style(layers): apply standardized formatting

layers/.eslintrc.js

@@ -5,63 +5,67 @@ module.exports = {
     jest: true,
     node: true,
   },
-  extends: [ 'plugin:@typescript-eslint/eslint-recommended', 'plugin:@typescript-eslint/recommended' ],
+  extends: [
+    'plugin:@typescript-eslint/recommended',
+    'plugin:prettier/recommended',
+  ],
   parser: '@typescript-eslint/parser',
-  plugins: ['@typescript-eslint'],
+  plugins: ['@typescript-eslint', 'prettier'],
   settings: {
     'import/resolver': {
       node: {},
       typescript: {
-        project: './tsconfig.es.json',
+        project: './tsconfig.json',
         alwaysTryTypes: true,
       },
     },
   },
   rules: {
-    '@typescript-eslint/ban-ts-ignore': ['off'],
-    '@typescript-eslint/camelcase': ['off'],
-    '@typescript-eslint/explicit-function-return-type': [ 'error', { allowExpressions: true } ],
-    '@typescript-eslint/explicit-member-accessibility': 'error',
-    '@typescript-eslint/indent': [ 'error', 2, { SwitchCase: 1 } ],
-    '@typescript-eslint/interface-name-prefix': ['off'],
-    '@typescript-eslint/member-delimiter-style': [ 'error', { multiline: { delimiter: 'none' } } ],
+    '@typescript-eslint/explicit-function-return-type': [
+      'error',
+      { allowExpressions: true },
+    ], // Enforce return type definitions for functions
+    '@typescript-eslint/explicit-member-accessibility': 'error', // Enforce explicit accessibility modifiers on class properties and methods (public, private, protected)
     '@typescript-eslint/member-ordering': [
+      // Standardize the order of class members
       'error',
       {
         default: {
           memberTypes: [
             'signature',
-            'public-field', // = ["public-static-field", "public-instance-field"]
-            'protected-field', // = ["protected-static-field", "protected-instance-field"]
-            'private-field', // = ["private-static-field", "private-instance-field"]
+            'public-field',
+            'protected-field',
+            'private-field',
             'constructor',
-            'public-method', // = ["public-static-method", "public-instance-method"]
-            'protected-method', // = ["protected-static-method", "protected-instance-method"]
-            'private-method', // = ["private-static-method", "private-instance-method"]
+            'public-method',
+            'protected-method',
+            'private-method',
           ],
           order: 'alphabetically',
         },
       },
     ],
-    '@typescript-eslint/no-explicit-any': 'error',
-    '@typescript-eslint/no-inferrable-types': ['off'],
-    '@typescript-eslint/no-unused-vars': [ 'error', { argsIgnorePattern: '^_' } ],
-    '@typescript-eslint/no-use-before-define': ['off'],
-    '@typescript-eslint/semi': [ 'error', 'always' ],
-    'array-bracket-spacing': [ 'error', 'always', { singleValue: false } ],
-    'arrow-body-style': [ 'error', 'as-needed' ],
-    'computed-property-spacing': [ 'error', 'never' ],
-    'func-style': [ 'warn', 'expression' ],
-    indent: [ 'error', 2, { SwitchCase: 1 } ],
-    'keyword-spacing': 'error',
-    'newline-before-return': 2,
-    'no-console': 0,
-    'no-multi-spaces': [ 'error', { ignoreEOLComments: false } ],
-    'no-multiple-empty-lines': [ 'error', { max: 1, maxBOF: 0 } ],
-    'no-throw-literal': 'error',
-    'object-curly-spacing': [ 'error', 'always' ],
-    'prefer-arrow-callback': 'error',
-    quotes: [ 'error', 'single', { allowTemplateLiterals: true } ],
-    semi: [ 'error', 'always' ]
+    '@typescript-eslint/no-explicit-any': 'error', // Disallow usage of the any type
+    '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }], // Disallow unused variables, except for variables starting with an underscore
+    '@typescript-eslint/no-use-before-define': ['off'], // Check if this rule is needed
+    'no-unused-vars': 'off', // Disable eslint core rule, since it's replaced by @typescript-eslint/no-unused-vars
+    // Rules from eslint core https://eslint.org/docs/latest/rules/
+    'array-bracket-spacing': ['error', 'never'], // Disallow spaces inside of array brackets
+    'computed-property-spacing': ['error', 'never'], // Disallow spaces inside of computed properties
+    'func-style': ['warn', 'expression'], // Enforce function expressions instead of function declarations
+    'keyword-spacing': 'error', // Enforce spaces after keywords and before parenthesis, e.g. if (condition) instead of if(condition)
+    'padding-line-between-statements': [
+      // Require an empty line before return statements
+      'error',
+      { blankLine: 'always', prev: '*', next: 'return' },
+    ],
+    'no-console': 0, // Allow console.log statements
+    'no-multi-spaces': ['error', { ignoreEOLComments: false }], // Disallow multiple spaces except for comments
+    'no-multiple-empty-lines': ['error', { max: 1, maxBOF: 0, maxEOF: 0 }], // Enforce no empty line at the beginning & end of files and max 1 empty line between consecutive statements
+    'no-throw-literal': 'error', // Disallow throwing literals as exceptions, e.g. throw 'error' instead of throw new Error('error')
+    'object-curly-spacing': ['error', 'always'], // Enforce spaces inside of curly braces in objects
+    'prefer-arrow-callback': 'error', // Enforce arrow functions instead of anonymous functions for callbacks
+    quotes: ['error', 'single', { allowTemplateLiterals: true }], // Enforce single quotes except for template strings
+    semi: ['error', 'always'], // Require semicolons instead of ASI (automatic semicolon insertion) at the end of statements
   },
 };

