tests/pools/abstract/abstract-pool.test.js

   1 const { expect } = require('expect')
   2 const {
   3   DynamicClusterPool,
   4   DynamicThreadPool,
   5   FixedClusterPool,
   6   FixedThreadPool,
   7   PoolEvents,
   8   WorkerChoiceStrategies,
   9   PoolTypes,
  10   WorkerTypes
  11 } = require('../../../lib')
  12 const { CircularArray } = require('../../../lib/circular-array')
  13 const { Queue } = require('../../../lib/queue')
  14
  15 describe('Abstract pool test suite', () => {
  16   const numberOfWorkers = 2
  17   class StubPoolWithRemoveAllWorker extends FixedThreadPool {
  18     removeAllWorker () {
  19       this.workerNodes = []
  20       this.promiseResponseMap.clear()
  21     }
  22   }
  23   class StubPoolWithIsMain extends FixedThreadPool {
  24     isMain () {
  25       return false
  26     }
  27   }
  28
  29   it('Simulate pool creation from a non main thread/process', () => {
  30     expect(
  31       () =>
  32         new StubPoolWithIsMain(
  33           numberOfWorkers,
  34           './tests/worker-files/thread/testWorker.js',
  35           {
  36             errorHandler: e => console.error(e)
  37           }
  38         )
  39     ).toThrowError('Cannot start a pool from a worker!')
  40   })
  41
  42   it('Verify that filePath is checked', () => {
  43     const expectedError = new Error(
  44       'Please specify a file with a worker implementation'
  45     )
  46     expect(() => new FixedThreadPool(numberOfWorkers)).toThrowError(
  47       expectedError
  48     )
  49     expect(() => new FixedThreadPool(numberOfWorkers, '')).toThrowError(
  50       expectedError
  51     )
  52   })
  53
  54   it('Verify that numberOfWorkers is checked', () => {
  55     expect(() => new FixedThreadPool()).toThrowError(
  56       'Cannot instantiate a pool without specifying the number of workers'
  57     )
  58   })
  59
  60   it('Verify that a negative number of workers is checked', () => {
  61     expect(
  62       () =>
  63         new FixedClusterPool(-1, './tests/worker-files/cluster/testWorker.js')
  64     ).toThrowError(
  65       new RangeError(
  66         'Cannot instantiate a pool with a negative number of workers'
  67       )
  68     )
  69   })
  70
  71   it('Verify that a non integer number of workers is checked', () => {
  72     expect(
  73       () =>
  74         new FixedThreadPool(0.25, './tests/worker-files/thread/testWorker.js')
  75     ).toThrowError(
  76       new TypeError(
  77         'Cannot instantiate a pool with a non safe integer number of workers'
  78       )
  79     )
  80   })
  81
  82   it('Verify that pool options are checked', async () => {
  83     let pool = new FixedThreadPool(
  84       numberOfWorkers,
  85       './tests/worker-files/thread/testWorker.js'
  86     )
  87     expect(pool.emitter).toBeDefined()
  88     expect(pool.opts.enableEvents).toBe(true)
  89     expect(pool.opts.restartWorkerOnError).toBe(true)
  90     expect(pool.opts.enableTasksQueue).toBe(false)
  91     expect(pool.opts.tasksQueueOptions).toBeUndefined()
  92     expect(pool.opts.workerChoiceStrategy).toBe(
  93       WorkerChoiceStrategies.ROUND_ROBIN
  94     )
  95     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
  96       runTime: { median: false },
  97       waitTime: { median: false },
  98       elu: { median: false }
  99     })
 100     expect(pool.opts.messageHandler).toBeUndefined()
 101     expect(pool.opts.errorHandler).toBeUndefined()
 102     expect(pool.opts.onlineHandler).toBeUndefined()
 103     expect(pool.opts.exitHandler).toBeUndefined()
 104     await pool.destroy()
 105     const testHandler = () => console.log('test handler executed')
 106     pool = new FixedThreadPool(
 107       numberOfWorkers,
 108       './tests/worker-files/thread/testWorker.js',
 109       {
 110         workerChoiceStrategy: WorkerChoiceStrategies.LEAST_USED,
 111         workerChoiceStrategyOptions: {
