Building High-Quality JavaScript Tools

on YouTube ↗25m

" summary

Jest claims adoption across 100s of companies and reports measurable gains: more than 100 companies adopt it in six months and codebases see about 35 more tests in the most recent six month window. Engineering work focuses on incremental performance rewrites (dependency analyzer, caching, parallel worker scheduling), clearer failure diffs, an immersive watch mode, snapshot assertions that store and compare outputs, and a working multi-project runner that runs many suites in one process.

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" chapters (13)

1. 0:00Start
2. 2:08Do we need a test framework?
3. 2:41RUNNING TESTS
4. 6:41Improve Module Resolution
5. 8:40Immersive Watch Mode
6. 9:19Snapshots
7. 12:31jest --projects yarn react relay
8. 15:44Modularity
9. 16:01One big repository
10. 16:17Jest's Packages
11. 16:35Jest's Platform
12. 18:15Packages also make Jest more hackable
13. 24:15Best Solutions

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