test: update Test_parseOpenAIResponseBody to use raw JSON for request body

Signed-off-by: Sivanantham Chinnaiyan <[email protected]>

Author: sivanantha321

internal/extproc/responses_processor_test.go

@@ -7,7 +7,6 @@ package extproc
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"io"
 	"log/slog"
@@ -38,16 +37,16 @@ func TestResponsesProcessorFactory(t *testing.T) {
 
 func Test_parseOpenAIResponseBody(t *testing.T) {
 	t.Run("ok", func(t *testing.T) {
-		req := openai.ResponseRequest{Model: "m1"}
-		b, _ := json.Marshal(req)
+		// Use raw JSON to avoid issues with union-type marshalling in test structs.
+		b := []byte(`{"model":"m1"}`)
 		model, rr, err := parseOpenAIResponseBody(&extprocv3.HttpBody{Body: b})
 		require.NoError(t, err)
 		require.Equal(t, "m1", model)
-		require.Equal(t, &req, rr)
+		// Ensure parsed request has the expected model value
+		require.Equal(t, "m1", rr.Model)
 	})
 	t.Run("error missing model", func(t *testing.T) {
-		req := openai.ResponseRequest{}
-		b, _ := json.Marshal(req)
+		b := []byte(`{}`)
 		_, _, err := parseOpenAIResponseBody(&extprocv3.HttpBody{Body: b})
 		require.Error(t, err)
 	})