 112           runTime: { median: true },
 113           weights: { 0: 300, 1: 200 }
 114         },
 115         enableEvents: false,
 116         restartWorkerOnError: false,
 117         enableTasksQueue: true,
 118         tasksQueueOptions: { concurrency: 2 },
 119         messageHandler: testHandler,
 120         errorHandler: testHandler,
 121         onlineHandler: testHandler,
 122         exitHandler: testHandler
 123       }
 124     )
 125     expect(pool.emitter).toBeUndefined()
 126     expect(pool.opts.enableEvents).toBe(false)
 127     expect(pool.opts.restartWorkerOnError).toBe(false)
 128     expect(pool.opts.enableTasksQueue).toBe(true)
 129     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 130     expect(pool.opts.workerChoiceStrategy).toBe(
 131       WorkerChoiceStrategies.LEAST_USED
 132     )
 133     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 134       runTime: { median: true },
 135       weights: { 0: 300, 1: 200 }
 136     })
 137     expect(pool.opts.messageHandler).toStrictEqual(testHandler)
 138     expect(pool.opts.errorHandler).toStrictEqual(testHandler)
 139     expect(pool.opts.onlineHandler).toStrictEqual(testHandler)
 140     expect(pool.opts.exitHandler).toStrictEqual(testHandler)
 141     await pool.destroy()
 142   })
 143
 144   it('Verify that pool options are validated', async () => {
 145     expect(
 146       () =>
 147         new FixedThreadPool(
 148           numberOfWorkers,
 149           './tests/worker-files/thread/testWorker.js',
 150           {
 151             workerChoiceStrategy: 'invalidStrategy'
 152           }
 153         )
 154     ).toThrowError("Invalid worker choice strategy 'invalidStrategy'")
 155     expect(
 156       () =>
 157         new FixedThreadPool(
 158           numberOfWorkers,
 159           './tests/worker-files/thread/testWorker.js',
 160           {
 161             workerChoiceStrategyOptions: 'invalidOptions'
 162           }
 163         )
 164     ).toThrowError(
 165       'Invalid worker choice strategy options: must be a plain object'
 166     )
 167     expect(
 168       () =>
 169         new FixedThreadPool(
 170           numberOfWorkers,
 171           './tests/worker-files/thread/testWorker.js',
 172           {
 173             workerChoiceStrategyOptions: { weights: {} }
 174           }
 175         )
 176     ).toThrowError(
 177       'Invalid worker choice strategy options: must have a weight for each worker node'
 178     )
 179     expect(
 180       () =>
 181         new FixedThreadPool(
 182           numberOfWorkers,
 183           './tests/worker-files/thread/testWorker.js',
 184           {
 185             workerChoiceStrategyOptions: { measurement: 'invalidMeasurement' }
 186           }
 187         )
 188     ).toThrowError(
 189       "Invalid worker choice strategy options: invalid measurement 'invalidMeasurement'"
 190     )
 191     expect(
 192       () =>
 193         new FixedThreadPool(
 194           numberOfWorkers,
 195           './tests/worker-files/thread/testWorker.js',
 196           {
 197             enableTasksQueue: true,
 198             tasksQueueOptions: { concurrency: 0 }
 199           }
 200         )
 201     ).toThrowError("Invalid worker tasks concurrency '0'")
 202     expect(
 203       () =>
 204         new FixedThreadPool(
 205           numberOfWorkers,
 206           './tests/worker-files/thread/testWorker.js',
 207           {
 208             enableTasksQueue: true,
 209             tasksQueueOptions: 'invalidTasksQueueOptions'
 210           }
 211         )
 212     ).toThrowError('Invalid tasks queue options: must be a plain object')
 213     expect(
 214       () =>
 215         new FixedThreadPool(
 216           numberOfWorkers,
 217           './tests/worker-files/thread/testWorker.js',
 218           {
 219             enableTasksQueue: true,
 220             tasksQueueOptions: { concurrency: 0.2 }
 221           }
 222         )
