation();
     return sass.SassList;
diff --git a/lib/index.ts b/lib/index.ts
index c79ffec2..69005262 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -12,6 +12,7 @@ export {sassFalse, sassTrue} from './src/value/boolean';
 export {SassColor} from './src/value/color';
 export {SassFunction} from './src/value/function';
 export {SassMap} from './src/value/map';
+export {SassMixin} from './src/value/mixin';
 export {SassNumber} from './src/value/number';
 export {SassString} from './src/value/string';
 export {Value} from './src/value';
diff --git a/lib/src/protofier.ts b/lib/src/protofier.ts
index 0092cc11..e2d7f951 100644
--- a/lib/src/protofier.ts
+++ b/lib/src/protofier.ts
@@ -24,6 +24,7 @@ import {
   CalculationOperation,
   CalculationOperator,
 } from './value/calculations';
+import {SassMixin} from './value/mixin';
 
 /**
  * A class that converts [Value] objects into protobufs.
@@ -119,6 +120,10 @@ export class Protofier {
         fn.signature = value.signature!;
         result.value = {case: 'hostFunction', value: fn};
       }
+    } else if (value instanceof SassMixin) {
+      const mixin = new proto.Value_CompilerMixin();
+      mixin.id = value.id;
+      result.value = {case: 'compilerMixin', value: mixin};
     } else if (value instanceof SassCalculation) {
       result.value = {
         case: 'calculation',
@@ -322,6 +327,9 @@ export class Protofier {
           'The compiler may not send Value.host_function.'
         );
 
+      case 'compilerMixin':
+        return new SassMixin(value.value.value.id);
+
       case 'calculation':
         return this.deprotofyCalculation(value.value.value);
 
diff --git a/lib/src/value/index.ts b/lib/src/value/index.ts
index d7c95f8e..6e5129fe 100644
--- a/lib/src/value/index.ts
+++ b/lib/src/value/index.ts
@@ -12,6 +12,7 @@ import {SassNumber} from './number';
 import {SassString} from './string';
 import {valueError} from '../utils';
 import {SassCalculation} from './calculations';
+import {SassMixin} from './mixin';
 
 /**
  * A SassScript value.
@@ -139,6 +140,17 @@ export abstract class Value implements ValueObject {
     // TODO(awjin): Narrow the return type to SassFunction.
   }
 
+  /**
+   * Casts `this` to `SassMixin`; throws if `this` isn't a mixin
+   * reference.
+   *
+   * If `this` came from a function argument, `name` is the argument name
+   * (without the `$`) and is used for error reporting.
+   */
+  assertMixin(name?: string): SassMixin {
+    throw valueError(`${this} is not a mixin reference`, name);
+  }
+
   /**
    * Casts `this` to `SassMap`; throws if `this` isn't a map.
    *
diff --git a/lib/src/value/mixin.ts b/lib/src/value/mixin.ts
new file mode 100644
index 00000000..1d8ecd86
--- /dev/null
+++ b/lib/src/value/mixin.ts
@@ -0,0 +1,41 @@
+// Copyright 2021 Google LLC. Use of this source code is governed by an
+// MIT-style license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+import {hash} from 'immutable';
+
+import {Value} from './index';
+
+/** A first-class SassScript mixin. */
+export class SassMixin extends Value {
+  /**
+   * This is the unique ID that the compiler uses to determine which mixin it
+   * refers to.
+   *
+   * This is marked as public so that the protofier can access it, but it's not
+   * part of the package's public API and should not be accessed by user code.
+   * It may be renamed or removed without warning in the future.
+   */
+  readonly id: number;
+
+  constructor(id: number) {
+    super();
+    this.id = id;
+  }
+
+  equals(other: Value): boolean {
+    return other instanceof SassMixin && other.id === this.id;
+  }
+
+  hashCode(): number {
+    return hash(this.id);
+  }
+
+  toString(): string {
+    return `<compiler mixin ${this.id}>`;
+  }
+
+  assertMixin(): SassMixin {
+    return this;
+  }
+}
diff --git a/package.json b/package.json
index 32bdafa6..567126ac 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "sass-embedded",
   "version": "1.68.0",
-  "protocol-version": "2.2.0",
+  "protocol-version": "2.3.0",
   "compiler-version": "1.68.0",
   "description": "Node.js library that communicates with Embedded Dart Sass using the Embedded Sass protocol",
   "repository": "sass/embedded-host-node",
diff --git a/tool/get-embedded-compiler.ts b/tool/get-embedded-compiler.ts
index 2b702a2a..cb8b7245 100644
--- a/tool/get-embedded-compiler.ts
+++ b/tool/get-embedded-compiler.ts
@@ -8,7 +8,7 @@ import * as shell from 'shelljs';
 import * as utils from './utils';
 
 /**
- * Downlaods and builds the Embedded Dart Sass compiler.
+ * Downloads and builds the Embedded Dart Sass compiler.
  *
  * Can check out and build the source from a Git `ref` or build from the source
  * at `path`. By default, checks out the latest revision from GitHub.