[ci] Improve parallelism of yarn test

Changes the `ci` argument to be an enum instead so the tests use all
available workers in GitHub actions.

When `ci === 'github'` also increase maxConcurrency and enable
workerThreads

ghstack-source-id: 7297ed89271c27746e636583f38c392dd777a369
Pull Request resolved: #30033

.circleci/config.yml

@@ -368,7 +368,7 @@ jobs:
     steps:
       - checkout
       - setup_node_modules
-      - run: yarn test <<parameters.args>> --ci
+      - run: yarn test <<parameters.args>> --ci=circleci
 
   yarn_test_build:
     docker: *docker

.github/workflows/runtime_test.yml

@@ -52,4 +52,4 @@ 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

scripts/jest/jest-cli.js

@@ -91,8 +91,8 @@ const argv = yargs
     ci: {
       describe: 'Run tests in CI',
       requiresArg: false,
-      type: 'boolean',
-      default: false,
+      type: 'choices',
+      choices: ['circleci', 'github'],
     },
     compactConsole: {
       alias: 'c',
@@ -309,10 +309,14 @@ function getCommandArgs() {
   }
 
   // CI Environments have limited workers.
-  if (argv.ci) {
+  if (argv.ci === 'circleci') {
     args.push('--maxWorkers=2');
   }
 
+  if (argv.ci === 'github') {
+    args.push('--maxConcurrency=10 --workerThreads=true');
+  }
+
   // Push the remaining args onto the command.
   // This will send args like `--watch` to Jest.
   args.push(...argv._);