add max-warnings option (#75)

The eslint CLI has a `--max-warnings` option which allows a user to
specify the maximun number of warnings after which the lint should
fail. This adds this same feature to esprint.

README.md

@@ -30,6 +30,7 @@ Options:
 |**`port`**|`{Number}`|(optional) Run the esprint background server on a specific port|
 |**`formatter`**|`{string}`|(optional) Use a specific output format - default: stylish|
 |**`quiet`**|`{boolean}`|(optional) Report errors only - default: false|
+|**`maxWarnings`**|`{number}`|(optional) The max number of warnings that should trigger a failure. The default is to not fail on warnings|
 
 ## Usage
 

src/Client.js

@@ -4,22 +4,25 @@ import { clearLine } from './cliUtils';
 
 export default class Client {
   constructor(options) {
-    const { port, formatter } = options;
+    const { port, formatter, maxWarnings } = options;
     const eslint = new CLIEngine();
     this.port = port;
     this.formatter = eslint.getFormatter(formatter);
+    this.maxWarnings = maxWarnings;
   }
 
   connect() {
     const d = dnode.connect(this.port);
     const formatter = this.formatter;
+    const maxWarnings = this.maxWarnings;
     d.on('remote', function(remote) {
       setInterval(() => {
         remote.status('', results => {
           if (!results.message) {
             d.end();
             console.log(formatter(results.records));
-            process.exit(results && results.errorCount > 0 ? 1 : 0);
+            process.exit(results && (results.errorCount > 0 ? 1 : 0
+              || results.warningCount > maxWarnings ? 1 : 0));
           } else {
             clearLine();
             process.stdout.write(results.message);

src/commands/check.js

@@ -10,6 +10,7 @@ export const check = (options) => {
     paths,
     formatter,
     rcPath,
+    maxWarnings,
     quiet,
   } = options;
 
@@ -31,6 +32,7 @@ export const check = (options) => {
 
       const lintFormatter = eslint.getFormatter(formatter);
       console.log(lintFormatter(records));
-      process.exit(results && results.errorCount > 0 ? 1 : 0);
+      process.exit(results && (results.errorCount > 0 ? 1 : 0
+        || results.warningCount > maxWarnings ? 1 : 0));
     });
 };

tests/fail-on-warning/.eslintignore

@@ -0,0 +1 @@
+__tests__/*

tests/fail-on-warning/.eslintrc.json

@@ -0,0 +1,9 @@
+{
+  "rules": {
+    "no-var": 1
+  },
+  "env": {
+    "es6": true
+  },
+  "root": true
+}

tests/fail-on-warning/.esprintrc

@@ -0,0 +1,12 @@
+
+{
+  "port": 5004 ,
+  "paths": [
+    "fixture.js"
+  ],
+
+  "ignored": [
+    "**/node_modules/**/*"
+  ],
+  "maxWarnings": 0
+}

tests/fail-on-warning/__tests__/fail-on-warning.test.js

@@ -0,0 +1,28 @@
+const path = require('path');
+const runEsprint = require('../../runEsprint.js');
+const killProcess = require('../../killProcess.js');
+const getPid = require('../../getPid.js');
+
+beforeEach(() => {
+  killProcess();
+});
+
+afterEach(() => {
+  killProcess();
+});
+
+test('Properly lints and returns errors with server', () => {
+  const results = runEsprint(path.join(__dirname, '..'));
+  const expectedError = expect.stringContaining('warning  Unexpected var, use let or const instead  no-var');
+  expect(results.error).toBeDefined();
+  expect(results.error.stdout.toString()).toEqual(expectedError);
+  expect(getPid()).toBeDefined();
+});
+
+test('Properly lints and returns errors without server', () => {
+  const results = runEsprint(path.join(__dirname, '..'), 'check');
+  const expectedError = expect.stringContaining('warning  Unexpected var, use let or const instead  no-var');
+  expect(results.error).toBeDefined();
+  expect(results.error.stdout.toString()).toEqual(expectedError);
+  expect(getPid()).toBeUndefined();
+});

tests/fail-on-warning/fixture.js

@@ -0,0 +1,2 @@
+var x=0;
+console.log(x);