Chore(dev-deps) Bump typescript-eslint to v8

eslint.config.js

@@ -41,7 +41,17 @@ export default tseslint.config(
   },
   {
     files: ['**/*.mts', '**/*.ts'],
-    extends: [...tseslint.configs.recommended],
+    extends: [...tseslint.configs.recommendedTypeChecked],
+    languageOptions: {
+      parserOptions: {
+        projectService: {
+          allowDefaultProject: ['packages/*/*.test.mts'],
+          defaultProject: './tsconfig.test.json',
+          maximumDefaultProjectFileMatchCount_THIS_WILL_SLOW_DOWN_LINTING: 20,
+        },
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
   },
   {
     files: ['**/*.cjs'],
@@ -55,6 +65,7 @@ export default tseslint.config(
   {
     files: ['packages/inquirer/test/**', 'packages/**/*.test.*'],
     rules: {
+      '@typescript-eslint/unbound-method': 'off',
       'n/no-extraneous-import': [
         'error',
         {

package.json

@@ -68,7 +68,7 @@
     "ts-node": "^10.9.2",
     "turbo": "^2.0.11",
     "typescript": "^5.5.4",
-    "typescript-eslint": "^7.18.0",
+    "typescript-eslint": "^8.0.0",
     "vitest": "^2.0.5"
   },
   "resolutions": {

packages/checkbox/src/index.mts

@@ -186,7 +186,7 @@ export default createPrompt(
           return ` ${item.separator}`;
         }
 
-        const line = item.name || item.value;
+        const line = String(item.name || item.value);
         if (item.disabled) {
           const disabledLabel =
             typeof item.disabled === 'string' ? item.disabled : '(disabled)';

packages/core/core.test.mts

@@ -579,6 +579,7 @@ describe('Error handling', () => {
   it('prevent returning promises from useEffect hook', async () => {
     const Prompt = (_config: object, done: (value: string) => void) => {
       // @ts-expect-error: Testing an invalid behavior.
+      // eslint-disable-next-line @typescript-eslint/require-await
       useEffect(async () => {
         done('done');
       }, []);
@@ -595,7 +596,7 @@ describe('Error handling', () => {
     await expect(answer).rejects.toBeInstanceOf(ValidationError);
   });
 
-  it('useEffect throws outside prompt', async () => {
+  it('useEffect throws outside prompt', () => {
     expect(() => {
       useEffect(() => {}, []);
     }).toThrowErrorMatchingInlineSnapshot(
@@ -606,7 +607,7 @@ describe('Error handling', () => {
     }).toThrow(HookError);
   });
 
-  it('useKeypress throws outside prompt', async () => {
+  it('useKeypress throws outside prompt', () => {
     expect(() => {
       useKeypress(() => {});
     }).toThrowErrorMatchingInlineSnapshot(

packages/core/src/lib/pagination/lines.test.mts → packages/core/lines.test.mts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { lines } from './lines.mjs';
+import { lines } from './src/lib/pagination/lines.mjs';
 
 function renderResult(result: string[]) {
   return `\n${result.join('\n')}\n`;

packages/core/src/lib/hook-engine.mts

@@ -63,10 +63,10 @@ export function readline(): InquirerReadline {
 }
 
 // Merge state updates happening within the callback function to avoid multiple renders.
-export function withUpdates<T extends (...args: any) => any>(
+export function withUpdates<R, T extends (...args: any[]) => R>(
   fn: T,
-): (...args: Parameters<T>) => ReturnType<T> {
-  const wrapped = (...args: any): ReturnType<T> => {
+): (...args: Parameters<T>) => R {
+  const wrapped = (...args: Parameters<T>): R => {
     const store = getStore();
     let shouldUpdate = false;
     const oldHandleChange = store.handleChange;
@@ -105,10 +105,10 @@ export function withPointer<Value, ReturnValue>(
 
   const { index } = store;
   const pointer: Pointer<Value> = {
-    get() {
+    get(): any {
       return store.hooks[index];
     },
-    set(value: any) {
+    set(value: unknown) {
       store.hooks[index] = value;
     },
     initialized: index in store.hooks,

packages/core/src/lib/make-theme.mts

@@ -4,7 +4,7 @@ import { defaultTheme, type Theme } from './theme.mjs';
 function isPlainObject(value: unknown): value is object {
   if (typeof value !== 'object' || value === null) return false;
 
