tools: lint for spacing around unary operators

Enable `space-unary-ops` in `.eslintrc`. This prohibits things like:

    i ++        // use `i++` instead
    typeof(foo) // use `typeof foo` or `typeof (foo)` instead

Ref: https://github.com/nodejs/node/pull/4772#discussion_r51732299
PR-URL: https://github.com/nodejs/node/pull/5063
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: Roman Reiss <me@silverwind.io>
Reviewed-By: James M Snell <jasnell@gmail.com>

.eslintrc

@@ -83,6 +83,8 @@ rules:
   space-after-keywords: 2
   ## no leading/trailing spaces in parens
   space-in-parens: [2, "never"]
+  ## no spaces with non-word unary operators, require for word unary operators
+  space-unary-ops: 2
 
   # ECMAScript 6
   # list: http://eslint.org/docs/rules/#ecmascript-6

lib/timers.js

@@ -327,7 +327,7 @@ function unrefdHandle() {
 Timeout.prototype.unref = function() {
   if (this._handle) {
     this._handle.unref();
-  } else if (typeof(this._onTimeout) === 'function') {
+  } else if (typeof this._onTimeout === 'function') {
     var now = Timer.now();
     if (!this._idleStart) this._idleStart = now;
     var delay = this._idleStart + this._idleTimeout - now;

test/parallel/test-child-process-exec-buffer.js

@@ -10,8 +10,8 @@ var str = 'hello';
 
 // default encoding
 exec('echo ' + str, function(err, stdout, stderr) {
-  assert.ok('string', typeof(stdout), 'Expected stdout to be a string');
-  assert.ok('string', typeof(stderr), 'Expected stderr to be a string');
+  assert.ok('string', typeof stdout, 'Expected stdout to be a string');
+  assert.ok('string', typeof stderr, 'Expected stderr to be a string');
   assert.equal(str + os.EOL, stdout);
 
   success_count++;

test/parallel/test-fs-read-stream-inherit.js

@@ -55,7 +55,7 @@ file.on('close', function() {
 var file3 = fs.createReadStream(fn, Object.create({encoding: 'utf8'}));
 file3.length = 0;
 file3.on('data', function(data) {
-  assert.equal('string', typeof(data));
+  assert.equal('string', typeof data);
   file3.length += data.length;
 
   for (var i = 0; i < data.length; i++) {

test/parallel/test-fs-read-stream.js

@@ -55,7 +55,7 @@ file.on('close', function() {
 var file3 = fs.createReadStream(fn, {encoding: 'utf8'});
 file3.length = 0;
 file3.on('data', function(data) {
-  assert.equal('string', typeof(data));
+  assert.equal('string', typeof data);
   file3.length += data.length;
 
   for (var i = 0; i < data.length; i++) {

test/parallel/test-http-byteswritten.js

@@ -16,7 +16,7 @@ var httpServer = http.createServer(function(req, res) {
 
   res.on('finish', function() {
     sawFinish = true;
-    assert(typeof(req.connection.bytesWritten) === 'number');
+    assert(typeof req.connection.bytesWritten === 'number');
     assert(req.connection.bytesWritten > 0);
   });
   res.writeHead(200, { 'Content-Type': 'text/plain' });

test/parallel/test-https-byteswritten.js

@@ -18,7 +18,7 @@ var body = 'hello world\n';
 
 var httpsServer = https.createServer(options, function(req, res) {
   res.on('finish', function() {
-    assert(typeof(req.connection.bytesWritten) === 'number');
+    assert(typeof req.connection.bytesWritten === 'number');
     assert(req.connection.bytesWritten > 0);
     httpsServer.close();
     console.log('ok');

test/parallel/test-vm-debug-context.js

@@ -21,8 +21,8 @@ assert.throws(function() {
   vm.runInDebugContext('(function(f) { f(f) })(function(f) { f(f) })');
 }, /RangeError/);
 
-assert.equal(typeof(vm.runInDebugContext('this')), 'object');
-assert.equal(typeof(vm.runInDebugContext('Debug')), 'object');
+assert.equal(typeof vm.runInDebugContext('this'), 'object');
+assert.equal(typeof vm.runInDebugContext('Debug'), 'object');
 
 assert.strictEqual(vm.runInDebugContext(), undefined);
 assert.strictEqual(vm.runInDebugContext(0), 0);

test/sequential/test-cluster-listening-port.js

@@ -12,7 +12,7 @@ if (cluster.isMaster) {
     // ensure that the port is not 0 or null
     assert(port);
     // ensure that the port is numerical
-    assert.strictEqual(typeof(port), 'number');
+    assert.strictEqual(typeof port, 'number');
     worker.kill();
   });
   process.on('exit', function() {