test: swap var->const/let and equal->strictEqual

Change instances of var with const/let.
Change assert.equal to assert.strictEqual.

PR-URL: https://github.com/nodejs/node/pull/9888
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-tls-no-sslv3.js

@@ -1,30 +1,30 @@
 'use strict';
-var common = require('../common');
+const common = require('../common');
-var assert = require('assert');
+const assert = require('assert');
 
 if (!common.hasCrypto) {
   common.skip('missing crypto');
   return;
 }
-var tls = require('tls');
+const tls = require('tls');
 
-var fs = require('fs');
+const fs = require('fs');
-var spawn = require('child_process').spawn;
+const spawn = require('child_process').spawn;
 
 if (common.opensslCli === false) {
   common.skip('node compiled without OpenSSL CLI.');
   return;
 }
 
-var cert = fs.readFileSync(common.fixturesDir + '/test_cert.pem');
+const cert = fs.readFileSync(common.fixturesDir + '/test_cert.pem');
-var key = fs.readFileSync(common.fixturesDir + '/test_key.pem');
+const key = fs.readFileSync(common.fixturesDir + '/test_key.pem');
-var server = tls.createServer({ cert: cert, key: key }, common.fail);
+const server = tls.createServer({ cert: cert, key: key }, common.fail);
-var errors = [];
+const errors = [];
-var stderr = '';
+let stderr = '';
 
 server.listen(0, '127.0.0.1', function() {
-  var address = this.address().address + ':' + this.address().port;
+  const address = this.address().address + ':' + this.address().port;
-  var args = ['s_client',
+  const args = ['s_client',
               '-ssl3',
               '-connect', address];
 
@@ -32,14 +32,14 @@ server.listen(0, '127.0.0.1', function() {
   if (common.isWindows)
     args.push('-no_rand_screen');
 
-  var client = spawn(common.opensslCli, args, { stdio: 'pipe' });
+  const client = spawn(common.opensslCli, args, { stdio: 'pipe' });
   client.stdout.pipe(process.stdout);
   client.stderr.pipe(process.stderr);
   client.stderr.setEncoding('utf8');
   client.stderr.on('data', (data) => stderr += data);
 
   client.once('exit', common.mustCall(function(exitCode) {
-    assert.equal(exitCode, 1);
+    assert.strictEqual(exitCode, 1);
     server.close();
   }));
 });
@@ -50,7 +50,7 @@ process.on('exit', function() {
   if (/unknown option -ssl3/.test(stderr)) {
     common.skip('`openssl s_client -ssl3` not supported.');
   } else {
-    assert.equal(errors.length, 1);
+    assert.strictEqual(errors.length, 1);
     assert(/:wrong version number/.test(errors[0].message));
   }
 });