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/thread/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/cluster/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.workerUsage).toStrictEqual({
 454         tasks: {
 455           executed: 0,
 456           executing: 0,
 457           queued: 0,
 458           failed: 0
 459         },
 460         runTime: {
 461           aggregate: 0,
 462           average: 0,
 463           median: 0,
 464           history: expect.any(CircularArray)
 465         },
 466         waitTime: {
 467           aggregate: 0,
 468           average: 0,
 469           median: 0,
 470           history: expect.any(CircularArray)
 471         },
 472         elu: {
 473           idle: {
 474             aggregate: 0,
 475             average: 0,
 476             median: 0,
 477             history: expect.any(CircularArray)
 478           },
 479           active: {
 480             aggregate: 0,
 481             average: 0,
 482             median: 0,
 483             history: expect.any(CircularArray)
 484           },
 485           utilization: 0
 486         }
 487       })
 488     }
 489     await pool.destroy()
 490   })
 491
 492   it('Verify that worker pool tasks queue are initialized', async () => {
 493     const pool = new FixedClusterPool(
 494       numberOfWorkers,
 495       './tests/worker-files/cluster/testWorker.js'
 496     )
 497     for (const workerNode of pool.workerNodes) {
 498       expect(workerNode.tasksQueue).toBeDefined()
 499       expect(workerNode.tasksQueue).toBeInstanceOf(Queue)
 500       expect(workerNode.tasksQueue.size).toBe(0)
 501     }
 502     await pool.destroy()
 503   })
 504
 505   it('Verify that worker pool tasks usage are computed', async () => {
 506     const pool = new FixedClusterPool(
 507       numberOfWorkers,
 508       './tests/worker-files/cluster/testWorker.js'
 509     )
 510     const promises = new Set()
 511     const maxMultiplier = 2
 512     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 513       promises.add(pool.execute())
 514     }
 515     for (const workerNode of pool.workerNodes) {
 516       expect(workerNode.workerUsage).toStrictEqual({
 517         tasks: {
 518           executed: 0,
 519           executing: maxMultiplier,
 520           queued: 0,
 521           failed: 0
 522         },
 523         runTime: {
 524           aggregate: 0,
 525           average: 0,
 526           median: 0,
 527           history: expect.any(CircularArray)
 528         },
 529         waitTime: {
 530           aggregate: 0,
 531           average: 0,
 532           median: 0,
 533           history: expect.any(CircularArray)
 534         },
 535         elu: {
 536           idle: {
 537             aggregate: 0,
 538             average: 0,
 539             median: 0,
 540             history: expect.any(CircularArray)
 541           },
 542           active: {
 543             aggregate: 0,
 544             average: 0,
 545             median: 0,
 546             history: expect.any(CircularArray)
 547           },
 548           utilization: 0
 549         }
 550       })
 551     }
 552     await Promise.all(promises)
 553     for (const workerNode of pool.workerNodes) {
 554       expect(workerNode.workerUsage).toStrictEqual({
 555         tasks: {
 556           executed: maxMultiplier,
 557           executing: 0,
 558           queued: 0,
 559           failed: 0
 560         },
 561         runTime: {
 562           aggregate: 0,
 563           average: 0,
 564           median: 0,
 565           history: expect.any(CircularArray)
 566         },
 567         waitTime: {
 568           aggregate: 0,
 569           average: 0,
 570           median: 0,
 571           history: expect.any(CircularArray)
 572         },
 573         elu: {
 574           idle: {
 575             aggregate: 0,
 576             average: 0,
 577             median: 0,
 578             history: expect.any(CircularArray)
 579           },
 580           active: {
 581             aggregate: 0,
 582             average: 0,
 583             median: 0,
 584             history: expect.any(CircularArray)
 585           },
 586           utilization: 0
 587         }
 588       })
 589     }
 590     await pool.destroy()
 591   })
 592
 593   it('Verify that worker pool tasks usage are reset at worker choice strategy change', async () => {
 594     const pool = new DynamicThreadPool(
 595       numberOfWorkers,
 596       numberOfWorkers,
 597       './tests/worker-files/thread/testWorker.js'
 598     )
 599     const promises = new Set()
 600     const maxMultiplier = 2
 601     for (let i = 0; i < numberOfWorkers * maxMultiplier; i++) {
 602       promises.add(pool.execute())
 603     }
 604     await Promise.all(promises)
 605     for (const workerNode of pool.workerNodes) {
 606       expect(workerNode.workerUsage).toStrictEqual({
 607         tasks: {
 608           executed: expect.any(Number),
 609           executing: 0,
 610           queued: 0,
 611           failed: 0
 612         },
 613         runTime: {
 614           aggregate: 0,
 615           average: 0,
 616           median: 0,
 617           history: expect.any(CircularArray)
 618         },
 619         waitTime: {
 620           aggregate: 0,
 621           average: 0,
 622           median: 0,
 623           history: expect.any(CircularArray)
 624         },
 625         elu: {
 626           idle: {
 627             aggregate: 0,
 628             average: 0,
 629             median: 0,
