Merge branch 'master' into no-floating-promises

packages/eslint-plugin/src/configs/README.md

@@ -6,6 +6,19 @@ These configs exist for your convenience. They contain configuration intended to
 
 TODO when all config is added.
 
+## eslint-recommended
+
+The `eslint-recommended` ruleset is meant to be used after extending `eslint:recommended`. It disables rules that are already checked by the Typescript compiler and enables rules that promote using more the more modern constructs Typescript allows for.
+
+```cjson
+{
+  "extends": [
+    "eslint:recommended",
+    "plugin:@typescript-eslint/eslint-recommended"
+  ]
+}
+```
+
 ## Recommended
 
 The recommended set is an **_opinionated_** set of rules that we think you should use because:

packages/eslint-plugin/src/configs/eslint-recommended.ts

@@ -0,0 +1,49 @@
+/**
+ * The goal of this ruleset is to update the eslint:recommended config to better
+ * suit Typescript. There are two main reasons to change the configuration:
+ * 1. The Typescript compiler natively checks some things that therefore don't
+ *    need extra rules anymore.
+ * 2. Typescript allows for more modern Javascript code that can thus be
+ *    enabled.
+ */
+export default {
+  overrides: [
+    {
+      files: ['*.ts', '*.tsx'],
+      rules: {
+        /**
+         * 1. Disable things that are checked by Typescript
+         */
+        //Checked by Typescript - ts(2378)
+        'getter-return': 'off',
+        // Checked by Typescript - ts(2300)
+        'no-dupe-args': 'off',
+        // Checked by Typescript - ts(1117)
+        'no-dupe-keys': 'off',
+        // Checked by Typescript - ts(7027)
+        'no-unreachable': 'off',
+        // Checked by Typescript - ts(2367)
+        'valid-typeof': 'off',
+        // Checked by Typescript - ts(2588)
+        'no-const-assign': 'off',
+        // Checked by Typescript - ts(2588)
+        'no-new-symbol': 'off',
+        // Checked by Typescript - ts(2376)
+        'no-this-before-super': 'off',
+        // This is checked by Typescript using the option `strictNullChecks`.
+        'no-undef': 'off',
+        /**
+         * 2. Enable more ideomatic code
+         */
+        // Typescript allows const and let instead of var.
+        'no-var': 'error',
+        'prefer-const': 'error',
+        // The spread operator/rest parameters should be prefered in Typescript.
+        'prefer-rest-params': 'error',
+        'prefer-spread': 'error',
+        // This is already checked by Typescript.
+        'no-dupe-class-members': 'error',
+      },
+    },
+  ],
+};

packages/eslint-plugin/src/index.ts

@@ -2,6 +2,7 @@ import requireIndex from 'requireindex';
 import path from 'path';
 
 import recommended from './configs/recommended.json';
+import eslintRecommended from './configs/eslint-recommended';
 
 const rules = requireIndex(path.join(__dirname, 'rules'));
 // eslint expects the rule to be on rules[name], not rules[name].default
@@ -18,5 +19,6 @@ export = {
   rules: rulesWithoutDefault,
   configs: {
     recommended,
+    eslintRecommended,
   },
 };

