chore: run tests in parallel on GitHub Actions (#10653)

Author: SimenB

.github/workflows/nodejs.yml

@@ -83,7 +83,10 @@ jobs:
         run: yarn
       - name: build
         run: yarn build:js
+      - name: Get number of CPU cores
+        id: cpu-cores
+        uses: SimenB/github-actions-cpu-cores@v1
       - name: run tests
-        run: yarn test-ci-partial
+        run: yarn test-ci-partial:parallel --max-workers ${{ steps.cpu-cores.outputs.count }}
         env:
           CI: true

package.json

@@ -98,7 +98,8 @@
     "publish": "yarn build-clean && yarn build && lerna publish --silent",
     "test-types": "yarn jest --config jest.config.types.js",
     "test-ci": "yarn jest-coverage --color -i --config jest.config.ci.js && yarn test-leak && node ./scripts/mapCoverage.js && codecov",
-    "test-ci-partial": "yarn jest --color -i --config jest.config.ci.js",
+    "test-ci-partial": "yarn test-ci-partial:parallel -i",
+    "test-ci-partial:parallel": "yarn jest --color --config jest.config.ci.js",
     "test-pretty-format-perf": "node packages/pretty-format/perf/test.js",
     "test-leak": "yarn jest -i --detectLeaks jest-mock jest-diff jest-repl pretty-format",
     "test": "yarn lint && yarn jest",