tslint: autofix of let -> const (#13033)

public/app/core/specs/backend_srv.test.ts

@@ -2,14 +2,14 @@ import { BackendSrv } from 'app/core/services/backend_srv';
 jest.mock('app/core/store');
 
 describe('backend_srv', function() {
-  let _httpBackend = options => {
+  const _httpBackend = options => {
     if (options.url === 'gateway-error') {
       return Promise.reject({ status: 502 });
     }
     return Promise.resolve({});
   };
 
-  let _backendSrv = new BackendSrv(_httpBackend, {}, {}, {}, {});
+  const _backendSrv = new BackendSrv(_httpBackend, {}, {}, {}, {});
 
   describe('when handling errors', () => {
     it('should return the http status code', async () => {

public/app/core/specs/file_export.test.ts

@@ -2,7 +2,7 @@ import * as fileExport from '../utils/file_export';
 import { beforeEach, expect } from 'test/lib/common';
 
 describe('file_export', () => {
-  let ctx: any = {};
+  const ctx: any = {};
 
   beforeEach(() => {
     ctx.seriesList = [
@@ -28,7 +28,7 @@ describe('file_export', () => {
 
   describe('when exporting series as rows', () => {
     it('should export points in proper order', () => {
-      let text = fileExport.convertSeriesListToCsv(ctx.seriesList, ctx.timeFormat);
+      const text = fileExport.convertSeriesListToCsv(ctx.seriesList, ctx.timeFormat);
       const expectedText =
         '"Series";"Time";"Value"\r\n' +
         '"series_1";"1500026100";1\r\n' +
@@ -48,7 +48,7 @@ describe('file_export', () => {
 
   describe('when exporting series as columns', () => {
     it('should export points in proper order', () => {
-      let text = fileExport.convertSeriesListToCsvColumns(ctx.seriesList, ctx.timeFormat);
+      const text = fileExport.convertSeriesListToCsvColumns(ctx.seriesList, ctx.timeFormat);
       const expectedText =
         '"Time";"series_1";"series_2"\r\n' +
         '"1500026100";1;11\r\n' +

public/app/core/specs/search.test.ts

@@ -12,7 +12,7 @@ describe('SearchCtrl', () => {
     search: (options: any) => {},
     getDashboardTags: () => {},
   };
-  let ctrl = new SearchCtrl({ $on: () => {} }, {}, {}, <SearchSrv>searchSrvStub);
+  const ctrl = new SearchCtrl({ $on: () => {} }, {}, {}, <SearchSrv>searchSrvStub);
 
   describe('Given an empty result', () => {
     beforeEach(() => {

public/app/core/specs/search_results.test.ts

@@ -12,7 +12,7 @@ describe('SearchResultsCtrl', () => {
   let ctrl;
 
   describe('when checking an item that is not checked', () => {
-    let item = { checked: false };
+    const item = { checked: false };
     let selectionChanged = false;
 
     beforeEach(() => {
@@ -31,7 +31,7 @@ describe('SearchResultsCtrl', () => {
   });
 
   describe('when checking an item that is checked', () => {
-    let item = { checked: true };
+    const item = { checked: true };
     let selectionChanged = false;
 
     beforeEach(() => {
@@ -72,7 +72,7 @@ describe('SearchResultsCtrl', () => {
         folderExpanded = true;
       };
 
-      let folder = {
+      const folder = {
         expanded: false,
         toggle: () => Promise.resolve(folder),
       };
@@ -94,7 +94,7 @@ describe('SearchResultsCtrl', () => {
         folderExpanded = true;
       };
 
-      let folder = {
+      const folder = {
         expanded: true,
         toggle: () => Promise.resolve(folder),
       };

public/app/core/specs/ticks.test.ts

@@ -2,7 +2,7 @@ import * as ticks from '../utils/ticks';
 
 describe('ticks', () => {
   describe('getFlotTickDecimals()', () => {
-    let ctx: any = {};
+    const ctx: any = {};
 
     beforeEach(() => {
       ctx.axis = {};

public/app/core/specs/time_series.test.ts

@@ -329,7 +329,7 @@ describe('TimeSeries', function() {
 
   describe('legend decimals', function() {
     let series, panel;
-    let height = 200;
+    const height = 200;
     beforeEach(function() {
       testData = {
         alias: 'test',
@@ -348,7 +348,7 @@ describe('TimeSeries', function() {
     });
 
     it('should set decimals based on Y axis (expect calculated decimals = 1)', function() {
-      let data = [series];
+      const data = [series];
       // Expect ticks with this data will have decimals = 1
       updateLegendValues(data, panel, height);
       expect(data[0].decimals).toBe(2);
@@ -358,21 +358,21 @@ describe('TimeSeries', function() {
       testData.datapoints = [[10, 2], [0, 3], [100, 4], [80, 5]];
       series = new TimeSeries(testData);
       series.getFlotPairs();
-      let data = [series];
+      const data = [series];
       updateLegendValues(data, panel, height);
       expect(data[0].decimals).toBe(0);
     });
 
     it('should set decimals to Y axis decimals + 1', function() {
       panel.yaxes[0].decimals = 2;
-      let data = [series];
+      const data = [series];
       updateLegendValues(data, panel, height);
       expect(data[0].decimals).toBe(3);
     });
 
     it('should set decimals to legend decimals value if it was set explicitly', function() {
       panel.decimals = 3;
-      let data = [series];
+      const data = [series];
       updateLegendValues(data, panel, height);
       expect(data[0].decimals).toBe(3);
     });

public/app/core/specs/value_select_dropdown.test.ts

@@ -3,7 +3,7 @@ import { ValueSelectDropdownCtrl } from '../directives/value_select_dropdown';
 import q from 'q';
 
 describe('SelectDropdownCtrl', () => {
-  let tagValuesMap: any = {};
+  const tagValuesMap: any = {};
 
   ValueSelectDropdownCtrl.prototype.onUpdated = jest.fn();
   let ctrl;