Crash when piping output from node/nodemon web server about fzf

[junegunn]

Thanks for the repro. I can reproduce the problem, and it definitely looks like nodemon is trying to read user input. So nodemon and fzf are both competing to read from /dev/tty at the same time, and it causes the problems.

Workaround 1. Prevent nodemon from reading user input

By redirecting /dev/null to its standard input.

node_modules/nodemon/bin/nodemon.js index.js < /dev/null | fzf --ansi --tail 10000 --tac

The problem is nodemon doesn't terminate after fzf exits.

Workaround 2. Make fzf start the process

fzf --ansi --tail 10000 --tac --bind 'start:reload:node_modules/nodemon/bin/nodemon.js index.js'

fzf starts nodemon process when it starts, and can terminate it when it exits.

(Works better with 5b52833)

[junegunn]

Does node_modules/.bin/ts-node src/index.ts take user input from keyboard?

fzf crashes

Are there any error messages?

[hboon]

Does node_modules/.bin/ts-node src/index.ts take user input from keyboard?

No.

Are there any error messages?

No. So, at a loss what to do to debug. I could run the GitHub version again if there's a way to enable logging somewhere.

[junegunn]

Can you provide minimal steps to reproduce the problem from my side? I don't have your project with index.ts so there's no way I can further look into the problem. Also, please don't assume that I know anything about the thing called "ts-node".

[hboon]

Ah, sorry, I was hoping to look for a way to get debug logs so I can gather more information first. Thanks for helping to look into this.

I was wrong, it wasn't ts-node, but nodemon which reproduces the issue. From the tool's README:

Monitor for any changes in your node.js application and automatically restart the server - perfect for development

I made a repo to reproduce the issue for me — https://github.com/hboon/nodemon-fzf/. It's really just running nodemon or a single source file that logs 1 line to STDOUT. There are 2 branches. (B) should be easier to get started (but trust…).

A. main — you will need to have pnpm installed and run pnpm i first to install the nodemon that is causing this)
B. with-node-modules — this includes nodemon already so you can skip (A), and don't need to install pnpm

Run this:

node_modules/nodemon/bin/nodemon.js index.js | fzf

index.js only logs a line to STDOUT so I suppose it's the way nodemon works that's causing an issue?

I'm hoping to use fzf for streaming server logs during development.

[hboon]

Both workarounds work for me. I'll use (2). Doesn't seem like 5b52833 is needed yet.

But all good. Thanks again!