Allow loops containing await

lib/no-loops.js

@@ -5,11 +5,33 @@ module.exports = function (context) {
     context.report(node, 'loops are not allowed', { identifier: node.name });
   }
 
+  var loopsContainAwait = []
+
+  function enterLoop() {
+    loopsContainAwait.unshift(false)
+  }
+
+  function exitLoop(node) {
+    if (!loopsContainAwait.shift()) reportLoopPresence(node)
+  }
+
+  function foundAwait() {
+    for (var i = 0; i < loopsContainAwait.length; i++) {
+      loopsContainAwait[i] = true
+    }
+  }
+
   return {
-    ForStatement: reportLoopPresence,
-    ForInStatement: reportLoopPresence,
-    WhileStatement: reportLoopPresence,
-    DoWhileStatement: reportLoopPresence,
-    ForOfStatement: reportLoopPresence
+    ForStatement: enterLoop,
+    'ForStatement:exit': exitLoop,
+    ForInStatement: enterLoop,
+    'ForInStatement:exit': exitLoop,
+    WhileStatement: enterLoop,
+    'WhileStatement:exit': exitLoop,
+    DoWhileStatement: enterLoop,
+    'DoWhileStatement:exit': exitLoop,
+    ForOfStatement: enterLoop,
+    'ForOfStatement:exit': exitLoop,
+    AwaitExpression: foundAwait
   };
 };

package.json

@@ -22,8 +22,8 @@
   },
   "homepage": "https://github.com/buildo/eslint-plugin-no-loops#readme",
   "devDependencies": {
-    "babel-eslint": "^6.1.0",
-    "eslint": "^2.0.0"
+    "babel-eslint": "8",
+    "eslint": "5"
   },
   "peerDependencies": {
     "eslint": ">=2.0.0"

tests/index.js

@@ -3,11 +3,29 @@
 var rule = require('../lib/no-loops.js');
 var RuleTester = require('eslint').RuleTester;
 
-var ruleTester = new RuleTester();
+var ruleTester = new RuleTester({ parserOptions: { ecmaVersion: 2018 } });
 ruleTester.run('no-loops', rule, {
   valid: [
     {
       code: '[1, 2, 3].map(function (i) { console.log(i); });'
+    },
+    {
+      code: 'async function ok() { for (var i = 0; i < n; i++) { await x[i]() } }'
+    },
+    {
+      code: 'const ok = async () => { for (const x of y) { for (const z of y) { await z() } } }'
+    },
+    {
+      code: 'async function ok() { for (const x of y) { await x() } }'
+    },
+    {
+      code: 'async function ok() { while (true) { await x() } }'
+    },
+    {
+      code: 'async function ok() { do { await x() } while (true) }'
+    },
+    {
+      code: 'const ok = async () => { for (const x of y) { for (const z in y) { await z() } } }'
     }
   ],
 
@@ -32,6 +50,16 @@ ruleTester.run('no-loops', rule, {
       code: 'for (i of [1, 2, 3]) { console.log(i) }',
       parser: 'babel-eslint',
       errors: [ { message: 'loops are not allowed' } ]
+    },
+    {
+      code: 'async function bad() { while (true) { x() } }',
+      parser: 'babel-eslint',
+      errors: [ { message: 'loops are not allowed' } ]
+    },
+    {
+      code: 'const ok = async () => { for (const x of y) { await x(); for (const z in y) { z() } } }',
+      parser: 'babel-eslint',
+      errors: [ { message: 'loops are not allowed' } ]
     }
   ]
 });