more functional design principles for tests

test/nuxt/logger.spec.js

@@ -8,10 +8,12 @@ const wait = (ms = 10) => new Promise(resolve => setTimeout(resolve, ms))
 describe('app/utils/logger', () => {
   const consoleMocks = {}
   const originalConsole = {}
-  let serverCalls
+  const testState = {
+    serverCalls: [],
+  }
 
   beforeEach(() => {
-    serverCalls = []
+    testState.serverCalls = []
     const calls = { log: [], error: [], warn: [], debug: [] }
 
     Object.keys(calls).forEach((key) => {
@@ -22,7 +24,7 @@ describe('app/utils/logger', () => {
 
     registerEndpoint('/api/log', async (event) => {
       const body = event.body || (await readBody(event).catch(() => ({})))
-      serverCalls.push(body)
+      testState.serverCalls.push(body)
       return { ok: true }
     }, { method: 'POST' })
   })
@@ -40,7 +42,7 @@ describe('app/utils/logger', () => {
       logError('Test message')
       await wait()
 
-      expect(serverCalls[0]).toMatchObject({
+      expect(testState.serverCalls[0]).toMatchObject({
         sessionId: 'session-123',
         userId: 'user-456',
       })
@@ -59,7 +61,7 @@ describe('app/utils/logger', () => {
       await wait()
 
       expect(consoleMocks[consoleKey]).toHaveBeenCalledWith(`[Test message]`, { key: 'value' })
-      expect(serverCalls[0]).toMatchObject({
+      expect(testState.serverCalls[0]).toMatchObject({
         level,
         message: 'Test message',
         data: { key: 'value' },
@@ -84,7 +86,7 @@ describe('app/utils/logger', () => {
       logError('Test message')
       await wait()
 
-      expect(serverCalls[0].timestamp).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/)
+      expect(testState.serverCalls[0].timestamp).toMatch(/^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}/)
     })
 
     it('handles null sessionId and userId', async () => {
@@ -92,7 +94,7 @@ describe('app/utils/logger', () => {
       logError('Test message')
       await wait()
 
-      const { sessionId, userId } = serverCalls[0]
+      const { sessionId, userId } = testState.serverCalls[0]
       expect(sessionId === null || sessionId === undefined).toBe(true)
       expect(userId === null || userId === undefined).toBe(true)
     })