Add NodePackageImporter by default if available

CHANGELOG.md

@@ -4,6 +4,11 @@
 
 - FEATURE: Add True `sass` option (`string` or Sass implementation instance,
   defaults to `'sass'`) to allow using either `sass` or `embedded-sass`.
+- FEATURE: Add the
+  [Node.js package importer](https://sass-lang.com/documentation/js-api/classes/nodepackageimporter/)
+  to the Sass `importers` option by default, if Dart Sass v1.71 or later is
+  available. Users can opt out by providing their own `importers` option, e.g.
+  `{ importers: [] }`.
 - BREAKING: Drop support for node < 18
 - INTERNAL: Remove `sass` as a peer-dependency.
 - INTERNAL: Update dependencies

README.md

@@ -223,9 +223,16 @@ To pass in a source string (and use `sass.compileString`), add `sourceType:
 
 The third (optional) argument to `runSass` accepts the [same
 options](https://sass-lang.com/documentation/js-api/interfaces/Options) that
-Sass' `compile` or `compileString` expect, and these are passed directly through
-to Sass. The only modification `runSass` makes is to add True's sass path to the
-`loadPaths` option, so `@use 'true';` works in your Sass test file.
+Sass' `compile` or `compileString` expect (e.g. `importers`, `loadPaths`, or
+`style`), and these are passed directly through to Sass.
+
+By default, True makes two modifications to these options. First, True's sass
+path is added to the `loadPaths` option, so `@use 'true';` works in your Sass
+test file. Second, if Dart Sass v1.71 or greater is installed, `importers` is
+set to an array containing the [Node.js package importer][pkg-importer], which
+supports `pkg:` imports to resolve `@use` and `@import` for external modules
+installed via npm or Yarn. If `importers` is set (even as an empty array
+`importers: []`), it will override this default importer.
 
 **Note:** True requires the
 [default Sass `'expanded'` output style](https://sass-lang.com/documentation/js-api/modules#OutputStyle),
@@ -234,22 +241,6 @@ and will not work if `{ style: 'compressed' }` is used in the third argument to
 
 ### Custom Importers
 
-If you use the Dart Sass [Node.js package importer][pkg-importer] (e.g. `@use
-'pkg:accoutrement'`), you'll need to include `NodePackageImporter` in the
-options passed to `runSass`:
-
-```js
-const path = require('node:path');
-const { pathToFileURL } = require('node:url');
-const { NodePackageImporter } = require('sass');
-const sassTrue = require('sass-true');
-
-const sassFile = path.join(__dirname, 'test.scss');
-sassTrue.runSass({ describe, it }, sassFile, {
-  importers: [new NodePackageImporter()],
-});
-```
-
 If you use tilde notation (e.g. `@use '~accoutrement/sass/tools'`) or another
 method for importing Sass files from `node_modules`, you'll need to tell
 `runSass` how to handle that. That will require writing a [custom

src/index.ts

@@ -73,6 +73,8 @@ export const runSass = function (
 ) {
   const trueOpts = Object.assign({}, trueOptions);
   const sassOpts = Object.assign({}, sassOptions);
+
+  // Add True's sass to `loadPaths`
   const sassPath = path.join(__dirname, '..', 'sass');
   if (sassOpts.loadPaths) {
     sassOpts.loadPaths.push(sassPath);
@@ -111,6 +113,15 @@ export const runSass = function (
     }
   }
 
+  // Add the Sass Node.js package importer, if available
+  if (!sassOpts.importers) {
+    try {
+      sassOpts.importers = [new compiler.NodePackageImporter()];
+    } catch (err) {
+      // skip if `NodePackageImporter` isn't available
+    }
+  }
+
   const compilerFn =
     trueOpts.sourceType === 'string' ? 'compileString' : 'compile';
   const parsedCss = compiler[compilerFn](src, sassOpts).css;

test/main.test.js

@@ -14,6 +14,11 @@ if (process.env.USE_BUILT) {
   sassTrue = require('../src');
 }
 
+const mock = function (name, cb) {
+  cb();
+};
+const trueOpts = { describe: mock, it: mock };
+
 describe('#fail', () => {
   it('formats failure message', () => {
     const msg = sassTrue.formatFailureMessage({
@@ -49,11 +54,8 @@ describe('#runSass', () => {
       '  }',
       '}',
     ].join('\n');
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
-      sassTrue.runSass({ describe: mock, it: mock }, sass, {
+      sassTrue.runSass(trueOpts, sass, {
         style: 'compressed',
       });
     };
@@ -78,11 +80,8 @@ describe('#runSass', () => {
       '  }',
       '}',
     ].join('\n');
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
-      sassTrue.runSass({ data: sass }, { describe: mock, it: mock });
+      sassTrue.runSass({ data: sass }, trueOpts);
     };
     expect(attempt).to.throw('do not match the new API');
   });
@@ -96,14 +95,8 @@ describe('#runSass', () => {
       '  }',
       '}',
     ].join('\n');
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
-      sassTrue.runSass(
-        { describe: mock, it: mock, sourceType: 'string' },
-        sass,
-      );
+      sassTrue.runSass({ ...trueOpts, sourceType: 'string' }, sass);
     };
     expect(attempt).to.throw('This test is meant to fail. [type: assert-true]');
   });
@@ -125,14 +118,10 @@ describe('#runSass', () => {
       '  }',
       '}',
     ].join('\n');
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
       sassTrue.runSass(
         {
-          describe: mock,
-          it: mock,
+          ...trueOpts,
           sourceType: 'string',
         },
         sass,
@@ -160,14 +149,10 @@ describe('#runSass', () => {
       '  }',
       '}',
     ].join('\n');
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
       sassTrue.runSass(
         {
-          describe: mock,
-          it: mock,
+          ...trueOpts,
           sourceType: 'string',
           sass: 'sass-embedded',
         },
@@ -178,14 +163,10 @@ describe('#runSass', () => {
   });
 
   it('can specify sass implementation to use [object]', () => {
-    const mock = function (name, cb) {
-      cb();
-    };
     const attempt = function () {
       sassTrue.runSass(
         {
-          describe: mock,
-          it: mock,
+          ...trueOpts,
           sass: {
             compile() {
               throw new Error('Custom sass implementation called');
@@ -199,14 +180,54 @@ describe('#runSass', () => {
   });
 
   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' }, '');
+      sassTrue.runSass({ ...trueOpts, sass: 'foobar' }, '');
     };
     expect(attempt).to.throw('Cannot find Dart Sass (`foobar`) dependency.');
   });
+
+  it('adds NodePackageImporter by default', () => {
+    const attempt = function () {
+      sassTrue.runSass(
+        {
+          ...trueOpts,
+          sass: {
+            NodePackageImporter: class {},
+            compile(src, opts) {
+              if (opts.importers[0] instanceof this.NodePackageImporter) {
+                throw new Error('NodePackageImporter added');
+              }
+              throw new Error('failed');
+            },
+          },
+        },
+        '',
+      );
+    };
+    expect(attempt).to.throw('NodePackageImporter added');
+  });
+
+  it('skips NodePackageImporter if `importers` option is provided', () => {
+    const attempt = function () {
+      sassTrue.runSass(
+        {
+          ...trueOpts,
+          sass: {
+            NodePackageImporter: class {},
+            compile(src, opts) {
+              if (opts.importers[0] instanceof this.NodePackageImporter) {
+                throw new Error('NodePackageImporter added');
+              }
+              throw new Error('failed');
+            },
+          },
+        },
+        '',
+        { importers: [] },
+      );
+    };
+    expect(attempt).to.throw('failed');
+  });
 });
 
 describe('#parse', () => {