modified test to test key collision and precedence

Signed-off-by: singhvibhanshu <singhvibhanshu@hotmail.com>

Author: singhvibhanshu

exporter/kafkaexporter/go.mod

@@ -21,6 +21,7 @@ require (
 	go.opentelemetry.io/collector/client v1.55.1-0.20260409104450-d686cf9058ce
 	go.opentelemetry.io/collector/component v1.55.1-0.20260409104450-d686cf9058ce
 	go.opentelemetry.io/collector/component/componenttest v0.149.1-0.20260409104450-d686cf9058ce
+	go.opentelemetry.io/collector/config/configopaque v1.55.1-0.20260409104450-d686cf9058ce
 	go.opentelemetry.io/collector/config/configoptional v1.55.1-0.20260409104450-d686cf9058ce
 	go.opentelemetry.io/collector/config/configretry v1.55.1-0.20260409104450-d686cf9058ce
 	go.opentelemetry.io/collector/confmap v1.55.1-0.20260409104450-d686cf9058ce
@@ -104,7 +105,6 @@ require (
 	github.com/xdg-go/stringprep v1.0.4 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/collector/config/configcompression v1.55.1-0.20260409104450-d686cf9058ce // indirect
-	go.opentelemetry.io/collector/config/configopaque v1.55.1-0.20260409104450-d686cf9058ce // indirect
 	go.opentelemetry.io/collector/config/configtls v1.55.1-0.20260409104450-d686cf9058ce // indirect
 	go.opentelemetry.io/collector/consumer/consumererror/xconsumererror v0.149.1-0.20260409104450-d686cf9058ce // indirect
 	go.opentelemetry.io/collector/consumer/consumertest v0.149.1-0.20260409104450-d686cf9058ce // indirect

exporter/kafkaexporter/internal/kafkaclient/franzgo_test.go

@@ -69,12 +69,13 @@ func TestExportData_MessageTooLarge(t *testing.T) {
 
 func TestMakeFranzMessages_RecordHeaders(t *testing.T) {
 	recordHeaders := configopaque.MapList{
-		{Name: "custom-header-1", Value: configopaque.String("value-1")},
-		{Name: "custom-header-2", Value: configopaque.String("value-2")},
+		{Name: "static-key-ONLY", Value: configopaque.String("static-value")},
+		{Name: "shared-key", Value: configopaque.String("static-value-override")},
 	}
 
 	md := client.NewMetadata(map[string][]string{
-		"dynamic-key": {"dynamic-value"},
+		"dynamic-key-ONLY": {"dynamic-value"},
+		"shared-key":       {"dynamic-value-wins"},
 	})
 	ctx := client.NewContext(t.Context(), client.Info{Metadata: md})
 
@@ -89,22 +90,22 @@ func TestMakeFranzMessages_RecordHeaders(t *testing.T) {
 	}
 
 	records := makeFranzMessages(msgs, recordHeaders)
-	setMessageHeaders(ctx, records, []string{"dynamic-key"})
+	setMessageHeaders(ctx, records, []string{"dynamic-key-ONLY", "shared-key"})
 
 	require.Len(t, records, 1, "expected exactly 1 record")
 	record := records[0]
 
 	assert.Equal(t, "test-topic", record.Topic)
 	assert.Equal(t, []byte("test-payload"), record.Value)
 
-	require.Len(t, record.Headers, 3, "expected exactly 3 headers (2 static, 1 dynamic)")
+	require.Len(t, record.Headers, 4, "expected exactly 4 headers on the record")
 
 	headerMap := make(map[string]string)
 	for _, h := range record.Headers {
 		headerMap[h.Key] = string(h.Value)
 	}
 
-	assert.Equal(t, "value-1", headerMap["custom-header-1"])
-	assert.Equal(t, "value-2", headerMap["custom-header-2"])
-	assert.Equal(t, "dynamic-value", headerMap["dynamic-key"])
+	assert.Equal(t, "static-value", headerMap["static-key-ONLY"], "static headers unique key failed")
+	assert.Equal(t, "dynamic-value", headerMap["dynamic-key-ONLY"], "dynamic headers unique key failed")
+	assert.Equal(t, "dynamic-value-wins", headerMap["shared-key"], "Precedence for common key failed")
 }