Opening/editing project file causes 100% CPU usage by tsserver

[pqvst]

• VSCode Version: 1.31.0-insider (1.31.0-insider) (also tested in latest non-insider release)
• OS Version: macOS 10.14.2 (18C54)

Steps to Reproduce:

1. Clone this repo: https://github.com/pqvst/vscode-cpu-issue-test
2. Open the folder in VSCode
3. Open browse.js
4. tsserver CPU usage goes to 100% for a while
5. Reopening the file or making any edit will again trigger high CPU usage

Expected results:
I expect to be able to work in my code base without having my fans go crazy.

Actual results:
Working in my code base causes my fans to go crazy.

Does this issue occur when all extensions are disabled?:
Yes

[mjbvz]

Thanks for the example project. I can't repo this however. @pqvst Have you perhaps configured the typescript.tsdk setting in VS Code so that we are using an older version of TypeScript for IntelliSense?

The 1 MB+ file makes this sound similar to #27960

[pqvst]

In my regular instance of vscode I have typescript.tsdk configured to be my global npm typescript package. I am able to reproduce the issue with both 3.3.1 and 3.3.3. However, I have also reproduced the issue in a clean install of the Insider build as well (using the default typescript sdk).

Note that my CPU usage spikes both when opening the large file, but also when just opening a file that requires the large file.

I also just noticed that when I open the large file (data.js) then both tsserver and window CPU usage spikes like crazy:

Another note. If I comment out the code in browse.js that uses the required data file, then CPU usage is normal. Not problems whatsoever.

However, if I add more usage, then the CPU spike lasts much longer:

It's odd that you're not able to reproduce the issue though 🤔

[sheetalkamat]

I don't think this has anything to do with large file but the type of file and its semantic analysis or operations like quick info,error checking. So this seems like dup of #27960 but not quite since the outlining doesn't cause issue as yet but the root cause seems similar.

