test: use assert.strictEqual / notStrictEqual for === and !== checks

`assert.ok(x === y)` / `assert(x !== y)` reduce to "Expected true, got
false" on failure — the actual operand values are lost, which makes
flaky-test debugging painful. Switching the affected call sites to
`assert.strictEqual(x, y)` / `assert.notStrictEqual(x, y)` preserves
any existing message argument and includes both operands in the
failure output automatically.

Add two `no-restricted-syntax` selectors in `eslint.config.mjs` to
prevent regressions, scoped to the existing `TEST_FILES` glob.

Author: watson

eslint.config.mjs

@@ -750,6 +750,22 @@ export default [
       'no-restricted-syntax': ['error', {
         selector: "CallExpression:matches([callee.name='doesNotThrow'], [callee.property.name='doesNotThrow'])",
         message: 'Do not use `assert.doesNotThrow()`. Execute the expression directly instead.',
+      }, {
+        // `assert(a === b)` / `assert.ok(a === b)` → `assert.strictEqual(a, b)`
+        selector:
+          'CallExpression[arguments.length<=2]' +
+          ':matches([callee.name="assert"], [callee.object.name="assert"][callee.property.name="ok"])' +
+          ' > BinaryExpression[operator="==="]:first-child',
+        message: 'Use `assert.strictEqual(a, b)` instead of `assert(a === b)` / `assert.ok(a === b)`. ' +
+          'The strict variant includes both values in the failure message automatically.',
+      }, {
+        // `assert(a !== b)` / `assert.ok(a !== b)` → `assert.notStrictEqual(a, b)`
+        selector:
+          'CallExpression[arguments.length<=2]' +
+          ':matches([callee.name="assert"], [callee.object.name="assert"][callee.property.name="ok"])' +
+          ' > BinaryExpression[operator="!=="]:first-child',
+        message: 'Use `assert.notStrictEqual(a, b)` instead of `assert(a !== b)` / `assert.ok(a !== b)`. ' +
+          'The strict variant includes both values in the failure message automatically.',
       }],
       'n/no-missing-require': 'off',
       'require-await': 'off',

integration-tests/helpers/index.js

@@ -46,7 +46,7 @@ const defaultStopProcTimeoutMs = 2_000
  */
 async function runAndCheckOutput (filename, cwd, expectedOut, expectedSource) {
   const proc = spawn(process.execPath, [filename], { cwd, stdio: 'pipe' })
-  assert(proc.pid !== undefined, 'Process PID is not available')
+  assert.notStrictEqual(proc.pid, undefined, 'Process PID is not available')
   const pid = proc.pid
   let out = await new Promise((resolve, reject) => {
     proc.once('error', reject)
@@ -162,9 +162,9 @@ function assertTelemetryPoints (pid, msgs, expectedTelemetryPoints) {
     }
 
     // Validate result metadata is present and has valid values
-    assert(typeof actualMetadata.result === 'string', 'result should be a string')
-    assert(typeof actualMetadata.result_class === 'string', 'result_class should be a string')
-    assert(typeof actualMetadata.result_reason === 'string', 'result_reason should be a string')
+    assert.strictEqual(typeof actualMetadata.result, 'string', 'result should be a string')
+    assert.strictEqual(typeof actualMetadata.result_class, 'string', 'result_class should be a string')
+    assert.strictEqual(typeof actualMetadata.result_reason, 'string', 'result_reason should be a string')
     assert(actualMetadata.result, 'result field should be present')
     assert(actualMetadata.result_class, 'result_class field should be present')
     assert(actualMetadata.result_reason, 'result_reason field should be present')
@@ -555,7 +555,7 @@ async function createSandbox (
 
     const match = dep.replaceAll(/['"]/g, '').match(/^(@?[^@]+)(@(.+))?$/)
 
