Polish webpack message output (#5174)

* Only install react-scripts in CI mode

* Link locally

* Re-enable all output tests

* 💄 Polish webpack output

* Test sass support message

* Add more tests, but disabled

* Format missing default export error

* Format aliased import

* Why was node-sass required? Odd

* Format webpack rejection error

* Re-enable unknown package test

* Format file not found error and catch module scope plugin error

* Re-disable case sensitive paths

* Intercept and format case sensitive path errors

* Test out of scope message formatting

* Run behavior on macOS

* Run behavior on Node 8 and 10, only Node 8 for macOS

* Add some debugging

* Update matcher

* Only check stderr

* Remove old snapshot

* More debug

* Remove debug

* Add new debug

* Disable test on linux

* Add comment for future

fixtures/output/webpack-message-formatting/__snapshots__/index.test.js.snap

@@ -1,12 +1,26 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`webpack message formatting formats aliased unknown export 1`] = `
+Object {
+  "stderr": "Creating an optimized production build...
+Failed to compile.
+
+./src/App.js
+Attempted import error: 'bar' is not exported from './AppUnknownExport' (imported as 'bar2').
+
+
+",
+  "stdout": "",
+}
+`;
+
 exports[`webpack message formatting formats babel syntax error 1`] = `
 Object {
   "stderr": "Creating an optimized production build...
 Failed to compile.
 
 ./src/App.js
-Syntax error: Unterminated JSX contents (8:12)
+Syntax error: Unterminated JSX contents (8:13)
 
    6 |       <div>
    7 |         <span>
@@ -25,16 +39,16 @@ Syntax error: Unterminated JSX contents (8:12)
 exports[`webpack message formatting formats css syntax error 1`] = `
 Object {
   "stderr": "Creating an optimized production build...
-Failed to compile.
-
-./src/AppCss.css
-Syntax Error: (3:2) Unexpected }
+Failed to compile.
 
-  1 | .App {
-  2 |   color: red;
-> 3 | }}
-    |  ^
-  4 | 
+./src/AppCss.css
+Syntax error: Unexpected } (3:2)
+
+  1 | .App {
+  2 |   color: red;
+> 3 | }}
+    |  ^
+  4 |
 
 
 ",
@@ -74,12 +88,58 @@ To ignore, add // eslint-disable-next-line to the line before.
 }
 `;
 
+exports[`webpack message formatting formats file not found error 1`] = `
+Object {
+  "stderr": "Creating an optimized production build...
+Failed to compile.
+
+./src/App.js
+Cannot find file './ThisFileSouldNotExist' in './src'.
+
+
+",
+  "stdout": "",
+}
+`;
+
 exports[`webpack message formatting formats missing package 1`] = `
 Object {
   "stderr": "Creating an optimized production build...
-Failed to compile.
-
-Module not found: Error: Can't resolve 'unknown-package' in '/private/var/folders/c3/vytj6_h56b77f_g72smntm3m0000gn/T/bf26e1d3700ad14275f6eefb5e4417c1/src'
+Failed to compile.
+
+./src/App.js
+Cannot find module: 'unknown-package'. Make sure this package is installed.
+
+You can install this package by running: yarn add unknown-package.
+
+
+",
+  "stdout": "",
+}
+`;
+
+exports[`webpack message formatting formats no default export 1`] = `
+Object {
+  "stderr": "Creating an optimized production build...
+Failed to compile.
+
+./src/App.js
+Attempted import error: './ExportNoDefault' does not contain a default export (imported as 'myImport').
+
+
+",
+  "stdout": "",
+}
+`;
+
+exports[`webpack message formatting formats out of scope error 1`] = `
+Object {
+  "stderr": "Creating an optimized production build...
+Failed to compile.
+
+./src/App.js
+You attempted to import ../OutOfScopeImport which falls outside of the project src/ directory. Relative imports outside of src/ are not supported.
+You can either move it inside src/, or add a symlink to it from project's node_modules/.
 
 
 ",
@@ -93,7 +153,22 @@ Object {
 Failed to compile.
 
 ./src/App.js
-1:1677-1680 './AppUnknownExport' does not contain an export named 'bar'.
+Attempted import error: 'bar' is not exported from './AppUnknownExport'.
+
+
+",
+  "stdout": "",
+}
+`;
+
+exports[`webpack message formatting helps when users tries to use sass 1`] = `
+Object {
+  "stderr": "Creating an optimized production build...
+Failed to compile.
+
+./src/AppSass.scss
+To import Sass files, you first need to install node-sass.
+Run \`npm install node-sass\` or \`yarn add node-sass\` inside your workspace.
 
