Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/service/upstream_response_model_test.go

@@ -0,0 +1,196 @@
+package service
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestUpstreamResponseModelObserverTerminalWinsAndRecordsConflict(t *testing.T) {
+	observer := &upstreamResponseModelObserver{}
+
+	observer.ObserveOpenAI([]byte(`{"type":"response.created","response":{"model":"gpt-5.5"}}`), "response.created")
+	observer.ObserveOpenAI([]byte(`{"type":"response.completed","response":{"model":"gpt-5.4"}}`), "response.completed")
+
+	require.Equal(t, "gpt-5.4", observer.Model())
+	require.True(t, observer.Conflict())
+}
+
+func TestUpstreamResponseModelObserverSupportsAnthropicAndGeminiShapes(t *testing.T) {
+	t.Run("anthropic", func(t *testing.T) {
+		observer := &upstreamResponseModelObserver{}
+		observer.ObserveAnthropic([]byte(`{"type":"message_start","message":{"model":"claude-sonnet-4-20250514"}}`))
+		require.Equal(t, "claude-sonnet-4-20250514", observer.Model())
+	})
+
+	t.Run("gemini outer and nested", func(t *testing.T) {
+		observer := &upstreamResponseModelObserver{}
+		observer.ObserveGemini([]byte(`{"response":{"modelVersion":"gemini-2.5-pro"}}`))
+		observer.ObserveGemini([]byte(`{"modelVersion":"gemini-2.5-pro-latest"}`))
+		require.Equal(t, "gemini-2.5-pro-latest", observer.Model())
+		require.True(t, observer.Conflict())
+	})
+}
+
+func TestUpstreamResponseModelObservationAttemptReset(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	c, _ := gin.CreateTestContext(nil)
+
+	first := beginUpstreamResponseModelObservation(c)
+	first.Observe("failed-attempt-model", false)
+	second := beginUpstreamResponseModelObservation(c)
+	second.Observe("successful-attempt-model", false)
+
+	require.Equal(t, "successful-attempt-model", observedUpstreamResponseModel(c))
+	require.False(t, observedUpstreamResponseModelConflict(c))
+}
+
+func TestUpstreamModelMismatchThreeStateAndCaseInsensitiveComparison(t *testing.T) {
+	require.Nil(t, upstreamModelMismatch("gpt-5.5", ""))
+
+	matched := upstreamModelMismatch("gpt-5.5", "GPT-5.5")
+	require.NotNil(t, matched)
+	require.False(t, *matched)
+
+	mismatched := upstreamModelMismatch("gpt-5.5", "gpt-5.4")
+	require.NotNil(t, mismatched)
+	require.True(t, *mismatched)
+}
+
+func TestUpstreamModelMismatchTreatsGrokBuildRuntimeIDsAsAliases(t *testing.T) {
+	tests := []struct {
+		name          string
+		sentModel     string
+		responseModel string
+	}{
+		{
+			name:          "issue 5634 grok 4.6",
+			sentModel:     "grok-4.6",
+			responseModel: "grok-4.6-build",
+		},
+		{
+			name:          "grok 4.6 latest",
+			sentModel:     "grok-4.6-latest",
+			responseModel: "grok-4.6-build",
+		},
+		{
+			name:          "issue 5647 grok 4.5 latest",
+			sentModel:     "grok-4.5-latest",
+			responseModel: "grok-4.5-build",
+		},
+		{
+			name:          "grok 4.5 canonical",
+			sentModel:     "grok-4.5",
+			responseModel: "GROK-4.5-BUILD",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mismatch := upstreamModelMismatch(tt.sentModel, tt.responseModel)
+
+			require.NotNil(t, mismatch)
+			require.False(t, *mismatch)
+		})
+	}
+}
+
+func TestUpstreamModelMismatchDoesNotCollapseDifferentModels(t *testing.T) {
+	tests := []struct {
+		name          string
+		sentModel     string
+		responseModel string
+	}{
+		{
+			name:          "different grok versions",
+			sentModel:     "grok-4.5",
+			responseModel: "grok-4.6-build",
+		},
+		{
+			name:          "unrelated build suffix",
+			sentModel:     "gpt-5.5",
+			responseModel: "gpt-5.5-build",
+		},
+		{
+			name:          "different grok runtime",
+			sentModel:     "grok-build-0.1",
+			responseModel: "grok-4.5-build",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			mismatch := upstreamModelMismatch(tt.sentModel, tt.responseModel)
+
+			require.NotNil(t, mismatch)
+			require.True(t, *mismatch)
+		})
+	}
+}
+
+func TestObserveOpenAISSEBodyIgnoresMalformedPayload(t *testing.T) {
+	observer := &upstreamResponseModelObserver{}
+	observeOpenAISSEBody(observer, "data: not-json\n\ndata: {\"type\":\"response.completed\",\"response\":{\"model\":\"gpt-5.4\"}}\n\n")
+
+	require.Equal(t, "gpt-5.4", observer.Model())
+	require.False(t, observer.Conflict())
+}
+
+func TestObserveAntigravityGeminiSSELineReadsWrapperModelWithoutUnwrap(t *testing.T) {
+	tests := []struct {
+		name    string
+		payload string
+		want    string
+	}{
+		{
+			name:    "top-level sibling",
+			payload: `{"modelVersion":"gemini-3-pro","response":{"candidates":[]}}`,
+			want:    "gemini-3-pro",
+		},
+		{
+			name:    "single wrapper",
+			payload: `{"response":{"modelVersion":"gemini-3-pro","candidates":[]}}`,
+			want:    "gemini-3-pro",
+		},
+		{
+			name:    "nested response after one wrapper",
+			payload: `{"response":{"response":{"modelVersion":"gemini-3-pro","candidates":[]}}}`,
+			want:    "gemini-3-pro",
+		},
+		{
+			name:    "outer declaration takes precedence",
+			payload: `{"modelVersion":"gemini-outer","response":{"modelVersion":"gemini-inner","candidates":[]}}`,
+			want:    "gemini-outer",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gin.SetMode(gin.TestMode)
+			c, _ := gin.CreateTestContext(nil)
+			beginUpstreamResponseModelObservation(c)
+
+			svc := &AntigravityGatewayService{}
+			svc.observeAntigravityGeminiSSELine(c, "data: "+tt.payload)
+
+			require.Equal(t, tt.want, observedUpstreamResponseModel(c))
+			require.False(t, observedUpstreamResponseModelConflict(c))
+		})
+	}
+}
+
+func TestUpstreamResponseModelObserverRejectsMalformedJSONWithModelField(t *testing.T) {
+	observer := &upstreamResponseModelObserver{}
+	observer.ObserveOpenAI([]byte(`{"response":{"model":"gpt-5.4"}`), "response.completed")
+
+	require.Empty(t, observer.Model())
+}
+
+func TestUpstreamResponseModelObserverBoundsUntrustedModelName(t *testing.T) {
+	observer := &upstreamResponseModelObserver{}
+	observer.Observe("  "+strings.Repeat("模", upstreamResponseModelMaxLength+1)+"  ", false)
+
+	require.Len(t, []rune(observer.Model()), upstreamResponseModelMaxLength)
+}