test: cover MCP auth guard and database error paths

Author: RedwindA

api/mcp_test.go

@@ -0,0 +1,41 @@
+package api
+
+import (
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/gotify/server/v3/mode"
+	"github.com/gotify/server/v3/test/testdb"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMCP_HandleWithoutApplication(t *testing.T) {
+	mode.Set(mode.TestDev)
+	recorder := httptest.NewRecorder()
+	ctx, _ := gin.CreateTestContext(recorder)
+	ctx.Request = httptest.NewRequest("POST", "/mcp", nil)
+
+	NewMCP(&MessageAPI{}, "1.0.0").Handle(ctx)
+
+	assert.Equal(t, 403, recorder.Code)
+	assert.Len(t, ctx.Errors, 1)
+}
+
+func TestMCP_ServerForRequestWithoutApplication(t *testing.T) {
+	a := NewMCP(&MessageAPI{}, "1.0.0")
+	assert.Nil(t, a.serverForRequest(httptest.NewRequest("POST", "/mcp", nil)))
+}
+
+func TestMCP_SendMessageDatabaseError(t *testing.T) {
+	mode.Set(mode.TestDev)
+	db := testdb.NewDBWithDefaultUser(t)
+	app := db.User(5).NewAppWithToken(3, "apptoken")
+	db.Close()
+
+	a := NewMCP(&MessageAPI{DB: db}, "1.0.0")
+	res, _, err := a.sendMessage(app, SendMessageInput{Message: "hi"})
+
+	assert.Nil(t, res)
+	assert.EqualError(t, err, "failed to send message")
+}