test(ci): deduplicate coverage command setup

scripts/coverage-partitions.spec.ts

@@ -28,6 +28,14 @@ async function temporaryRoot(): Promise<string> {
   return await mkdtemp(join(tmpdir(), 'dsh-coverage-partitions-'))
 }
 
+function successfulCommandRecorder(commands: CoverageCommand[]) {
+  return vi.fn(async (command: CoverageCommand) => {
+    commands.push(command)
+    await writeBlob(command)
+    return passed
+  })
+}
+
 describe('coverage partition count', () => {
   it.each([
     [undefined, undefined],
@@ -77,11 +85,7 @@ describe('coverage partition coordinator', () => {
   it('runs every single-worker partition before one merged threshold check', async () => {
     const root = await temporaryRoot()
     const commands: CoverageCommand[] = []
-    const runCommand = vi.fn(async (command: CoverageCommand) => {
-      commands.push(command)
-      await writeBlob(command)
-      return passed
-    })
+    const runCommand = successfulCommandRecorder(commands)
     const coordinator = new CoveragePartitionCoordinator({
       root,
       partitions: 3,
@@ -128,11 +132,7 @@ describe('coverage partition coordinator', () => {
   it('runs a native pnpm entrypoint directly', async () => {
     const root = await temporaryRoot()
     const commands: CoverageCommand[] = []
-    const runCommand = vi.fn(async (command: CoverageCommand) => {
-      commands.push(command)
-      await writeBlob(command)
-      return passed
-    })
+    const runCommand = successfulCommandRecorder(commands)
     const coordinator = new CoveragePartitionCoordinator({
       root,
       partitions: 2,