Vitest - Element Plus - Debug

⚠️ UPDATED WITH THE LATEST FINDING IN vitest-dev/vitest#579

A playground to help identify potential performance improvements in Vitest:

• Simple calc.js & 100 test files (node env)
• Simple NativeButton.vue & 100 test files (jsdom env)
• Simple ElementButton.vue & 100 test files (jsdom env)
• element-plus is aliased to element-plus/dist/index.full.mjs for better performance.
• Added Jest for comparison.

Install

npm install

the ./multiplicated-tests directory is created using the ./multiplicate.sh script. It just copies the spec.test.js, ./NativeButton.test.js and ./ElementButton.test.js files 100 times.

Run

Run 100 tests with vitest/jest:

npm run vitest-calc
npm run vitest-native
npm run vitest-element
npm run jest-calc
npm run jest-native
npm run jest-element

Results

On M1 MacBook Pro:

All of the following runs are testing 100 test files

npm run vitest-calc    ~2.4s (node)
npm run vitest-native  ~6.3s (jsdom)
npm run vitest-element ~6.9s (jsdom)

// The Jest tests are using cache
npm run jest-calc      ~1.5s (node)
npm run jest-native    ~2.5s (jsdom)
npm run jest-element   ~4.7s (jsdom)

Interesting observation: if we change calc.test.js env from node to jsdom, then Jest runs the tests 0.5s slower but Vitest - 3.1s slower. Perhaps this is because Vitest loads/initializes jsdom 100 times(once per worker)?

npm run jest-calc    ~2.0s (jsdom) // compared to ~1.5s (node)
npm run vitest-calc  ~5.5s (jsdom) // compared to ~2.4s (node)