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

backend/internal/service/image_billing_size_test.go

@@ -0,0 +1,110 @@
+package service
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestClassifyImageBillingTier(t *testing.T) {
+	tests := []struct {
+		name     string
+		size     string
+		wantTier string
+		wantOK   bool
+	}{
+		{name: "explicit 2k square", size: "2048x2048", wantTier: "2K", wantOK: true},
+		{name: "explicit 2k landscape", size: "2048x1152", wantTier: "2K", wantOK: true},
+		{name: "explicit 4k landscape", size: "3840x2160", wantTier: "4K", wantOK: true},
+		{name: "explicit 4k portrait", size: "2160x3840", wantTier: "4K", wantOK: true},
+		{name: "long edge 1k", size: "1024X768", wantTier: "1K", wantOK: true},
+		{name: "long edge 2k", size: "1280x768", wantTier: "2K", wantOK: true},
+		{name: "long edge 4k", size: "2560x1600", wantTier: "4K", wantOK: true},
+		{name: "tier string 1k", size: "1k", wantTier: "1K", wantOK: true},
+		{name: "empty", size: "", wantOK: false},
+		{name: "auto", size: "auto", wantOK: false},
+		{name: "invalid", size: "not-a-size", wantOK: false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotTier, gotOK := ClassifyImageBillingTier(tt.size)
+			require.Equal(t, tt.wantOK, gotOK)
+			require.Equal(t, tt.wantTier, gotTier)
+		})
+	}
+}
+
+func TestResolveImageBillingSize(t *testing.T) {
+	tests := []struct {
+		name          string
+		inputSize     string
+		outputSizes   []string
+		wantBilling   string
+		wantOutput    string
+		wantSource    string
+		wantBreakdown map[string]int
+	}{
+		{
+			name:          "output wins over input",
+			inputSize:     "1024x1024",
+			outputSizes:   []string{"3840x2160"},
+			wantBilling:   "4K",
+			wantOutput:    "3840x2160",
+			wantSource:    ImageSizeSourceOutput,
+			wantBreakdown: map[string]int{"4K": 1},
+		},
+		{
+			name:        "input fallback",
+			inputSize:   "1024x1024",
+			wantBilling: "1K",
+			wantSource:  ImageSizeSourceInput,
+		},
+		{
+			name:        "auto defaults",
+			inputSize:   "auto",
+			wantBilling: "2K",
+			wantSource:  ImageSizeSourceDefault,
+		},
+		{
+			name:        "empty defaults",
+			inputSize:   "",
+			wantBilling: "2K",
+			wantSource:  ImageSizeSourceDefault,
+		},
+		{
+			name:        "invalid defaults",
+			inputSize:   "largest",
+			wantBilling: "2K",
+			wantSource:  ImageSizeSourceDefault,
+		},
+		{
+			name:          "mixed output chooses highest tier",
+			inputSize:     "1024x1024",
+			outputSizes:   []string{"1024x1024", "3840x2160", "1280x720"},
+			wantBilling:   "4K",
+			wantOutput:    "1024x1024",
+			wantSource:    ImageSizeSourceOutput,
+			wantBreakdown: map[string]int{"1K": 1, "2K": 1, "4K": 1},
+		},
+		{
+			name:        "unparseable output falls back to parseable input",
+			inputSize:   "2048x1152",
+			outputSizes: []string{"auto"},
+			wantBilling: "2K",
+			wantOutput:  "auto",
+			wantSource:  ImageSizeSourceInput,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := ResolveImageBillingSize(tt.inputSize, tt.outputSizes)
+			require.Equal(t, tt.wantBilling, got.BillingSize)
+			require.Equal(t, tt.inputSize, got.InputSize)
+			require.Equal(t, tt.wantOutput, got.OutputSize)
+			require.Equal(t, tt.wantSource, got.Source)
+			require.Equal(t, tt.wantBreakdown, got.Breakdown)
+		})
+	}
+}