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     await pool.destroy()
 410     pool = new DynamicClusterPool(
 411       numberOfWorkers,
 412       numberOfWorkers * 2,
 413       './tests/worker-files/cluster/testWorker.js'
 414     )
 415     expect(pool.info).toStrictEqual({
 416       type: PoolTypes.dynamic,
 417       worker: WorkerTypes.cluster,
 418       minSize: numberOfWorkers,
 419       maxSize: numberOfWorkers * 2,
 420       workerNodes: numberOfWorkers,
 421       idleWorkerNodes: numberOfWorkers,
 422       busyWorkerNodes: 0,
 423       executedTasks: 0,
 424       executingTasks: 0,
 425       queuedTasks: 0,
 426       maxQueuedTasks: 0,
 427       failedTasks: 0
 428     })
 429     await pool.destroy()
 430   })
 431
 432   it('Simulate worker not found', async () => {
 433     const pool = new StubPoolWithRemoveAllWorker(
 434       numberOfWorkers,
 435       './tests/worker-files/thread/testWorker.js',
 436       {
 437         errorHandler: e => console.error(e)
 438       }
 439     )
 440     expect(pool.workerNodes.length).toBe(numberOfWorkers)
 441     // Simulate worker not found.
 442     pool.removeAllWorker()
 443     expect(pool.workerNodes.length).toBe(0)
 444     await pool.destroy()
 445   })
 446
 447   it('Verify that worker pool tasks usage are initialized', async () => {
 448     const pool = new FixedClusterPool(
 449       numberOfWorkers,
 450       './tests/worker-files/cluster/testWorker.js'
 451     )
 452     for (const workerNode of pool.workerNodes) {
 453       expect(workerNode.usage).toStrictEqual({
 454         tasks: {
 455           executed: 0,
 456           executing: 0,
 457           queued: 0,
 458           maxQueued: 0,
 459           failed: 0
 460         },
 461         runTime: {
 462           aggregate: 0,
 463           average: 0,
 464           median: 0,
 465           history: expect.any(CircularArray)
 466         },
 467         waitTime: {
 468           aggregate: 0,
 469           average: 0,
 470           median: 0,
 471           history: expect.any(CircularArray)
 472         },
 473         elu: {
 474           idle: {
 475             aggregate: 0,
 476             average: 0,
 477             median: 0,
 478             history: expect.any(CircularArray)
 479           },
 480           active: {
 481             aggregate: 0,
 482             average: 0,
 483             median: 0,
 484             history: expect.any(CircularArray)
 485           },
 486           utilization: 0
 487         }
 488       })
 489     }
 490     await pool.destroy()
 491   })
 492
 493   it('Verify that worker pool tasks queue are initialized', async () => {
 494     const pool = new FixedClusterPool(
 495       numberOfWorkers,
 496       './tests/worker-files/cluster/testWorker.js'
 497     )
 498     for (const workerNode of pool.workerNodes) {
 499       expect(workerNode.tasksQueue).toBeDefined()
 500       expect(workerNode.tasksQueue).toBeInstanceOf(Queue)
 501       expect(workerNode.tasksQueue.size).toBe(0)
 502       expect(workerNode.tasksQueue.maxSize).toBe(0)
 503     }
 504     await pool.destroy()
 505   })
 506
 507   it('Verify that worker pool tasks usage are computed', async () => {
 508     const pool = new FixedClusterPool(
 509       numberOfWorkers,
 510       './tests/worker-files/cluster/testWorker.js'
 511     )
 512     const promises = new Set()
 513     const maxMultiplier = 2
 514     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 515       promises.add(pool.execute())
 516     }
 517     for (const workerNode of pool.workerNodes) {
 518       expect(workerNode.usage).toStrictEqual({
 519         tasks: {
 520           executed: 0,
 521           executing: maxMultiplier,
 522           queued: 0,
 523           maxQueued: 0,
 524           failed: 0
 525         },
 526         runTime: {
 527           aggregate: 0,
 528           average: 0,
 529           median: 0,
 530           history: expect.any(CircularArray)
 531         },
 532         waitTime: {
 533           aggregate: 0,
 534           average: 0,
 535           median: 0,
 536           history: expect.any(CircularArray)
 537         },
 538         elu: {
 539           idle: {
 540             aggregate: 0,
 541             average: 0,
 542             median: 0,
 543             history: expect.any(CircularArray)
 544           },
 545           active: {
 546             aggregate: 0,
 547             average: 0,
 548             median: 0,
 549             history: expect.any(CircularArray)
 550           },
 551           utilization: 0
 552         }
 553       })
 554     }
 555     await Promise.all(promises)
 556     for (const workerNode of pool.workerNodes) {
 557       expect(workerNode.usage).toStrictEqual({
 558         tasks: {
