Retrieve errors/warnings from compilation.children if needed (#93)

Author: Lyrkan

package.json

@@ -32,6 +32,7 @@
     "webpack": "^4.0.0"
   },
   "devDependencies": {
+    "autoprefixer": "^9.6.0",
     "babel-core": "^6.23.1",
     "babel-eslint": "^10.0.1",
     "babel-loader": "^7.1.4",
@@ -46,6 +47,7 @@
     "memory-fs": "^0.4.1",
     "mini-css-extract-plugin": "^0.6.0",
     "node-sass": "^4.12.0",
+    "postcss-loader": "^3.0.0",
     "sass": "^1.20.1",
     "sass-loader": "^7.1.0",
     "style-loader": "^0.23.1",

src/friendly-errors-plugin.js

@@ -142,7 +142,19 @@ function extractErrorsFromStats(stats, type) {
     // compilers depend on the same module.
     return uniqueBy(errors, error => error.message);
   }
-  return stats.compilation[type];
+
+  const findErrorsRecursive = (compilation) => {
+    const errors = compilation[type];
+    if (errors.length === 0 && compilation.children) {
+      for (const child of compilation.children) {
+        errors.push(...findErrorsRecursive(child));
+      }
+    }
+
+    return uniqueBy(errors, error => error.message);
+  };
+
+  return findErrorsRecursive(stats.compilation);
 }
 
 function isMultiStats(stats) {

test/fixtures/multi-postcss-warnings/index.css

@@ -0,0 +1,4 @@
+body {
+	display: grid;
+	grid-gap: 1px;
+}

test/fixtures/multi-postcss-warnings/index2.css

@@ -0,0 +1,4 @@
+body {
+	display: grid;
+	grid-auto-flow: row;
+}

test/fixtures/multi-postcss-warnings/postcss.config.js

@@ -0,0 +1,7 @@
+module.exports = {
+  plugins: {
+    autoprefixer: {
+      grid: true,
+    }
+  }
+};

test/fixtures/multi-postcss-warnings/webpack.config.js

@@ -0,0 +1,41 @@
+// postcss-loader warnings test (multi-compiler version)
+const FriendlyErrorsWebpackPlugin = require('../../../index');
+
+const COMMON_CONFIG = {
+  mode: 'production',
+  output: {
+    path: __dirname + '/dist',
+  },
+  plugins: [
+    new FriendlyErrorsWebpackPlugin(),
+  ],
+  module: {
+    rules: [
+      {
+        test: /\.css$/,
+        exclude: /node_modules/,
+        use: [
+          {
+            loader: 'css-loader',
+            options: {
+              importLoaders: 1,
+            },
+          },
+          {
+            loader: 'postcss-loader',
+            options: {
+              config: {
+                path: __dirname + '/postcss.config.js'
+              }
+            },
+          },
+        ],
+      }
+    ]
+  },
+};
+
+module.exports = [
+  Object.assign({}, { entry: __dirname + '/index.css' }, COMMON_CONFIG),
+  Object.assign({}, { entry: __dirname + '/index2.css' }, COMMON_CONFIG),
+];

test/fixtures/postcss-warnings/index.css

@@ -0,0 +1,4 @@
+body {
+	display: grid;
+	grid-gap: 1px;
+}

test/fixtures/postcss-warnings/postcss.config.js

@@ -0,0 +1,7 @@
+module.exports = {
+  plugins: {
+    autoprefixer: {
+      grid: true,
+    }
+  }
+};

test/fixtures/postcss-warnings/webpack.config.js

@@ -0,0 +1,37 @@
+// postcss-loader warnings test
+const FriendlyErrorsWebpackPlugin = require('../../../index');
+
+module.exports = {
+  mode: 'production',
+  entry: __dirname + '/index.css',
+  output: {
+    path: __dirname + '/dist',
+  },
+  plugins: [
+    new FriendlyErrorsWebpackPlugin(),
+  ],
+  module: {
+    rules: [
+      {
+        test: /\.css$/,
+        exclude: /node_modules/,
+        use: [
+          {
+            loader: 'css-loader',
+            options: {
+              importLoaders: 1,
+            },
+          },
+          {
+            loader: 'postcss-loader',
+            options: {
+              config: {
+                path: __dirname + '/postcss.config.js'
+              }
+            },
+          },
+        ],
+      }
+    ]
+  },
+};

test/integration.spec.js

@@ -161,3 +161,44 @@ it('integration : webpack multi compiler : module-errors', async() => {
     '* ./non-existing in ./test/fixtures/multi-compiler-module-errors/index.js',
   ]);
 });
+
+it('integration : postcss-loader : warnings', async() => {
+
+  const logs = await executeAndGetLogs('./fixtures/postcss-warnings/webpack.config');
+  expect(logs).toEqual([
+    'WARNING  Compiled with 1 warnings',
+    '',
+    'warning  in ./test/fixtures/postcss-warnings/index.css',
+    '',
+    `Module Warning (from ./node_modules/postcss-loader/src/index.js):
+Warning
+
+(3:2) grid-gap only works if grid-template(-areas) is being used`,
+    ''
+  ]);
+});
+
+it('integration : postcss-loader : warnings (multi-compiler version)', async() => {
+
+  const logs = await executeAndGetLogs('./fixtures/multi-postcss-warnings/webpack.config');
+  expect(logs).toEqual([
+    'WARNING  Compiled with 1 warnings',
+    '',
+    'warning  in ./test/fixtures/multi-postcss-warnings/index.css',
+    '',
+    `Module Warning (from ./node_modules/postcss-loader/src/index.js):
+Warning
+
+(3:2) grid-gap only works if grid-template(-areas) is being used`,
+    '',
+    'WARNING  Compiled with 1 warnings',
+    '',
+    'warning  in ./test/fixtures/multi-postcss-warnings/index2.css',
+    '',
+    `Module Warning (from ./node_modules/postcss-loader/src/index.js):
+Warning
+
+(3:2) grid-auto-flow works only if grid-template-rows and grid-template-columns are present in the same rule`,
+    ''
+  ]);
+});