fix: fix worker function type definition and validation

[poolifier.git] / tests / pools / selection-strategies / selection-strategies.test.js

diff --git a/tests/pools/selection-strategies/selection-strategies.test.js b/tests/pools/selection-strategies/selection-strategies.test.js
index d9a01684e9b5b54c85675d3eb9f7573df0b1ea0d..2fcbba5a95054b20311baa45892e26f24733b1fe 100644 (file)
--- a/tests/pools/selection-strategies/selection-strategies.test.js
+++ b/tests/pools/selection-strategies/selection-strategies.test.js
@@ -2,7 +2,8 @@ const { expect } = require('expect')
 const {
   WorkerChoiceStrategies,
   DynamicThreadPool,
-  FixedThreadPool
+  FixedThreadPool,
+  FixedClusterPool
 } = require('../../../lib/index')
 
 describe('Selection strategies test suite', () => {
@@ -11,7 +12,8 @@ describe('Selection strategies test suite', () => {
 
   it('Verify that WorkerChoiceStrategies enumeration provides string values', () => {
     expect(WorkerChoiceStrategies.ROUND_ROBIN).toBe('ROUND_ROBIN')
-    expect(WorkerChoiceStrategies.LESS_RECENTLY_USED).toBe('LESS_RECENTLY_USED')
+    expect(WorkerChoiceStrategies.LESS_USED).toBe('LESS_USED')
+    expect(WorkerChoiceStrategies.LESS_BUSY).toBe('LESS_BUSY')
     expect(WorkerChoiceStrategies.FAIR_SHARE).toBe('FAIR_SHARE')
     expect(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN).toBe(
       'WEIGHTED_ROUND_ROBIN'
@@ -31,56 +33,127 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify ROUND_ROBIN strategy is taken at pool creation', async () => {
-    const pool = new FixedThreadPool(
-      max,
-      './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
-    )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.ROUND_ROBIN
-    )
-    expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy().nextWorkerIndex
-    ).toBe(0)
-    // We need to clean up the resources after our test
-    await pool.destroy()
+  it('Verify available strategies are taken at pool creation', async () => {
+    for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
+      const pool = new FixedThreadPool(
+        max,
+        './tests/worker-files/thread/testWorker.js',
+        { workerChoiceStrategy }
+      )
+      expect(pool.opts.workerChoiceStrategy).toBe(workerChoiceStrategy)
+      expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
+        workerChoiceStrategy
+      )
+      await pool.destroy()
+    }
   })
 
-  it('Verify ROUND_ROBIN strategy can be set after pool creation', async () => {
-    const pool = new DynamicThreadPool(
-      min,
+  it('Verify available strategies can be set after pool creation', async () => {
+    for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
+      const pool = new DynamicThreadPool(
+        min,
+        max,
+        './tests/worker-files/thread/testWorker.js'
+      )
+      pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+      expect(pool.opts.workerChoiceStrategy).toBe(workerChoiceStrategy)
+      expect(pool.workerChoiceStrategyContext.workerChoiceStrategy).toBe(
+        workerChoiceStrategy
+      )
+      await pool.destroy()
+    }
+  })
+
+  it('Verify available strategies default internals at pool creation', async () => {
+    const pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js'
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.ROUND_ROBIN)
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.ROUND_ROBIN
-    )
-    // We need to clean up the resources after our test
+    for (const workerChoiceStrategy of Object.values(WorkerChoiceStrategies)) {
+      if (workerChoiceStrategy === WorkerChoiceStrategies.ROUND_ROBIN) {
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).nextWorkerNodeId
+        ).toBe(0)
+      } else if (workerChoiceStrategy === WorkerChoiceStrategies.FAIR_SHARE) {
+        for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(workerChoiceStrategy)
+          .workerLastVirtualTaskTimestamp.keys()) {
+          expect(
+            pool.workerChoiceStrategyContext.workerChoiceStrategies
+              .get(workerChoiceStrategy)
+              .workerLastVirtualTaskTimestamp.get(workerNodeKey).start
+          ).toBe(0)
+          expect(
+            pool.workerChoiceStrategyContext.workerChoiceStrategies
+              .get(workerChoiceStrategy)
+              .workerLastVirtualTaskTimestamp.get(workerNodeKey).end
+          ).toBe(0)
+        }
+      } else if (
+        workerChoiceStrategy === WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
+      ) {
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).currentWorkerNodeId
+        ).toBe(0)
+        expect(
+          pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+            workerChoiceStrategy
+          ).defaultWorkerWeight
+        ).toBeGreaterThan(0)
