test: source map (#1180)

Author: evilebottnawi

test/__snapshots__/sourceMap-option.test.js.snap

@@ -1,5 +1,21 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`"sourceMap" option false should generate source maps when css was extracted: errors 1`] = `Array []`;
+
+exports[`"sourceMap" option false should generate source maps when css was extracted: extracted css 1`] = `
+".nested {
+  color: blue;
+}
+
+.class {
+  color: red;
+}
+
+"
+`;
+
+exports[`"sourceMap" option false should generate source maps when css was extracted: warnings 1`] = `Array []`;
+
 exports[`"sourceMap" option false should not generate source maps when previous loader does not generate source maps: errors 1`] = `Array []`;
 
 exports[`"sourceMap" option false should not generate source maps when previous loader does not generate source maps: module 1`] = `

test/sourceMap-option.test.js

@@ -742,5 +742,48 @@ describe('"sourceMap" option', () => {
       expect(getWarnings(stats)).toMatchSnapshot('warnings');
       expect(getErrors(stats)).toMatchSnapshot('errors');
     });
+
+    it('should generate source maps when css was extracted', async () => {
+      const compiler = getCompiler(
+        './source-map/basic.js',
+        {},
+        {
+          output: {
+            path: path.resolve(__dirname, '../outputs'),
+            filename: '[name].bundle.js',
+            chunkFilename: '[name].chunk.js',
+            publicPath: '/webpack/public/path/',
+          },
+          plugins: [
+            new MiniCssExtractPlugin({
+              filename: '[name].css',
+            }),
+          ],
+          module: {
+            rules: [
+              {
+                test: /\.css$/i,
+                rules: [
+                  {
+                    loader: MiniCssExtractPlugin.loader,
+                  },
+                  {
+                    loader: path.resolve(__dirname, '../src'),
+                    options: { sourceMap: false },
+                  },
+                ],
+              },
+            ],
+          },
+        }
+      );
+      const stats = await compile(compiler);
+
+      expect(readAsset('main.css', compiler, stats)).toMatchSnapshot(
+        'extracted css'
+      );
+      expect(getWarnings(stats)).toMatchSnapshot('warnings');
+      expect(getErrors(stats)).toMatchSnapshot('errors');
+    });
   });
 });