profiling: replace sourceMapCount with hasMissingSourceMaps (#7843)

szegedi · claude · web-flow · commit 031533a0f87f · 2026-03-23T14:36:01.000Z
Replace the `sourceMapCount` info field with a boolean
`hasMissingSourceMaps` that checks each profile's comments for the
`dd:has-missing-map-files` token emitted by @datadog/pprof when
source files declare a sourceMappingURL but the map file is missing.

Co-authored-by: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/packages/dd-trace/src/profiling/profiler.js b/packages/dd-trace/src/profiling/profiler.js
@@ -32,6 +32,14 @@ function findWebSpan (startedSpans, spanId) {
   return false
 }
 
+const MISSING_SOURCE_MAPS_TOKEN = 'dd:has-missing-map-files'
+
+function profileHasMissingSourceMaps (profile) {
+  const strings = profile?.stringTable?.strings
+  if (!strings) return false
+  return profile.comment?.some(idx => strings[idx] === MISSING_SOURCE_MAPS_TOKEN) ?? false
+}
+
 function processInfo (infos, info, type) {
   if (Object.keys(info).length > 0) {
     infos[type] = info
@@ -49,7 +57,6 @@ class Profiler extends EventEmitter {
   #logger
   #profileSeq = 0
   #spanFinishListener
-  #sourceMapCount = 0
   #timer
 
   constructor () {
@@ -195,10 +202,10 @@ class Profiler extends EventEmitter {
         mapper = new SourceMapper(config.debugSourceMaps)
         mapper.loadDirectory(process.cwd())
           .then(() => {
-            this.#sourceMapCount = mapper.infoMap.size
             if (config.debugSourceMaps) {
+              const count = mapper.infoMap.size
               this.#logger.debug(() => {
-                return this.#sourceMapCount === 0
+                return count === 0
                   ? 'Found no source maps'
                   : `Found source maps for following files: [${[...mapper.infoMap.keys()].join(', ')}]`
               })
@@ -315,7 +322,7 @@ class Profiler extends EventEmitter {
     return {
       serverless: this.serverless,
       settings: this.#config.systemInfoReport,
-      sourceMapCount: this.#sourceMapCount,
+      hasMissingSourceMaps: false,
     }
   }
 
@@ -362,6 +369,9 @@ class Profiler extends EventEmitter {
             ? await compressionFn(encoded, this.#compressionOptions)
             : encoded
           encodedProfiles[profiler.type] = compressed
+          if (profileHasMissingSourceMaps(profile)) {
+            infos.hasMissingSourceMaps = true
+          }
           processInfo(infos, info, profiler.type)
           this.#logger.debug(() => {
             const profileJson = JSON.stringify(profile, (_, value) => {
diff --git a/packages/dd-trace/test/profiling/profiler.spec.js b/packages/dd-trace/test/profiling/profiler.spec.js
@@ -388,61 +388,44 @@ describe('profiler', function () {
       assert.strictEqual(infos.serverless, false)
     })
 
-    it('should include sourceMapCount: 0 when source maps are disabled', async () => {
-      exporterPromise = new Promise(resolve => {
-        exporter.export = (exportSpec) => {
-          resolve(exportSpec)
-          return Promise.resolve()
-        }
+    it('should set hasMissingSourceMaps to true when any profile has the comment token', async () => {
+      const token = 'dd:has-missing-map-files'
+      wallProfiler.profile.returns({
+        comment: [1],
+        stringTable: { strings: ['', token] },
       })
 
-      await profiler._start(makeStartOptions({ sourceMap: false }))
-
-      clock.tick(interval)
-
-      const { infos } = await exporterPromise
-
-      assert.strictEqual(infos.sourceMapCount, 0)
-    })
-
-    it('should include sourceMapCount: 0 when no source maps are found', async () => {
       exporterPromise = new Promise(resolve => {
         exporter.export = (exportSpec) => {
           resolve(exportSpec)
           return Promise.resolve()
         }
       })
 
-      profiler._start(makeStartOptions({ sourceMap: true }))
-      await Promise.resolve() // flush .then() callback so #sourceMapCount is set
+      await profiler._start(makeStartOptions())
 
       clock.tick(interval)
 
       const { infos } = await exporterPromise
 
-      assert.strictEqual(infos.sourceMapCount, 0)
+      assert.strictEqual(infos.hasMissingSourceMaps, true)
     })
 
-    it('should include sourceMapCount with the number of loaded source maps', async () => {
-      mapperInstance.infoMap.set('file1.js', {})
-      mapperInstance.infoMap.set('file2.js', {})
-      mapperInstance.infoMap.set('file3.js', {})
-
+    it('should set hasMissingSourceMaps to false when no profile has the comment token', async () => {
       exporterPromise = new Promise(resolve => {
         exporter.export = (exportSpec) => {
           resolve(exportSpec)
           return Promise.resolve()
         }
       })
 
-      profiler._start(makeStartOptions({ sourceMap: true }))
-      await Promise.resolve() // flush .then() callback so #sourceMapCount is set
+      await profiler._start(makeStartOptions())
 
       clock.tick(interval)
 
       const { infos } = await exporterPromise
 
-      assert.strictEqual(infos.sourceMapCount, 3)
+      assert.strictEqual(infos.hasMissingSourceMaps, false)
     })
   })
 
@@ -520,9 +503,12 @@ describe('profiler', function () {
       assert.strictEqual(infos.serverless, true)
     })
 
-    it('should include sourceMapCount in export infos', async () => {
-      mapperInstance.infoMap.set('file1.js', {})
-      mapperInstance.infoMap.set('file2.js', {})
+    it('should set hasMissingSourceMaps to true when any profile has the comment token', async () => {
+      const token = 'dd:has-missing-map-files'
+      wallProfiler.profile.returns({
+        comment: [1],
+        stringTable: { strings: ['', token] },
+      })
 
       exporterPromise = new Promise(resolve => {
         exporter.export = (exportSpec) => {
@@ -531,8 +517,7 @@ describe('profiler', function () {
         }
       })
 
-      profiler._start(makeStartOptions({ sourceMap: true }))
-      await Promise.resolve() // flush .then() callback so #sourceMapCount is set
+      profiler._start(makeStartOptions())
 
       // flushAfterIntervals + 1 because it flushes after last interval
       for (let i = 0; i < flushAfterIntervals + 1; i++) {
@@ -541,7 +526,7 @@ describe('profiler', function () {
 
       const { infos } = await exporterPromise
 
-      assert.strictEqual(infos.sourceMapCount, 2)
+      assert.strictEqual(infos.hasMissingSourceMaps, true)
     })
   })
 })