+        for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(workerChoiceStrategy)
+          .workersTaskRunTime.keys()) {
+          expect(
+            pool.workerChoiceStrategyContext.workerChoiceStrategies
+              .get(workerChoiceStrategy)
+              .workersTaskRunTime.get(workerNodeKey).weight
+          ).toBeGreaterThan(0)
+          expect(
+            pool.workerChoiceStrategyContext.workerChoiceStrategies
+              .get(workerChoiceStrategy)
+              .workersTaskRunTime.get(workerNodeKey).runTime
+          ).toBe(0)
+        }
+      }
+    }
     await pool.destroy()
   })
 
   it('Verify ROUND_ROBIN strategy default tasks usage statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
     ).toBe(false)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
     ).toBe(false)
     // We need to clean up the resources after our test
     await pool.destroy()
@@ -92,9 +165,6 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
     )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.ROUND_ROBIN
-    )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = []
     for (let i = 0; i < max * 2; i++) {
@@ -112,9 +182,6 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.ROUND_ROBIN }
     )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.ROUND_ROBIN
-    )
     // TODO: Create a better test to cover `RoundRobinWorkerChoiceStrategy#choose`
     const promises = []
     for (let i = 0; i < max * 2; i++) {
@@ -125,15 +192,49 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
+  it('Verify ROUND_ROBIN strategy runtime behavior', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
+    let pool = new FixedClusterPool(
+      max,
+      './tests/worker-files/cluster/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    let results = new Set()
+    for (let i = 0; i < max; i++) {
+      results.add(pool.chooseWorkerNode()[1].worker.id)
+    }
+    expect(results.size).toBe(max)
+    await pool.destroy()
+    pool = new FixedThreadPool(
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
+    )
+    results = new Set()
+    for (let i = 0; i < max; i++) {
+      results.add(pool.chooseWorkerNode()[1].worker.threadId)
+    }
+    expect(results.size).toBe(max)
+    await pool.destroy()
+  })
+
   it('Verify ROUND_ROBIN strategy internals are resets after setting it', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy().nextWorkerIndex
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).nextWorkerNodeId
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeId
     ).toBe(0)
     await pool.destroy()
     pool = new DynamicThreadPool(
@@ -142,73 +243,64 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js',
       { workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.nextWorkerIndex
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).nextWorkerNodeId
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).nextWorkerNodeId
     ).toBe(0)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify LESS_RECENTLY_USED strategy is taken at pool creation', async () => {
-    const pool = new FixedThreadPool(
-      max,
-      './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_RECENTLY_USED }
-    )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.LESS_RECENTLY_USED
-    )
-    // We need to clean up the resources after our test
-    await pool.destroy()
-  })
-
-  it('Verify LESS_RECENTLY_USED strategy can be set after pool creation', async () => {
-    const pool = new FixedThreadPool(
-      max,
-      './tests/worker-files/thread/testWorker.js'
-    )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.LESS_RECENTLY_USED)
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.LESS_RECENTLY_USED
-    )
-    // We need to clean up the resources after our test
-    await pool.destroy()
-  })
-
-  it('Verify LESS_RECENTLY_USED strategy default tasks usage statistics requirements', async () => {
+  it('Verify LESS_USED strategy default tasks usage statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LESS_USED
     let pool = new FixedThreadPool(
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.LESS_RECENTLY_USED)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
     ).toBe(false)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.LESS_RECENTLY_USED)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
     ).toBe(false)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify LESS_RECENTLY_USED strategy can be run in a fixed pool', async () => {
+  it('Verify LESS_USED strategy can be run in a fixed pool', async () => {
     const pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_RECENTLY_USED }
+      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_USED }
     )
-    // TODO: Create a better test to cover `LessRecentlyUsedWorkerChoiceStrategy#choose`
