switch to banning general usage

Author: Hweinstock

.eslintrc.js

@@ -178,7 +178,7 @@ module.exports = {
         'aws-toolkits/no-console-log': 'error',
         'aws-toolkits/no-json-stringify-in-log': 'error',
         'aws-toolkits/no-printf-mismatch': 'error',
-        'aws-toolkits/no-async-in-foreach': 'error',
+        'aws-toolkits/no-foreach': 'error',
         'no-restricted-imports': [
             'error',
             {

plugins/eslint-plugin-aws-toolkits/index.ts

@@ -11,7 +11,7 @@ import NoStringExecForChildProcess from './lib/rules/no-string-exec-for-child-pr
 import NoConsoleLog from './lib/rules/no-console-log'
 import noJsonStringifyInLog from './lib/rules/no-json-stringify-in-log'
 import noPrintfMismatch from './lib/rules/no-printf-mismatch'
-import noAsyncInForEach from './lib/rules/no-async-in-foreach'
+import noForeach from './lib/rules/no-foreach'
 
 const rules = {
     'no-await-on-vscode-msg': NoAwaitOnVscodeMsg,
@@ -22,7 +22,7 @@ const rules = {
     'no-console-log': NoConsoleLog,
     'no-json-stringify-in-log': noJsonStringifyInLog,
     'no-printf-mismatch': noPrintfMismatch,
-    'no-async-in-foreach': noAsyncInForEach,
+    'no-foreach': noForeach,
 }
 
 export { rules }

plugins/eslint-plugin-aws-toolkits/lib/rules/no-async-in-foreach.ts

@@ -0,0 +1,43 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { ESLintUtils, TSESTree } from '@typescript-eslint/utils'
+import { AST_NODE_TYPES } from '@typescript-eslint/types'
+import { Rule } from 'eslint'
+
+export const errMsg = 'Avoid using .forEach as it can lead to race conditions'
+
+export default ESLintUtils.RuleCreator.withoutDocs({
+    meta: {
+        docs: {
+            description: 'disallow async functions with .forEach',
+            recommended: 'recommended',
+        },
+        messages: {
+            errMsg,
+        },
+        type: 'problem',
+        fixable: 'code',
+        schema: [],
+    },
+    defaultOptions: [],
+    create(context) {
+        return {
+            CallExpression(node: TSESTree.CallExpression) {
+                if (
+                    node.callee.type === AST_NODE_TYPES.MemberExpression &&
+                    node.callee.property.type === AST_NODE_TYPES.Identifier &&
+                    node.callee.property.name === 'forEach' &&
+                    node.arguments.length >= 1
+                ) {
+                    return context.report({
+                        node: node,
+                        messageId: 'errMsg',
+                    })
+                }
+            },
+        }
+    },
+}) as unknown as Rule.RuleModule

plugins/eslint-plugin-aws-toolkits/lib/rules/no-foreach.ts

@@ -0,0 +1,36 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { rules } from '../../index'
+import { errMsg } from '../../lib/rules/no-foreach'
+import { getRuleTester } from '../testUtil'
+
+getRuleTester().run('no-foreach', rules['no-foreach'], {
+    valid: ['list.map(f)', 'list.find(f)', 'list.forAll(f)', 'o.forEachItem(f)', ''],
+
+    invalid: [
+        { code: 'list.forEach((a) => await Promise.resolve(a * a))', errors: [errMsg] },
+        { code: 'list.forEach(async (a: any) => console.log(x))', errors: [errMsg] },
+        { code: 'list.forEach((a) => a.forEach(async (b) => a * b))', errors: [errMsg] },
+        { code: 'list.forEach(async function () {})', errors: [errMsg] },
+        { code: 'function f(){} \n list.forEach(f)', errors: [errMsg] },
+        { code: 'const f = async () => {} \n list.forEach(f)', errors: [errMsg] },
+        { code: 'const f = async function () {} \n list.forEach(f)', errors: [errMsg] },
+        { code: 'class c { \n public async f() {} \n } \n [].forEach((new c().f))', errors: [errMsg] },
+        {
+            code: 'class c { \n public async f() {} \n } \n const c2 = new c() \n list.forEach(c2.f)',
+            errors: [errMsg],
+        },
+        { code: 'function f() { \n return async function () {}} \n [].forEach(f())', errors: [errMsg] },
+        {
+            code: 'function f() { \n return new (class c { \n public async f2() {} \n })().f2 \n } \n list.forEach(f())',
+            errors: [errMsg],
+        },
+        {
+            code: 'function f() { \n return function f2() { \n return function f3() { \n return function f4() { \n return function f5() { \n return async function f6() { \n \n } \n } \n } \n } \n } \n } \n list.forEach(f()()()()())',
+            errors: [errMsg],
+        },
+    ],
+})