-  let proto = value;
+  let proto: unknown = value;
   while (Object.getPrototypeOf(proto) !== null) {
     proto = Object.getPrototypeOf(proto);
   }

packages/core/src/lib/use-keypress.mts

@@ -5,7 +5,7 @@ import { useEffect } from './use-effect.mjs';
 import { withUpdates } from './hook-engine.mjs';
 
 export function useKeypress(
-  userHandler: (event: KeypressEvent, rl: InquirerReadline) => void,
+  userHandler: (event: KeypressEvent, rl: InquirerReadline) => void | Promise<void>,
 ) {
   const signal = useRef(userHandler);
   signal.current = userHandler;
@@ -14,7 +14,7 @@ export function useKeypress(
     let ignore = false;
     const handler = withUpdates((_input: string, event: KeypressEvent) => {
       if (ignore) return;
-      signal.current(event, rl);
+      void signal.current(event, rl);
     });
 
     rl.input.on('keypress', handler);

packages/core/src/lib/use-state.mts

@@ -1,7 +1,6 @@
 import { withPointer, handleChange } from './hook-engine.mjs';
 
-// eslint-disable-next-line @typescript-eslint/ban-types
-type NotFunction<T> = T extends Function ? never : T;
+type NotFunction<T> = T extends (...args: never) => unknown ? never : T;
 
 export function useState<Value>(
   defaultValue: NotFunction<Value> | (() => Value),

packages/editor/editor.test.mts

@@ -13,7 +13,10 @@ async function editorAction(error: undefined | Error, value?: string) {
   if (!lastCall) throw new Error("editor wasn't open");
 
   // Bugfix: The callback error value is nullable.
-  const editCallback = lastCall[1] as (error: undefined | Error, value: string) => void;
+  const editCallback = lastCall[1] as (
+    error: undefined | Error,
+    value: string,
+  ) => void | Promise<void>;
   await editCallback(error, value ?? '');
 }
 

packages/editor/src/index.mts

@@ -22,7 +22,7 @@ type EditorConfig = {
 };
 
 export default createPrompt<string, EditorConfig>((config, done) => {
-  const { waitForUseInput = true, validate = () => true } = config;
+  const { waitForUseInput = true, postfix = '.txt', validate = () => true } = config;
   const theme = makeTheme(config.theme);
 
   const [status, setStatus] = useState<string>('pending');
@@ -34,31 +34,28 @@ export default createPrompt<string, EditorConfig>((config, done) => {
 
   function startEditor(rl: InquirerReadline) {
     rl.pause();
-    editAsync(
-      value,
-      // Note: The bind call isn't strictly required. But we need it for our mocks to work as expected.
-      AsyncResource.bind(async (error, answer) => {
-        rl.resume();
-        if (error) {
-          setError(error.toString());
+
+    // Note: The bind call isn't strictly required. But we need it for our mocks to work as expected.
+    const editCallback = AsyncResource.bind(async (error: Error, answer: string) => {
+      rl.resume();
+      if (error) {
+        setError(error.toString());
+      } else {
+        setStatus('loading');
+        const isValid = await validate(answer);
+        if (isValid === true) {
+          setError(undefined);
+          setStatus('done');
+          done(answer);
         } else {
-          setStatus('loading');
-          const isValid = await validate(answer);
-          if (isValid === true) {
-            setError(undefined);
-            setStatus('done');
-            done(answer);
-          } else {
-            setValue(answer);
-            setError(isValid || 'You must provide a valid value');
-            setStatus('pending');
-          }
+          setValue(answer);
+          setError(isValid || 'You must provide a valid value');
+          setStatus('pending');
         }
-      }),
-      {
-        postfix: config.postfix || '.txt',
-      },
-    );
+      }
+    });
+
+    editAsync(value, (error, answer) => void editCallback(error, answer), { postfix });
   }
 
   useEffect((rl) => {

packages/inquirer/test/inquirer.test.mts → packages/inquirer/inquirer.test.mts

@@ -10,11 +10,11 @@ import tty from 'node:tty';
 import { vi, expect, beforeEach, afterEach, describe, it, expectTypeOf } from 'vitest';
 import { Observable } from 'rxjs';
 import type { InquirerReadline } from '@inquirer/type';
-import inquirer, { type QuestionMap } from '../src/index.mjs';
-import type { Answers, Question } from '../src/types.mjs';
-import { _ } from '../src/ui/prompt.mjs';
+import inquirer, { type QuestionMap } from './src/index.mjs';
+import type { Answers, Question } from './src/types.mjs';
+import { _ } from './src/ui/prompt.mjs';
 
