add tests

public/app/plugins/datasource/stackdriver/components/Filter.tsx

@@ -52,11 +52,13 @@ export class Filter extends React.Component<Props, State> {
       hideGroupBys,
     };
     scopeProps.loading = this.loadLabels(scopeProps);
-
     this.component = loader.load(this.element, scopeProps, template);
   }
 
   componentDidUpdate(prevProps: Props) {
+    if (!this.element) {
+      return;
+    }
     const scope = this.component.getScope();
     if (prevProps.metricType !== this.props.metricType) {
       scope.loading = this.loadLabels(scope);

public/app/plugins/datasource/stackdriver/components/QueryEditor.test.tsx

+import React from 'react';
+import renderer from 'react-test-renderer';
+import { QueryEditor, Props, DefaultTarget } from './QueryEditor';
+
+const props: Props = {
+  onQueryChange: target => {},
+  onExecuteQuery: () => {},
+  target: DefaultTarget,
+  events: { on: () => {} },
+  datasource: { templateSrv: { variables: [] } },
+};
+
+describe('QueryEditor', () => {
+  it('renders correctly', () => {
+    const tree = renderer.create(<QueryEditor {...props} />).toJSON();
+    expect(tree).toMatchSnapshot();
+  });
+});

public/app/plugins/datasource/stackdriver/components/QueryEditor.tsx

@@ -26,7 +26,7 @@ interface State extends Target {
   [key: string]: any;
 }
 
-const DefaultTarget: State = {
+export const DefaultTarget: State = {
   defaultProject: 'loading project...',
   metricType: '',
   metricKind: '',

public/app/plugins/datasource/stackdriver/functions.test.ts

+import { getAlignmentOptionsByMetric } from './functions';
+import { ValueTypes, MetricKind } from './constants';
+
+describe('functions', () => {
+  let result;
+  describe('getAlignmentOptionsByMetric', () => {
+    describe('when double and gauge is passed', () => {
+      beforeEach(() => {
+        result = getAlignmentOptionsByMetric(ValueTypes.DOUBLE, MetricKind.GAUGE);
+      });
+
+      it('should return all alignment options except two', () => {
+        expect(result.length).toBe(9);
+        expect(result.map(o => o.value)).toEqual(
+          expect.not.arrayContaining(['REDUCE_COUNT_TRUE', 'REDUCE_COUNT_FALSE'])
+        );
+      });
+    });
+
+    describe('when double and delta is passed', () => {
+      beforeEach(() => {
+        result = getAlignmentOptionsByMetric(ValueTypes.DOUBLE, MetricKind.DELTA);
+      });
+
+      it('should return all alignment options except four', () => {
+        expect(result.length).toBe(9);
+        expect(result.map(o => o.value)).toEqual(
+          expect.not.arrayContaining([
+            'ALIGN_COUNT_TRUE',
+            'ALIGN_COUNT_FALSE',
+            'ALIGN_FRACTION_TRUE',
+            'ALIGN_INTERPOLATE',
+          ])
+        );
+      });
+    });
+  });
+});