+    // TODO: Create a better test to cover `LessUsedWorkerChoiceStrategy#choose`
     const promises = []
     for (let i = 0; i < max * 2; i++) {
       promises.push(pool.execute())
@@ -218,14 +310,14 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify LESS_RECENTLY_USED strategy can be run in a dynamic pool', async () => {
+  it('Verify LESS_USED strategy can be run in a dynamic pool', async () => {
     const pool = new DynamicThreadPool(
       min,
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_RECENTLY_USED }
+      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_USED }
     )
-    // TODO: Create a better test to cover `LessRecentlyUsedWorkerChoiceStrategy#choose`
+    // TODO: Create a better test to cover `LessUsedWorkerChoiceStrategy#choose`
     const promises = []
     for (let i = 0; i < max * 2; i++) {
       promises.push(pool.execute())
@@ -235,67 +327,107 @@ describe('Selection strategies test suite', () => {
     await pool.destroy()
   })
 
-  it('Verify FAIR_SHARE strategy is taken at pool creation', async () => {
-    const pool = new FixedThreadPool(
+  it('Verify LESS_BUSY strategy default tasks usage statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.LESS_BUSY
+    let pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.FAIR_SHARE }
+      { workerChoiceStrategy }
     )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.FAIR_SHARE
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
+    await pool.destroy()
+    pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
-      .workerLastVirtualTaskTimestamp.keys()) {
-      expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerLastVirtualTaskTimestamp.get(worker).start
-      ).toBe(0)
-      expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerLastVirtualTaskTimestamp.get(worker).end
-      ).toBe(0)
-    }
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
+    ).toBe(false)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify FAIR_SHARE strategy can be set after pool creation', async () => {
+  it('Verify LESS_BUSY strategy can be run in a fixed pool', async () => {
     const pool = new FixedThreadPool(
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_BUSY }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.FAIR_SHARE
+    // TODO: Create a better test to cover `LessBusyWorkerChoiceStrategy#choose`
+    const promises = []
+    for (let i = 0; i < max * 2; i++) {
+      promises.push(pool.execute())
+    }
+    await Promise.all(promises)
+    // We need to clean up the resources after our test
+    await pool.destroy()
+  })
+
+  it('Verify LESS_BUSY strategy can be run in a dynamic pool', async () => {
+    const pool = new DynamicThreadPool(
+      min,
+      max,
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy: WorkerChoiceStrategies.LESS_BUSY }
     )
+    // TODO: Create a better test to cover `LessBusyWorkerChoiceStrategy#choose`
+    const promises = []
+    for (let i = 0; i < max * 2; i++) {
+      promises.push(pool.execute())
+    }
+    await Promise.all(promises)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
   it('Verify FAIR_SHARE strategy default tasks usage statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.FAIR_SHARE
     let pool = new FixedThreadPool(
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
     ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
     ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -312,6 +444,11 @@ describe('Selection strategies test suite', () => {
       promises.push(pool.execute())
     }
     await Promise.all(promises)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workerLastVirtualTaskTimestamp.size
+    ).toBe(pool.workerNodes.length)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -325,36 +462,46 @@ describe('Selection strategies test suite', () => {
     )
     // TODO: Create a better test to cover `FairShareChoiceStrategy#choose`
     const promises = []
-    for (let i = 0; i < max * 2; i++) {
+    const maxMultiplier = 2
+    for (let i = 0; i < max * maxMultiplier; i++) {
       promises.push(pool.execute())
     }
     await Promise.all(promises)
+    // if (process.platform !== 'win32') {
+    //   expect(
+    //     pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+    //       pool.workerChoiceStrategyContext.workerChoiceStrategy
+    //     ).workerLastVirtualTaskTimestamp.size
+    //   ).toBe(pool.workerNodes.length)
+    // }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
   it('Verify FAIR_SHARE strategy internals are resets after setting it', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.FAIR_SHARE
     let pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js'
     )
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerLastVirtualTaskTimestamp
-    ).toBeUndefined()
