fix: clear stale baggage items before extracting new ones from carrier (#7507)

steveofficer · web-flow · commit 662ff4c31e82 · 2026-03-12T08:17:33.000-04:00
When _extractBaggageItems extracts baggage from a carrier, it previously
accumulated new items on top of existing baggage in async local storage,
causing stale baggage from previous requests to leak into subsequent
traces and outbound SQS messages.

Moves the baggage cleanup to the very first line of _extractBaggageItems()
so stale baggage is cleared even when the current carrier has no baggage
header or baggage is not in the extraction propagation styles.

Added test covering the no-baggage-header scenario.
diff --git a/packages/dd-trace/src/opentracing/propagation/text_map.js b/packages/dd-trace/src/opentracing/propagation/text_map.js
@@ -667,6 +667,7 @@ class TextMapPropagator {
   }
 
   _extractBaggageItems (carrier, spanContext) {
+    removeAllBaggageItems()
     if (!this._hasPropagationStyle('extract', 'baggage')) return
     if (!carrier?.baggage) return
     const baggages = carrier.baggage.split(',')
diff --git a/packages/dd-trace/test/opentracing/propagation/text_map.spec.js b/packages/dd-trace/test/opentracing/propagation/text_map.spec.js
@@ -750,6 +750,37 @@ describe('TextMapPropagator', () => {
       assert.deepStrictEqual(getAllBaggageItems(), { foo: 'bar' })
     })
 
+    it('should clear pre-existing baggage items before extracting new ones', () => {
+      removeAllBaggageItems()
+      setBaggageItem('stale', 'leftover')
+      setBaggageItem('foo', 'old-value')
+      assert.deepStrictEqual(getAllBaggageItems(), { stale: 'leftover', foo: 'old-value' })
+
+      const carrier = {
+        'x-datadog-trace-id': '123',
+        'x-datadog-parent-id': '456',
+        baggage: 'foo=new-value,fresh=added',
+      }
+      propagator.extract(carrier)
+
+      assert.deepStrictEqual(getAllBaggageItems(), { foo: 'new-value', fresh: 'added' })
+      assert.strictEqual(getBaggageItem('stale'), undefined)
+    })
+
+    it('should clear pre-existing baggage items when carrier has no baggage header', () => {
+      removeAllBaggageItems()
+      setBaggageItem('stale', 'leftover')
+      assert.deepStrictEqual(getAllBaggageItems(), { stale: 'leftover' })
+
+      const carrier = {
+        'x-datadog-trace-id': '123',
+        'x-datadog-parent-id': '456',
+      }
+      propagator.extract(carrier)
+
+      assert.deepStrictEqual(getAllBaggageItems(), {})
+    })
+
     it('should convert signed IDs to unsigned', () => {
       textMap['x-datadog-trace-id'] = '-123'
       textMap['x-datadog-parent-id'] = '-456'

Original file line number	Diff line number	Diff line change
`@@ -667,6 +667,7 @@ class TextMapPropagator {`
`667`	`667`	`}`
`668`	`668`
`669`	`669`	`_extractBaggageItems (carrier, spanContext) {`
	`670`	`+ removeAllBaggageItems()`
`670`	`671`	`if (!this._hasPropagationStyle('extract', 'baggage')) return`
`671`	`672`	`if (!carrier?.baggage) return`
`672`	`673`	`const baggages = carrier.baggage.split(',')`