Dashboard: Add dashboard validation warning to save drawer (#55732)

* add api route for validating a dashboard json

* add feature flag for showDashboardValidationWarnings

* tidy up

* comments and messages

* swagger specs

* fix typo

* more swagger

* tests!

* tidy test a little bit

* no more ioutil

* api will return different status code depending on validation error

* clean up

* handle 4xx errors

* remove console.log

* fix backend tests

* tidy up

* Swagger: Exclude alpha endpoints

Co-authored-by: Sofia Papagiannaki <1632407+papagian@users.noreply.github.com>

pkg/api/dashboard_test.go

@@ -728,6 +728,60 @@ func TestDashboardAPIEndpoint(t *testing.T) {
 		})
 	})
 
+	t.Run("Given a dashboard to validate", func(t *testing.T) {
+		sqlmock := mockstore.SQLStoreMock{}
+
+		t.Run("When an invalid dashboard json is posted", func(t *testing.T) {
+			cmd := models.ValidateDashboardCommand{
+				Dashboard: "{\"hello\": \"world\"}",
+			}
+
+			role := org.RoleAdmin
+			postValidateScenario(t, "When calling POST on", "/api/dashboards/validate", "/api/dashboards/validate", cmd, role, func(sc *scenarioContext) {
+				callPostDashboard(sc)
+
+				result := sc.ToJSON()
+				assert.Equal(t, 422, sc.resp.Code)
+				assert.False(t, result.Get("isValid").MustBool())
+				assert.NotEmpty(t, result.Get("message").MustString())
+			}, &sqlmock)
+		})
+
+		t.Run("When a dashboard with a too-low schema version is posted", func(t *testing.T) {
+			cmd := models.ValidateDashboardCommand{
+				Dashboard: "{\"schemaVersion\": 1}",
+			}
+
+			role := org.RoleAdmin
+			postValidateScenario(t, "When calling POST on", "/api/dashboards/validate", "/api/dashboards/validate", cmd, role, func(sc *scenarioContext) {
+				callPostDashboard(sc)
+
+				result := sc.ToJSON()
+				assert.Equal(t, 412, sc.resp.Code)
+				assert.False(t, result.Get("isValid").MustBool())
+				assert.Equal(t, "invalid schema version", result.Get("message").MustString())
+			}, &sqlmock)
+		})
+
+		t.Run("When a valid dashboard is posted", func(t *testing.T) {
+			devenvDashboard, readErr := os.ReadFile("../../devenv/dev-dashboards/home.json")
+			assert.Empty(t, readErr)
+
+			cmd := models.ValidateDashboardCommand{
+				Dashboard: string(devenvDashboard),
+			}
+
+			role := org.RoleAdmin
+			postValidateScenario(t, "When calling POST on", "/api/dashboards/validate", "/api/dashboards/validate", cmd, role, func(sc *scenarioContext) {
+				callPostDashboard(sc)
+
+				result := sc.ToJSON()
+				assert.Equal(t, 200, sc.resp.Code)
+				assert.True(t, result.Get("isValid").MustBool())
+			}, &sqlmock)
+		})
+	})
+
 	t.Run("Given two dashboards being compared", func(t *testing.T) {
 		fakeDashboardVersionService := dashvertest.NewDashboardVersionServiceFake()
 		fakeDashboardVersionService.ExpectedDashboardVersions = []*dashver.DashboardVersion{
@@ -1053,6 +1107,42 @@ func postDashboardScenario(t *testing.T, desc string, url string, routePattern s
 	})
 }
 
+func postValidateScenario(t *testing.T, desc string, url string, routePattern string, cmd models.ValidateDashboardCommand,
+	role org.RoleType, fn scenarioFunc, sqlmock sqlstore.Store) {
+	t.Run(fmt.Sprintf("%s %s", desc, url), func(t *testing.T) {
+		cfg := setting.NewCfg()
+		hs := HTTPServer{
+			Cfg:                   cfg,
+			ProvisioningService:   provisioning.NewProvisioningServiceMock(context.Background()),
+			Live:                  newTestLive(t, sqlstore.InitTestDB(t)),
+			QuotaService:          &quotaimpl.Service{Cfg: cfg},
+			LibraryPanelService:   &mockLibraryPanelService{},
+			LibraryElementService: &mockLibraryElementService{},
+			SQLStore:              sqlmock,
+			Features:              featuremgmt.WithFeatures(),
+			Coremodels:            registry.NewBase(nil),
+		}
+
+		sc := setupScenarioContext(t, url)
+		sc.defaultHandler = routing.Wrap(func(c *models.ReqContext) response.Response {
+			c.Req.Body = mockRequestBody(cmd)
+			c.Req.Header.Add("Content-Type", "application/json")
+			sc.context = c
+			sc.context.SignedInUser = &user.SignedInUser{
+				OrgID:  testOrgID,
+				UserID: testUserID,
+			}
+			sc.context.OrgRole = role
+
+			return hs.ValidateDashboard(c)
+		})
+
+		sc.m.Post(routePattern, sc.defaultHandler)
+
+		fn(sc)
+	})
+}
+
 func postDiffScenario(t *testing.T, desc string, url string, routePattern string, cmd dtos.CalculateDiffOptions,
 	role org.RoleType, fn scenarioFunc, sqlmock sqlstore.Store, fakeDashboardVersionService *dashvertest.FakeDashboardVersionService) {
 	t.Run(fmt.Sprintf("%s %s", desc, url), func(t *testing.T) {