From 83c63c5f931f8548cf0c640deb02f4a52d705628 Mon Sep 17 00:00:00 2001
From: Jerry Yan <792602257@qq.com>
Date: Tue, 28 Apr 2026 22:28:47 +0800
Subject: [PATCH] feat(notify): dummy notifier writing structured log lines

---
 internal/infra/notify/dummy.go      | 32 +++++++++++++++++++++++++++++
 internal/infra/notify/dummy_test.go | 26 +++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 internal/infra/notify/dummy.go
 create mode 100644 internal/infra/notify/dummy_test.go

diff --git a/internal/infra/notify/dummy.go b/internal/infra/notify/dummy.go
new file mode 100644
index 0000000..e2c7af1
--- /dev/null
+++ b/internal/infra/notify/dummy.go
@@ -0,0 +1,32 @@
+package notify
+
+import (
+	"context"
+	"log/slog"
+)
+
+// DummyNotifier 仅用于本地与测试环境，将通知以结构化日志形式打印，不做任何
+// 真实外发。生产环境如未配置真实 Notifier，可注册此实现作为兜底，避免投递
+// 流程因缺少 channel 而中断。
+type DummyNotifier struct {
+	log *slog.Logger
+}
+
+// NewDummyNotifier 用调用方提供的 logger 构造 DummyNotifier。logger 为 nil 时
+// 调用 Send 会 panic，这是显式契约——上层负责传入有效 logger。
+func NewDummyNotifier(log *slog.Logger) *DummyNotifier { return &DummyNotifier{log: log} }
+
+// Name 返回 ChannelDummy，标识该 Notifier 的通道身份。
+func (d *DummyNotifier) Name() Channel { return ChannelDummy }
+
+// Send 将消息以 Info 级别结构化日志输出。ctx 在 dummy 实现中不消费，
+// 真实通道（email/webhook/IM）应尊重 ctx 的取消与超时。
+func (d *DummyNotifier) Send(_ context.Context, msg Message) error {
+	d.log.Info("notify[dummy]",
+		"topic", msg.Topic,
+		"severity", string(msg.Severity),
+		"user_id", msg.UserID.String(),
+		"title", msg.Title,
+	)
+	return nil
+}
diff --git a/internal/infra/notify/dummy_test.go b/internal/infra/notify/dummy_test.go
new file mode 100644
index 0000000..e4383e0
--- /dev/null
+++ b/internal/infra/notify/dummy_test.go
@@ -0,0 +1,26 @@
+package notify
+
+import (
+	"bytes"
+	"context"
+	"log/slog"
+	"testing"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDummy_Send_LogsAndReturnsNil(t *testing.T) {
+	var buf bytes.Buffer
+	log := slog.New(slog.NewJSONHandler(&buf, nil))
+	d := NewDummyNotifier(log)
+
+	require.Equal(t, ChannelDummy, d.Name())
+	err := d.Send(context.Background(), Message{
+		ID: uuid.New(), UserID: uuid.New(),
+		Topic: "x", Severity: SeverityInfo, Title: "hi", Body: "world",
+	})
+	require.NoError(t, err)
+	require.Contains(t, buf.String(), "notify[dummy]")
+	require.Contains(t, buf.String(), `"topic":"x"`)
+}