chore: Migrate block of unit tests to node:test (#2570)

test/unit/adaptive-sampler.test.js

@@ -1,163 +1,151 @@
 /*
- * Copyright 2020 New Relic Corporation. All rights reserved.
+ * Copyright 2024 New Relic Corporation. All rights reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
 
 'use strict'
 
-const tap = require('tap')
+const test = require('node:test')
+const assert = require('node:assert')
+const sinon = require('sinon')
 
 const helper = require('../lib/agent_helper')
 const AdaptiveSampler = require('../../lib/adaptive-sampler')
-const sinon = require('sinon')
 
-tap.test('AdaptiveSampler', (t) => {
-  let sampler = null
-  const shared = {
-    'should count the number of traces sampled': (t) => {
-      t.equal(sampler.sampled, 0)
-      t.ok(sampler.shouldSample(0.1234))
-      t.equal(sampler.sampled, 1)
-      t.end()
-    },
-
-    'should not sample transactions with priorities lower than the min': (t) => {
-      t.equal(sampler.sampled, 0)
-      sampler._samplingThreshold = 0.5
-      t.notOk(sampler.shouldSample(0))
-      t.equal(sampler.sampled, 0)
-      t.ok(sampler.shouldSample(1))
-      t.equal(sampler.sampled, 1)
-      t.end()
-    },
-
-    'should adjust the min priority when throughput increases': (t) => {
-      sampler._reset(sampler.samplingTarget)
-      sampler._seen = 2 * sampler.samplingTarget
-      sampler._adjustStats(sampler.samplingTarget)
-      t.equal(sampler.samplingThreshold, 0.5)
-      t.end()
-    },
-
-    'should only take the first 10 on the first harvest': (t) => {
-      t.equal(sampler.samplingThreshold, 0)
-
-      // Change this to maxSampled if we change the way the back off works.
-      for (let i = 0; i <= 2 * sampler.samplingTarget; ++i) {
-        sampler.shouldSample(0.99999999)
-      }
-
-      t.equal(sampler.sampled, 10)
-      t.equal(sampler.samplingThreshold, 1)
-      t.end()
-    },
-
-    'should backoff on sampling after reaching the sampled target': (t) => {
-      sampler._seen = 10 * sampler.samplingTarget
-
-      // Flag the sampler as not in the first period
-      sampler._reset()
-
-      // The minimum sampled priority is not adjusted until the `target` number of
-      // transactions have been sampled, this is why the first 10 checks are all
-      // 0.9. At that point the current count of seen transactions should be close
-      // to the previous period's transaction count.
-      //
-      // In this test, however, the seen for this period is small compared the
-      // previous period (10 vs 100). This causes the MSP to drop to 0.3 but
-      // quickly normalizes again. This is an artifact of the test's use of infinite
-      // priority transactions in order to make the test predictable.
-      const epsilon = 0.000001
-      const expectedMSP = [
-        0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.316227766016838, 0.5500881229337736,
-        0.6957797474657306, 0.7910970452225743, 0.8559144986383691, 0.9013792551037068,
-        0.9340820391176599, 0.9580942670418969, 0.976025777575764, 0.9896031249412947, 1.0
-      ]
-
-      // Change this to maxSampled if we change the way the back off works.
-      for (let i = 0; i <= 2 * sampler.samplingTarget; ++i) {
-        const expected = expectedMSP[i]
-        t.ok(
-          sampler.samplingThreshold >= expected - epsilon &&
-            sampler.samplingThreshold <= expected + epsilon
-        )
-
-        sampler.shouldSample(Infinity)
-      }
-      t.end()
+const shared = {
+  'should count the number of traces sampled': (t) => {
+    const { sampler } = t.nr
+    assert.equal(sampler.sampled, 0)
+    assert.ok(sampler.shouldSample(0.1234))
+    assert.equal(sampler.sampled, 1)
+  },
+
+  'should not sample transactions with priorities lower than the min': (t) => {
+    const { sampler } = t.nr
+    assert.equal(sampler.sampled, 0)
+    sampler._samplingThreshold = 0.5
+    assert.equal(sampler.shouldSample(0), false)
+    assert.equal(sampler.sampled, 0)
+    assert.ok(sampler.shouldSample(1))
+    assert.equal(sampler.sampled, 1)
+  },
+
+  'should adjust the min priority when throughput increases': (t) => {
+    const { sampler } = t.nr
+    sampler._reset(sampler.samplingTarget)
+    sampler._seen = 2 * sampler.samplingTarget
+    sampler._adjustStats(sampler.samplingTarget)
+    assert.equal(sampler.samplingThreshold, 0.5)
+  },
+
+  'should only take the first 10 on the first harvest': (t) => {
+    const { sampler } = t.nr
+    assert.equal(sampler.samplingThreshold, 0)
+
+    // Change this to maxSampled if we change the way the back off works.
+    for (let i = 0; i <= 2 * sampler.samplingTarget; ++i) {
+      sampler.shouldSample(0.99999999)
     }
-  }
 