Info 134  [15:18:15.505] request:
    {"seq":9,"type":"request","command":"geterr","arguments":{"delay":0,"files":["c:/temp/vscode-cpu-issue-test/browse.js"]}}
Perf 135  [15:18:15.506] 9::geterr: async elapsed time (in milliseconds) 0.8629
Info 136  [15:18:15.506] event:
    {"seq":0,"type":"event","event":"syntaxDiag","body":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","diagnostics":[]}}
Info 137  [15:18:15.513] event:
    {"seq":0,"type":"event","event":"semanticDiag","body":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","diagnostics":[]}}
Info 138  [15:18:27.873] event:
    {"seq":0,"type":"event","event":"suggestionDiag","body":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","diagnostics":[{"start":{"line":1,"offset":11},"end":{"line":1,"offset":28},"text":"File is a CommonJS module; it may be converted to an ES6 module.","code":80001,"category":"suggestion"},{"start":{"line":4,"offset":7},"end":{"line":4,"offset":11},"text":"'AByB' is declared but its value is never read.","code":6133,"category":"suggestion","reportsUnnecessary":true},{"start":{"line":5,"offset":7},"end":{"line":5,"offset":11},"text":"'AByC' is declared but its value is never read.","code":6133,"category":"suggestion","reportsUnnecessary":true},{"start":{"line":6,"offset":7},"end":{"line":6,"offset":11},"text":"'AByD' is declared but its value is never read.","code":6133,"category":"suggestion","reportsUnnecessary":true}]}}
Info 139  [15:18:27.873] event:
    {"seq":0,"type":"event","event":"requestCompleted","body":{"request_seq":9}}
Info 140  [15:19:59.906] request:
    {"seq":10,"type":"request","command":"quickinfo","arguments":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","line":4,"offset":21}}
Perf 141  [15:19:59.916] 10::quickinfo: elapsed time (in milliseconds) 10.1018
Info 142  [15:19:59.916] response:
    {"seq":0,"type":"response","command":"quickinfo","request_seq":10,"success":false,"message":"No content available."}
Info 143  [15:20:0.119] request:
    {"seq":11,"type":"request","command":"quickinfo","arguments":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","line":4,"offset":25}}
Perf 144  [15:20:0.861] 11::quickinfo: elapsed time (in milliseconds) 741.5116
Info 145  [15:20:0.861] response:
    {"seq":0,"type":"response","command":"quickinfo","request_seq":11,"success":true,"body":{"kind":"method","kindModifiers":"declare","start":{"line":4,"offset":22},"end":{"line":4,"offset":29},"displayString":"(method) LoDashImplicitWrapper<{ \"e0\": { \"a\": string; \"b\": string; \"c\": string; \"d\": string; \"e\": string; \"f\": string; \"g\": string; \"h\": string; \"i\": string; \"j\": string; \"k\": string; \"l\": string; \"m\": string; }; \"e1\": { \"a\": string; \"b\": string; \"c\": string; \"d\": string; \"e\": string; \"f\": string; ... 6 more ...; \"m\": string; }; ... 6103 more ...; \"e6105\": { ...; }; }>.groupBy<{\n    \"e0\": {\n        \"a\": string;\n        \"b\": string;\n        \"c\": string;\n        \"d\": string;\n        \"e\": string;\n        \"f\": string;\n        \"g\": string;\n        \"h\": string;\n        \"i\": string;\n        \"j\": string;\n        \"k\": string;\n        \"l\": string;\n        \"m\": string;\n    };\n    \"e1\": {\n        \"a\": string;\n        \"b\": string;\n        \"c\": string;\n        \"d\": string;\n        \"e\": string;\n        \"f\": string;\n        \"g\": string;\n        ... 5 more ...;\n        \"m\": string;\n    };\n    ... 6103 more ...;\n    \"e6105\": {\n        ...;\n    };\n}>(this: _.LoDashImplicitWrapper<...>, iteratee?: _.ValueIteratee<...>): _.LoDashImplicitWrapper<...> (+1 overload)","documentation":"","tags":[{"name":"see","text":"_.groupBy"},{"name":"see","text":"_.groupBy"}]}}
Info 146  [15:20:3.720] request:
    {"seq":12,"type":"request","command":"quickinfo","arguments":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","line":4,"offset":39}}
Info 147  [15:20:8.243] response:
    {"seq":0,"type":"response","command":"quickinfo","request_seq":12,"success":true,"body":{"canceled":true}}
Info 148  [15:20:8.245] request:
    {"seq":13,"type":"request","command":"quickinfo","arguments":{"file":"c:/temp/vscode-cpu-issue-test/browse.js","line":4,"offset":38}}
Perf 149  [15:20:10.349] 13::quickinfo: elapsed time (in milliseconds) 2104.7219
Info 150  [15:20:10.349] response:
    {"seq":0,"type":"response","command":"quickinfo","request_seq":13,"success":true,"body":{"kind":"method","kindModifiers":"declare","start":{"line":4,"offset":35},"end":{"line":4,"offset":44},"displayString":"(method) LoDashImplicitWrapper<Dictionary<({ \"a\": string; \"b\": string; \"c\": string; \"d\": string; \"e\": string; \"f\": string; \"g\": string; \"h\": string; \"i\": string; \"j\": string; \"k\": string; \"l\": string; \"m\": string; } | { \"a\": string; \"b\": string; \"c\": string; \"d\": string; \"e\": string; \"f\": string; ... 6 more ...; \"m\": string; } | ... 6103 more ... | { ...; })[]>>.mapValues<({\n    \"a\": string;\n    \"b\": string;\n    \"c\": string;\n    \"d\": string;\n    \"e\": string;\n    \"f\": string;\n    \"g\": string;\n    \"h\": string;\n    \"i\": string;\n    \"j\": string;\n    \"k\": string;\n    \"l\": string;\n    \"m\": string;\n} | {\n    \"a\": string;\n    \"b\": string;\n    \"c\": string;\n    \"d\": string;\n    \"e\": string;\n    \"f\": string;\n    \"g\": string;\n    ... 5 more ...;\n    \"m\": string;\n} | ... 6103 more ... | {\n    ...;\n})[], string[]>(this: _.LoDashImplicitWrapper<...>, callback: _.ObjectIterator<...>): _.LoDashImplicitWrapper<...> (+11 overloads)","documentation":"","tags":[{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues\nTODO: This would be better if we had a separate overload for obj: NumericDictionary that returned a NumericDictionary,\n  but TypeScript cannot select overload signatures based on number vs string index key type."},{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues\nTODO: This would be better if we had a separate overload for obj: NumericDictionary that returned a NumericDictionary,\n  but TypeScript cannot select overload signatures based on number vs string index key type."},{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues\nTODO: This would be better if we had a separate overload for obj: NumericDictionary that returned a NumericDictionary,\n  but TypeScript cannot select overload signatures based on number vs string index key type."},{"name":"see","text":"_.mapValues\nTODO: This would be better if we had a separate overload for obj: NumericDictionary that returned a NumericDictionary,\n  but TypeScript cannot select overload signatures based on number vs string index key type."},{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues\nTODO: This would be better if we had a separate overload for obj: NumericDictionary that returned a NumericDictionary,\n  but TypeScript cannot select overload signatures based on number vs string index key type."},{"name":"see","text":"_.mapValues"},{"name":"see","text":"_.mapValues"}]}}