[ci] Improve parallelism of yarn test

This PR adds parallelism similar to our existing circleci setup for
running yarn tests with the various test params. It does this by
sharding tests into `$SHARD_COUNT` number of groups, then spawning a job
for each of them and using jest's built in `--shard` option.

Effectively this means that the job will spawn an additional (where `n`
is the number of test params)

`n * $SHARD_COUNT` number of jobs to run tests in parallel

for a total of `n + (n * $SHARD_COUNT)` jobs. This does mean the
GitHub UI at the bottom of each PR gets longer and unfortunately it's
not sorted in any way as far as I can tell. But if something goes wrong
it should still be easy to find out what the problem is.

The PR also changes the `ci` argument for jest-cli to be an enum instead
so the tests use all available workers in GitHub actions. This will have
to live around for a bit until we can fully migrate off of circleci.

ghstack-source-id: 08f2d16353
Pull Request resolved: https://github.com/facebook/react/pull/30033

.github/workflows/fuzz_tests.yml

@@ -28,5 +28,5 @@ jobs:
       shell: bash
     - name: Run fuzz tests
       run: |-
-        FUZZ_TEST_SEED=$RANDOM yarn test fuzz --ci
-        FUZZ_TEST_SEED=$RANDOM yarn test --prod fuzz --ci
+        FUZZ_TEST_SEED=$RANDOM yarn test fuzz --ci=github
+        FUZZ_TEST_SEED=$RANDOM yarn test --prod fuzz --ci=github

.github/workflows/runtime_test.yml

@@ -7,37 +7,67 @@ on:
     paths-ignore:
       - 'compiler/**'
 
+env:
+  # Number of workers (one per shard) to spawn
+  SHARD_COUNT: 5
+
 jobs:
-  test:
-    name: yarn test
+  # Define the various test parameters and parallelism for this workflow
+  build_test_params:
+    name: Build test params
     runs-on: ubuntu-latest
-    continue-on-error: true
+    outputs:
+      params: ${{ steps.define-params.outputs.result }}
+      shard_id: ${{ steps.define-shards.outputs.result }}
+    steps:
+      - uses: actions/github-script@v7
+        id: define-shards
+        with:
+          script: |
+            function range(from, to) {
+              const arr = [];
+              for (let n = from; n <= to; n++) {
+                arr.push(n);
+              }
+              return arr;
+            }
+            return range(1, process.env.SHARD_COUNT);
+      - uses: actions/github-script@v7
+        id: define-params
+        with:
+          script: |
+            return [
+              "-r=stable --env=development",
+              "-r=stable --env=production",
+              "-r=experimental --env=development",
+              "-r=experimental --env=production",
+              "-r=www-classic --env=development --variant=false",
+              "-r=www-classic --env=production --variant=false",
+              "-r=www-classic --env=development --variant=true",
+              "-r=www-classic --env=production --variant=true",
+              "-r=www-modern --env=development --variant=false",
+              "-r=www-modern --env=production --variant=false",
+              "-r=www-modern --env=development --variant=true",
+              "-r=www-modern --env=production --variant=true",
+              "-r=xplat --env=development --variant=false",
+              "-r=xplat --env=development --variant=true",
+              "-r=xplat --env=production --variant=false",
+              "-r=xplat --env=production --variant=true",
+              // TODO: Test more persistent configurations?
+              "-r=stable --env=development --persistent",
+              "-r=experimental --env=development --persistent"
+            ];
+
+  # Spawn a job for each shard for a given set of test params
+  test:
+    name: yarn test ${{ matrix.params }} (Shard ${{ matrix.shard_id }})
+    runs-on: ubuntu-latest
+    needs: build_test_params
     strategy:
       matrix:
-        # Intentionally passing these as strings instead of creating a
-        # separate parameter per CLI argument, since it's easier to
-        # control/see which combinations we want to run.
-        params: [
-          "-r=stable --env=development",
-          "-r=stable --env=production",
-          "-r=experimental --env=development",
-          "-r=experimental --env=production",
-          "-r=www-classic --env=development --variant=false",
-          "-r=www-classic --env=production --variant=false",
-          "-r=www-classic --env=development --variant=true",
-          "-r=www-classic --env=production --variant=true",
-          "-r=www-modern --env=development --variant=false",
-          "-r=www-modern --env=production --variant=false",
-          "-r=www-modern --env=development --variant=true",
-          "-r=www-modern --env=production --variant=true",
-          "-r=xplat --env=development --variant=false",
-          "-r=xplat --env=development --variant=true",
-          "-r=xplat --env=production --variant=false",
-          "-r=xplat --env=production --variant=true",
-          # TODO: Test more persistent configurations?
-          "-r=stable --env=development --persistent",
-          "-r=experimental --env=development --persistent"
-        ]
+        params: ${{ fromJSON(needs.build_test_params.outputs.params) }}
+        shard_id: ${{ fromJSON(needs.build_test_params.outputs.shard_id) }}
+    continue-on-error: true
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -52,4 +82,4 @@ jobs:
           path: "**/node_modules"
           key: ${{ runner.arch }}-${{ runner.os }}-modules-${{ hashFiles('yarn.lock') }}
       - run: yarn install --frozen-lockfile
-      - run: yarn test ${{ matrix.params }} --ci
+      - run: yarn test ${{ matrix.params }} --ci=github --shard=${{ matrix.shard_id }}/${{ env.SHARD_COUNT }}