Add no-process-exit rule

docs/rules/no-process-exit.md

@@ -0,0 +1,18 @@
+# Disallow `process.exit()`
+
+This rule is an extension to [ESLint's `no-process-exit`](http://eslint.org/docs/rules/no-process-exit) rule, that allows `process.exit()` to be called in files that start with a hashbang `#!/usr/bin/env node`.
+
+
+## Fail
+
+```js
+process.exit(0);
+```
+
+
+## Pass
+
+```js
+#!/usr/bin/env node
+process.exit(0);
+```

index.js

@@ -2,6 +2,7 @@
 
 module.exports = {
 	rules: {
+		'no-process-exit': require('./rules/no-process-exit'),
 		'throw-new-error': require('./rules/throw-new-error')
 	},
 	configs: {
@@ -14,6 +15,7 @@ module.exports = {
 				sourceType: 'module'
 			},
 			rules: {
+				'xo/no-process-exit': 'error',
 				'xo/throw-new-error': 'error'
 			}
 		}

readme.md

@@ -31,7 +31,8 @@ Configure it in `package.json`.
 			"xo"
 		],
 		"rules": {
-			"xo/throw-new-error": "error",
+			"xo/no-process-exit": "error",
+			"xo/throw-new-error": "error"
 		}
 	}
 }
@@ -40,6 +41,7 @@ Configure it in `package.json`.
 
 ## Rules
 
+- [no-process-exit](docs/rules/no-process-exit.md) - Disallow `process.exit()`.
 - [throw-new-error](docs/rules/throw-new-error.md) - Require `new` when throwing an error. *(fixable)*
 
 

rules/no-process-exit.js

@@ -0,0 +1,19 @@
+"use strict";
+
+module.exports = function (context) {
+	var startsWithHashBang = context.getSourceCode().lines[0].indexOf('#!') === 0;
+	return {
+		CallExpression: function (node) {
+			if (startsWithHashBang) {
+				return;
+			}
+
+			var callee = node.callee;
+			if (callee.type === "MemberExpression" &&
+					callee.object.name === "process" &&
+					callee.property.name === "exit") {
+				context.report(node, "Don't use process.exit(); throw an error instead.");
+			}
+		}
+	};
+};

test/no-process-exit.js

@@ -0,0 +1,47 @@
+import test from 'ava';
+import {RuleTester} from 'eslint';
+import rule from '../rules/no-process-exit';
+
+const ruleTester = new RuleTester({
+	env: {
+		es6: true
+	}
+});
+
+test(() => {
+	ruleTester.run('no-process-exit', rule, {
+		valid: [
+			'Process.exit()',
+			'var exit = process.exit;',
+			'f(process.exit)',
+			'#!/usr/bin/env node\nprocess.exit(0);',
+			''
+		],
+		invalid: [
+			{
+				code: 'process.exit(0);',
+				errors: [{
+					ruleId: 'no-process-exit',
+					message: 'Don\'t use process.exit(); throw an error instead.',
+					type: 'CallExpression'
+				}]
+			},
+			{
+				code: 'process.exit(1);',
+				errors: [{
+					ruleId: 'no-process-exit',
+					message: 'Don\'t use process.exit(); throw an error instead.',
+					type: 'CallExpression'
+				}]
+			},
+			{
+				code: 'f(process.exit(1));',
+				errors: [{
+					ruleId: 'no-process-exit',
+					message: 'Don\'t use process.exit(); throw an error instead.',
+					type: 'CallExpression'
+				}]
+			}
+		]
+	});
+});