-  t.test('in serverless mode', (t) => {
-    let agent = null
-    t.beforeEach(() => {
-      agent = helper.loadMockedAgent({
-        serverless_mode: {
-          enabled: true
-        }
-      })
-      sampler = agent.transactionSampler
-    })
-
-    t.afterEach(() => {
-      helper.unloadAgent(agent)
-      sampler = null
-    })
+    assert.equal(sampler.sampled, 10)
+    assert.equal(sampler.samplingThreshold, 1)
+  },
+
+  'should backoff on sampling after reaching the sampled target': (t) => {
+    const { sampler } = t.nr
+    sampler._seen = 10 * sampler.samplingTarget
+
+    // Flag the sampler as not in the first period
+    sampler._reset()
+
+    // The minimum sampled priority is not adjusted until the `target` number of
+    // transactions have been sampled, this is why the first 10 checks are all
+    // 0.9. At that point the current count of seen transactions should be close
+    // to the previous period's transaction count.
+    //
+    // In this test, however, the seen for this period is small compared the
+    // previous period (10 vs 100). This causes the MSP to drop to 0.3 but
+    // quickly normalizes again. This is an artifact of the test's use of infinite
+    // priority transactions in order to make the test predictable.
+    const epsilon = 0.000001
+    const expectedMSP = [
+      0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.9, 0.316227766016838, 0.5500881229337736,
+      0.6957797474657306, 0.7910970452225743, 0.8559144986383691, 0.9013792551037068,
+      0.9340820391176599, 0.9580942670418969, 0.976025777575764, 0.9896031249412947, 1.0
+    ]
+
+    // Change this to maxSampled if we change the way the back off works.
+    for (let i = 0; i <= 2 * sampler.samplingTarget; ++i) {
+      const expected = expectedMSP[i]
+      assert.ok(
+        sampler.samplingThreshold >= expected - epsilon &&
+          sampler.samplingThreshold <= expected + epsilon
+      )
+
+      sampler.shouldSample(Infinity)
+    }
+  }
+}
 
-    Object.getOwnPropertyNames(shared).forEach((testName) => {
-      t.test(testName, shared[testName])
+test('in serverless mode', async (t) => {
+  t.beforeEach((ctx) => {
+    ctx.nr = {}
+    ctx.nr.agent = helper.loadMockedAgent({
+      serverless_mode: { enabled: true }
     })
-
-    t.test(
-      'should reset itself after a transaction outside the window has been created',
-      async (t) => {
-        const spy = sinon.spy(sampler, '_reset')
-        sampler.samplingPeriod = 50
-        t.equal(spy.callCount, 0)
-        agent.emit('transactionStarted', { timer: { start: Date.now() } })
-        t.equal(spy.callCount, 1)
-
-        return new Promise((resolve) => {
-          setTimeout(() => {
-            t.equal(spy.callCount, 1)
-            agent.emit('transactionStarted', { timer: { start: Date.now() } })
-            t.equal(spy.callCount, 2)
-            resolve()
-          }, 100)
-        })
-      }
-    )
-    t.end()
+    ctx.nr.sampler = ctx.nr.agent.transactionSampler
   })
 
-  t.test('in standard mode', (t) => {
-    t.beforeEach(() => {
-      sampler = new AdaptiveSampler({
-        period: 100,
-        target: 10
-      })
-    })
-
-    t.afterEach(() => {
-      sampler.samplePeriod = 0 // Clear sample interval.
-    })
+  t.afterEach((ctx) => {
+    helper.unloadAgent(ctx.nr.agent)
+  })
 
-    Object.getOwnPropertyNames(shared).forEach((testName) => {
-      t.test(testName, shared[testName])
-    })
+  for (const [name, fn] of Object.entries(shared)) {
+    await t.test(name, fn)
+  }
 
-    t.test('should reset itself according to the period', async (t) => {
+  await t.test(
+    'should reset itself after a transaction outside the window has been created',
+    async (t) => {
+      const { agent, sampler } = t.nr
       const spy = sinon.spy(sampler, '_reset')
       sampler.samplingPeriod = 50
+      assert.equal(spy.callCount, 0)
+      agent.emit('transactionStarted', { timer: { start: Date.now() } })
+      assert.equal(spy.callCount, 1)
 
-      return new Promise((resolve) => {
+      await new Promise((resolve) => {
         setTimeout(() => {
-          t.equal(spy.callCount, 4)
+          assert.equal(spy.callCount, 1)
+          agent.emit('transactionStarted', { timer: { start: Date.now() } })
+          assert.equal(spy.callCount, 2)
           resolve()
-        }, 235)
+        }, 100)
       })
+    }
+  )
+})
+
+test('in standard mode', async (t) => {
+  t.beforeEach((ctx) => {
+    ctx.nr = {}
+    ctx.nr.sampler = new AdaptiveSampler({ period: 100, target: 10 })
+  })
+
+  for (const [name, fn] of Object.entries(shared)) {
+    await t.test(name, fn)
+  }
+
+  await t.test('should reset itself according to the period', async (t) => {
+    const { sampler } = t.nr
+    const spy = sinon.spy(sampler, '_reset')
+    sampler.samplingPeriod = 50
+
+    await new Promise((resolve) => {
+      setTimeout(() => {
+        assert.equal(spy.callCount, 4)
+        resolve()
+      }, 235)
     })
-    t.end()
   })
-  t.end()
 })