make alert tab create alert button work with default datasource (#40334)

public/app/features/alerting/unified/PanelAlertTabContent.test.tsx

@@ -34,9 +34,16 @@ const dataSources = {
   prometheus: mockDataSource<PromOptions>({
     name: 'Prometheus',
     type: DataSourceType.Prometheus,
+    isDefault: false,
+  }),
+  default: mockDataSource<PromOptions>({
+    name: 'Default',
+    type: DataSourceType.Prometheus,
+    isDefault: true,
   }),
 };
 dataSources.prometheus.meta.alerting = true;
+dataSources.default.meta.alerting = true;
 
 const mocks = {
   getAllDataSources: typeAsJestMock(getAllDataSources),
@@ -165,6 +172,10 @@ describe('PanelAlertTabContent', () => {
     dsService.datasources[dataSources.prometheus.name] = new PrometheusDatasource(
       dataSources.prometheus
     ) as DataSourceApi<any, any>;
+    dsService.datasources[dataSources.default.name] = new PrometheusDatasource(dataSources.default) as DataSourceApi<
+      any,
+      any
+    >;
     setDataSourceSrv(dsService);
   });
 
@@ -189,6 +200,28 @@ describe('PanelAlertTabContent', () => {
     });
   });
 
+  it('Will work with default datasource', async () => {
+    await renderAlertTabContent(dashboard, ({
+      ...panel,
+      datasource: undefined,
+      maxDataPoints: 100,
+      interval: '10s',
+    } as any) as PanelModel);
+    const button = await ui.createButton.find();
+    const href = button.href;
+    const match = href.match(/alerting\/new\?defaults=(.*)&returnTo=/);
+    expect(match).toHaveLength(2);
+    const defaults = JSON.parse(decodeURIComponent(match![1]));
+    expect(defaults.queries[0].model).toEqual({
+      expr: 'sum(some_metric [5m])) by (app)',
+      refId: 'A',
+      datasource: 'Default',
+      interval: '',
+      intervalMs: 300000,
+      maxDataPoints: 100,
+    });
+  });
+
   it('Will take into account datasource minInterval', async () => {
     ((getDatasourceSrv() as any) as MockDataSourceSrv).datasources[dataSources.prometheus.name].interval = '7m';
 

public/app/features/alerting/unified/utils/rule-form.ts

@@ -229,8 +229,8 @@ const dataQueriesToGrafanaQueries = async (
 ): Promise<AlertQuery[]> => {
   const result: AlertQuery[] = [];
   for (const target of queries) {
-    const dsName = target.datasource || datasourceName;
+    const datasource = await getDataSourceSrv().get(target.datasource || datasourceName);
-    const datasource = await getDataSourceSrv().get(dsName);
+    const dsName = datasource.name;
 
     const range = rangeUtil.relativeToTimeRange(relativeTimeRange);
     const { interval, intervalMs } = getIntervals(range, minInterval ?? datasource.interval, maxDataPoints);