fix(typescript-estree): improve missing project file error msg (#866)

Fixes #853

Author: bradzacher

packages/eslint-plugin/tests/rules/no-unnecessary-type-assertion.test.ts

@@ -99,12 +99,6 @@ foo(str!);
     `
 declare function a(a: string): any;
 declare const b: string | null;
-class Mx {
-  @a(b!)
-  private prop = 1;
-}
-    `,
-    `
 class Mx {
   @a(b!)
   private prop = 1;

packages/eslint-plugin/tests/rules/restrict-plus-operands.test.ts

@@ -26,37 +26,37 @@ ruleTester.run('restrict-plus-operands', rule, {
     `var foo = BigInt(1) + 1n`,
     `var foo = 1n; foo + 2n`,
     `
-function test () : number { return 2; }
+function test(s: string, n: number) : number { return 2; }
 var foo = test("5.5", 10) + 10;
-            `,
+    `,
     `
 var x = 5;
 var z = 8.2;
 var foo = x + z;
-            `,
+    `,
     `
 var w = "6.5";
 var y = "10";
 var foo = y + w;
-            `,
+    `,
     'var foo = 1 + 1;',
     "var foo = '1' + '1';",
     `
 var pair: { first: number, second: string } = { first: 5, second: "10" };
 var foo = pair.first + 10;
-            `,
+    `,
     `
 var pair: { first: number, second: string } = { first: 5, second: "10" };
 var foo = pair.first + (10 as number);
-            `,
+    `,
     `
 var pair: { first: number, second: string } = { first: 5, second: "10" };
 var foo = "5.5" + pair.second;
-            `,
+    `,
     `
 var pair: { first: number, second: string } = { first: 5, second: "10" };
 var foo = ("5.5" as string) + pair.second;
-            `,
+    `,
     `const foo = 'hello' + (someBoolean ? 'a' : 'b') + (() => someBoolean ? 'c' : 'd')() + 'e';`,
     `const balls = true;`,
     `balls === true;`,

packages/parser/README.md

@@ -52,25 +52,30 @@ The following additional configuration options are available by specifying them
 
   - Note that if this setting is specified and `createDefaultProgram` is not, you must only lint files that are included in the projects as defined by the provided `tsconfig.json` files. If your existing configuration does not include all of the files you would like to lint, you can create a separate `tsconfig.eslint.json` as follows:
 
-  ```ts
-  {
-    "extends": "./tsconfig.json", // path to existing tsconfig
-    "include": [
-      "src/**/*.ts",
-      "test/**/*.ts",
-      // etc
-    ]
-  }
-  ```
+    ```ts
+    {
+      // extend your base config so you don't have to redefine your compilerOptions
+      "extends": "./tsconfig.json",
+      "include": [
+        "src/**/*.ts",
+        "test/**/*.ts",
+        "typings/**/*.ts",
+        // etc
+
+        // if you have a mixed JS/TS codebase, don't forget to include your JS files
+        "src/**/*.js"
+      ]
+    }
+    ```
 
 - **`tsconfigRootDir`** - default `undefined`. This option allows you to provide the root directory for relative tsconfig paths specified in the `project` option above.
 
-- **`createDefaultProgram`** - default `false`. This option allows you to request that when the `project` setting is specified, files will be allowed when not included in the projects defined by the provided `tsconfig.json` files. However, this may incur significant performance costs, so this option is primarily included for backwards-compatibility. See the **`project`** section for more information.
-
 - **`extraFileExtensions`** - default `undefined`. This option allows you to provide one or more additional file extensions which should be considered in the TypeScript Program compilation. E.g. a `.vue` file
 
 - **`warnOnUnsupportedTypeScriptVersion`** - default `true`. This option allows you to toggle the warning that the parser will give you if you use a version of TypeScript which is not explicitly supported
 
