[heft-jest-plugin] Add a patch to update the Jest ScriptTransformer to disable cache reads/writes#3606
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D4N14L merged 9 commits intomicrosoft:mainfrom Aug 30, 2022
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Regarding the description, specifically, cache files for the Heft Typescript Jest transformer are counterproductive, since all the transformer does is read a file from disk and feed it to Jest, so the cache file does nothing useful and adds an extra I/O round trip. |
…in different processes without the same node resolver cache
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Won't quite work as written
dmichon-msft
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Aug 30, 2022
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Summary
Jest uses cache files to speed up execution time. However, use of cache files with the heft-jest-plugin seems to cause more problems than it solves (adds I/O overhead, encounters race conditions). We already delete the cache before execution in an attempt to avoid some of these issues. Additionally, cache files for the heft-jest-plugin typescript jest transformer only read a file from disk and feed it to Jest, which means these cache files serve little purpose. This PR patches Jest to disable cache reads/writes entirely.
Fixes jestjs/jest#4444
How it was tested
Tested by debugging into the execution and validating that the patched script is used.