layers/bin/layers.ts

@@ -11,4 +11,4 @@ new LayerPublisherStack(app, 'LayerPublisherStack', {
   powertoolsPackageVersion: app.node.tryGetContext('PowertoolsPackageVersion'),
   layerName: 'AWSLambdaPowertoolsTypeScript',
   ssmParameterLayerArn: SSM_PARAM_LAYER_ARN,
-});
+});

layers/jest.config.js

@@ -8,38 +8,21 @@ module.exports = {
   transform: {
     '^.+\\.ts?$': 'ts-jest',
   },
-  moduleFileExtensions: [ 'js', 'ts' ],
-  'collectCoverageFrom': [
-    '**/src/**/*.ts',
-    '!**/node_modules/**',
-  ],
-  'testMatch': ['**/?(*.)+(spec|test).ts'],
-  'roots': [
-    '<rootDir>/src',
-    '<rootDir>/tests',
-  ],
-  'testPathIgnorePatterns': [
-    '/node_modules/',
-  ],
-  'testEnvironment': 'node',
-  'coveragePathIgnorePatterns': [
-    '/node_modules/',
-    '/types/',
-  ],
-  'coverageThreshold': {
-    'global': {
-      'statements': 100,
-      'branches': 100,
-      'functions': 100,
-      'lines': 100,
+  moduleFileExtensions: ['js', 'ts'],
+  collectCoverageFrom: ['**/src/**/*.ts', '!**/node_modules/**'],
+  testMatch: ['**/?(*.)+(spec|test).ts'],
+  roots: ['<rootDir>/src', '<rootDir>/tests'],
+  testPathIgnorePatterns: ['/node_modules/'],
+  testEnvironment: 'node',
+  coveragePathIgnorePatterns: ['/node_modules/', '/types/'],
+  coverageThreshold: {
+    global: {
+      statements: 100,
+      branches: 100,
+      functions: 100,
+      lines: 100,
     },
   },
-  'coverageReporters': [
-    'json-summary',
-    'text',
-    'lcov'
-  ],
-  'setupFiles': [
-    '<rootDir>/tests/helpers/populateEnvironmentVariables.ts'
-  ]
-};
+  coverageReporters: ['json-summary', 'text', 'lcov'],
+  setupFiles: ['<rootDir>/tests/helpers/populateEnvironmentVariables.ts'],
+};

layers/package.json

@@ -12,13 +12,14 @@
     "test": "echo 'Not applicable'",
     "cdk": "cdk",
     "package": "echo 'Not applicable'",
-    "lint": "eslint --ext .ts --no-error-on-unmatched-pattern src tests",
-    "lint-fix": "eslint --fix --ext .ts --fix --no-error-on-unmatched-pattern src tests",
+    "lint": "eslint --ext .ts,.js --no-error-on-unmatched-pattern .",
+    "lint-fix": "eslint --fix --ext .ts,.js --fix --no-error-on-unmatched-pattern .",
     "test:unit": "jest --group=unit",
     "test:e2e": "RUNTIME=nodejs14x jest --group=e2e"
   },
   "lint-staged": {
-    "*.ts": "npm run lint-fix"
+    "*.ts": "npm run lint-fix",
+    "*.js": "npm run lint-fix"
   },
   "repository": {
     "type": "git",
@@ -36,4 +37,4 @@
   "devDependencies": {
     "source-map-support": "^0.5.21"
   }
-}
+}

