more functional design principles for tests

test/integration/shutdown.spec.js

@@ -2,23 +2,25 @@ import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
 import { registerCleanup, graceful, initShutdownHandlers, clearCleanup } from '../../server/utils/shutdown.js'
 
 describe('shutdown integration', () => {
-  let originalExit
-  let exitCalls
-  let originalOn
+  const testState = {
+    originalExit: null,
+    exitCalls: [],
+    originalOn: null,
+  }
 
   beforeEach(() => {
     clearCleanup()
-    exitCalls = []
-    originalExit = process.exit
+    testState.exitCalls = []
+    testState.originalExit = process.exit
     process.exit = vi.fn((code) => {
-      exitCalls.push(code)
+      testState.exitCalls.push(code)
     })
-    originalOn = process.on
+    testState.originalOn = process.on
   })
 
   afterEach(() => {
-    process.exit = originalExit
-    process.on = originalOn
+    process.exit = testState.originalExit
+    process.on = testState.originalOn
     clearCleanup()
   })
 
@@ -30,7 +32,7 @@ describe('shutdown integration', () => {
     initShutdownHandlers()
     expect(process.on).toHaveBeenCalledWith('SIGTERM', expect.any(Function))
     expect(process.on).toHaveBeenCalledWith('SIGINT', expect.any(Function))
-    process.on = originalOn
+    process.on = testState.originalOn
   })
 
   it('signal handler calls graceful', async () => {
@@ -42,8 +44,8 @@ describe('shutdown integration', () => {
     const sigtermHandler = handlers.SIGTERM
     expect(sigtermHandler).toBeDefined()
     await sigtermHandler()
-    expect(exitCalls.length).toBeGreaterThan(0)
-    process.on = originalOn
+    expect(testState.exitCalls.length).toBeGreaterThan(0)
+    process.on = testState.originalOn
   })
 
   it('signal handler handles graceful error', async () => {
@@ -58,8 +60,8 @@ describe('shutdown integration', () => {
       throw new Error('Force error')
     })
     await sigintHandler()
-    expect(exitCalls.length).toBeGreaterThan(0)
-    process.on = originalOn
+    expect(testState.exitCalls.length).toBeGreaterThan(0)
+    process.on = testState.originalOn
   })
 
   it('covers timeout path in graceful', async () => {
@@ -68,7 +70,7 @@ describe('shutdown integration', () => {
     })
     graceful()
     await new Promise(resolve => setTimeout(resolve, 100))
-    expect(exitCalls.length).toBeGreaterThan(0)
+    expect(testState.exitCalls.length).toBeGreaterThan(0)
   })
 
   it('covers graceful catch block', async () => {
@@ -76,6 +78,6 @@ describe('shutdown integration', () => {
       throw new Error('Test error')
     })
     await graceful()
-    expect(exitCalls.length).toBeGreaterThan(0)
+    expect(testState.exitCalls.length).toBeGreaterThan(0)
   })
 })