The latest updates on your projects. Learn more about Vercel for Git ↗︎

Thank you for your contribution! ❤️

You can try out this pull request locally by installing Rollup via

npm install rollup/rollup#fix/tweak-sourcemaps-merge

Notice: Ensure you have installed the latest stable Rust toolchain. If you haven't installed it yet, please see https://www.rust-lang.org/tools/install to learn how to download Rustup and install Rust.

or load it into the REPL:
https://rollup-o0kkk7jpm-rollup-js.vercel.app/repl/?pr=5985

Performance report

• BUILD: 7046ms, 789 MB (+4%)
  • initialize: 0ms, 24.6 MB
  • generate module graph: 2532ms (-141ms, -5.3%), 571 MB
    • generate ast: 1147ms (-46ms, -3.9%), 562 MB
  • sort and bind modules: 401ms, 618 MB
  • mark included statements: 4001ms (+80ms, +2.0%), 789 MB (+4%)
    • treeshaking pass 1: 2371ms (+86ms, +3.7%), 770 MB (+2%)
    • treeshaking pass 2: 459ms, 785 MB
    • treeshaking pass 3: 395ms, 775 MB (+2%)
    • treeshaking pass 4: 382ms, 783 MB
    • treeshaking pass 5: 380ms, 789 MB (+4%)
• GENERATE: 699ms, 1.04 GB
  • initialize render: 0ms, 894 MB
  • generate chunks: 58ms, 912 MB
    • optimize chunks: 0ms, 902 MB
  • render chunks: 621ms, 1 GB (+3%)
  • transform chunks: 16ms, 1.04 GB
  • generate bundle: 0ms, 1.04 GB

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.78%. Comparing base (5dcce11) to head (e77df78).
Report is 1 commits behind head on master.

@@           Coverage Diff           @@
##           master    #5985   +/-   ##
=======================================
  Coverage   98.78%   98.78%           
=======================================
  Files         270      270           
  Lines        8735     8745   +10     
  Branches     1510     1512    +2     
=======================================
+ Hits         8629     8639   +10     
  Misses         73       73           
  Partials       33       33           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

This PR has been released as part of rollup@4.44.0. You can test it via npm install rollup.

Not 100% sure there might be some performance impact but it looks reasonable to me to go with it.

We did notice a performance impact, I opened #6056 about it. I linked a repro repo with some measurements; in our real world case the build time increased from about 1 to about 2 minutes. This is caused by a huge 3rd party library that we bundle with our code. During our build, the traceSegment function is called about 16.5 million times, with an average of about 700k segments.

We will work around this by excluding the lib from sourcemap generation. I intend to open a PR to add a rollup option to support this (a bit like is done in this gist ); in the meantime we can work around the issue with patch-package.

Not 100% sure there might be some performance impact but it looks reasonable to me to go with it.

We did notice a performance impact, I opened #6056 about it. I linked a repro repo with some measurements; in our real world case the build time increased from about 1 to about 2 minutes. This is caused by a huge 3rd party library that we bundle with our code. During our build, the traceSegment function is called about 16.5 million times, with an average of about 700k segments.

We will work around this by excluding the lib from sourcemap generation. I intend to open a PR to add a rollup option to support this (a bit like is done in this gist ); in the meantime we can work around the issue with patch-package.

Thank you very much for reporting this performance regression — we didn’t expect it to have such a big impact. I’m thinking there might still be room for optimization in the fallback logic. If it really can’t be improved, I think we could consider reverting this commit or going with your suggestion to exclude minified JS files.