+- **`createDefaultProgram`** - default `false`. This option allows you to request that when the `project` setting is specified, files will be allowed when not included in the projects defined by the provided `tsconfig.json` files. **Using this option will incur significant performance costs. This option is primarily included for backwards-compatibility.** See the **`project`** section above for more information.
+
 ### .eslintrc.json
 
 ```json

packages/typescript-estree/jest.config.js

@@ -10,4 +10,12 @@ module.exports = {
   collectCoverageFrom: ['src/**/*.{js,jsx,ts,tsx}'],
   moduleFileExtensions: ['ts', 'tsx', 'js', 'jsx', 'json', 'node'],
   coverageReporters: ['text-summary', 'lcov'],
+  globals: {
+    'ts-jest': {
+      diagnostics: {
+        // ignore the diagnostic error for the invalidFileErrors fixtures
+        ignoreCodes: [5056],
+      },
+    },
+  },
 };

packages/typescript-estree/src/convert.ts

@@ -67,7 +67,7 @@ export class Converter {
    */
   constructor(ast: ts.SourceFile, options: ConverterOptions) {
     this.ast = ast;
-    this.options = options;
+    this.options = { ...options };
   }
 
   getASTMaps(): ASTMaps {

packages/typescript-estree/src/parser.ts

@@ -1,3 +1,4 @@
+import path from 'path';
 import semver from 'semver';
 import * as ts from 'typescript'; // leave this as * as ts so people using util package don't need syntheticDefaultImports
 import { astConverter } from './ast-converter';
@@ -9,6 +10,7 @@ import { TSESTree } from './ts-estree';
 import {
   calculateProjectParserOptions,
   createProgram,
+  defaultCompilerOptions,
 } from './tsconfig-parser';
 
 /**
@@ -87,9 +89,39 @@ function getASTFromProject(
   );
 
   if (!astAndProgram && !createDefaultProgram) {
-    throw new Error(
-      `If "parserOptions.project" has been set for @typescript-eslint/parser, ${filePath} must be included in at least one of the projects provided.`,
-    );
+    // the file was either not matched within the tsconfig, or the extension wasn't expected
+    const errorLines = [
+      '"parserOptions.project" has been set for @typescript-eslint/parser.',
+      `The file does not match your project config: ${filePath}.`,
+    ];
+    let hasMatchedAnError = false;
+
+    const fileExtension = path.extname(filePath);
+    if (!['.ts', '.tsx', '.js', '.jsx'].includes(fileExtension)) {
+      const nonStandardExt = `The extension for the file (${fileExtension}) is non-standard`;
+      if (extra.extraFileExtensions && extra.extraFileExtensions.length > 0) {
+        if (!extra.extraFileExtensions.includes(fileExtension)) {
+          errorLines.push(
+            `${nonStandardExt}. It should be added to your existing "parserOptions.extraFileExtensions".`,
+          );
+          hasMatchedAnError = true;
+        }
+      } else {
+        errorLines.push(
+          `${nonStandardExt}. You should add "parserOptions.extraFileExtensions" to your config.`,
+        );
+        hasMatchedAnError = true;
+      }
+    }
+
+    if (!hasMatchedAnError) {
+      errorLines.push(
+        'The file must be included in at least one of the projects provided.',
+      );
+      hasMatchedAnError = true;
+    }
+
+    throw new Error(errorLines.join('\n'));
   }
 
   return astAndProgram;
@@ -158,6 +190,7 @@ function createNewProgram(code: string): ASTAndProgram {
       noResolve: true,
       target: ts.ScriptTarget.Latest,
       jsx: extra.jsx ? ts.JsxEmit.Preserve : undefined,
+      ...defaultCompilerOptions,
     },
     compilerHost,
   );

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

@@ -9,9 +9,10 @@ import { Extra } from './parser-options';
 /**
  * Default compiler options for program generation from single root file
  */
-const defaultCompilerOptions: ts.CompilerOptions = {
+export const defaultCompilerOptions: ts.CompilerOptions = {
   allowNonTsExtensions: true,
   allowJs: true,
+  checkJs: true,
 };
 
 /**
@@ -109,7 +110,7 @@ export function calculateProjectParserOptions(
     // create compiler host
     const watchCompilerHost = ts.createWatchCompilerHost(
       tsconfigPath,
-      /*optionsToExtend*/ { allowNonTsExtensions: true } as ts.CompilerOptions,
+      defaultCompilerOptions,
       ts.sys,
       ts.createSemanticDiagnosticsBuilderProgram,
       diagnosticReporter,

packages/typescript-estree/tests/fixtures/invalidFileErrors/js/included.js

@@ -0,0 +1 @@
+export var a = true;

packages/typescript-estree/tests/fixtures/invalidFileErrors/js/included.jsx

@@ -0,0 +1 @@
+export var a = true;

packages/typescript-estree/tests/fixtures/invalidFileErrors/js/notIncluded.js

@@ -0,0 +1 @@
+export var a = true;