stdin and stdout cannot be process.stdin or process.stdout..?

[busticated]

hi there 👋

thanks for the awesome lib 🙏

i ran into some odd behavior and i'm wondering what's up. using this script:

#!/usr/bin/env node

const Enquirer = require('enquirer');


(async () => {
	console.log(':::: Running repro script....');
	try {
		const stdin = process.stdin;
		const stdout = process.stdout;
		const enquirer = new Enquirer({ stdin, stdout });
		const answer = await enquirer.prompt({
			type: 'input',
			name: 'test',
			message: 'Type something...'
		});
		console.log(answer);
	} catch (error){
		console.error(':::: ERROR:', error);
		return process.exit(1);
	}
})();

...i get the following output:

:::: Running repro script....
:::: ERROR: RangeError: Maximum call stack size exceeded
    at Function.keys (<anonymous>)
    at Object.exports.mixin (/Users/me/test/node_modules/enquirer/lib/utils.js:193:26)
    at Object.exports.merge (/Users/me/test/node_modules/enquirer/lib/utils.js:215:33)
    at Object.exports.mixin (/Users/me/test/node_modules/enquirer/lib/utils.js:199:33)
    at Object.exports.merge (/Users/me/test/node_modules/enquirer/lib/utils.js:215:33)
    at Object.exports.mixin (/Users/me/test/node_modules/enquirer/lib/utils.js:199:33)
    at Object.exports.merge (/Users/me/test/node_modules/enquirer/lib/utils.js:215:33)
    at Object.exports.mixin (/Users/me/test/node_modules/enquirer/lib/utils.js:199:33)
    at Object.exports.merge (/Users/me/test/node_modules/enquirer/lib/utils.js:215:33)
    at Object.exports.mixin (/Users/me/test/node_modules/enquirer/lib/utils.js:199:33)

when i delete console.log(':::: Running repro script....');, i get:

(node:13715) UnhandledPromiseRejectionWarning: TypeError: stream.listenerCount is not a function
    at emitKeypressEvents (readline.js:1165:14)
    at new Interface (readline.js:241:5)
    at Object.createInterface (readline.js:92:10)
    at Function.keypress.listen (/Users/me/test/node_modules/enquirer/lib/keypress.js:202:21)
    at Input.start (/Users/me/test/node_modules/enquirer/lib/prompt.js:180:28)
    at Input.initialize (/Users/me/test/node_modules/enquirer/lib/prompt.js:220:16)
    at /Users/me/test/node_modules/enquirer/lib/prompt.js:236:18

when i don't pass in stdin (e.g. new Enquirer({ stdout });), i get:

(node:13725) UnhandledPromiseRejectionWarning: TypeError: this.stdout.write is not a function
    at Input.cursorHide (/Users/me/test/node_modules/enquirer/lib/prompt.js:59:17)
    at module.exports (/Users/me/test/node_modules/enquirer/lib/placeholder.js:19:10)
    at Input.format (/Users/me/test/node_modules/enquirer/lib/types/string.js:156:14)
    at async Input.render (/Users/me/test/node_modules/enquirer/lib/types/string.js:172:18)
    at async Input.initialize (/Users/me/test/node_modules/enquirer/lib/prompt.js:221:5)
    at async /Users/me/test/node_modules/enquirer/lib/prompt.js:236:7

...and the process hangs until i press CTRL+C.

ultimately, i'm trying to wrap enquirer such that a series of ui helpers all use the same stdin, stdout, and stderr in order to make testing easier, etc.

my env info:

• macOS v10.15.6
• Node v12.18.3
• Enquirer v2.3.6

[doowb]

Hi @busticated and thanks for the issue.

It looks like the merge/mixin logic here needs to take into account that existing.value and desc.value may already be the same object.

Changing the if expression to the following seems to fix it (your repro works and the tests still pass):

if (isObject(existing.value) && existing.value !== desc.value) { ... }

A PR with this change is welcome, otherwise, someone here will try to get it fixed as soon as possible. In the meantime, are you able to write your tests without passing the stdin and stdout into Enquirer?

//edit: btw... huge fan of Particle 😀 ... I participated in the original Spark kickstarter, but haven't actively kept up with the latest changes, but looking through the GitHub org, it's great to see all of the Node.js packages.

[busticated]

hi @doowb 👋 thanks for taking a look 🙏

Changing the if expression to the following seems to fix it

yep, that seems to do it - i threw together a PR over here 👉 #309 - all feedback welcome.

btw... huge fan of Particle 😀

awesome! sent ya an email 😁