Add option to specify sass implementation to use

CHANGELOG.md

@@ -2,7 +2,10 @@
 
 ## 8.0.0-beta.0 (unreleased)
 
+- FEATURE: Add True `sass` option (`string` or Sass implementation instance,
+  defaults to `'sass'`) to allow using either `sass` or `embedded-sass`.
 - BREAKING: Drop support for node < 18
+- INTERNAL: Remove `sass` as a peer-dependency.
 - INTERNAL: Update dependencies
 
 ## 7.0.1 (01/04/24)

package.json

@@ -63,9 +63,6 @@
     "release": "run-s commit docs",
     "prepack": "yarn run release"
   },
-  "peerDependencies": {
-    "sass": ">=1.45.0"
-  },
   "dependencies": {
     "@adobe/css-tools": "^4.3.3",
     "jest-diff": "^29.7.0",
@@ -92,6 +89,7 @@
     "postcss": "^8.4.35",
     "prettier": "^3.2.5",
     "sass": "^1.71.1",
+    "sass-embedded": "^1.71.1",
     "sassdoc": "^2.7.4",
     "sassdoc-theme-herman": "^5.0.1",
     "stylelint": "^16.2.1",

src/index.ts

@@ -1,5 +1,8 @@
-/* eslint-disable @typescript-eslint/no-use-before-define */
 /* eslint-disable no-use-before-define */
+/* eslint-disable @typescript-eslint/no-use-before-define */
+
+import assert from 'node:assert';
+import path from 'node:path';
 
 import {
   CssAtRuleAST,
@@ -9,12 +12,8 @@ import {
   parse as cssParse,
   stringify as cssStringify,
 } from '@adobe/css-tools';
-import * as assert from 'assert';
 import { diffStringsUnified } from 'jest-diff';
 import { find, forEach, last, startsWith } from 'lodash';
-import * as path from 'path';
-import type { Options, StringOptions } from 'sass';
-import { compile, compileString } from 'sass';
 
 import * as constants from './constants';
 import {
@@ -28,6 +27,7 @@ import {
 export interface TrueOptions {
   describe: (description: string, fn: () => void) => void;
   it: (description: string, fn: () => void) => void;
+  sass?: any;
   sourceType?: 'path' | 'string';
   contextLines?: number;
 }
@@ -69,7 +69,7 @@ export type Parser = (rule: Rule, ctx: Context) => Parser;
 export const runSass = function (
   trueOptions: TrueOptions,
   src: string,
-  sassOptions?: Options<'sync'> | StringOptions<'sync'>,
+  sassOptions?: any,
 ) {
   const trueOpts = Object.assign({}, trueOptions);
   const sassOpts = Object.assign({}, sassOptions);
@@ -83,12 +83,29 @@ export const runSass = function (
   // Warn if arguments match v6 API
   if (typeof src !== 'string' || !trueOptions.describe || !trueOptions.it) {
     throw new Error(
-      'The arguments provided to `runSass` do not match the new API introduced in True v7. Refer to the v7 release notes for migration documentation: https://github.com/oddbird/true/releases/tag/v7.0.0',
+      'The arguments provided to `runSass` do not match the new API ' +
+        'introduced in True v7. Refer to the v7 release notes ' +
+        'for migration documentation: ' +
+        'https://github.com/oddbird/true/releases/tag/v7.0.0',
     );
   }
 
-  const compiler = trueOpts.sourceType === 'string' ? compileString : compile;
-  const parsedCss = compiler(src, sassOpts).css;
+  let compiler;
+  if (trueOpts.sass && typeof trueOpts.sass !== 'string') {
+    compiler = trueOpts.sass;
+  } else {
+    const sassPkg = trueOpts.sass ?? 'sass';
+    try {
+      // eslint-disable-next-line global-require
+      compiler = require(sassPkg);
+    } catch (err) {
+      throw new Error(`Cannot find Dart Sass (\`${sassPkg}\`) dependency.`);
+    }
+  }
+
+  const compilerFn =
+    trueOpts.sourceType === 'string' ? 'compileString' : 'compile';
+  const parsedCss = compiler[compilerFn](src, sassOpts).css;
   const modules = parse(parsedCss, trueOpts.contextLines);
 
   forEach(modules, (module) => {

test/main.test.js

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-var-requires */
 /* eslint-disable global-require */
 
-const path = require('path');
+const path = require('node:path');
 
 const { expect } = require('chai');
 const { diffStringsUnified } = require('jest-diff');
@@ -114,6 +114,70 @@ describe('#runSass', () => {
     };
     expect(attempt).not.to.throw();
   });
+
+  it('can specify sass implementation to use [string]', () => {
+    const sass = [
+      '@use "true" as *;',
+      '@include test-module("Module") {',
+      '  @include test("Test") {',
+      '    @include assert("Assertion") {',
+      '      @include output() {',
+      '        -property: value;',
+      '      }',
+      '      @include expect() {',
+      '        -property: value;',
+      '      }',
+      '    }',
+      '  }',
+      '}',
+    ].join('\n');
+    const mock = function (name, cb) {
+      cb();
+    };
+    const attempt = function () {
+      sassTrue.runSass(
+        {
+          describe: mock,
+          it: mock,
+          sourceType: 'string',
+          sass: 'sass-embedded',
+        },
+        sass,
+      );
+    };
+    expect(attempt).not.to.throw();
+  });
+
+  it('can specify sass implementation to use [object]', () => {
+    const mock = function (name, cb) {
+      cb();
+    };
+    const attempt = function () {
+      sassTrue.runSass(
+        {
+          describe: mock,
+          it: mock,
+          sass: {
+            compile() {
+              throw new Error('Custom sass implementation called');
+            },
+          },
+        },
+        '',
+      );
+    };
+    expect(attempt).to.throw('Custom sass implementation called');
+  });
+
+  it('throws if sass implementation is not found', () => {
+    const mock = function (name, cb) {
+      cb();
+    };
+    const attempt = function () {
+      sassTrue.runSass({ describe: mock, it: mock, sass: 'foobar' }, '');
+    };
+    expect(attempt).to.throw('Cannot find Dart Sass (`foobar`) dependency.');
+  });
 });
 
 describe('#parse', () => {

test/sass.test.js

@@ -1,7 +1,7 @@
 /* eslint-disable @typescript-eslint/no-var-requires */
 /* eslint-disable global-require */
 
-const path = require('path');
+const path = require('node:path');
 
 const sassFile = path.join(__dirname, 'scss', 'test.scss');
 let runSass;