egoist/poi

Breakpoints sometimes don't work in Chrome devtools until save

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#688 opened on May 3, 2020

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 (3 comments) (0 reactions) (0 assignees)JavaScript (5,251 stars) (324 forks)batch import
help wantednot-staletype: bug

Description

I'm having an intermittent problem in Chrome DevTools.

I can set a breakpoint and it sometimes it will, and sometimes it won't work.

I know it's the right file, because when I go back to my IDE and hit save, the page will reload, and the breakpoint will get hit.

It feels like some kind of caching issue; I will have to resave the file I am setting the breakpoint in for it to be caught.

I don't think I'm doing anything special, in this case, it's just a TypeScript model that is consumed by a component tree.

I've had various situations when it wasn't working; I'll update this ticket as I discover them.

Contributor guide

Tech stack
javascripttypescript
Domain
build systemtoolingdeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
basic understanding of source mapsfamiliarity with Chrome DevTools debuggingbasic knowledge of webpack bundling
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
Investigate the source map generation and caching behavior in the poi bundler. Check if the issue is related to how webpack dev server handles hot module replacement (HMR) and source maps. Look for existing discussions or PRs about breakpoint reliability, and consider testing with different source map settings (e.g., 'cheap module source map' vs 'source map'). The issue mentions that saving the file in the IDE triggers a page reload and makes breakpoints work, so focus on understanding the caching mechanism and whether the bundler correctly updates source maps on file changes.