fix(propagator-jaeger): 0-pad span-id to match 16-symbol validation (#2694)

Co-authored-by: Daniel Dyla <dyladan@users.noreply.github.com>

Author: Nikolay Lagutko

packages/opentelemetry-propagator-jaeger/src/JaegerPropagator.ts

@@ -141,9 +141,10 @@ function deserializeSpanContext(serializedString: string): SpanContext | null {
     return null;
   }
 
-  const [_traceId, spanId, , flags] = headers;
+  const [_traceId, _spanId, , flags] = headers;
 
   const traceId = _traceId.padStart(32, '0');
+  const spanId = _spanId.padStart(16, '0');
   const traceFlags = flags.match(/^[0-9a-f]{2}$/i) ? parseInt(flags) & 1 : 1;
 
   return { traceId, spanId, isRemote: true, traceFlags };

packages/opentelemetry-propagator-jaeger/test/JaegerPropagator.test.ts

@@ -299,6 +299,21 @@ describe('JaegerPropagator', () => {
       assert(typeof firstEntry !== 'undefined');
       assert(firstEntry.value === 'one');
     });
+
+    it('should 0-pad span and trace id from header', () => {
+      carrier[UBER_TRACE_ID_HEADER] = '4cda95b652f4a1592b449d5929fda1b:e0c63257de34c92:0:01';
+      const extractedSpanContext = trace.getSpanContext(
+        jaegerPropagator.extract(
+          ROOT_CONTEXT,
+          carrier,
+          defaultTextMapGetter
+        )
+      );
+
+      assert.ok(extractedSpanContext);
+      assert.equal(extractedSpanContext.spanId, '0e0c63257de34c92');
+      assert.equal(extractedSpanContext.traceId, '04cda95b652f4a1592b449d5929fda1b');
+    });
   });
 
   describe('.fields()', () => {