Define adapter interfaces and fake implementations

internal/adapters/notify/fake_test.go

@@ -0,0 +1,31 @@
+package notify
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestFakeSenderCapturesRequestAndReturnsResult(t *testing.T) {
+	fake := &FakeSender{}
+	req := SendRequest{Subject: "done", Body: "body"}
+
+	res, err := fake.Send(context.Background(), req)
+	if err != nil {
+		t.Fatalf("Send() error = %v", err)
+	}
+	if len(fake.Requests) != 1 || fake.Requests[0].Subject != "done" {
+		t.Fatalf("requests = %#v, want captured request", fake.Requests)
+	}
+	if res.ProviderMessageID == "" {
+		t.Fatal("provider message id should be set")
+	}
+}
+
+func TestFakeSenderError(t *testing.T) {
+	fake := &FakeSender{Err: errors.New("boom")}
+	_, err := fake.Send(context.Background(), SendRequest{})
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+}