[TestNowHeader] Add small tests for the x-test-now header

services/backend/tests/api/testTimeHeader.test.ts

@@ -0,0 +1,38 @@
+import express from 'express'
+import request from 'supertest'
+import { describe, it, assert } from 'vitest'
+
+import { testTimeMiddleware } from '../../src/middleware/testTime'
+import { now } from '../../src/util/clock'
+
+describe('test time middleware', () => {
+  it('uses the date from the x-test-now header', async () => {
+    const app = express()
+    app.use(testTimeMiddleware)
+    app.get('/', (_request, response) => response.send(now().toISOString()))
+
+    const response = await request(app).get('/').set('x-test-now', '2026-03-01T12:00:00.000Z')
+
+    assert.strictEqual(response.text, '2026-03-01T12:00:00.000Z')
+  })
+
+  it('the acual current date if x-test-now header missing', async () => {
+    const app = express()
+    app.use(testTimeMiddleware)
+    app.get('/', (_request, response) => response.send(now().toISOString()))
+
+    const response = await request(app).get('/')
+
+    assert.notStrictEqual(response.text, '2026-03-01T12:00:00.000Z')
+  })
+
+  it('the acual current date if x-test-now header has incorrect date', async () => {
+    const app = express()
+    app.use(testTimeMiddleware)
+    app.get('/', (_request, response) => response.send(now().toISOString()))
+
+    const response = await request(app).get('/').set('x-test-now', 'moimoi mitä kuuluu')
+
+    assert.notStrictEqual(response.text, '2026-03-01T12:00:00.000Z')
+  })
+})