Fix flaky tests and improve the main workflow

.github/workflows/tests-main.yml

@@ -55,8 +55,9 @@ jobs:
         run: pnpm nx run-many --all --skip-nx-cache  --target=bundle --output-style=stream
         if: ${{ matrix.os == 'ubuntu-latest' && matrix.node == '24.1.0' }}
       - name: Unit tests
-        run: pnpm vitest run
+        run: pnpm vitest run ${{ env.POOL_OPTIONS }}
         env:
+          POOL_OPTIONS: ${{ matrix.os == 'macos-latest' && '--pool forks' || '' }}
           VITEST_MIN_THREADS: "1"
           VITEST_MAX_THREADS: "4"
       - name: Send Slack notification on failure

packages/app/src/cli/services/function/build.test.ts

@@ -29,6 +29,14 @@ import {build as esBuild} from 'esbuild'
 vi.mock('@shopify/cli-kit/node/fs')
 vi.mock('@shopify/cli-kit/node/system')
 
+vi.mock('./binaries.js', async (importOriginal) => {
+  const actual: any = await importOriginal()
+  return {
+    ...actual,
+    downloadBinary: vi.fn(),
+  }
+})
+
 vi.mock('esbuild', async () => {
   const esbuild: any = await vi.importActual('esbuild')
   return {

packages/app/src/cli/utilities/app/http-reverse-proxy.test.ts

@@ -97,8 +97,8 @@ function getTestReverseProxy(protocol: 'http' | 'https') {
         res.end('Response from target server 2')
       })
 
-      targetServer1.listen(ports.targetPort1)
-      targetServer2.listen(ports.targetPort2)
+      await new Promise<void>((resolve) => targetServer1.listen(ports.targetPort1, resolve))
+      await new Promise<void>((resolve) => targetServer2.listen(ports.targetPort2, resolve))
 
       const abortController = new AbortController()
       const {server: proxyServer} = await getProxyingWebServer(
@@ -111,12 +111,12 @@ function getTestReverseProxy(protocol: 'http' | 'https') {
         protocol === 'https' ? localhostCert : undefined,
       )
 
-      proxyServer.listen(ports.proxyPort)
+      await new Promise<void>((resolve) => proxyServer.listen(ports.proxyPort, resolve))
       await use({targetServer1, targetServer2, proxyServer, abortController})
 
-      proxyServer.close()
-      targetServer1.close()
-      targetServer2.close()
+      await new Promise<void>((resolve) => proxyServer.close(() => resolve()))
+      await new Promise<void>((resolve) => targetServer1.close(() => resolve()))
+      await new Promise<void>((resolve) => targetServer2.close(() => resolve()))
     },
   })
 }