Add required option to input prompt (#1455)

Co-authored-by: Simon Boudrias <admin@simonboudrias.com>

packages/input/input.test.mts

@@ -154,6 +154,24 @@ describe('input prompt', () => {
     expect(getScreen()).toMatchInlineSnapshot(`"? What is your name Mikey"`);
   });
 
+  it('shows validation message if user did not provide any value', async () => {
+    const { answer, events, getScreen } = await render(input, {
+      message: `What's your favorite food?`,
+      required: true,
+    });
+
+    events.keypress('enter');
+    await Promise.resolve();
+    expect(getScreen()).toMatchInlineSnapshot(`
+      "? What's your favorite food?
+      > You must provide a value"
+    `);
+
+    events.type('Quinoa');
+    events.keypress('enter');
+    await expect(answer).resolves.toEqual('Quinoa');
+  });
+
   it('handle editing the answer (properly tracks cursor position)', async () => {
     const { answer, events, getScreen } = await render(input, {
       message: 'What is your name',

packages/input/src/index.mts

@@ -13,13 +13,14 @@ import type { PartialDeep } from '@inquirer/type';
 type InputConfig = {
   message: string;
   default?: string;
+  required?: boolean;
   transformer?: (value: string, { isFinal }: { isFinal: boolean }) => string;
   validate?: (value: string) => boolean | string | Promise<string | boolean>;
   theme?: PartialDeep<Theme>;
 };
 
 export default createPrompt<string, InputConfig>((config, done) => {
-  const { validate = () => true } = config;
+  const { required, validate = () => true } = config;
   const theme = makeTheme(config.theme);
   const [status, setStatus] = useState<string>('pending');
   const [defaultValue = '', setDefaultValue] = useState<string>(config.default);
@@ -38,7 +39,9 @@ export default createPrompt<string, InputConfig>((config, done) => {
     if (isEnterKey(key)) {
       const answer = value || defaultValue;
       setStatus('loading');
-      const isValid = await validate(answer);
+
+      const isValid =
+        required && !answer ? 'You must provide a value' : await validate(answer);
       if (isValid === true) {
         setValue(answer);
         setStatus('done');