[Performance regression] Performance regression in Typescript 5.1 on large files

[moufmouf]

🔎 Search Terms

performance regression, Typescript 5.1

🕗 Version & Regression Information

• This changed between versions 5.0.4 and 5.1
• This changed in commit 511921e1e205f52304559a35e58e16eb9213ecb3 (detected via every-ts)
• This is the behavior in every version I tried after 5.1, including the latest 5.6 version

⏯ Playground Link

https://github.com/moufmouf/typescript-perf-issue

💻 Code

See Github repo for the code sample (the issue is that very big files take wayyyyy longer to be analyzed)

🙁 Actual behavior

The issue is that the compilation time of some very large files (22k lines) has increased significantly between v5.0 and v5.1 (and is still very long in the latest 5.6 release)

The file I'm trying to compile is 22k lines long.

Compilation time in v5.0: 6s. Compilation time in v5.1: 110s.

This is a 18x increase.

I generated trace files but I don't know how to interpret them.

Tracefile for 5.0: traceDir_5.0.log Tracefile for 5.1: traceDir_5.1.log

🙂 Expected behavior

The analysis time would not greatly differ between 5.0 and recent releases.

Additional information about the issue

The file that is suddenly taking very long to analyze was generated using ts-proto.

I could perfectly disable the analysis for this file (since it was autogenerated) but there is probably an underlying issue.

For the record, the original file comes from the WorkAdventure project (https://github.com/workadventure/workadventure)

[s3xysteak]

After updating to vscode@1.95, the Typescript IntelliSense is so slow😥. I'm not sure is that related to this issue.

[jakebailey]

@s3xysteak TypeScript 5.1 was ages ago. If things got slower when updating to this month's VS Code version, your issue is definitely not this issue.