#132 Override questions with prompts.override

lib/index.js

@@ -12,9 +12,17 @@ const noop = () => {};
  */
 async function prompt(questions=[], { onSubmit=noop, onCancel=noop }={}) {
   const answers = {};
+  const override = prompt._override || {};
   questions = [].concat(questions);
   let answer, question, quit, name, type;
 
+  const getFormattedAnswer = async (question, answer, skipValidation = false) => {
+    if (!skipValidation && question.validate && question.validate(answer) !== true) {
+      return;
+    }
+    return question.format ? await question.format(answer, answers) : answer
+  };
+
   for (question of questions) {
     ({ name, type } = question);
 
@@ -39,10 +47,18 @@ async function prompt(questions=[], { onSubmit=noop, onCancel=noop }={}) {
       throw new Error(`prompt type (${type}) is not defined`);
     }
 
+    if (override[question.name] !== undefined) {
+      answer = await getFormattedAnswer(question, override[question.name]);
+      if (answer !== undefined) {
+        answers[name] = answer;
+        continue;
+      }
+    }
+
     try {
       // Get the injected answer if there is one or prompt the user
       answer = prompt._injected ? getInjectedAnswer(prompt._injected) : await prompts[type](question);
-      answers[name] = answer = question.format ? await question.format(answer, answers) : answer;
+      answers[name] = answer = await getFormattedAnswer(question, answer, true);
       quit = await onSubmit(question, answer, answers);
     } catch (err) {
       quit = !(await onCancel(question, answers));
@@ -64,7 +80,11 @@ function getInjectedAnswer(injected) {
 }
 
 function inject(answers) {
-  prompt._injected = (prompt._injected || []).concat(answers)
+  prompt._injected = (prompt._injected || []).concat(answers);
+}
+
+function override(answers) {
+  prompt._override = Object.assign({}, answers);
 }
 
-module.exports = Object.assign(prompt, { prompt, prompts, inject });
+module.exports = Object.assign(prompt, { prompt, prompts, inject, override });

readme.md

@@ -207,6 +207,38 @@ let onCancel = prompt => {
 let response = await prompts(questions, { onCancel });
 ```
 
+### override
+
+Type: `Function`
+
+Preanswer questions by passing an object with answers to `prompts.override`.
+Powerful when combined with arguments of process.
+
+**Example**
+```js
+const prompts = require('prompts');
+prompts.override(require('yargs').argv);
+
+const response = await prompts([
+  {
+    type: 'text',
+    name: 'twitter',
+    message: `What's your twitter handle?`
+  },
+  {
+    type: 'multiselect',
+    name: 'color',
+    message: 'Pick colors',
+    choices: [
+      { title: 'Red', value: '#ff0000' },
+      { title: 'Green', value: '#00ff00' },
+      { title: 'Blue', value: '#0000ff' }
+    ],
+  }
+]);
+
+console.log(response);
+```
 
 ### inject(values)