fix baggage extraction (#4935)

Author: ida613

packages/dd-trace/src/opentracing/propagation/text_map.js

@@ -339,11 +339,11 @@ class TextMapPropagator {
           context._links.push(link)
         }
       }
+    }
 
-      if (this._config.tracePropagationStyle.extract.includes('baggage') && carrier.baggage) {
-        context = context || new DatadogSpanContext()
-        this._extractBaggageItems(carrier, context)
-      }
+    if (this._hasPropagationStyle('extract', 'baggage') && carrier.baggage) {
+      context = context || new DatadogSpanContext()
+      this._extractBaggageItems(carrier, context)
     }
 
     return context || this._extractSqsdContext(carrier)

packages/dd-trace/test/opentracing/propagation/text_map.spec.js

@@ -406,7 +406,6 @@ describe('TextMapPropagator', () => {
     })
 
     it('should extract otel baggage items with special characters', () => {
-      process.env.DD_TRACE_BAGGAGE_ENABLED = true
       config = new Config()
       propagator = new TextMapPropagator(config)
       const carrier = {
@@ -452,6 +451,20 @@ describe('TextMapPropagator', () => {
       expect(spanContextD._baggageItems).to.deep.equal({})
     })
 
+    it('should extract baggage when it is the only propagation style', () => {
+      config = new Config({
+        tracePropagationStyle: {
+          extract: ['baggage']
+        }
+      })
+      propagator = new TextMapPropagator(config)
+      const carrier = {
+        baggage: 'foo=bar'
+      }
+      const spanContext = propagator.extract(carrier)
+      expect(spanContext._baggageItems).to.deep.equal({ foo: 'bar' })
+    })
+
     it('should convert signed IDs to unsigned', () => {
       textMap['x-datadog-trace-id'] = '-123'
       textMap['x-datadog-parent-id'] = '-456'