-    assert(match !== null, `Invalid dependency format: ${dep}`)
+    assert.notStrictEqual(match, null, `Invalid dependency format: ${dep}`)
 
     const name = match[1]
     const range = match[3] || ''
@@ -1090,7 +1090,7 @@ function assertObjectContainsImpl (actual, expected, msg, useMatchers) {
     } else if (useMatchers && val === ANY_NUMBER) {
       assert.strictEqual(typeof actual[key], 'number', `Expected ${key} to be a number but got ${typeof actual[key]}`)
     } else if (useMatchers && val === ANY_VALUE) {
-      assert.ok(actual[key] !== undefined, `Expected ${key} to be present but it was undefined`)
+      assert.notStrictEqual(actual[key], undefined, `Expected ${key} to be present but it was undefined`)
     } else if (val !== null && typeof val === 'object') {
       assertObjectContainsImpl(actual[key], val, msg, useMatchers)
     } else {

integration-tests/profiler/profiler.spec.js

@@ -67,7 +67,7 @@ function expectProfileMessagePromise (agent, timeout,
         })
       }
       if (expectSeq) {
-        assert(event.tags_profiler.indexOf(',profile_seq:') !== -1)
+        assert.notStrictEqual(event.tags_profiler.indexOf(',profile_seq:'), -1)
       }
     } catch (e) {
       e.message += ` ${JSON.stringify({ headers, files, event })}`
@@ -162,7 +162,7 @@ class NetworkEventProcessor extends TimelineEventProcessor {
 
   decorateEvent (ev, pl) {
     // Exactly one of these is defined
-    assert.ok(!!pl.address !== !!pl.host, this.encoded)
+    assert.notStrictEqual(!!pl.address, !!pl.host, this.encoded)
     if (pl.address) {
       ev.address = this.strings.strings[pl.address]
     } else {

packages/datadog-instrumentations/test/fs.spec.js

@@ -13,14 +13,14 @@ describe('fs instrumentation', () => {
   it('require node:fs should work', () => {
     return agent.load('node:fs', undefined, { flushInterval: 1 }).then(() => {
       const fs = require('node:fs')
-      assert(fs !== undefined)
+      assert.notStrictEqual(fs, undefined)
     })
   })
 
   it('require fs should work', () => {
     return agent.load('fs', undefined, { flushInterval: 1 }).then(() => {
       const fs = require('fs')
-      assert(fs !== undefined)
+      assert.notStrictEqual(fs, undefined)
     })
   })
 })

packages/datadog-instrumentations/test/http.spec.js

@@ -89,7 +89,7 @@ describe('client', () => {
 
           sinon.assert.called(startChannelCb)
           const ctx = getContextFromStubByUrl(url, startChannelCb)
-          assert(ctx !== null)
+          assert.notStrictEqual(ctx, null)
           assert(ctx.abortController instanceof AbortController)
         })
 
@@ -181,7 +181,7 @@ describe('client', () => {
               // Necessary because the tracer makes extra requests to the agent
               if (asyncStartChannelCb.called) {
                 const ctx = getContextFromStubByUrl(url, asyncStartChannelCb)
-                assert(ctx === null)
+                assert.strictEqual(ctx, null)
               }
 
               done()
@@ -292,7 +292,7 @@ describe('client', () => {
             res.on('end', () => {
               try {
                 const payload = getResponseFinishPayload(url, responseFinishChannelCb)
-                assert(typeof payload.body === 'string')
+                assert.strictEqual(typeof payload.body, 'string')
 
                 const expectedBody = chunks.join('')
                 assert.strictEqual(payload.body, expectedBody)
@@ -324,7 +324,7 @@ describe('client', () => {
             res.on('end', () => {
               try {
                 const payload = getResponseFinishPayload(url, responseFinishChannelCb)
-                assert(typeof payload.body === 'string')
+                assert.strictEqual(typeof payload.body, 'string')
 