 630             history: expect.any(CircularArray)
 631           },
 632           active: {
 633             aggregate: 0,
 634             average: 0,
 635             median: 0,
 636             history: expect.any(CircularArray)
 637           },
 638           utilization: 0
 639         }
 640       })
 641       expect(workerNode.workerUsage.tasks.executed).toBeGreaterThan(0)
 642       expect(workerNode.workerUsage.tasks.executed).toBeLessThanOrEqual(
 643         maxMultiplier
 644       )
 645     }
 646     pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
 647     for (const workerNode of pool.workerNodes) {
 648       expect(workerNode.workerUsage).toStrictEqual({
 649         tasks: {
 650           executed: 0,
 651           executing: 0,
 652           queued: 0,
 653           failed: 0
 654         },
 655         runTime: {
 656           aggregate: 0,
 657           average: 0,
 658           median: 0,
 659           history: expect.any(CircularArray)
 660         },
 661         waitTime: {
 662           aggregate: 0,
 663           average: 0,
 664           median: 0,
 665           history: expect.any(CircularArray)
 666         },
 667         elu: {
 668           idle: {
 669             aggregate: 0,
 670             average: 0,
 671             median: 0,
 672             history: expect.any(CircularArray)
 673           },
 674           active: {
 675             aggregate: 0,
 676             average: 0,
 677             median: 0,
 678             history: expect.any(CircularArray)
 679           },
 680           utilization: 0
 681         }
 682       })
 683       expect(workerNode.workerUsage.runTime.history.length).toBe(0)
 684       expect(workerNode.workerUsage.waitTime.history.length).toBe(0)
 685     }
 686     await pool.destroy()
 687   })
 688
 689   it("Verify that pool event emitter 'full' event can register a callback", async () => {
 690     const pool = new DynamicThreadPool(
 691       numberOfWorkers,
 692       numberOfWorkers,
 693       './tests/worker-files/thread/testWorker.js'
 694     )
 695     const promises = new Set()
 696     let poolFull = 0
 697     let poolInfo
 698     pool.emitter.on(PoolEvents.full, info => {
 699       ++poolFull
 700       poolInfo = info
 701     })
 702     for (let i = 0; i < numberOfWorkers * 2; i++) {
 703       promises.add(pool.execute())
 704     }
 705     await Promise.all(promises)
 706     // The `full` event is triggered when the number of submitted tasks at once reach the max number of workers in the dynamic pool.
 707     // So in total numberOfWorkers * 2 times for a loop submitting up to numberOfWorkers * 2 tasks to the dynamic pool with min = max = numberOfWorkers.
 708     expect(poolFull).toBe(numberOfWorkers * 2)
 709     expect(poolInfo).toStrictEqual({
 710       type: PoolTypes.dynamic,
 711       worker: WorkerTypes.thread,
 712       minSize: expect.any(Number),
 713       maxSize: expect.any(Number),
 714       workerNodes: expect.any(Number),
 715       idleWorkerNodes: expect.any(Number),
 716       busyWorkerNodes: expect.any(Number),
 717       executedTasks: expect.any(Number),
 718       executingTasks: expect.any(Number),
 719       queuedTasks: expect.any(Number),
 720       maxQueuedTasks: expect.any(Number),
 721       failedTasks: expect.any(Number)
 722     })
 723     await pool.destroy()
 724   })
 725
 726   it("Verify that pool event emitter 'busy' event can register a callback", async () => {
 727     const pool = new FixedThreadPool(
 728       numberOfWorkers,
 729       './tests/worker-files/thread/testWorker.js'
 730     )
 731     const promises = new Set()
 732     let poolBusy = 0
 733     let poolInfo
 734     pool.emitter.on(PoolEvents.busy, info => {
 735       ++poolBusy
 736       poolInfo = info
 737     })
 738     for (let i = 0; i < numberOfWorkers * 2; i++) {
 739       promises.add(pool.execute())
 740     }
 741     await Promise.all(promises)
 742     // The `busy` event is triggered when the number of submitted tasks at once reach the number of fixed pool workers.
 743     // So in total numberOfWorkers + 1 times for a loop submitting up to numberOfWorkers * 2 tasks to the fixed pool.
 744     expect(poolBusy).toBe(numberOfWorkers + 1)
 745     expect(poolInfo).toStrictEqual({
 746       type: PoolTypes.fixed,
 747       worker: WorkerTypes.thread,
 748       minSize: expect.any(Number),
 749       maxSize: expect.any(Number),
 750       workerNodes: expect.any(Number),
 751       idleWorkerNodes: expect.any(Number),
 752       busyWorkerNodes: expect.any(Number),
 753       executedTasks: expect.any(Number),
 754       executingTasks: expect.any(Number),
 755       queuedTasks: expect.any(Number),
 756       maxQueuedTasks: expect.any(Number),
 757       failedTasks: expect.any(Number)
 758     })
 759     await pool.destroy()
 760   })
 761
 762   it('Verify that multiple tasks worker is working', async () => {
 763     const pool = new DynamicClusterPool(
 764       numberOfWorkers,
 765       numberOfWorkers * 2,
 766       './tests/worker-files/cluster/testMultiTasksWorker.js'
 767     )
 768     const data = { n: 10 }
 769     const result0 = await pool.execute(data)
 770     expect(result0).toBe(false)
 771     const result1 = await pool.execute(data, 'jsonIntegerSerialization')
 772     expect(result1).toBe(false)
 773     const result2 = await pool.execute(data, 'factorial')
 774     expect(result2).toBe(3628800)
 775     const result3 = await pool.execute(data, 'fibonacci')
 776     expect(result3).toBe(89)
 777   })
 778 })