feat: add sub2api compatibility

service/settings_test.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -61,6 +62,56 @@ func TestBuildModelChannelURLNormalizesArkPlanTaskPath(t *testing.T) {
 	}
 }
 
+func TestBuildModelChannelURLAcceptsVersionedSub2APIBaseURL(t *testing.T) {
+	got := BuildModelChannelURL(model.ModelChannel{BaseURL: "https://sub2api.example.com/v1"}, "/images/generations")
+	want := "https://sub2api.example.com/v1/images/generations"
+	if got != want {
+		t.Fatalf("BuildModelChannelURL = %q, want %q", got, want)
+	}
+}
+
+func TestNormalizePrivateSettingDefaultsSub2APIImageResponseFormatToURL(t *testing.T) {
+	setting := normalizePrivateSetting(model.PrivateSetting{Channels: []model.ModelChannel{{Compatibility: "sub2api"}}})
+	if got := setting.Channels[0].RequestOptions.ImageResponseFormat; got != "url" {
+		t.Fatalf("image response format = %q, want url", got)
+	}
+}
+
+func TestAdminTestChannelModelUsesImageGenerationProbeForImageModels(t *testing.T) {
+	var gotPath string
+	var gotPayload map[string]any
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		gotPath = r.URL.Path
+		if err := json.NewDecoder(r.Body).Decode(&gotPayload); err != nil {
+			t.Fatalf("Decode request body: %v", err)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = w.Write([]byte(`{"data":[{"url":"https://example.com/image.png"}]}`))
+	}))
+	defer server.Close()
+
+	result, err := testAdminChannelModel(model.ModelChannel{
+		Compatibility: "sub2api",
+		BaseURL:       server.URL + "/v1",
+		APIKey:        "test-key",
+	}, "gpt-image-2")
+	if err != nil {
+		t.Fatalf("testAdminChannelModel returned error: %v", err)
+	}
+	if result != "ok" {
+		t.Fatalf("result = %q, want ok", result)
+	}
+	if gotPath != "/v1/images/generations" {
+		t.Fatalf("path = %q, want /v1/images/generations", gotPath)
+	}
+	if gotPayload["model"] != "gpt-image-2" {
+		t.Fatalf("model = %#v", gotPayload["model"])
+	}
+	if gotPayload["response_format"] != "url" {
+		t.Fatalf("response_format = %#v, want url", gotPayload["response_format"])
+	}
+}
+
 func TestNormalizeSettingsPublishesEnabledChannelModelsAndRepairsDefaults(t *testing.T) {
 	settings := normalizeSettings(model.Settings{
 		Public: model.PublicSetting{