test: resolution logic (#852)

src/getPossibleRequests.js

@@ -1,6 +1,6 @@
 import path from 'path';
 
-import utils from 'loader-utils';
+import { urlToRequest } from 'loader-utils';
 
 // Examples:
 // - ~package
@@ -9,7 +9,7 @@ import utils from 'loader-utils';
 // - ~@org/
 // - ~@org/package
 // - ~@org/package/
-const matchModuleImport = /^~([^/]+|[^/]+\/|@[^/]+[/][^/]+|@[^/]+\/?|@[^/]+[/][^/]+\/)$/;
+const isModuleImport = /^~([^/]+|[^/]+\/|@[^/]+[/][^/]+|@[^/]+\/?|@[^/]+[/][^/]+\/)$/;
 
 /**
  * When libsass tries to resolve an import, it uses a special algorithm.
@@ -22,10 +22,10 @@ const matchModuleImport = /^~([^/]+|[^/]+\/|@[^/]+[/][^/]+|@[^/]+\/?|@[^/]+[/][^
  * @returns {Array<string>}
  */
 export default function getPossibleRequests(url, forWebpackResolver = false) {
-  const request = utils.urlToRequest(url);
+  const request = urlToRequest(url);
 
   // In case there is module request, send this to webpack resolver
-  if (forWebpackResolver && matchModuleImport.test(url)) {
+  if (forWebpackResolver && isModuleImport.test(url)) {
     return [request, url];
   }
 

src/webpackImporter.js

@@ -11,6 +11,7 @@ import path from 'path';
 import getPossibleRequests from './getPossibleRequests';
 
 const matchCss = /\.css$/i;
+const isModuleImport = /^~([^/]+|[^/]+\/|@[^/]+[/][^/]+|@[^/]+\/?|@[^/]+[/][^/]+\/)$/;
 
 /**
  * Returns an importer that uses webpack's resolving algorithm.
@@ -84,7 +85,7 @@ function webpackImporter(loaderContext, includePaths) {
 
     let resolutionMap = [];
 
-    if (includePaths.length > 0 && !isFileScheme) {
+    if (includePaths.length > 0 && !isFileScheme && !isModuleImport.test(url)) {
       // The order of import precedence is as follows:
       //
       // 1. Filesystem imports relative to the base file.

test/__snapshots__/loader.test.js.snap

@@ -292,6 +292,60 @@ exports[`loader should prefer "mainFiles" over "mainFields" when the field conta
 
 exports[`loader should prefer "mainFiles" over "mainFields" when the field contains "js" file (node-sass) (scss): warnings 1`] = `Array []`;
 
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (sass): css 1`] = `
+".load-me {
+  color: red;
+}
+
+.class {
+  color: blue;
+}"
+`;
+
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (sass): errors 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (sass): warnings 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (scss): css 1`] = `
+".load-me {
+  color: red;
+}
+
+.class {
+  color: blue;
+}"
+`;
+
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (scss): errors 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (dart-sass) (scss): warnings 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (sass): css 1`] = `
+".load-me {
+  color: red; }
+
+.class {
+  color: blue; }
+"
+`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (sass): errors 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (sass): warnings 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (scss): css 1`] = `
+".load-me {
+  color: red; }
+
+.class {
+  color: blue; }
+"
+`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (scss): errors 1`] = `Array []`;
+
+exports[`loader should prefer "mainFiles" with extension over without (node-sass) (scss): warnings 1`] = `Array []`;
+
 exports[`loader should respect resolving directory with the "index" file from "process.cwd()"  (dart-sass) (sass): css 1`] = `
 ".dir-with-underscore-index {
   color: red;

test/helpers/getCodeFromSass.js

@@ -256,6 +256,10 @@ function getCodeFromSass(testId, options) {
     testFolder,
     'node_modules/package-with-js-main-field/index.scss'
   );
+  const pathToPackageWithIndex = path.resolve(
+    testFolder,
+    'node_modules/package-with-index/_index.scss'
+  );
   const pathToLanguage = isSass
     ? path.resolve(testFolder, 'sass/language.sass')
     : path.resolve(testFolder, 'scss/language.scss');
@@ -718,6 +722,7 @@ function getCodeFromSass(testId, options) {
           pathToPackageWithJsAndCssMainFiles
         )
         .replace(/^~package-with-js-main-field/, pathToPackageWithJsMainField)
+        .replace(/^~package-with-index/, pathToPackageWithIndex)
         .replace(/^file:language/, pathToLanguage)
         .replace(/^~/, testNodeModules);
     }

test/loader.test.js

@@ -445,6 +445,28 @@ describe('loader', () => {
         expect(getErrors(stats)).toMatchSnapshot('errors');
       });
 
+      it(`should prefer "mainFiles" with extension over without (${implementationName}) (${syntax})`, async () => {
+        const testId = getTestId(
+          'import-prefer-main-files-with-extension',
+          syntax
+        );
+        const options = {
+          implementation: getImplementationByName(implementationName),
+          sassOptions: {
+            includePaths: ['node_modules/foundation-sites/scss'],
+          },
+        };
+        const compiler = getCompiler(testId, { loader: { options } });
+        const stats = await compile(compiler);
+        const codeFromBundle = getCodeFromBundle(stats, compiler);
+        const codeFromSass = getCodeFromSass(testId, options);
+
+        expect(codeFromBundle.css).toBe(codeFromSass.css);
+        expect(codeFromBundle.css).toMatchSnapshot('css');
+        expect(getWarnings(stats)).toMatchSnapshot('warnings');
+        expect(getErrors(stats)).toMatchSnapshot('errors');
+      });
+
       it(`should work and use the "_index" file in package (${implementationName}) (${syntax})`, async () => {
         const testId = getTestId('import-_index', syntax);
         const options = {

test/sass/import-prefer-main-files-with-extension.sass

@@ -0,0 +1,4 @@
+@import "~package-with-index"
+
+.class
+  color: blue

test/scss/import-prefer-main-files-with-extension.scss

@@ -0,0 +1,5 @@
+@import "~package-with-index";
+
+.class {
+  color: blue;
+}