 559           executed: maxMultiplier,
 560           executing: 0,
 561           queued: 0,
 562           maxQueued: 0,
 563           failed: 0
 564         },
 565         runTime: {
 566           aggregate: 0,
 567           average: 0,
 568           median: 0,
 569           history: expect.any(CircularArray)
 570         },
 571         waitTime: {
 572           aggregate: 0,
 573           average: 0,
 574           median: 0,
 575           history: expect.any(CircularArray)
 576         },
 577         elu: {
 578           idle: {
 579             aggregate: 0,
 580             average: 0,
 581             median: 0,
 582             history: expect.any(CircularArray)
 583           },
 584           active: {
 585             aggregate: 0,
 586             average: 0,
 587             median: 0,
 588             history: expect.any(CircularArray)
 589           },
 590           utilization: 0
 591         }
 592       })
 593     }
 594     await pool.destroy()
 595   })
 596
 597   it('Verify that worker pool tasks usage are reset at worker choice strategy change', async () => {
 598     const pool = new DynamicThreadPool(
 599       numberOfWorkers,
 600       numberOfWorkers,
 601       './tests/worker-files/thread/testWorker.js'
 602     )
 603     const promises = new Set()
 604     const maxMultiplier = 2
 605     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 606       promises.add(pool.execute())
 607     }
 608     await Promise.all(promises)
 609     for (const workerNode of pool.workerNodes) {
 610       expect(workerNode.usage).toStrictEqual({
 611         tasks: {
 612           executed: expect.any(Number),
 613           executing: 0,
 614           queued: 0,
 615           maxQueued: 0,
 616           failed: 0
 617         },
 618         runTime: {
 619           aggregate: 0,
 620           average: 0,
 621           median: 0,
 622           history: expect.any(CircularArray)
 623         },
 624         waitTime: {
 625           aggregate: 0,
 626           average: 0,
 627           median: 0,
 628           history: expect.any(CircularArray)
 629         },
 630         elu: {
 631           idle: {
 632             aggregate: 0,
 633             average: 0,
 634             median: 0,
 635             history: expect.any(CircularArray)
 636           },
 637           active: {
 638             aggregate: 0,
 639             average: 0,
 640             median: 0,
 641             history: expect.any(CircularArray)
 642           },
 643           utilization: 0
 644         }
 645       })
 646       expect(workerNode.usage.tasks.executed).toBeGreaterThan(0)
 647       expect(workerNode.usage.tasks.executed).toBeLessThanOrEqual(maxMultiplier)
 648     }
 649     pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
 650     for (const workerNode of pool.workerNodes) {
 651       expect(workerNode.usage).toStrictEqual({
 652         tasks: {
 653           executed: 0,
 654           executing: 0,
 655           queued: 0,
 656           maxQueued: 0,
 657           failed: 0
 658         },
 659         runTime: {
 660           aggregate: 0,
 661           average: 0,
 662           median: 0,
 663           history: expect.any(CircularArray)
 664         },
 665         waitTime: {
 666           aggregate: 0,
 667           average: 0,
 668           median: 0,
 669           history: expect.any(CircularArray)
 670         },
 671         elu: {
 672           idle: {
 673             aggregate: 0,
 674             average: 0,
 675             median: 0,
 676             history: expect.any(CircularArray)
 677           },
 678           active: {
 679             aggregate: 0,
 680             average: 0,
 681             median: 0,
 682             history: expect.any(CircularArray)
 683           },
 684           utilization: 0
 685         }
 686       })
 687       expect(workerNode.usage.runTime.history.length).toBe(0)
 688       expect(workerNode.usage.waitTime.history.length).toBe(0)
 689     }
 690     await pool.destroy()
 691   })
 692
 693   it("Verify that pool event emitter 'full' event can register a callback", async () => {
 694     const pool = new DynamicThreadPool(
 695       numberOfWorkers,
 696       numberOfWorkers,
 697       './tests/worker-files/thread/testWorker.js'
 698     )
 699     const promises = new Set()
 700     let poolFull = 0
 701     let poolInfo
 702     pool.emitter.on(PoolEvents.full, info => {
 703       ++poolFull
 704       poolInfo = info
 705     })
 706     for (let i = 0; i < numberOfWorkers * 2; i++) {
 707       promises.add(pool.execute())
 708     }
 709     await Promise.all(promises)
 710     // The `full` event is triggered when the number of submitted tasks at once reach the max number of workers in the dynamic pool.
