lint: disallow console.log and similar

Author: hayemaxi

.eslintrc.js

@@ -159,6 +159,7 @@ module.exports = {
         'aws-toolkits/no-banned-usages': 'error',
         'aws-toolkits/no-incorrect-once-usage': 'error',
         'aws-toolkits/no-string-exec-for-child-process': 'error',
+        'aws-toolkits/no-console-log': 'error',
 
         'no-restricted-imports': [
             'error',

CONTRIBUTING.md

@@ -477,6 +477,8 @@ The package.json 'devDependencies' includes `eslint-plugin-aws-toolkits`. This i
 3. Register your rule in `plugins/eslint-plugin-aws-toolkits/index.ts`.
 4. Enable your rule in `.eslintrc`.
 
+Writing lint rules can be tricky if you are unfamiliar with the process. Use an AST viewer such as https://astexplorer.net/
+
 ### AWS SDK generator
 
 When the AWS SDK does not (yet) support a service but you have an API

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

@@ -8,13 +8,15 @@ import NoBannedUsages from './lib/rules/no-banned-usages'
 import NoIncorrectOnceUsage from './lib/rules/no-incorrect-once-usage'
 import NoOnlyInTests from './lib/rules/no-only-in-tests'
 import NoStringExecForChildProcess from './lib/rules/no-string-exec-for-child-process'
+import NoConsoleLog from './lib/rules/no-console-log'
 
 const rules = {
     'no-await-on-vscode-msg': NoAwaitOnVscodeMsg,
     'no-banned-usages': NoBannedUsages,
     'no-incorrect-once-usage': NoIncorrectOnceUsage,
     'no-only-in-tests': NoOnlyInTests,
     'no-string-exec-for-child-process': NoStringExecForChildProcess,
+    'no-console-log': NoConsoleLog,
 }
 
 export { rules }

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

@@ -0,0 +1,61 @@
+/*!
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * Enforce usage of our getLogger() function instead of using node's built in console.log() and similar.
+ * An eslint rule already exists for this (https://eslint.org/docs/latest/rules/no-console), but this
+ * rule is trivial to implement and we can add our own error message, so here it is.
+ */
+
+import { ESLintUtils, TSESTree } from '@typescript-eslint/utils'
+import { AST_NODE_TYPES } from '@typescript-eslint/types'
+import { Rule } from 'eslint'
+
+export const errMsg =
+    'do not use console.log, console.warn, or console.err, or similar; instead, use `getLogger().info`, `getLogger().warn`, etc; disable this rule for files that cannot import getLogger()'
+
+const disallowFunctions = new Set(['info', 'debug', 'error', 'warn', 'log'])
+
+export default ESLintUtils.RuleCreator.withoutDocs({
+    meta: {
+        docs: {
+            description: 'disallow use of console.log() to encourage use of getLogger()',
+            recommended: 'recommended',
+        },
+        messages: {
+            errMsg,
+        },
+        type: 'problem',
+        fixable: 'code',
+        schema: [],
+    },
+    defaultOptions: [],
+    create(context) {
+        return {
+            MemberExpression(node: TSESTree.MemberExpression) {
+                // Exception for anything that isn't extension code (in a src/ folder) (e.g. build scripts, tests)
+                if (context.physicalFilename.includes('test') || !context.physicalFilename.includes('src')) {
+                    return
+                }
+
+                // Validate this node
+                if (
+                    node.object.type !== AST_NODE_TYPES.Identifier ||
+                    node.object.name !== 'console' ||
+                    node.property.type !== AST_NODE_TYPES.Identifier
+                ) {
+                    return
+                }
+
+                if (disallowFunctions.has(node.property.name)) {
+                    return context.report({
+                        node,
+                        messageId: 'errMsg',
+                    })
+                }
+            },
+        }
+    },
+}) as unknown as Rule.RuleModule

plugins/eslint-plugin-aws-toolkits/test/rules/no-console-log.test.ts

@@ -0,0 +1,52 @@
+/*!
+ * 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-console-log'
+import { getRuleTester } from '../testUtil'
+
+getRuleTester().run('no-console-log', rules['no-console-log'], {
+    valid: [
+        {
+            code: "getLogger().warn('my message')",
+            filename: '/src/client.ts',
+        },
+        {
+            code: "console.log('hi')",
+            filename: '/scripts/build.ts',
+        },
+        {
+            code: "console.log('hi')",
+            filename: '/src/test/client.test.ts',
+        },
+    ],
+    invalid: [
+        {
+            code: "console.log('test')",
+            filename: '/src/client.ts',
+            errors: [errMsg],
+        },
+        {
+            code: "console.warn('test')",
+            filename: '/src/client.ts',
+            errors: [errMsg],
+        },
+        {
+            code: "console.error('test')",
+            filename: '/src/client.ts',
+            errors: [errMsg],
+        },
+        {
+            code: "console.debug('test')",
+            filename: '/src/client.ts',
+            errors: [errMsg],
+        },
+        {
+            code: "console.info('test')",
+            filename: '/src/client.ts',
+            errors: [errMsg],
+        },
+    ],
+})