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerLastVirtualTaskTimestamp
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+      .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
       .workerLastVirtualTaskTimestamp.keys()) {
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerLastVirtualTaskTimestamp.get(worker).start
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workerLastVirtualTaskTimestamp.get(workerNodeKey).start
       ).toBe(0)
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerLastVirtualTaskTimestamp.get(worker).end
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workerLastVirtualTaskTimestamp.get(workerNodeKey).end
       ).toBe(0)
     }
     await pool.destroy()
@@ -364,101 +511,61 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js'
     )
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.workerLastVirtualTaskTimestamp
-    ).toBeUndefined()
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.FAIR_SHARE)
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
-      .workerChoiceStrategy.workerLastVirtualTaskTimestamp.keys()) {
-      expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerChoiceStrategy.workerLastVirtualTaskTimestamp.get(worker).start
-      ).toBe(0)
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workerLastVirtualTaskTimestamp
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+      .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+      .workerLastVirtualTaskTimestamp.keys()) {
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerChoiceStrategy.workerLastVirtualTaskTimestamp.get(worker).end
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workerLastVirtualTaskTimestamp.get(workerNodeKey).start
       ).toBe(0)
-    }
-    // We need to clean up the resources after our test
-    await pool.destroy()
-  })
-
-  it('Verify WEIGHTED_ROUND_ROBIN strategy is taken at pool creation', async () => {
-    const pool = new FixedThreadPool(
-      max,
-      './tests/worker-files/thread/testWorker.js',
-      { workerChoiceStrategy: WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN }
-    )
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
-    )
-    expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .previousWorkerIndex
-    ).toBe(0)
-    expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .currentWorkerIndex
-    ).toBe(0)
-    expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .defaultWorkerWeight
-    ).toBeGreaterThan(0)
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
-      .workersTaskRunTime.keys()) {
-      expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workersTaskRunTime.get(worker).weight
-      ).toBeGreaterThan(0)
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workersTaskRunTime.get(worker).runTime
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workerLastVirtualTaskTimestamp.get(workerNodeKey).end
       ).toBe(0)
     }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify WEIGHTED_ROUND_ROBIN strategy can be set after pool creation', async () => {
-    const pool = new FixedThreadPool(
-      max,
-      './tests/worker-files/thread/testWorker.js'
-    )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN)
-    expect(pool.opts.workerChoiceStrategy).toBe(
-      WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
-    )
-    // We need to clean up the resources after our test
-    await pool.destroy()
-  })
-
   it('Verify WEIGHTED_ROUND_ROBIN strategy default tasks usage statistics requirements', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
     ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
     await pool.destroy()
     pool = new DynamicThreadPool(
       min,
       max,
-      './tests/worker-files/thread/testWorker.js'
+      './tests/worker-files/thread/testWorker.js',
+      { workerChoiceStrategy }
     )
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .requiredStatistics.runTime
+      pool.workerChoiceStrategyContext.getRequiredStatistics().runTime
+    ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime
     ).toBe(true)
+    expect(
+      pool.workerChoiceStrategyContext.getRequiredStatistics().medRunTime
+    ).toBe(false)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -475,6 +582,11 @@ describe('Selection strategies test suite', () => {
       promises.push(pool.execute())
     }
     await Promise.all(promises)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).workersTaskRunTime.size
+    ).toBe(pool.workerNodes.length)
     // We need to clean up the resources after our test
     await pool.destroy()
   })
@@ -488,43 +600,64 @@ describe('Selection strategies test suite', () => {
     )
     // TODO: Create a better test to cover `WeightedRoundRobinWorkerChoiceStrategy#choose`
     const promises = []
