test: cleanup test-os.js

Moved from var to const.
Moved from .equal to .strictEqual.
Added more checks about the type of the returned values.

PR-URL: https://github.com/nodejs/node/pull/8606
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>

test/parallel/test-os.js

@@ -1,74 +1,91 @@
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var os = require('os');
-var path = require('path');
-
+const common = require('../common');
+const assert = require('assert');
+const os = require('os');
+const path = require('path');
+
+const is = {
+  string: (value) => { assert.strictEqual(typeof value, 'string'); },
+  number: (value) => { assert.strictEqual(typeof value, 'number'); },
+  array: (value) => { assert.ok(Array.isArray(value)); },
+  object: (value) => {
+    assert.strictEqual(typeof value, 'object');
+    assert.notStrictEqual(value, null);
+  }
+};
 
 process.env.TMPDIR = '/tmpdir';
 process.env.TMP = '/tmp';
 process.env.TEMP = '/temp';
 if (common.isWindows) {
-  assert.equal(os.tmpdir(), '/temp');
+  assert.strictEqual(os.tmpdir(), '/temp');
   process.env.TEMP = '';
-  assert.equal(os.tmpdir(), '/tmp');
+  assert.strictEqual(os.tmpdir(), '/tmp');
   process.env.TMP = '';
   const expected = (process.env.SystemRoot || process.env.windir) + '\\temp';
-  assert.equal(os.tmpdir(), expected);
+  assert.strictEqual(os.tmpdir(), expected);
   process.env.TEMP = '\\temp\\';
-  assert.equal(os.tmpdir(), '\\temp');
+  assert.strictEqual(os.tmpdir(), '\\temp');
   process.env.TEMP = '\\tmpdir/';
-  assert.equal(os.tmpdir(), '\\tmpdir/');
+  assert.strictEqual(os.tmpdir(), '\\tmpdir/');
   process.env.TEMP = '\\';
-  assert.equal(os.tmpdir(), '\\');
+  assert.strictEqual(os.tmpdir(), '\\');
   process.env.TEMP = 'C:\\';
-  assert.equal(os.tmpdir(), 'C:\\');
+  assert.strictEqual(os.tmpdir(), 'C:\\');
 } else {
-  assert.equal(os.tmpdir(), '/tmpdir');
+  assert.strictEqual(os.tmpdir(), '/tmpdir');
   process.env.TMPDIR = '';
-  assert.equal(os.tmpdir(), '/tmp');
+  assert.strictEqual(os.tmpdir(), '/tmp');
   process.env.TMP = '';
-  assert.equal(os.tmpdir(), '/temp');
+  assert.strictEqual(os.tmpdir(), '/temp');
   process.env.TEMP = '';
-  assert.equal(os.tmpdir(), '/tmp');
+  assert.strictEqual(os.tmpdir(), '/tmp');
   process.env.TMPDIR = '/tmpdir/';
-  assert.equal(os.tmpdir(), '/tmpdir');
+  assert.strictEqual(os.tmpdir(), '/tmpdir');
   process.env.TMPDIR = '/tmpdir\\';
-  assert.equal(os.tmpdir(), '/tmpdir\\');
+  assert.strictEqual(os.tmpdir(), '/tmpdir\\');
   process.env.TMPDIR = '/';
-  assert.equal(os.tmpdir(), '/');
+  assert.strictEqual(os.tmpdir(), '/');
 }
 
-var endianness = os.endianness();
+const endianness = os.endianness();
 console.log('endianness = %s', endianness);
+is.string(endianness);
 assert.ok(/[BL]E/.test(endianness));
 
-var hostname = os.hostname();
+const hostname = os.hostname();
 console.log('hostname = %s', hostname);
+is.string(hostname);
 assert.ok(hostname.length > 0);
 
-var uptime = os.uptime();
+const uptime = os.uptime();
 console.log('uptime = %d', uptime);
+is.number(uptime);
 assert.ok(uptime > 0);
 
-var cpus = os.cpus();
+const cpus = os.cpus();
 console.log('cpus = ', cpus);
+is.array(cpus);
 assert.ok(cpus.length > 0);
 
-var type = os.type();
+const type = os.type();
 console.log('type = ', type);
+is.string(type);
 assert.ok(type.length > 0);
 
-var release = os.release();
+const release = os.release();
 console.log('release = ', release);
+is.string(release);
 assert.ok(release.length > 0);
 
-var platform = os.platform();
+const platform = os.platform();
 console.log('platform = ', platform);
+is.string(platform);
 assert.ok(platform.length > 0);
 
-var arch = os.arch();
+const arch = os.arch();
 console.log('arch = ', arch);
+is.string(arch);
 assert.ok(arch.length > 0);
 
 if (!common.isSunOS) {
@@ -79,7 +96,7 @@ if (!common.isSunOS) {
 }
 
 
-var interfaces = os.networkInterfaces();
+const interfaces = os.networkInterfaces();
 console.error(interfaces);
 switch (platform) {
   case 'linux':
@@ -104,29 +121,30 @@ switch (platform) {
     }
 }
 
-var EOL = os.EOL;
+const EOL = os.EOL;
 assert.ok(EOL.length > 0);
 
 
-var home = os.homedir();
+const home = os.homedir();
 
 console.log('homedir = ' + home);
-assert.ok(typeof home === 'string');
+is.string(home);
 assert.ok(home.indexOf(path.sep) !== -1);
 
 if (common.isWindows && process.env.USERPROFILE) {
-  assert.equal(home, process.env.USERPROFILE);
+  assert.strictEqual(home, process.env.USERPROFILE);
   delete process.env.USERPROFILE;
   assert.ok(os.homedir().indexOf(path.sep) !== -1);
   process.env.USERPROFILE = home;
 } else if (!common.isWindows && process.env.HOME) {
-  assert.equal(home, process.env.HOME);
+  assert.strictEqual(home, process.env.HOME);
   delete process.env.HOME;
   assert.ok(os.homedir().indexOf(path.sep) !== -1);
   process.env.HOME = home;
 }
 
 const pwd = os.userInfo();
+is.object(pwd);
 const pwdBuf = os.userInfo({ encoding: 'buffer' });
 
 if (common.isWindows) {
@@ -137,15 +155,15 @@ if (common.isWindows) {
   assert.strictEqual(pwdBuf.gid, -1);
   assert.strictEqual(pwdBuf.shell, null);
 } else {
-  assert.strictEqual(typeof pwd.uid, 'number');
-  assert.strictEqual(typeof pwd.gid, 'number');
+  is.number(pwd.uid);
+  is.number(pwd.gid);
   assert.notStrictEqual(pwd.shell.indexOf(path.sep), -1);
   assert.strictEqual(pwd.uid, pwdBuf.uid);
   assert.strictEqual(pwd.gid, pwdBuf.gid);
   assert.strictEqual(pwd.shell, pwdBuf.shell.toString('utf8'));
 }
 
-assert.strictEqual(typeof pwd.username, 'string');
+is.string(pwd.username);
 assert.notStrictEqual(pwd.homedir.indexOf(path.sep), -1);
 assert.strictEqual(pwd.username, pwdBuf.username.toString('utf8'));
 assert.strictEqual(pwd.homedir, pwdBuf.homedir.toString('utf8'));