feat: add timeout option to prompt (Close #37) (#38)

README.md

@@ -41,6 +41,8 @@ Available options:
 | replace | Replace each character with the specified string when `silent` is true | string | '' |
 | input | Input stream to read from | [Stream](https://nodejs.org/api/process.html#process_process_stdin) | process.stdin |
 | output | Output stream to write to | [Stream](https://nodejs.org/api/process.html#process_process_stdout) | process.stdout |
+| timeout | Timeout in ms | number | 0 |
+| useDefaultOnTimeout | Return default value if timed out | boolean | false |
 
 The same **options** are available to **all functions** but with different default values.
 
@@ -103,6 +105,19 @@ The same **options** are available to **all functions** but with different defau
     })();
     ```
 
+- Ask for a name with timeout:
+
+    ```js
+    const promptly = require('promptly');
+
+    (async () => {
+        const name = await promptly.prompt('Name: ', { timeout: 3000 });
+        console.log(name);
+    })();
+    ```
+
+    It throws an `Error("timed out")` if timeout is reached and no default value is provided
+
 #### Validators
 
 The validators have two purposes: to check and transform input.

lib/getOptions.js

@@ -7,12 +7,14 @@ function getOptions(options) {
         retry: true,
         trim: true,
         default: undefined,
+        useDefaultOnTimeout: false,
 
         // `read` package options
         silent: false,
         replace: '',
         input: process.stdin,
         output: process.stdout,
+        timeout: 0,
 
         ...options,
     };

lib/prompt.js

@@ -5,14 +5,25 @@ const { promisify } = require('util');
 const read = promisify(require('read'));
 
 async function prompt(message, options) {
+    let value;
+
     // Read input
-    let value = await read({
-        prompt: message,
-        silent: options.silent,
-        replace: options.replace,
-        input: options.input,
-        output: options.output,
-    });
+    // Manage timeout
+    try {
+        value = await read({
+            prompt: message,
+            silent: options.silent,
+            replace: options.replace,
+            input: options.input,
+            output: options.output,
+            timeout: options.timeout,
+        });
+    } catch (err) {
+        if (err.message !== 'timed out' || options.default === undefined || !options.useDefaultOnTimeout) {
+            throw Object.assign(new Error(err.message), { code: 'TIMEDOUT' });
+        }
+        value = options.default;
+    }
 
     // Trim?
     if (options.trim) {

package.json

@@ -23,7 +23,7 @@
   ],
   "scripts": {
     "lint": "eslint .",
-    "test": "jest --env node --coverage",
+    "test": "jest --env node --coverage --runInBand",
     "prerelease": "npm t && npm run lint",
     "release": "standard-version",
     "postrelease": "git push --follow-tags origin HEAD && npm publish"

test/prompt.test.js

@@ -190,3 +190,21 @@ it('should write input using options.replace to stdout if silent is enabled', as
     expect(process.stdout.write).toHaveBeenCalledWith('a');
     expect(process.stdout.write).not.toHaveBeenCalledWith('z');
 });
+
+it('should timeout if user is not fast enough', async () => {
+    await expect(promptly.prompt('prompt: ', { timeout: 10 })).rejects.toEqual(new Error('timed out'));
+});
+
+it('should take default value if timed out with timeoutToDefault', async () => {
+    expect(await promptly.prompt('prompt: ', { timeout: 10, default: 'plop', useDefaultOnTimeout: true })).toEqual('plop');
+    expect(await promptly.prompt('prompt: ', { timeout: 10, default: '', useDefaultOnTimeout: true })).toEqual('');
+});
+
+it('should take default value if timed out', async () => {
+    await expect(promptly.prompt('prompt: ', { timeout: 10, default: 'plop' })).rejects.toEqual(new Error('timed out'));
+});
+
+it('should take input value if not timed out', async () => {
+    sendLine('plop2', 10);
+    expect(await promptly.prompt('prompt: ', { timeout: 20, default: 'plop' })).toEqual('plop2');
+});