test(pay): 补 fake 三态/MockChannelEnabled 装配/devmock 端点/gateway currency_mismatch/限流 bucket 回收

internal/providerbuild/registry_build_test.go

@@ -96,3 +96,54 @@ func TestBuildRegistry(t *testing.T) {
 		})
 	}
 }
+
+// TestBuildRegistryMockChannelEnabled 覆盖 config.C.MockChannelEnabled=true 时的
+// fake 装配分支:注册表含 "fake",且其结算币种被设成 ["CNY","USDT"](CNY 排首位,
+// 对齐 pangolin 下单实际结算币种,见 registry.go 顶部注释)。config.C 是包级全局,
+// 测试内直接改字段 + defer 复原,避免污染同包/其它包测试的默认值(与
+// handler 包 ratelimit_test.go / refund_test.go 的 config.C 约定一致)。
+func TestBuildRegistryMockChannelEnabled(t *testing.T) {
+	prev := config.C.MockChannelEnabled
+	config.C.MockChannelEnabled = true
+	defer func() { config.C.MockChannelEnabled = prev }()
+
+	acctReg := accounts.New(nil)
+	reg := providerbuild.BuildRegistry(acctReg)
+
+	methods := reg.Methods()
+	found := false
+	for _, m := range methods {
+		if m == "fake" {
+			found = true
+		}
+	}
+	if !found {
+		t.Fatalf("MockChannelEnabled=true 时 Methods() 应含 fake, got %v", methods)
+	}
+
+	fp, err := reg.Get("fake")
+	if err != nil {
+		t.Fatalf("Get(fake): %v", err)
+	}
+	caps := fp.Capabilities()
+	if len(caps.SettleCurrencies) == 0 || caps.SettleCurrencies[0] != "CNY" {
+		t.Fatalf("mock 装配应把 fake 结算币种设成 CNY 优先, got %v", caps.SettleCurrencies)
+	}
+}
+
+// TestBuildRegistryMockChannelDisabledByDefault 反向覆盖:MockChannelEnabled=false
+// (生产默认值)时注册表不含 "fake",证明 mock 渠道对生产零影响。
+func TestBuildRegistryMockChannelDisabledByDefault(t *testing.T) {
+	prev := config.C.MockChannelEnabled
+	config.C.MockChannelEnabled = false
+	defer func() { config.C.MockChannelEnabled = prev }()
+
+	acctReg := accounts.New(nil)
+	reg := providerbuild.BuildRegistry(acctReg)
+
+	for _, m := range reg.Methods() {
+		if m == "fake" {
+			t.Fatalf("MockChannelEnabled=false(默认)时 Methods() 不应含 fake, got %v", reg.Methods())
+		}
+	}
+}