add another failing test that shows "data loss" in go context

experimental/bridge/opentracing/mix_test.go

@@ -25,6 +25,8 @@ type mixedAPIsTestCase struct {
 func getMixedAPIsTestCases() []mixedAPIsTestCase {
 	st := newSimpleTest()
 	cast := newCurrentActiveSpanTest()
+	coin := newContextIntactTest()
+
 	return []mixedAPIsTestCase{
 		{
 			desc:  "simple otel -> ot -> otel",
@@ -50,6 +52,18 @@ func getMixedAPIsTestCases() []mixedAPIsTestCase {
 			run:   cast.runOTOtelOT,
 			check: cast.check,
 		},
+		{
+			desc:  "context intact otel -> ot -> otel",
+			setup: coin.setup,
+			run:   coin.runOtelOTOtel,
+			check: coin.check,
+		},
+		{
+			desc:  "context intact ot -> otel -> ot",
+			setup: coin.setup,
+			run:   coin.runOTOtelOT,
+			check: coin.check,
+		},
 	}
 }
 
@@ -160,6 +174,84 @@ func (cast *currentActiveSpanTest) recordSpans(ctx context.Context) {
 	cast.recordedActiveOTSpanIDs = append(cast.recordedActiveOTSpanIDs, spanID)
 }
 
+type contextIntactTest struct {
+	contextKeyValues []internal.MockContextKeyValue
+
+	recordedContextValues []interface{}
+	recordIdx             int
+}
+
+type coin1Key struct{}
+
+type coin1Value struct{}
+
+type coin2Key struct{}
+
+type coin2Value struct{}
+
+type coin3Key struct{}
+
+type coin3Value struct{}
+
+func newContextIntactTest() *contextIntactTest {
+	return &contextIntactTest{
+		contextKeyValues: []internal.MockContextKeyValue{
+			internal.MockContextKeyValue{
+				Key:   coin1Key{},
+				Value: coin1Value{},
+			},
+			internal.MockContextKeyValue{
+				Key:   coin2Key{},
+				Value: coin2Value{},
+			},
+			internal.MockContextKeyValue{
+				Key:   coin3Key{},
+				Value: coin3Value{},
+			},
+		},
+	}
+}
+
+func (coin *contextIntactTest) setup(t *testing.T, tracer *internal.MockTracer) {
+	tracer.SpareContextKeyValues = append(tracer.SpareContextKeyValues, coin.contextKeyValues...)
+
+	coin.recordedContextValues = nil
+	coin.recordIdx = 0
+}
+
+func (coin *contextIntactTest) check(t *testing.T, tracer *internal.MockTracer) {
+	if len(coin.recordedContextValues) != len(coin.contextKeyValues) {
+		t.Errorf("Expected to have %d recorded context values, got %d", len(coin.contextKeyValues), len(coin.recordedContextValues))
+	}
+
+	minLen := min(len(coin.recordedContextValues), len(coin.contextKeyValues))
+	for i := 0; i < minLen; i++ {
+		key := coin.contextKeyValues[i].Key
+		value := coin.contextKeyValues[i].Value
+		gotValue := coin.recordedContextValues[i]
+		if value != gotValue {
+			t.Errorf("Expected value %#v for key %#v, got %#v", value, key, gotValue)
+		}
+	}
+}
+
+func (coin *contextIntactTest) runOtelOTOtel(t *testing.T, ctx context.Context) {
+	runOtelOTOtel(t, ctx, "coin", coin.recordValue)
+}
+
+func (coin *contextIntactTest) runOTOtelOT(t *testing.T, ctx context.Context) {
+	runOTOtelOT(t, ctx, "coin", coin.recordValue)
+}
+
+func (coin *contextIntactTest) recordValue(ctx context.Context) {
+	if coin.recordIdx >= len(coin.contextKeyValues) {
+		return
+	}
+	key := coin.contextKeyValues[coin.recordIdx].Key
+	coin.recordIdx++
+	coin.recordedContextValues = append(coin.recordedContextValues, ctx.Value(key))
+}
+
 func checkTraceAndSpans(t *testing.T, tracer *internal.MockTracer, expectedTraceID otelcore.TraceID, expectedSpanIDs []uint64) {
 	expectedSpanCount := len(expectedSpanIDs)