DataSources: Patch legacy instances so they have the required properties and functions (#41594)

* DataSources: Patch legacy instances so they have the required properties and functions

* Missed setting components

packages/grafana-data/src/types/datasource.ts

@@ -205,11 +205,8 @@ abstract class DataSourceApi<
     this.name = instanceSettings.name;
     this.id = instanceSettings.id;
     this.type = instanceSettings.type;
-    this.meta = {} as DataSourcePluginMeta;
+    this.meta = instanceSettings.meta;
     this.uid = instanceSettings.uid;
-    if (!this.uid) {
-      this.uid = this.name; // Internal datasources do not have a UID (-- Grafana --)
-    }
   }
 
   /**

public/app/features/plugins/datasource_srv.ts

@@ -144,13 +144,13 @@ export class DatasourceSrv implements DataSourceService {
     }
 
     // find the metadata
-    const dsConfig = this.settingsMapByUid[key] ?? this.settingsMapByName[key] ?? this.settingsMapById[key];
-    if (!dsConfig) {
+    const instanceSettings = this.settingsMapByUid[key] ?? this.settingsMapByName[key] ?? this.settingsMapById[key];
+    if (!instanceSettings) {
       return Promise.reject({ message: `Datasource ${key} was not found` });
     }
 
     try {
-      const dsPlugin = await importDataSourcePlugin(dsConfig.meta);
+      const dsPlugin = await importDataSourcePlugin(instanceSettings.meta);
       // check if its in cache now
       if (this.datasources[key]) {
         return this.datasources[key];
@@ -162,21 +162,31 @@ export class DatasourceSrv implements DataSourceService {
 
       if (useAngular) {
         instance = getLegacyAngularInjector().instantiate(dsPlugin.DataSourceClass, {
-          instanceSettings: dsConfig,
+          instanceSettings,
         });
       } else {
-        instance = new dsPlugin.DataSourceClass(dsConfig);
+        instance = new dsPlugin.DataSourceClass(instanceSettings);
       }
 
       instance.components = dsPlugin.components;
-      instance.meta = dsConfig.meta;
+
+      // Some old plugins does not extend DataSourceApi so we need to manually patch them
+      if (!(instance instanceof DataSourceApi)) {
+        const anyInstance = instance as any;
+        anyInstance.name = instanceSettings.name;
+        anyInstance.id = instanceSettings.id;
+        anyInstance.type = instanceSettings.type;
+        anyInstance.meta = instanceSettings.meta;
+        anyInstance.uid = instanceSettings.uid;
+        (instance as any).getRef = DataSourceApi.prototype.getRef;
+      }
 
       // store in instance cache
       this.datasources[key] = instance;
       this.datasources[instance.uid] = instance;
       return instance;
     } catch (err) {
-      appEvents.emit(AppEvents.alertError, [dsConfig.name + ' plugin failed', err.toString()]);
+      appEvents.emit(AppEvents.alertError, [instanceSettings.name + ' plugin failed', err.toString()]);
       return Promise.reject({ message: `Datasource: ${key} was not found` });
     }
   }

public/app/features/plugins/specs/datasource_srv.test.ts

@@ -1,5 +1,5 @@
 import { DatasourceSrv } from 'app/features/plugins/datasource_srv';
-import { DataSourceInstanceSettings, DataSourcePlugin } from '@grafana/data';
+import { DataSourceApi, DataSourceInstanceSettings, DataSourcePlugin, DataSourcePluginMeta } from '@grafana/data';
 
 // Datasource variable $datasource with current value 'BBB'
 const templateSrv: any = {
@@ -31,7 +31,7 @@ class TestDataSource {
 }
 
 jest.mock('../plugin_loader', () => ({
-  importDataSourcePlugin: () => {
+  importDataSourcePlugin: (meta: DataSourcePluginMeta) => {
     return Promise.resolve(new DataSourcePlugin(TestDataSource as any));
   },
 }));
@@ -115,6 +115,15 @@ describe('datasource_srv', () => {
         expect(dsByUid.meta).toBe(dsByName.meta);
         expect(dsByUid).toBe(dsByName);
       });
+
+      it('should patch legacy datasources', async () => {
+        expect(TestDataSource instanceof DataSourceApi).toBe(false);
+        const instance = await dataSourceSrv.get('mmm');
+        expect(instance.name).toBe('mmm');
+        expect(instance.type).toBe('test-db');
+        expect(instance.uid).toBe('uid-code-mmm');
+        expect(instance.getRef()).toEqual({ type: 'test-db', uid: 'uid-code-mmm' });
+      });
     });
 
     describe('when getting instance settings', () => {