 711     // So in total numberOfWorkers * 2 times for a loop submitting up to numberOfWorkers * 2 tasks to the dynamic pool with min = max = numberOfWorkers.
 712     expect(poolFull).toBe(numberOfWorkers * 2)
 713     expect(poolInfo).toStrictEqual({
 714       type: PoolTypes.dynamic,
 715       worker: WorkerTypes.thread,
 716       minSize: expect.any(Number),
 717       maxSize: expect.any(Number),
 718       workerNodes: expect.any(Number),
 719       idleWorkerNodes: expect.any(Number),
 720       busyWorkerNodes: expect.any(Number),
 721       executedTasks: expect.any(Number),
 722       executingTasks: expect.any(Number),
 723       queuedTasks: expect.any(Number),
 724       maxQueuedTasks: expect.any(Number),
 725       failedTasks: expect.any(Number)
 726     })
 727     await pool.destroy()
 728   })
 729
 730   it("Verify that pool event emitter 'busy' event can register a callback", async () => {
 731     const pool = new FixedThreadPool(
 732       numberOfWorkers,
 733       './tests/worker-files/thread/testWorker.js'
 734     )
 735     const promises = new Set()
 736     let poolBusy = 0
 737     let poolInfo
 738     pool.emitter.on(PoolEvents.busy, info => {
 739       ++poolBusy
 740       poolInfo = info
 741     })
 742     for (let i = 0; i < numberOfWorkers * 2; i++) {
 743       promises.add(pool.execute())
 744     }
 745     await Promise.all(promises)
 746     // The `busy` event is triggered when the number of submitted tasks at once reach the number of fixed pool workers.
 747     // So in total numberOfWorkers + 1 times for a loop submitting up to numberOfWorkers * 2 tasks to the fixed pool.
 748     expect(poolBusy).toBe(numberOfWorkers + 1)
 749     expect(poolInfo).toStrictEqual({
 750       type: PoolTypes.fixed,
 751       worker: WorkerTypes.thread,
 752       minSize: expect.any(Number),
 753       maxSize: expect.any(Number),
 754       workerNodes: expect.any(Number),
 755       idleWorkerNodes: expect.any(Number),
 756       busyWorkerNodes: expect.any(Number),
 757       executedTasks: expect.any(Number),
 758       executingTasks: expect.any(Number),
 759       queuedTasks: expect.any(Number),
 760       maxQueuedTasks: expect.any(Number),
 761       failedTasks: expect.any(Number)
 762     })
 763     await pool.destroy()
 764   })
 765
 766   it('Verify that multiple tasks worker is working', async () => {
 767     const pool = new DynamicClusterPool(
 768       numberOfWorkers,
 769       numberOfWorkers * 2,
 770       './tests/worker-files/cluster/testMultiTasksWorker.js'
 771     )
 772     const data = { n: 10 }
 773     const result0 = await pool.execute(data)
 774     expect(result0).toBe(false)
 775     const result1 = await pool.execute(data, 'jsonIntegerSerialization')
 776     expect(result1).toBe(false)
 777     const result2 = await pool.execute(data, 'factorial')
 778     expect(result2).toBe(3628800)
 779     const result3 = await pool.execute(data, 'fibonacci')
 780     expect(result3).toBe(55)
 781   })
 782 })