 223     ).toThrowError('Invalid worker tasks concurrency: must be an integer')
 224   })
 225
 226   it('Verify that worker choice strategy options can be set', async () => {
 227     const pool = new FixedThreadPool(
 228       numberOfWorkers,
 229       './tests/worker-files/thread/testWorker.js',
 230       { workerChoiceStrategy: WorkerChoiceStrategies.FAIR_SHARE }
 231     )
 232     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 233       runTime: { median: false },
 234       waitTime: { median: false },
 235       elu: { median: false }
 236     })
 237     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 238       .workerChoiceStrategies) {
 239       expect(workerChoiceStrategy.opts).toStrictEqual({
 240         runTime: { median: false },
 241         waitTime: { median: false },
 242         elu: { median: false }
 243       })
 244     }
 245     expect(
 246       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 247     ).toStrictEqual({
 248       runTime: {
 249         aggregate: true,
 250         average: true,
 251         median: false
 252       },
 253       waitTime: {
 254         aggregate: false,
 255         average: false,
 256         median: false
 257       },
 258       elu: {
 259         aggregate: true,
 260         average: true,
 261         median: false
 262       }
 263     })
 264     pool.setWorkerChoiceStrategyOptions({
 265       runTime: { median: true },
 266       elu: { median: true }
 267     })
 268     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 269       runTime: { median: true },
 270       elu: { median: true }
 271     })
 272     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 273       .workerChoiceStrategies) {
 274       expect(workerChoiceStrategy.opts).toStrictEqual({
 275         runTime: { median: true },
 276         elu: { median: true }
 277       })
 278     }
 279     expect(
 280       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 281     ).toStrictEqual({
 282       runTime: {
 283         aggregate: true,
 284         average: false,
 285         median: true
 286       },
 287       waitTime: {
 288         aggregate: false,
 289         average: false,
 290         median: false
 291       },
 292       elu: {
 293         aggregate: true,
 294         average: false,
 295         median: true
 296       }
 297     })
 298     pool.setWorkerChoiceStrategyOptions({
 299       runTime: { median: false },
 300       elu: { median: false }
 301     })
 302     expect(pool.opts.workerChoiceStrategyOptions).toStrictEqual({
 303       runTime: { median: false },
 304       elu: { median: false }
 305     })
 306     for (const [, workerChoiceStrategy] of pool.workerChoiceStrategyContext
 307       .workerChoiceStrategies) {
 308       expect(workerChoiceStrategy.opts).toStrictEqual({
 309         runTime: { median: false },
 310         elu: { median: false }
 311       })
 312     }
 313     expect(
 314       pool.workerChoiceStrategyContext.getTaskStatisticsRequirements()
 315     ).toStrictEqual({
 316       runTime: {
 317         aggregate: true,
 318         average: true,
 319         median: false
 320       },
 321       waitTime: {
 322         aggregate: false,
 323         average: false,
 324         median: false
 325       },
 326       elu: {
 327         aggregate: true,
 328         average: true,
 329         median: false
 330       }
 331     })
 332     expect(() =>
 333       pool.setWorkerChoiceStrategyOptions('invalidWorkerChoiceStrategyOptions')
 334     ).toThrowError(
 335       'Invalid worker choice strategy options: must be a plain object'
 336     )
 337     expect(() =>
 338       pool.setWorkerChoiceStrategyOptions({ weights: {} })
 339     ).toThrowError(
 340       'Invalid worker choice strategy options: must have a weight for each worker node'
 341     )
 342     expect(() =>
 343       pool.setWorkerChoiceStrategyOptions({ measurement: 'invalidMeasurement' })
 344     ).toThrowError(
