Chore: update datasource test

public/app/plugins/datasource/loki/datasource.test.ts

@@ -889,6 +889,24 @@ describe('applyTemplateVariables', () => {
   });
 });
 
+describe('getTimeRange*()', () => {
+  it('exposes the current time range', () => {
+    const ds = createLokiDatasource();
+    const timeRange = ds.getTimeRange();
+
+    expect(timeRange.from).toBeDefined();
+    expect(timeRange.to).toBeDefined();
+  });
+
+  it('exposes time range as params', () => {
+    const ds = createLokiDatasource();
+    const params = ds.getTimeRangeParams();
+
+    // Returns a very big integer, so we stringify it for the assertion
+    expect(JSON.stringify(params)).toEqual('{"start":1524650400000000000,"end":1524654000000000000}');
+  });
+});
+
 describe('Variable support', () => {
   it('has Loki variable support', () => {
     const ds = createLokiDatasource(templateSrvStub);

public/app/plugins/datasource/loki/mocks.ts

@@ -18,7 +18,7 @@ const rawRange = {
 };
 
 const defaultTimeSrvMock = {
-  timeRange: () => ({
+  timeRange: jest.fn().mockReturnValue({
     from: rawRange.from,
     to: rawRange.to,
     raw: rawRange,