Express + Pry is Laggy

[bayleedev]

Original Comment

Using express with pry causes it to be unresponsive and difficult to use.

import pry from 'pryjs'

// Ping
router.get('/ping', (req, res) => {
  eval(pry.it)
  res.json({ status:'UP' });
});

[zlwaterfield]

Hey @blainesch any movement on this issue?

[bayleedev]

No movement, feel free to take a stab at it. I don't have any leads as of yet.

[zlwaterfield]

@blainesch all good, after some digging here is what I have found. There are actually two issues I am seeing:

1. Laggy in express - I tested this on a small express project and there lag is not present. This leads me to believe it has to do with the large size of my project. Maybe there is somewhere that all files/lines are being looped over causing a latency after each keydown

2. The incorrect line number is being used so the whereami is incorrect. - The command.coffee file that finds the file and line number using the error stack @stack = new Error().stack and this is return a line number much higher than the actual. This is because I am using babel-watch. But the weird thing is the find_file returns the line number is from the compiled ES6 and file location/ file content from the uncompiled ES6 code.

The laggy behaviour seems to be improved when the line number is correct (tested by hard coding the line number). Any ideas on where to continue from here?

Update: The on data event is not triggering for every keypress so its not a lag its the event is only hitting every couple keypresses. this.options.stdin.on('data', this.keypress); https://github.com/blainesch/pry.js/blob/master/src/pry/sync_prompt.coffee#L60.

[bayleedev]

Interesting find. I wonder why it's not being triggered sometimes.