 345       "Invalid worker choice strategy options: invalid measurement 'invalidMeasurement'"
 346     )
 347     await pool.destroy()
 348   })
 349
 350   it('Verify that tasks queue can be enabled/disabled', async () => {
 351     const pool = new FixedThreadPool(
 352       numberOfWorkers,
 353       './tests/worker-files/thread/testWorker.js'
 354     )
 355     expect(pool.opts.enableTasksQueue).toBe(false)
 356     expect(pool.opts.tasksQueueOptions).toBeUndefined()
 357     pool.enableTasksQueue(true)
 358     expect(pool.opts.enableTasksQueue).toBe(true)
 359     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 1 })
 360     pool.enableTasksQueue(true, { concurrency: 2 })
 361     expect(pool.opts.enableTasksQueue).toBe(true)
 362     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 363     pool.enableTasksQueue(false)
 364     expect(pool.opts.enableTasksQueue).toBe(false)
 365     expect(pool.opts.tasksQueueOptions).toBeUndefined()
 366     await pool.destroy()
 367   })
 368
 369   it('Verify that tasks queue options can be set', async () => {
 370     const pool = new FixedThreadPool(
 371       numberOfWorkers,
 372       './tests/worker-files/thread/testWorker.js',
 373       { enableTasksQueue: true }
 374     )
 375     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 1 })
 376     pool.setTasksQueueOptions({ concurrency: 2 })
 377     expect(pool.opts.tasksQueueOptions).toStrictEqual({ concurrency: 2 })
 378     expect(() =>
 379       pool.setTasksQueueOptions('invalidTasksQueueOptions')
 380     ).toThrowError('Invalid tasks queue options: must be a plain object')
 381     expect(() => pool.setTasksQueueOptions({ concurrency: 0 })).toThrowError(
 382       "Invalid worker tasks concurrency '0'"
 383     )
 384     expect(() => pool.setTasksQueueOptions({ concurrency: 0.2 })).toThrowError(
 385       'Invalid worker tasks concurrency: must be an integer'
 386     )
 387     await pool.destroy()
 388   })
 389
 390   it('Verify that pool info is set', async () => {
 391     let pool = new FixedThreadPool(
 392       numberOfWorkers,
 393       './tests/worker-files/thread/testWorker.js'
 394     )
 395     expect(pool.info).toStrictEqual({
 396       type: PoolTypes.fixed,
 397       worker: WorkerTypes.thread,
 398       minSize: numberOfWorkers,
 399       maxSize: numberOfWorkers,
 400       workerNodes: numberOfWorkers,
 401       idleWorkerNodes: numberOfWorkers,
 402       busyWorkerNodes: 0,
 403       executedTasks: 0,
 404       executingTasks: 0,
 405       queuedTasks: 0,
 406       maxQueuedTasks: 0,
 407       failedTasks: 0
 408     })
 409     for (const workerNode of pool.workerNodes) {
 410       console.log('thread:workerNode.info', workerNode.info)
 411     }
 412     await pool.destroy()
 413     pool = new DynamicClusterPool(
 414       numberOfWorkers,
 415       numberOfWorkers * 2,
 416       './tests/worker-files/cluster/testWorker.js'
 417     )
 418     expect(pool.info).toStrictEqual({
 419       type: PoolTypes.dynamic,
 420       worker: WorkerTypes.cluster,
 421       minSize: numberOfWorkers,
 422       maxSize: numberOfWorkers * 2,
 423       workerNodes: numberOfWorkers,
 424       idleWorkerNodes: numberOfWorkers,
 425       busyWorkerNodes: 0,
 426       executedTasks: 0,
 427       executingTasks: 0,
 428       queuedTasks: 0,
 429       maxQueuedTasks: 0,
 430       failedTasks: 0
 431     })
 432     for (const workerNode of pool.workerNodes) {
 433       console.log('cluster:workerNode.info', workerNode.info)
 434     }
 435     await pool.destroy()
 436   })
 437
 438   it('Simulate worker not found', async () => {
 439     const pool = new StubPoolWithRemoveAllWorker(
 440       numberOfWorkers,
 441       './tests/worker-files/thread/testWorker.js',
 442       {
 443         errorHandler: e => console.error(e)
 444       }
 445     )
 446     expect(pool.workerNodes.length).toBe(numberOfWorkers)
 447     // Simulate worker not found.