-declare module '../src/index.mjs' {
+declare module './src/index.mjs' {
   interface QuestionMap {
     stub: { answer?: string | boolean; message: string };
     stub2: { answer?: string | boolean; message: string; default: string };
@@ -43,7 +43,7 @@ class StubPrompt {
 
 class StubFailingPrompt {
   run() {
-    return Promise.reject('This test prompt always reject');
+    return Promise.reject(new Error('This test prompt always reject'));
   }
 
   close() {}
@@ -635,13 +635,14 @@ describe('inquirer.prompt(...)', () => {
 
     it('should not run prompt if answer exists for question', async () => {
       const answers = await inquirer.prompt(
+        // @ts-expect-error Passing wrong type on purpose.
         [
           {
             type: 'input',
             name: 'prefilled',
-            when: throwFunc.bind(undefined, 'when') as any,
-            validate: throwFunc.bind(undefined, 'validate') as any,
-            transformer: throwFunc.bind(undefined, 'transformer') as any,
+            when: throwFunc.bind(undefined, 'when'),
+            validate: throwFunc.bind(undefined, 'validate'),
+            transformer: throwFunc.bind(undefined, 'transformer'),
             message: 'message',
             default: 'newValue',
           },
@@ -654,13 +655,14 @@ describe('inquirer.prompt(...)', () => {
 
     it('should not run prompt if nested answer exists for question', async () => {
       const answers = await inquirer.prompt(
+        // @ts-expect-error Passing wrong type on purpose.
         [
           {
             type: 'input',
             name: 'prefilled.nested',
-            when: throwFunc.bind(undefined, 'when') as any,
-            validate: throwFunc.bind(undefined, 'validate') as any,
-            transformer: throwFunc.bind(undefined, 'transformer') as any,
+            when: throwFunc.bind(undefined, 'when'),
+            validate: throwFunc.bind(undefined, 'validate'),
+            transformer: throwFunc.bind(undefined, 'transformer'),
             message: 'message',
             default: 'newValue',
           },
@@ -741,7 +743,7 @@ describe('inquirer.prompt(...)', () => {
   });
 
   describe('#restoreDefaultPrompts()', () => {
-    it('restore default prompts', async () => {
+    it('restore default prompts', () => {
       class StubPrompt {
         run = vi.fn(() => {
           return Promise.resolve('bar');
@@ -891,6 +893,8 @@ describe('Non-TTY checks', () => {
 });
 
 describe('set utility function tests', () => {
+  /* eslint-disable @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-unsafe-member-access */
+
   it('Should set an objects property when provided a path and a value', () => {
     const obj: any = {};
     const path = 'a.b';
@@ -931,4 +935,6 @@ describe('set utility function tests', () => {
 
     expect(obj.a.b).toBe('c');
   });
+
+  /* eslint-enable @typescript-eslint/no-unsafe-argument, @typescript-eslint/no-unsafe-member-access */
 });

packages/inquirer/src/index.mts

@@ -49,11 +49,9 @@ const defaultPrompts: PromptCollection = {
   search,
 };
 
-type PromptReturnType<T> =
-  | (Promise<Prettify<T>> & {
-      ui: PromptsRunner<Prettify<T>>;
-    })
-  | never;
+type PromptReturnType<T> = Promise<Prettify<T>> & {
+  ui: PromptsRunner<Prettify<T>>;
+};
 
 /**
  * Create a new self-contained prompt module.
@@ -98,6 +96,7 @@ export function createPromptModule(opt?: StreamOptions) {
     try {
       return runner.run(questions, answers);
     } catch (error) {
+      // eslint-disable-next-line @typescript-eslint/prefer-promise-reject-errors
       const promise = Promise.reject(error);
       return Object.assign(promise, { ui: runner });
     }

packages/inquirer/src/types.mts

@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import {
+import type {
   input,
   select,
   number,
@@ -75,13 +75,13 @@ type PromptConfigMap<A extends Answers> = {
 
 export type Question<A extends Answers> = PromptConfigMap<A>[keyof PromptConfigMap<A>];
 
-export type QuestionAnswerMap<A extends Answers> =
-  | Readonly<{ [name in KeyUnion<A>]: Omit<Question<A>, 'name'> }>
-  | never;
+export type QuestionAnswerMap<A extends Answers> = Readonly<{
+  [name in KeyUnion<A>]: Omit<Question<A>, 'name'>;
+}>;
 
-export type QuestionArray<A extends Answers> = readonly Question<A>[] | never;
+export type QuestionArray<A extends Answers> = readonly Question<A>[];
 
-export type QuestionObservable<A extends Answers> = Observable<Question<A>> | never;
+export type QuestionObservable<A extends Answers> = Observable<Question<A>>;
 
 export type StreamOptions = Prettify<
   Parameters<typeof input>[1] & { skipTTYChecks?: boolean }