Previews: return an empty array, rather than a null, if a dashboard has no datasources (#52961)

pkg/services/thumbs/datasources_lookup.go

@@ -60,7 +60,7 @@ func getDatasourceUIDs(resp *backend.DataResponse, uid string) ([]string, error)
 }
 
 func filterOutGrafanaDs(uids []string) []string {
-	var filtered []string
+	filtered := make([]string, 0)
 	for _, uid := range uids {
 		if uid != grafanads.DatasourceUID {
 			filtered = append(filtered, uid)

pkg/services/thumbs/datasources_lookup_test.go

@@ -18,6 +18,11 @@ var (
 	exampleListFrameJSON string
 	exampleListFrame     = &data.Frame{}
 	_                    = exampleListFrame.UnmarshalJSON([]byte(exampleListFrameJSON))
+
+	//go:embed testdata/empty_search_response_frame.json
+	listFrameJSONWithNoDatasources string
+	listFrameWithNoDatasources     = &data.Frame{}
+	_                              = listFrameWithNoDatasources.UnmarshalJSON([]byte(listFrameJSONWithNoDatasources))
 )
 
 func TestShouldParseUidFromSearchResponseFrame(t *testing.T) {
@@ -41,6 +46,28 @@ func TestShouldParseUidFromSearchResponseFrame(t *testing.T) {
 	require.Equal(t, []string{"datasource-2", "datasource-3", "datasource-4"}, uids)
 }
 
+func TestShouldReturnEmptyArrayIfThereAreNoDatasources(t *testing.T) {
+	searchService := &searchV2.MockSearchService{}
+	dsLookup := &dsUidsLookup{
+		searchService: searchService,
+		crawlerAuth:   &crawlerAuth{},
+		features:      featuremgmt.WithFeatures(featuremgmt.FlagPanelTitleSearch),
+	}
+
+	dashboardUid := "abc"
+	searchService.On("IsDisabled").Return(false)
+	searchService.On("DoDashboardQuery", mock.Anything, mock.Anything, mock.Anything, searchV2.DashboardQuery{
+		UIDs: []string{dashboardUid},
+	}).Return(&backend.DataResponse{
+		Frames: []*data.Frame{listFrameWithNoDatasources},
+	})
+
+	uids, err := dsLookup.getDatasourceUidsForDashboard(context.Background(), dashboardUid, 1)
+	require.NoError(t, err)
+	require.Equal(t, []string{}, uids)
+	require.NotNil(t, uids)
+}
+
 func TestShouldReturnNullIfSearchServiceIsDisabled(t *testing.T) {
 	searchService := &searchV2.MockSearchService{}
 	dsLookup := &dsUidsLookup{

pkg/services/thumbs/testdata/empty_search_response_frame.json

@@ -0,0 +1,120 @@
+{
+  "schema": {
+    "name": "Query results",
+    "refId": "Search",
+    "meta": {
+      "type": "search-results",
+      "custom": {
+        "count": 106,
+        "locationInfo": {
+          "yboVMzb7z": {
+            "name": "gdev dashboards",
+            "kind": "folder",
+            "url": "/dashboards/f/yboVMzb7z/gdev-dashboards"
+          }
+        },
+        "sortBy": "name_sort"
+      }
+    },
+    "fields": [
+      {
+        "name": "kind",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        }
+      },
+      {
+        "name": "uid",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        }
+      },
+      {
+        "name": "name",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        }
+      },
+      {
+        "name": "panel_type",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        }
+      },
+      {
+        "name": "url",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        },
+        "config": {
+          "links": [
+            {
+              "title": "link",
+              "url": "${__value.text}"
+            }
+          ]
+        }
+      },
+      {
+        "name": "tags",
+        "type": "other",
+        "typeInfo": {
+          "frame": "json.RawMessage",
+          "nullable": true
+        }
+      },
+      {
+        "name": "ds_uid",
+        "type": "other",
+        "typeInfo": {
+          "frame": "json.RawMessage",
+          "nullable": false
+        }
+      },
+      {
+        "name": "location",
+        "type": "string",
+        "typeInfo": {
+          "frame": "string"
+        }
+      }
+    ]
+  },
+  "data": {
+    "values": [
+      [
+        "dashboard"
+      ],
+      [
+        "ujaM1h6nz"
+      ],
+      [
+        "abc2"
+      ],
+      [
+        ""
+      ],
+      [
+        "/dashboards/f/ujaM1h6nz/abc2"
+      ],
+      [
+        [
+          "gdev"
+        ]
+      ],
+      [
+        [
+          "grafana"
+        ]
+      ],
+      [
+        ""
+      ]
+    ]
+  }
+}