Add support for default value

packages/core/index.js

@@ -78,7 +78,7 @@ class StateManager {
     }
 
     this.setState({ value: this.rl.line, error: null });
-    onKeypress(value, key, this.getState(), this.setState);
+    onKeypress(this.rl.line, key, this.getState(), this.setState);
   }
 
   startLoading() {
@@ -95,7 +95,15 @@ class StateManager {
   }
 
   async onSubmit() {
-    const { validate, filter, value } = this.getState();
+    const state = this.getState();
+    const { validate, filter, default: defaultValue } = state;
+
+    // If no answer was provided, use default value.
+    let { value } = state;
+    if (!value) {
+      value = defaultValue;
+    }
+
     const showLoader = setTimeout(this.startLoading, 500);
     this.rl.pause();
     try {

packages/core/test.js

@@ -258,7 +258,7 @@ describe('createPrompt()', () => {
     rl.input.emit('keypress', 'a value', { name: 'foo' });
     expect(onKeypress).toHaveBeenCalledTimes(1);
     expect(onKeypress).toHaveBeenLastCalledWith(
-      'a value',
+      'new value',
       { name: 'foo' },
       expect.objectContaining({
         message: 'Question',

packages/input/__snapshots__/test.js.snap

@@ -3,3 +3,9 @@
 exports[`Input prompt renders in done state 1`] = `"? Question: answer"`;
 
 exports[`Input prompt renders in idle state 1`] = `"? Question: answer"`;
+
+exports[`Input prompt supports defaults 1`] = `"? Question: (foo) "`;
+
+exports[`Input prompt supports defaults 2`] = `"? Question: "`;
+
+exports[`Input prompt supports defaults 3`] = `"? Question: bar"`;

packages/input/demo.js

@@ -17,7 +17,7 @@ const isHex = value =>
     },
     validate: value => isHex(value) || 'Pass a valid hex value'
   });
-  console.log('Answer: ', answer);
+  console.log('Answer:', answer);
 
   answer = await input({
     message: '(Slow validation) provide a number:',
@@ -33,13 +33,19 @@ const isHex = value =>
         );
       })
   });
-  console.log('Answer: ', answer);
+  console.log('Answer:', answer);
 
   answer = await input({
     message: () =>
       new Promise(resolve => {
         setTimeout(() => resolve('(Slow message) Input any value:'), 3000);
       })
   });
-  console.log('Answer: ', answer);
+  console.log('Answer:', answer);
+
+  answer = await input({
+    message: "What's your favorite food?",
+    default: 'Croissant'
+  });
+  console.log('Answer:', answer);
 })();

packages/input/index.js

@@ -1,11 +1,31 @@
 const { createPrompt } = require('@inquirer/core');
 const chalk = require('chalk');
 
-module.exports = createPrompt({}, state => {
-  const { prefix, message, value, status } = state;
-  let formattedValue = value;
-  if (status === 'done') {
-    formattedValue = chalk.cyan(value);
+module.exports = createPrompt(
+  {
+    canRemoveDefault: true,
+    onKeypress: (value, key, { canRemoveDefault }, setState) => {
+      const newState = { canRemoveDefault: !value };
+
+      // Allow user to remove the default value by pressing backspace
+      if (canRemoveDefault && key.name === 'backspace') {
+        newState.default = undefined;
+      }
+      setState(newState);
+    }
+  },
+  state => {
+    const { prefix, message, value = '', status } = state;
+    let formattedValue = value;
+    if (status === 'done') {
+      formattedValue = chalk.cyan(value);
+    }
+
+    let defaultValue = '';
+    if (state.default && status !== 'done' && !value) {
+      defaultValue = chalk.dim(` (${state.default})`);
+    }
+
+    return `${prefix} ${message}${defaultValue} ${formattedValue}`;
   }
-  return `${prefix} ${message} ${formattedValue}`;
-});
+);

packages/input/test.js

@@ -20,4 +20,58 @@ describe('Input prompt', () => {
     });
     expect(output).toMatchSnapshot();
   });
+
+  it('supports defaults', () => {
+    const withDefault = Input.render({
+      prefix: '?',
+      message: 'Question:',
+      default: 'foo',
+      status: 'idle'
+    });
+    expect(withDefault).toMatchSnapshot();
+    expect(withDefault).toContain('foo');
+
+    const whenDone = Input.render({
+      prefix: '?',
+      message: 'Question:',
+      default: 'foo',
+      status: 'done'
+    });
+    expect(whenDone).toMatchSnapshot();
+    expect(whenDone).not.toContain('foo');
+
+    const withAnswer = Input.render({
+      prefix: '?',
+      message: 'Question:',
+      default: 'foo',
+      value: 'bar',
+      status: 'done'
+    });
+    expect(withAnswer).toMatchSnapshot();
+    expect(withAnswer).toContain('bar');
+    expect(withAnswer).not.toContain('foo');
+  });
+
+  it('handles keypress', () => {
+    const setState = jest.fn();
+    const backspace = { name: 'backspace' };
+
+    // Allow removing the default value
+    Input.config.onKeypress('', backspace, { canRemoveDefault: true }, setState);
+    expect(setState).toHaveBeenLastCalledWith({
+      default: undefined,
+      canRemoveDefault: true
+    });
+
+    // Doesn't allow removing if there's a value
+    Input.config.onKeypress('a', backspace, { canRemoveDefault: true }, setState);
+    expect(setState).toHaveBeenLastCalledWith({
+      canRemoveDefault: false
+    });
+
+    Input.config.onKeypress('', backspace, { canRemoveDefault: false }, setState);
+    expect(setState).toHaveBeenLastCalledWith({
+      canRemoveDefault: true
+    });
+  });
 });