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@imhoffd
Last active April 19, 2024 19:46
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Parallelizing Jest in GitHub Actions
name: CI
on: [push]
jobs:
setup:
runs-on: ubuntu-latest
outputs:
test-chunks: ${{ steps['set-test-chunks'].outputs['test-chunks'] }}
test-chunk-ids: ${{ steps['set-test-chunk-ids'].outputs['test-chunk-ids'] }}
steps:
- uses: actions/checkout@v2
- run: npm install
- id: set-test-chunks
name: Set Chunks
run: echo "::set-output name=test-chunks::$(npx jest --listTests --json | jq -cM '[_nwise(length / 2 | ceil)]')"
- id: set-test-chunk-ids
name: Set Chunk IDs
run: echo "::set-output name=test-chunk-ids::$(echo $CHUNKS | jq -cM 'to_entries | map(.key)')"
env:
CHUNKS: ${{ steps['set-test-chunks'].outputs['test-chunks'] }}
test:
runs-on: ubuntu-latest
name: test (chunk ${{ matrix.chunk }})
needs:
- setup
strategy:
matrix:
chunk: ${{ fromJson(needs.setup.outputs['test-chunk-ids']) }}
steps:
- uses: actions/checkout@v2
- run: npm install
- name: jest
run: echo $CHUNKS | jq '.[${{ matrix.chunk }}] | .[] | @text' | xargs npx jest
env:
CHUNKS: ${{ needs.setup.outputs['test-chunks'] }}
@havenchyk
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Thanks! seems it will be available in jest@28

@finalight
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i got this error when using the above github actions

Error reading JToken from JsonReader. Path '', line 0, position 0.,.github/workflows/chunks.yml (Line: 75, Col: 16): Unexpected type of value '', expected type: Sequence.

any idea how to resolve this?

@CharlieGreenman
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Do you have to specify the length manually, or is there a way to set up that automatically? For instance, for every 100 tests, create a new test chunk

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