packages/typescript-estree/README.md

@@ -66,7 +66,19 @@ Parses the given string of code with the options provided and returns an ESTree-
    * When value is `false`, no logging will occur.
    * When value is not provided, `console.log()` will be used.
    */
-  loggerFn: undefined
+  loggerFn: undefined,
+
+  /**
+   * Allows the user to control whether or not two-way AST node maps are preserved
+   * during the AST conversion process.
+   *
+   * By default: the AST node maps are NOT preserved, unless `project` has been specified,
+   * in which case the maps are made available on the returned `parserServices`.
+   *
+   * NOTE: If `preserveNodeMaps` is explicitly set by the user, it will be respected,
+   * regardless of whether or not `project` is in use.
+   */
+  preserveNodeMaps: undefined
 }
 ```
 

packages/typescript-estree/src/ast-converter.ts

@@ -7,7 +7,7 @@ import { Extra } from './parser-options';
 export default function astConverter(
   ast: ts.SourceFile,
   extra: Extra,
-  shouldProvideParserServices: boolean,
+  shouldPreserveNodeMaps: boolean,
 ) {
   /**
    * The TypeScript compiler produced fundamental parse errors when parsing the
@@ -23,7 +23,7 @@ export default function astConverter(
   const instance = new Converter(ast, {
     errorOnUnknownASTType: extra.errorOnUnknownASTType || false,
     useJSXTextNode: extra.useJSXTextNode || false,
-    shouldProvideParserServices,
+    shouldPreserveNodeMaps,
   });
 
   const estree = instance.convertProgram();
@@ -42,9 +42,7 @@ export default function astConverter(
     estree.comments = convertComments(ast, extra.code);
   }
 
-  const astMaps = shouldProvideParserServices
-    ? instance.getASTMaps()
-    : undefined;
+  const astMaps = shouldPreserveNodeMaps ? instance.getASTMaps() : undefined;
 
   return { estree, astMaps };
 }

packages/typescript-estree/src/convert.ts

@@ -26,7 +26,7 @@ const SyntaxKind = ts.SyntaxKind;
 interface ConverterOptions {
   errorOnUnknownASTType: boolean;
   useJSXTextNode: boolean;
-  shouldProvideParserServices: boolean;
+  shouldPreserveNodeMaps: boolean;
 }
 
 /**
@@ -168,7 +168,7 @@ export class Converter {
     node: ts.Node,
     result: TSESTree.BaseNode | null,
   ) {
-    if (result && this.options.shouldProvideParserServices) {
+    if (result && this.options.shouldPreserveNodeMaps) {
       if (!this.tsNodeToESTreeNodeMap.has(node)) {
         this.tsNodeToESTreeNodeMap.set(node, result);
       }
@@ -217,7 +217,7 @@ export class Converter {
       result.loc = getLocFor(result.range[0], result.range[1], this.ast);
     }
 
-    if (result && this.options.shouldProvideParserServices) {
+    if (result && this.options.shouldPreserveNodeMaps) {
       this.esTreeNodeToTSNodeMap.set(result, node);
     }
     return result as T;

packages/typescript-estree/src/parser-options.ts

@@ -18,6 +18,7 @@ export interface Extra {
   projects: string[];
   tsconfigRootDir: string;
   extraFileExtensions: string[];
+  preserveNodeMaps?: boolean;
 }
 
 export interface ParserOptions {
@@ -34,6 +35,7 @@ export interface ParserOptions {
   filePath?: string;
   tsconfigRootDir?: string;
   extraFileExtensions?: string[];
+  preserveNodeMaps?: boolean;
 }
 
 export interface ParserWeakMap<TKey, TValueBase> {

packages/typescript-estree/src/parser.ts

@@ -57,6 +57,7 @@ function resetExtra(): void {
     code: '',
     tsconfigRootDir: process.cwd(),
     extraFileExtensions: [],
+    preserveNodeMaps: undefined,
   };
 }
 
@@ -241,6 +242,18 @@ function applyParserOptionsToExtra(options: ParserOptions): void {
   ) {
     extra.extraFileExtensions = options.extraFileExtensions;
   }
+  /**
+   * Allow the user to enable or disable the preservation of the AST node maps
+   * during the conversion process.
+   *
+   * NOTE: For backwards compatibility we also preserve node maps in the case where `project` is set,
+   * and `preserveNodeMaps` is not explicitly set to anything.
+   */
+  extra.preserveNodeMaps =
+    typeof options.preserveNodeMaps === 'boolean' && options.preserveNodeMaps;
+  if (options.preserveNodeMaps === undefined && extra.projects.length > 0) {
+    extra.preserveNodeMaps = true;
+  }
 }
 
 function warnAboutTSVersion(): void {
@@ -372,11 +385,19 @@ export function parseAndGenerateServices<
     options,
     shouldProvideParserServices,
   );
+  /**
+   * Determine whether or not two-way maps of converted AST nodes should be preserved
+   * during the conversion process
+   */
+  const shouldPreserveNodeMaps =
+    extra.preserveNodeMaps !== undefined
+      ? extra.preserveNodeMaps
+      : shouldProvideParserServices;
   /**
    * Convert the TypeScript AST to an ESTree-compatible one, and optionally preserve
    * mappings between converted and original AST nodes
    */
-  const { estree, astMaps } = convert(ast, extra, shouldProvideParserServices);
+  const { estree, astMaps } = convert(ast, extra, shouldPreserveNodeMaps);
   /**
    * Even if TypeScript parsed the source code ok, and we had no problems converting the AST,
    * there may be other syntactic or semantic issues in the code that we can optionally report on.
@@ -395,11 +416,11 @@ export function parseAndGenerateServices<
     services: {
       program: shouldProvideParserServices ? program : undefined,
       esTreeNodeToTSNodeMap:
-        shouldProvideParserServices && astMaps
+        shouldPreserveNodeMaps && astMaps
           ? astMaps.esTreeNodeToTSNodeMap
           : undefined,
       tsNodeToESTreeNodeMap:
-        shouldProvideParserServices && astMaps
+        shouldPreserveNodeMaps && astMaps
           ? astMaps.tsNodeToESTreeNodeMap
           : undefined,
     },

packages/typescript-estree/src/tsconfig-parser.ts

@@ -89,7 +89,10 @@ export function calculateProjectParserOptions(
 
     if (typeof existingWatch !== 'undefined') {
       // get new program (updated if necessary)
-      results.push(existingWatch.getProgram().getProgram());
+      const updatedProgram = existingWatch.getProgram().getProgram();
+      updatedProgram.getTypeChecker(); // sets parent pointers in source files
+      results.push(updatedProgram);
+
       continue;
     }
 

packages/typescript-estree/tests/lib/convert.ts

@@ -18,7 +18,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect(instance.convertProgram()).toMatchSnapshot();
   });
@@ -29,7 +29,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect((instance as any).deeplyCopy(ast.statements[0])).toMatchSnapshot();
   });
@@ -40,7 +40,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect((instance as any).deeplyCopy(ast.statements[0])).toMatchSnapshot();
   });
@@ -51,7 +51,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect(
       (instance as any).deeplyCopy((ast.statements[0] as any).expression),
@@ -64,7 +64,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect((instance as any).deeplyCopy(ast)).toMatchSnapshot();
   });
@@ -75,7 +75,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: true,
       useJSXTextNode: false,
-      shouldProvideParserServices: false,
+      shouldPreserveNodeMaps: false,
     });
     expect(() => instance.convertProgram()).toThrow(
       'Unknown AST_NODE_TYPE: "TSJSDocNullableType"',
@@ -93,7 +93,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: true,
+      shouldPreserveNodeMaps: true,
     });
     instance.convertProgram();
     const maps = instance.getASTMaps();
@@ -127,7 +127,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: true,
+      shouldPreserveNodeMaps: true,
     });
     instance.convertProgram();
     const maps = instance.getASTMaps();
@@ -160,7 +160,7 @@ describe('convert', () => {
     const instance = new Converter(ast, {
       errorOnUnknownASTType: false,
       useJSXTextNode: false,
-      shouldProvideParserServices: true,
+      shouldPreserveNodeMaps: true,
     });
     const program = instance.convertProgram();
     const maps = instance.getASTMaps();