 448     pool.removeAllWorker()
 449     expect(pool.workerNodes.length).toBe(0)
 450     await pool.destroy()
 451   })
 452
 453   it('Verify that worker pool tasks usage are initialized', async () => {
 454     const pool = new FixedClusterPool(
 455       numberOfWorkers,
 456       './tests/worker-files/cluster/testWorker.js'
 457     )
 458     for (const workerNode of pool.workerNodes) {
 459       expect(workerNode.usage).toStrictEqual({
 460         tasks: {
 461           executed: 0,
 462           executing: 0,
 463           queued: 0,
 464           maxQueued: 0,
 465           failed: 0
 466         },
 467         runTime: {
 468           aggregate: 0,
 469           average: 0,
 470           median: 0,
 471           history: expect.any(CircularArray)
 472         },
 473         waitTime: {
 474           aggregate: 0,
 475           average: 0,
 476           median: 0,
 477           history: expect.any(CircularArray)
 478         },
 479         elu: {
 480           idle: {
 481             aggregate: 0,
 482             average: 0,
 483             median: 0,
 484             history: expect.any(CircularArray)
 485           },
 486           active: {
 487             aggregate: 0,
 488             average: 0,
 489             median: 0,
 490             history: expect.any(CircularArray)
 491           },
 492           utilization: 0
 493         }
 494       })
 495     }
 496     await pool.destroy()
 497   })
 498
 499   it('Verify that worker pool tasks queue are initialized', async () => {
 500     const pool = new FixedClusterPool(
 501       numberOfWorkers,
 502       './tests/worker-files/cluster/testWorker.js'
 503     )
 504     for (const workerNode of pool.workerNodes) {
 505       expect(workerNode.tasksQueue).toBeDefined()
 506       expect(workerNode.tasksQueue).toBeInstanceOf(Queue)
 507       expect(workerNode.tasksQueue.size).toBe(0)
 508       expect(workerNode.tasksQueue.maxSize).toBe(0)
 509     }
 510     await pool.destroy()
 511   })
 512
 513   it('Verify that worker pool tasks usage are computed', async () => {
 514     const pool = new FixedClusterPool(
 515       numberOfWorkers,
 516       './tests/worker-files/cluster/testWorker.js'
 517     )
 518     const promises = new Set()
 519     const maxMultiplier = 2
 520     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 521       promises.add(pool.execute())
 522     }
 523     for (const workerNode of pool.workerNodes) {
 524       expect(workerNode.usage).toStrictEqual({
 525         tasks: {
 526           executed: 0,
 527           executing: maxMultiplier,
 528           queued: 0,
 529           maxQueued: 0,
 530           failed: 0
 531         },
 532         runTime: {
 533           aggregate: 0,
 534           average: 0,
 535           median: 0,
 536           history: expect.any(CircularArray)
 537         },
 538         waitTime: {
 539           aggregate: 0,
 540           average: 0,
 541           median: 0,
 542           history: expect.any(CircularArray)
 543         },
 544         elu: {
 545           idle: {
 546             aggregate: 0,
 547             average: 0,
 548             median: 0,
 549             history: expect.any(CircularArray)
 550           },
 551           active: {
 552             aggregate: 0,
 553             average: 0,
 554             median: 0,
 555             history: expect.any(CircularArray)
 556           },
 557           utilization: 0
 558         }
 559       })
 560     }
 561     await Promise.all(promises)
 562     for (const workerNode of pool.workerNodes) {
 563       expect(workerNode.usage).toStrictEqual({
 564         tasks: {
 565           executed: maxMultiplier,
 566           executing: 0,
 567           queued: 0,
 568           maxQueued: 0,
 569           failed: 0
 570         },
 571         runTime: {
 572           aggregate: 0,
 573           average: 0,
 574           median: 0,
 575           history: expect.any(CircularArray)
 576         },
 577         waitTime: {
 578           aggregate: 0,
 579           average: 0,
 580           median: 0,
 581           history: expect.any(CircularArray)
 582         },
 583         elu: {
 584           idle: {