                 const expectedBody = chunks.join('')
                 assert.strictEqual(payload.body, expectedBody)
@@ -358,7 +358,7 @@ describe('client', () => {
             res.on('end', () => {
               try {
                 const payload = getResponseFinishPayload(url, responseFinishChannelCb)
-                assert(typeof payload.body === 'string')
+                assert.strictEqual(typeof payload.body, 'string')
                 const expectedBody = chunks.join('')
                 assert.strictEqual(payload.body, expectedBody)
 

packages/datadog-plugin-ai/test/index.spec.js

@@ -162,7 +162,7 @@ describe('Plugin', () => {
         })
 
         assert.ok(result.text, 'Expected result to be truthy')
-        assert.ok(experimentalTelemetry.tracer === myTracer, 'Tracer should be set when `isEnabled` is true')
+        assert.strictEqual(experimentalTelemetry.tracer, myTracer, 'Tracer should be set when `isEnabled` is true')
 
         await checkTraces
       })
@@ -203,7 +203,7 @@ describe('Plugin', () => {
         })
 
         assert.ok(result.text, 'Expected result to be truthy')
-        assert.ok(experimentalTelemetry.tracer === myTracer, 'Tracer should not override provided tracer')
+        assert.strictEqual(experimentalTelemetry.tracer, myTracer, 'Tracer should not override provided tracer')
 
         await checkTraces
       })

packages/datadog-plugin-anthropic/test/index.spec.js

@@ -40,9 +40,9 @@ describe('Plugin', () => {
           temperature: 0.5,
         })
 
-        assert.ok(
-          typeof promise.withResponse === 'function',
-          'Expected custom Anthropic APIPromise to have a withResponse method'
+        assert.strictEqual(
+          typeof promise.withResponse, 'function',
+          'Expected custom Anthropic APIPromise to have a withResponse method',
         )
 
         const result = await promise
@@ -69,9 +69,9 @@ describe('Plugin', () => {
             stream: true,
           })
 
-          assert.ok(
-            typeof promise.withResponse === 'function',
-            'Expected custom Anthropic APIPromise to have a withResponse method'
+          assert.strictEqual(
+            typeof promise.withResponse, 'function',
+            'Expected custom Anthropic APIPromise to have a withResponse method',
           )
 
           const stream = await promise

packages/datadog-plugin-google-cloud-pubsub/test/pubsub-push-subscription.spec.js

@@ -100,8 +100,8 @@ describe('Push Subscription Plugin', () => {
             })
 
             // Verify delivery_duration_ms
-            assert.ok(pubsubSpan.metrics['pubsub.delivery_duration_ms'] !== undefined)
-            assert.ok(typeof pubsubSpan.metrics['pubsub.delivery_duration_ms'] === 'number')
+            assert.notStrictEqual(pubsubSpan.metrics['pubsub.delivery_duration_ms'], undefined)
+            assert.strictEqual(typeof pubsubSpan.metrics['pubsub.delivery_duration_ms'], 'number')
             assert.ok(pubsubSpan.metrics['pubsub.delivery_duration_ms'] >= 0)
           })
           .then(done)

packages/dd-trace/test/aiguard/index.spec.js

@@ -487,7 +487,7 @@ describe('AIGuard SDK', () => {
       await aiguard.evaluate(prompt, { block: false })
     })
     await agent.assertSomeTraces(traces => {
-      assert.ok(traces[0].length === 2, 'Trace should contain two spans root + ai_guard')
+      assert.strictEqual(traces[0].length, 2, 'Trace should contain two spans root + ai_guard')
       for (const span of traces[0]) {
         if (span.name === 'root') {
           assert.strictEqual(span.meta[EVENT_TAG_KEY], 'true')

packages/dd-trace/test/appsec/reporter.spec.js

@@ -84,7 +84,7 @@ describe('reporter', () => {
     it('should return empty object when providing no headers', () => {
       const result = Reporter.filterHeaders(null)
 
-      assert.ok(Object.keys(result).length === 0)
+      assert.strictEqual(Object.keys(result).length, 0)
     })
 
     it('should filter and format headers from passlist', () => {