-    for (let i = 0; i < max * 2; i++) {
+    const maxMultiplier =
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).defaultWorkerWeight * 50
+    for (let i = 0; i < max * maxMultiplier; i++) {
       promises.push(pool.execute())
     }
     await Promise.all(promises)
+    if (process.platform !== 'win32') {
+      expect(
+        pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+          pool.workerChoiceStrategyContext.workerChoiceStrategy
+        ).workersTaskRunTime.size
+      ).toBe(pool.workerNodes.length)
+    }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
   it('Verify WEIGHTED_ROUND_ROBIN strategy internals are resets after setting it', async () => {
+    const workerChoiceStrategy = WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN
     let pool = new FixedThreadPool(
       max,
       './tests/worker-files/thread/testWorker.js'
     )
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workersTaskRunTime
-    ).toBeUndefined()
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN)
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).currentWorkerNodeId
+    ).toBeDefined()
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .previousWorkerIndex
-    ).toBe(0)
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).defaultWorkerWeight
+    ).toBeDefined()
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workersTaskRunTime
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .currentWorkerIndex
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).currentWorkerNodeId
     ).toBe(0)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .defaultWorkerWeight
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).defaultWorkerWeight
     ).toBeGreaterThan(0)
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
+    for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+      .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
       .workersTaskRunTime.keys()) {
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workersTaskRunTime.get(worker).runTime
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workersTaskRunTime.get(workerNodeKey).runTime
       ).toBe(0)
     }
     await pool.destroy()
@@ -534,36 +667,45 @@ describe('Selection strategies test suite', () => {
       './tests/worker-files/thread/testWorker.js'
     )
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.workersTaskRunTime
-    ).toBeUndefined()
-    pool.setWorkerChoiceStrategy(WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN)
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).currentWorkerNodeId
+    ).toBeDefined()
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.previousWorkerIndex
-    ).toBe(0)
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).defaultWorkerWeight
+    ).toBeDefined()
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.currentWorkerIndex
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        workerChoiceStrategy
+      ).workersTaskRunTime
+    ).toBeDefined()
+    pool.setWorkerChoiceStrategy(workerChoiceStrategy)
+    expect(
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).currentWorkerNodeId
     ).toBe(0)
     expect(
-      pool.workerChoiceStrategyContext.getWorkerChoiceStrategy()
-        .workerChoiceStrategy.defaultWorkerWeight
+      pool.workerChoiceStrategyContext.workerChoiceStrategies.get(
+        pool.workerChoiceStrategyContext.workerChoiceStrategy
+      ).defaultWorkerWeight
     ).toBeGreaterThan(0)
-    for (const worker of pool.workerChoiceStrategyContext
-      .getWorkerChoiceStrategy()
-      .workerChoiceStrategy.workersTaskRunTime.keys()) {
+    for (const workerNodeKey of pool.workerChoiceStrategyContext.workerChoiceStrategies
+      .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+      .workersTaskRunTime.keys()) {
       expect(
-        pool.workerChoiceStrategyContext
-          .getWorkerChoiceStrategy()
-          .workerChoiceStrategy.workersTaskRunTime.get(worker).runTime
+        pool.workerChoiceStrategyContext.workerChoiceStrategies
+          .get(pool.workerChoiceStrategyContext.workerChoiceStrategy)
+          .workersTaskRunTime.get(workerNodeKey).runTime
       ).toBe(0)
     }
     // We need to clean up the resources after our test
     await pool.destroy()
   })
 
-  it('Verify unknown strategies throw error', () => {
+  it('Verify unknown strategy throw error', () => {
     expect(
       () =>
         new DynamicThreadPool(
@@ -572,8 +714,6 @@ describe('Selection strategies test suite', () => {
           './tests/worker-files/thread/testWorker.js',
           { workerChoiceStrategy: 'UNKNOWN_STRATEGY' }
         )
-    ).toThrowError(
-      new Error("Worker choice strategy 'UNKNOWN_STRATEGY' not found")
-    )
+    ).toThrowError("Invalid worker choice strategy 'UNKNOWN_STRATEGY'")
   })
 })