 585             aggregate: 0,
 586             average: 0,
 587             median: 0,
 588             history: expect.any(CircularArray)
 589           },
 590           active: {
 591             aggregate: 0,
 592             average: 0,
 593             median: 0,
 594             history: expect.any(CircularArray)
 595           },
 596           utilization: 0
 597         }
 598       })
 599     }
 600     await pool.destroy()
 601   })
 602
 603   it('Verify that worker pool tasks usage are reset at worker choice strategy change', async () => {
 604     const pool = new DynamicThreadPool(
 605       numberOfWorkers,
 606       numberOfWorkers,
 607       './tests/worker-files/thread/testWorker.js'
 608     )
 609     const promises = new Set()
 610     const maxMultiplier = 2
 611     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 612       promises.add(pool.execute())
 613     }
 614     await Promise.all(promises)
 615     for (const workerNode of pool.workerNodes) {
 616       expect(workerNode.usage).toStrictEqual({
 617         tasks: {
 618           executed: expect.any(Number),
 619           executing: 0,
 620           queued: 0,
 621           maxQueued: 0,
 622           failed: 0
 623         },
 624         runTime: {
 625           aggregate: 0,
 626           average: 0,
 627           median: 0,
 628           history: expect.any(CircularArray)
 629         },
 630         waitTime: {
 631           aggregate: 0,
 632           average: 0,
 633           median: 0,
 634           history: expect.any(CircularArray)
 635         },
 636         elu: {
 637           idle: {
 638             aggregate: 0,
 639             average: 0,
 640             median: 0,
 641             history: expect.any(CircularArray)
 642           },
 643           active: {
 644             aggregate: 0,
 645             average: 0,
 646             median: 0,
 647             history: expect.any(CircularArray)
 648           },
 649           utilization: 0
 650         }
 651       })
 652       expect(workerNode.usage.tasks.executed).toBeGreaterThan(0)
 653       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(maxMultiplier)
 654     }
 655     pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
 656     for (const workerNode of pool.workerNodes) {
 657       expect(workerNode.usage).toStrictEqual({
 658         tasks: {
 659           executed: 0,
 660           executing: 0,
 661           queued: 0,
 662           maxQueued: 0,
 663           failed: 0
 664         },
 665         runTime: {
 666           aggregate: 0,
 667           average: 0,
 668           median: 0,
 669           history: expect.any(CircularArray)
 670         },
 671         waitTime: {
 672           aggregate: 0,
 673           average: 0,
 674           median: 0,
 675           history: expect.any(CircularArray)
 676         },
 677         elu: {
 678           idle: {
 679             aggregate: 0,
 680             average: 0,
 681             median: 0,
 682             history: expect.any(CircularArray)
 683           },
 684           active: {
 685             aggregate: 0,
 686             average: 0,
 687             median: 0,
 688             history: expect.any(CircularArray)
 689           },
 690           utilization: 0
 691         }
 692       })
 693       expect(workerNode.usage.runTime.history.length).toBe(0)
 694       expect(workerNode.usage.waitTime.history.length).toBe(0)
 695     }
 696     await pool.destroy()
 697   })
 698
 699   it("Verify that pool event emitter 'full' event can register a callback", async () => {
 700     const pool = new DynamicThreadPool(
 701       numberOfWorkers,
 702       numberOfWorkers,
 703       './tests/worker-files/thread/testWorker.js'
 704     )
 705     const promises = new Set()
 706     let poolFull = 0
 707     let poolInfo
 708     pool.emitter.on(PoolEvents.full, info => {
 709       ++poolFull
 710       poolInfo = info
 711     })
 712     for (let i = 0; i < numberOfWorkers * 2; i++) {
 713       promises.add(pool.execute())
 714     }
 715     await Promise.all(promises)
 716     // The `full` event is triggered when the number of submitted tasks at once reach the max number of workers in the dynamic pool.