layers/src/layer-publisher-stack.ts

@@ -1,9 +1,4 @@
-import {
-  CfnOutput,
-  RemovalPolicy,
-  Stack,
-  StackProps
-} from 'aws-cdk-lib';
+import { CfnOutput, RemovalPolicy, Stack, StackProps } from 'aws-cdk-lib';
 import { Construct } from 'constructs';
 import {
   LayerVersion,
@@ -14,39 +9,49 @@ import {
 import { StringParameter } from 'aws-cdk-lib/aws-ssm';
 
 export interface LayerPublisherStackProps extends StackProps {
-  readonly layerName?: string
-  readonly powertoolsPackageVersion?: string
-  readonly ssmParameterLayerArn: string
+  readonly layerName?: string;
+  readonly powertoolsPackageVersion?: string;
+  readonly ssmParameterLayerArn: string;
 }
 
 export class LayerPublisherStack extends Stack {
   public readonly lambdaLayerVersion: LayerVersion;
-  public constructor(scope: Construct, id: string, props: LayerPublisherStackProps) {
+  public constructor(
+    scope: Construct,
+    id: string,
+    props: LayerPublisherStackProps
+  ) {
     super(scope, id, props);
 
     const { layerName, powertoolsPackageVersion } = props;
 
-    console.log(`publishing layer ${layerName} version : ${powertoolsPackageVersion}`);
+    console.log(
+      `publishing layer ${layerName} version : ${powertoolsPackageVersion}`
+    );
 
     this.lambdaLayerVersion = new LayerVersion(this, 'LambdaPowertoolsLayer', {
       layerVersionName: props?.layerName,
       description: `AWS Lambda Powertools for TypeScript version ${powertoolsPackageVersion}`,
       compatibleRuntimes: [
         Runtime.NODEJS_14_X,
         Runtime.NODEJS_16_X,
-        Runtime.NODEJS_18_X
+        Runtime.NODEJS_18_X,
       ],
       license: 'MIT-0',
       // This is needed because the following regions do not support the compatibleArchitectures property #1400
       // ...(![ 'eu-south-2', 'eu-central-2', 'ap-southeast-4' ].includes(Stack.of(this).region) ? { compatibleArchitectures: [Architecture.X86_64] } : {}),
       code: Code.fromAsset('../tmp'),
     });
 
-    const layerPermission = new CfnLayerVersionPermission(this, 'PublicLayerAccess', {
-      action: 'lambda:GetLayerVersion',
-      layerVersionArn: this.lambdaLayerVersion.layerVersionArn,
-      principal: '*',
-    });
+    const layerPermission = new CfnLayerVersionPermission(
+      this,
+      'PublicLayerAccess',
+      {
+        action: 'lambda:GetLayerVersion',
+        layerVersionArn: this.lambdaLayerVersion.layerVersionArn,
+        principal: '*',
+      }
+    );
 
     layerPermission.applyRemovalPolicy(RemovalPolicy.RETAIN);
     this.lambdaLayerVersion.applyRemovalPolicy(RemovalPolicy.RETAIN);

layers/tests/e2e/constants.ts

@@ -2,4 +2,4 @@ export const RESOURCE_NAME_PREFIX = 'Layers-E2E';
 export const ONE_MINUTE = 60 * 1000;
 export const TEST_CASE_TIMEOUT = 3 * ONE_MINUTE;
 export const SETUP_TIMEOUT = 5 * ONE_MINUTE;
-export const TEARDOWN_TIMEOUT = 5 * ONE_MINUTE;
+export const TEARDOWN_TIMEOUT = 5 * ONE_MINUTE;

layers/tests/e2e/layerPublisher.class.test.functionCode.ts

@@ -4,20 +4,22 @@ import { Metrics } from '@aws-lambda-powertools/metrics';
 import { Tracer } from '@aws-lambda-powertools/tracer';
 
 const logger = new Logger({
-  logLevel: 'DEBUG'
+  logLevel: 'DEBUG',
 });
 const metrics = new Metrics();
 const tracer = new Tracer();
 
 export const handler = (): void => {
-
   // Check that the packages version matches the expected one
   try {
     const packageJSON = JSON.parse(
-      readFileSync('/opt/nodejs/node_modules/@aws-lambda-powertools/logger/package.json', {
-        encoding: 'utf8',
-        flag: 'r',
-      })
+      readFileSync(
+        '/opt/nodejs/node_modules/@aws-lambda-powertools/logger/package.json',
+        {
+          encoding: 'utf8',
+          flag: 'r',
+        }
+      )
     );
 
     if (packageJSON.version != process.env.POWERTOOLS_PACKAGE_VERSION) {
@@ -42,5 +44,4 @@ export const handler = (): void => {
   tracer.annotateColdStart();
   handlerSegment.close();
   tracer.setSegment(segment);
-
-};
+};