1 files changed, 60 insertions, 0 deletions
diff --git a/internal/routing/router_test.go b/internal/routing/router_test.go
new file mode 100644
index 0000000..62dc656
--- /dev/null
+++ b/internal/routing/router_test.go
@@ -0,0 +1,60 @@
+package routing
+
+import (
+	"testing"
+
+	"aigw/internal/catalog"
+	"aigw/internal/config"
+	"aigw/internal/domain"
+)
+
+func TestPlanHonorsPriorityAndProtocol(t *testing.T) {
+	cfg := config.Config{
+		Providers: []config.ProviderConfig{
+			{ID: "openai-primary", Protocol: domain.ProtocolOpenAI, BaseURL: "https://one.test", APIKey: "one"},
+			{ID: "openai-fallback", Protocol: domain.ProtocolOpenAI, BaseURL: "https://two.test", APIKey: "two"},
+			{ID: "anthropic", Protocol: domain.ProtocolAnthropic, BaseURL: "https://three.test", APIKey: "three"},
+		},
+		Models: []config.ModelConfig{{
+			ID: "public/model",
+			Routes: []config.RouteConfig{
+				{Provider: "openai-fallback", UpstreamModel: "fallback", Priority: 10, Weight: 1},
+				{Provider: "anthropic", UpstreamModel: "claude", Priority: 0, Weight: 1},
+				{Provider: "openai-primary", UpstreamModel: "primary", Priority: 0, Weight: 1},
+			},
+		}},
+	}
+	router := New(catalog.New(cfg))
+	plan, err := router.Plan("public/model", domain.ProtocolOpenAI)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(plan) != 2 || plan[0].Provider.ID != "openai-primary" || plan[1].Provider.ID != "openai-fallback" {
+		t.Fatalf("unexpected plan: %+v", plan)
+	}
+}
+
+func TestPlanUsesWeightsForPrimarySelection(t *testing.T) {
+	cfg := config.Config{
+		Providers: []config.ProviderConfig{
+			{ID: "one", Protocol: domain.ProtocolOpenAI, BaseURL: "https://one.test", APIKey: "one"},
+			{ID: "two", Protocol: domain.ProtocolOpenAI, BaseURL: "https://two.test", APIKey: "two"},
+		},
+		Models: []config.ModelConfig{{ID: "public/model", Routes: []config.RouteConfig{
+			{Provider: "one", UpstreamModel: "one", Weight: 3},
+			{Provider: "two", UpstreamModel: "two", Weight: 1},
+		}}},
+	}
+	router := New(catalog.New(cfg))
+	counts := map[string]int{}
+	for range 8 {
+		plan, err := router.Plan("public/model", domain.ProtocolOpenAI)
+		if err != nil {
+			t.Fatal(err)
+		}
+		counts[plan[0].Provider.ID]++
+	}
+	if counts["one"] != 6 || counts["two"] != 2 {
+		t.Fatalf("unexpected weighted distribution: %+v", counts)
+	}
+}