 
 ",

fixtures/output/webpack-message-formatting/index.test.js

@@ -1,4 +1,8 @@
-const { bootstrap, getOutputProduction } = require('../../utils');
+const {
+  bootstrap,
+  getOutputDevelopment,
+  getOutputProduction,
+} = require('../../utils');
 const fs = require('fs-extra');
 const path = require('path');
 const Semaphore = require('async-sema');
@@ -19,7 +23,7 @@ describe('webpack message formatting', () => {
     semaphore.release();
   });
 
-  xit('formats babel syntax error', async () => {
+  it('formats babel syntax error', async () => {
     fs.copySync(
       path.join(__dirname, 'src', 'AppBabel.js'),
       path.join(testDirectory, 'src', 'App.js')
@@ -29,8 +33,7 @@ describe('webpack message formatting', () => {
     expect(response).toMatchSnapshot();
   });
 
-  xit('formats css syntax error', async () => {
-    // TODO: fix me!
+  it('formats css syntax error', async () => {
     fs.copySync(
       path.join(__dirname, 'src', 'AppCss.js'),
       path.join(testDirectory, 'src', 'App.js')
@@ -40,8 +43,7 @@ describe('webpack message formatting', () => {
     expect(response).toMatchSnapshot();
   });
 
-  xit('formats unknown export', async () => {
-    // TODO: fix me!
+  it('formats unknown export', async () => {
     fs.copySync(
       path.join(__dirname, 'src', 'AppUnknownExport.js'),
       path.join(testDirectory, 'src', 'App.js')
@@ -51,8 +53,27 @@ describe('webpack message formatting', () => {
     expect(response).toMatchSnapshot();
   });
 
-  xit('formats missing package', async () => {
-    // TODO: fix me!
+  it('formats aliased unknown export', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppAliasUnknownExport.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputProduction({ directory: testDirectory });
+    expect(response).toMatchSnapshot();
+  });
+
+  it('formats no default export', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppNoDefault.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputProduction({ directory: testDirectory });
+    expect(response).toMatchSnapshot();
+  });
+
+  it('formats missing package', async () => {
     fs.copySync(
       path.join(__dirname, 'src', 'AppMissingPackage.js'),
       path.join(testDirectory, 'src', 'App.js')
@@ -85,4 +106,52 @@ describe('webpack message formatting', () => {
     const response = await getOutputProduction({ directory: testDirectory });
     expect(response).toMatchSnapshot();
   });
+
+  it('helps when users tries to use sass', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppSass.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputProduction({ directory: testDirectory });
+    expect(response).toMatchSnapshot();
+  });
+
+  it('formats file not found error', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppUnknownFile.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputProduction({ directory: testDirectory });
+    expect(response).toMatchSnapshot();
+  });
+
+  it('formats case sensitive path error', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppIncorrectCase.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputDevelopment({ directory: testDirectory });
+    if (process.platform === 'darwin') {
+      expect(response.stderr).toMatch(
+        `Cannot find file: 'export5.js' does not match the corresponding name on disk: './src/Export5.js'.`
+      );
+    } else {
+      expect(response.stderr).not.toEqual(''); // TODO: figure out how we can test this on Linux/Windows
+      // I believe getting this working requires we tap into enhanced-resolve
+      // pipeline, which is debt we don't want to take on right now.
+    }
+  });
+
+  it('formats out of scope error', async () => {
+    fs.copySync(
+      path.join(__dirname, 'src', 'AppOutOfScopeImport.js'),
+      path.join(testDirectory, 'src', 'App.js')
+    );
+
+    const response = await getOutputProduction({ directory: testDirectory });
+    expect(response).toMatchSnapshot();
+  });
 });

fixtures/output/webpack-message-formatting/package.json

@@ -1,9 +1,7 @@
 {
   "dependencies": {
-    "node-sass": "4.x",
     "react": "latest",
-    "react-dom": "latest",
-    "react-scripts": "latest"
+    "react-dom": "latest"
   },
   "browserslist": [
     ">0.2%"

fixtures/output/webpack-message-formatting/src/AppAliasUnknownExport.js

@@ -0,0 +1,13 @@
+import React, { Component } from 'react';
+import { bar as bar2 } from './AppUnknownExport';
+
+class App extends Component {
+  componentDidMount() {
+    bar2();
+  }
+  render() {
+    return <div />;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/AppIncorrectCase.js

@@ -0,0 +1,10 @@
+import React, { Component } from 'react';
+import five from './export5';
+
+class App extends Component {
+  render() {
+    return <div className="App">{five}</div>;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/AppNoDefault.js

@@ -0,0 +1,10 @@
+import React, { Component } from 'react';
+import myImport from './ExportNoDefault';
+
+class App extends Component {
+  render() {
+    return <div className="App">{myImport}</div>;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/AppOutOfScopeImport.js

@@ -0,0 +1,10 @@
+import React, { Component } from 'react';
+import myImport from '../OutOfScopeImport';
+
+class App extends Component {
+  render() {
+    return <div className="App">{myImport}</div>;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/AppSass.js

@@ -0,0 +1,10 @@
+import React, { Component } from 'react';
+import './AppSass.scss';
+
+class App extends Component {
+  render() {
+    return <div className="App" />;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/AppSass.scss

@@ -0,0 +1,3 @@
+.App {
+  color: red;
+}

fixtures/output/webpack-message-formatting/src/AppUnknownFile.js

@@ -0,0 +1,10 @@
+import React, { Component } from 'react';
+import DefaultExport from './ThisFileSouldNotExist';
+
+class App extends Component {
+  render() {
+    return <div className="App" />;
+  }
+}
+
+export default App;

fixtures/output/webpack-message-formatting/src/Export5.js

@@ -0,0 +1 @@
+export default 5;

fixtures/output/webpack-message-formatting/src/ExportNoDefault.js

@@ -0,0 +1 @@
+export const six = 6;