 717     // So in total numberOfWorkers * 2 times for a loop submitting up to numberOfWorkers * 2 tasks to the dynamic pool with min = max = numberOfWorkers.
 718     expect(poolFull).toBe(numberOfWorkers * 2)
 719     expect(poolInfo).toStrictEqual({
 720       type: PoolTypes.dynamic,
 721       worker: WorkerTypes.thread,
 722       minSize: expect.any(Number),
 723       maxSize: expect.any(Number),
 724       workerNodes: expect.any(Number),
 725       idleWorkerNodes: expect.any(Number),
 726       busyWorkerNodes: expect.any(Number),
 727       executedTasks: expect.any(Number),
 728       executingTasks: expect.any(Number),
 729       queuedTasks: expect.any(Number),
 730       maxQueuedTasks: expect.any(Number),
 731       failedTasks: expect.any(Number)
 732     })
 733     await pool.destroy()
 734   })
 735
 736   it("Verify that pool event emitter 'busy' event can register a callback", async () => {
 737     const pool = new FixedThreadPool(
 738       numberOfWorkers,
 739       './tests/worker-files/thread/testWorker.js'
 740     )
 741     const promises = new Set()
 742     let poolBusy = 0
 743     let poolInfo
 744     pool.emitter.on(PoolEvents.busy, info => {
 745       ++poolBusy
 746       poolInfo = info
 747     })
 748     for (let i = 0; i < numberOfWorkers * 2; i++) {
 749       promises.add(pool.execute())
 750     }
 751     await Promise.all(promises)
 752     // The `busy` event is triggered when the number of submitted tasks at once reach the number of fixed pool workers.
 753     // So in total numberOfWorkers + 1 times for a loop submitting up to numberOfWorkers * 2 tasks to the fixed pool.
 754     expect(poolBusy).toBe(numberOfWorkers + 1)
 755     expect(poolInfo).toStrictEqual({
 756       type: PoolTypes.fixed,
 757       worker: WorkerTypes.thread,
 758       minSize: expect.any(Number),
 759       maxSize: expect.any(Number),
 760       workerNodes: expect.any(Number),
 761       idleWorkerNodes: expect.any(Number),
 762       busyWorkerNodes: expect.any(Number),
 763       executedTasks: expect.any(Number),
 764       executingTasks: expect.any(Number),
 765       queuedTasks: expect.any(Number),
 766       maxQueuedTasks: expect.any(Number),
 767       failedTasks: expect.any(Number)
 768     })
 769     await pool.destroy()
 770   })
 771
 772   it('Verify that multiple tasks worker is working', async () => {
 773     const pool = new DynamicClusterPool(
 774       numberOfWorkers,
 775       numberOfWorkers * 2,
 776       './tests/worker-files/cluster/testMultiTasksWorker.js'
 777     )
 778     const data = { n: 10 }
 779     const result0 = await pool.execute(data)
 780     expect(result0).toBe(false)
 781     const result1 = await pool.execute(data, 'jsonIntegerSerialization')
 782     expect(result1).toBe(false)
 783     const result2 = await pool.execute(data, 'factorial')
 784     expect(result2).toBe(3628800)
 785     const result3 = await pool.execute(data, 'fibonacci')
 786     expect(result3).toBe(55)
 787   })
 788 })