test(runtime-core): add tests for scheduler (#462)

packages/runtime-core/__tests__/scheduler.spec.ts

@@ -0,0 +1,233 @@
+import { queueJob, nextTick, queuePostFlushCb } from '../src/scheduler'
+
+describe('scheduler', () => {
+  it('nextTick', async () => {
+    const calls: string[] = []
+    const dummyThen = Promise.resolve().then()
+    const job1 = () => {
+      calls.push('job1')
+    }
+    const job2 = () => {
+      calls.push('job2')
+    }
+    nextTick(job1)
+    job2()
+
+    expect(calls.length).toBe(1)
+    await dummyThen
+    // job1 will be pushed in nextTick
+    expect(calls.length).toBe(2)
+    expect(calls).toMatchObject(['job2', 'job1'])
+  })
+
+  describe('queueJob', () => {
+    it('basic usage', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+      }
+      const job2 = () => {
+        calls.push('job2')
+      }
+      queueJob(job1)
+      queueJob(job2)
+      expect(calls).toEqual([])
+      await nextTick()
+      expect(calls).toEqual(['job1', 'job2'])
+    })
+
+    it('should dedupe queued jobs', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+      }
+      const job2 = () => {
+        calls.push('job2')
+      }
+      queueJob(job1)
+      queueJob(job2)
+      queueJob(job1)
+      queueJob(job2)
+      expect(calls).toEqual([])
+      await nextTick()
+      expect(calls).toEqual(['job1', 'job2'])
+    })
+
+    it('queueJob while flushing', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+        // job2 will be excuted after job1 at the same tick
+        queueJob(job2)
+      }
+      const job2 = () => {
+        calls.push('job2')
+      }
+      queueJob(job1)
+
+      await nextTick()
+      expect(calls).toEqual(['job1', 'job2'])
+    })
+  })
+
+  describe('queuePostFlushCb', () => {
+    it('basic usage', async () => {
+      const calls: string[] = []
+      const cb1 = () => {
+        calls.push('cb1')
+      }
+      const cb2 = () => {
+        calls.push('cb2')
+      }
+      const cb3 = () => {
+        calls.push('cb3')
+      }
+
+      queuePostFlushCb([cb1, cb2])
+      queuePostFlushCb(cb3)
+
+      expect(calls).toEqual([])
+      await nextTick()
+      expect(calls).toEqual(['cb1', 'cb2', 'cb3'])
+    })
+
+    it('should dedupe queued postFlushCb', async () => {
+      const calls: string[] = []
+      const cb1 = () => {
+        calls.push('cb1')
+      }
+      const cb2 = () => {
+        calls.push('cb2')
+      }
+      const cb3 = () => {
+        calls.push('cb3')
+      }
+
+      queuePostFlushCb([cb1, cb2])
+      queuePostFlushCb(cb3)
+
+      queuePostFlushCb([cb1, cb3])
+      queuePostFlushCb(cb2)
+
+      expect(calls).toEqual([])
+      await nextTick()
+      expect(calls).toEqual(['cb1', 'cb2', 'cb3'])
+    })
+
+    it('queuePostFlushCb while flushing', async () => {
+      const calls: string[] = []
+      const cb1 = () => {
+        calls.push('cb1')
+        // cb2 will be excuted after cb1 at the same tick
+        queuePostFlushCb(cb2)
+      }
+      const cb2 = () => {
+        calls.push('cb2')
+      }
+      queuePostFlushCb(cb1)
+
+      await nextTick()
+      expect(calls).toEqual(['cb1', 'cb2'])
+    })
+  })
+
+  describe('queueJob w/ queuePostFlushCb', () => {
+    it('queueJob inside postFlushCb', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+      }
+      const cb1 = () => {
+        // queueJob in postFlushCb
+        calls.push('cb1')
+        queueJob(job1)
+      }
+
+      queuePostFlushCb(cb1)
+      await nextTick()
+      expect(calls).toEqual(['cb1', 'job1'])
+    })
+
+    it('queueJob & postFlushCb inside postFlushCb', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+      }
+      const cb1 = () => {
+        calls.push('cb1')
+        queuePostFlushCb(cb2)
+        // job1 will executed before cb2
+        // Job has higher priority than postFlushCb
+        queueJob(job1)
+      }
+      const cb2 = () => {
+        calls.push('cb2')
+      }
+
+      queuePostFlushCb(cb1)
+      await nextTick()
+      expect(calls).toEqual(['cb1', 'job1', 'cb2'])
+    })
+
+    it('postFlushCb inside queueJob', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+        // postFlushCb in queueJob
+        queuePostFlushCb(cb1)
+      }
+      const cb1 = () => {
+        calls.push('cb1')
+      }
+
+      queueJob(job1)
+      await nextTick()
+      expect(calls).toEqual(['job1', 'cb1'])
+    })
+
+    it('queueJob & postFlushCb inside queueJob', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+        // cb1 will executed after job2
+        // Job has higher priority than postFlushCb
+        queuePostFlushCb(cb1)
+        queueJob(job2)
+      }
+      const job2 = () => {
+        calls.push('job2')
+      }
+      const cb1 = () => {
+        calls.push('cb1')
+      }
+
+      queueJob(job1)
+      await nextTick()
+      expect(calls).toEqual(['job1', 'job2', 'cb1'])
+    })
+
+    it('nested queueJob w/ postFlushCb', async () => {
+      const calls: string[] = []
+      const job1 = () => {
+        calls.push('job1')
+
+        queuePostFlushCb(cb1)
+        queueJob(job2)
+      }
+      const job2 = () => {
+        calls.push('job2')
+        queuePostFlushCb(cb2)
+      }
+      const cb1 = () => {
+        calls.push('cb1')
+      }
+      const cb2 = () => {
+        calls.push('cb2')
+      }
+
+      queueJob(job1)
+      await nextTick()
+      expect(calls).toEqual(['job1', 'job2', 'cb1', 'cb2'])
+    })
+  })
+})