doc: add no-var, prefer-const in doc eslintrc

PR-URL: https://github.com/nodejs/node/pull/12563
Refs: https://github.com/nodejs/node/pull/12557#issuecomment-296015032
Reviewed-By: Teddy Katz <teddy.katz@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/doc/guides/writing-tests.md b/doc/guides/writing-tests.md
index 70690e2fda..3cb87623ae 100644
--- a/doc/guides/writing-tests.md
+++ b/doc/guides/writing-tests.md
@@ -141,22 +141,22 @@ this with a real test from the test suite.
 
 ```javascript
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var http = require('http');
+require('../common');
+const assert = require('assert');
+const http = require('http');
 
-var request = 0;
-var response = 0;
+let request = 0;
+let response = 0;
 process.on('exit', function() {
   assert.equal(request, 1, 'http server "request" callback was not called');
   assert.equal(response, 1, 'http request "response" callback was not called');
 });
 
-var server = http.createServer(function(req, res) {
+const server = http.createServer(function(req, res) {
   request++;
   res.end();
 }).listen(0, function() {
-  var options = {
+  const options = {
     agent: null,
     port: this.address().port
   };
@@ -172,14 +172,13 @@ This test could be greatly simplified by using `common.mustCall` like this:
 
 ```javascript
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var http = require('http');
+const common = require('../common');
+const http = require('http');
 
-var server = http.createServer(common.mustCall(function(req, res) {
+const server = http.createServer(common.mustCall(function(req, res) {
   res.end();
 })).listen(0, function() {
-  var options = {
+  const options = {
     agent: null,
     port: this.address().port
   };