test: convert var->const/let in tests

test/.eslintrc

@@ -1,7 +1,13 @@
 ## Test-specific linter rules
 
 rules:
-  ## common module is mandatory in tests
-  required-modules: [2, common]
+  # ECMAScript 6
+  # http://eslint.org/docs/rules/#ecmascript-6
+  no-var: 2
+  prefer-const: 2
+
+  # Custom rules in tools/eslint-rules
   prefer-assert-iferror: 2
   prefer-assert-methods: 2
+  ## common module is mandatory in tests
+  required-modules: [2, common]

test/addons/buffer-free-callback/test.js

@@ -5,8 +5,8 @@ const common = require('../../common');
 const binding = require(`./build/${common.buildType}/binding`);
 
 function check(size, alignment, offset) {
-  var buf = binding.alloc(size, alignment, offset);
-  var slice = buf.slice(size >>> 1);
+  let buf = binding.alloc(size, alignment, offset);
+  let slice = buf.slice(size >>> 1);
 
   buf = null;
   binding.check(slice);

test/addons/load-long-path/test.js

@@ -14,9 +14,9 @@ common.refreshTmpDir();
 // make a path that is more than 260 chars long.
 // Any given folder cannot have a name longer than 260 characters,
 // so create 10 nested folders each with 30 character long names.
-var addonDestinationDir = path.resolve(common.tmpDir);
+let addonDestinationDir = path.resolve(common.tmpDir);
 
-for (var i = 0; i < 10; i++) {
+for (let i = 0; i < 10; i++) {
   addonDestinationDir = path.join(addonDestinationDir, 'x'.repeat(30));
   fs.mkdirSync(addonDestinationDir);
 }
@@ -28,7 +28,7 @@ const addonPath = path.join(__dirname,
 const addonDestinationPath = path.join(addonDestinationDir, 'binding.node');
 
 // Copy binary to long path destination
-var contents = fs.readFileSync(addonPath);
+const contents = fs.readFileSync(addonPath);
 fs.writeFileSync(addonDestinationPath, contents);
 
 // Attempt to load at long path destination

test/addons/make-callback-recurse/test.js

@@ -65,7 +65,7 @@ assert.throws(function() {
   results.push(2);
 
   setImmediate(common.mustCall(function() {
-    for (var i = 0; i < results.length; i++) {
+    for (let i = 0; i < results.length; i++) {
       assert.strictEqual(results[i], i,
                          `verifyExecutionOrder(${arg}) results: ${results}`);
     }

test/addons/repl-domain-abort/test.js

@@ -4,27 +4,27 @@ const assert = require('assert');
 const repl = require('repl');
 const stream = require('stream');
 const path = require('path');
-var buildType = process.config.target_defaults.default_configuration;
-var buildPath = path.join(__dirname, 'build', buildType, 'binding');
+const buildType = process.config.target_defaults.default_configuration;
+let buildPath = path.join(__dirname, 'build', buildType, 'binding');
 // On Windows, escape backslashes in the path before passing it to REPL.
 if (common.isWindows)
   buildPath = buildPath.replace(/\\/g, '/');
-var cb_ran = false;
+let cb_ran = false;
 
 process.on('exit', function() {
   assert(cb_ran);
   console.log('ok');
 });
 
-var lines = [
+const lines = [
   // This line shouldn't cause an assertion error.
   'require(\'' + buildPath + '\')' +
   // Log output to double check callback ran.
   '.method(function() { console.log(\'cb_ran\'); });',
 ];
 
-var dInput = new stream.Readable();
-var dOutput = new stream.Writable();
+const dInput = new stream.Readable();
+const dOutput = new stream.Writable();
 
 dInput._read = function _read(size) {
   while (lines.length > 0 && this.push(lines.shift()));
@@ -38,7 +38,7 @@ dOutput._write = function _write(chunk, encoding, cb) {
   cb();
 };
 
-var options = {
+const options = {
   input: dInput,
   output: dOutput,
   terminal: false,

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-at-max.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
   return;
 }
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength);
+  buf = Buffer.allocUnsafe(kStringMaxLength);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-ascii.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 1);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 1);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-base64.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 1);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 1);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-binary.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 1);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 1);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);
@@ -33,7 +34,7 @@ assert.throws(function() {
   buf.toString('latin1');
 }, /"toString\(\)" failed/);
 
-var maxString = buf.toString('latin1', 1);
+let maxString = buf.toString('latin1', 1);
 assert.strictEqual(maxString.length, kStringMaxLength);
 // Free the memory early instead of at the end of the next assignment
 maxString = undefined;

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-hex.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 1);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 1);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-1-utf8.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 1);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 1);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max-by-2.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength + 2);
+  buf = Buffer.allocUnsafe(kStringMaxLength + 2);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/addons/stringbytes-external-exceed-max/test-stringbytes-external-exceed-max.js

@@ -14,8 +14,9 @@ if (!common.enoughTestMem) {
 // v8::String::kMaxLength defined in v8.h
 const kStringMaxLength = process.binding('buffer').kStringMaxLength;
 
+let buf;
 try {
-  var buf = Buffer.allocUnsafe(kStringMaxLength * 2 + 2);
+  buf = Buffer.allocUnsafe(kStringMaxLength * 2 + 2);
 } catch (e) {
   // If the exception is not due to memory confinement then rethrow it.
   if (e.message !== 'Array buffer allocation failed') throw (e);

test/common.js

@@ -212,7 +212,7 @@ exports.hasIPv6 = Object.keys(ifaces).some(function(name) {
  * the process aborts.
  */
 exports.childShouldThrowAndAbort = function() {
-  var testCmd = '';
+  let testCmd = '';
   if (!exports.isWindows) {
     // Do not create core files, as it can take a lot of disk space on
     // continuous testing and developers' machines

test/debugger/helper-debugger-repl.js

@@ -4,12 +4,12 @@ const assert = require('assert');
 const spawn = require('child_process').spawn;
 
 process.env.NODE_DEBUGGER_TIMEOUT = 2000;
-var port = common.PORT;
+const port = common.PORT;
 
-var child;
-var buffer = '';
-var expected = [];
-var quit;
+let child;
+let buffer = '';
+const expected = [];
+let quit;
 
 function startDebugger(scriptToDebug) {
   scriptToDebug = process.env.NODE_DEBUGGER_TEST_SCRIPT ||
@@ -34,23 +34,23 @@ function startDebugger(scriptToDebug) {
     console.log(line);
     assert.ok(expected.length > 0, 'Got unexpected line: ' + line);
 
-    var expectedLine = expected[0].lines.shift();
+    const expectedLine = expected[0].lines.shift();
     assert.ok(line.match(expectedLine) !== null, line + ' != ' + expectedLine);
 
     if (expected[0].lines.length === 0) {
-      var callback = expected[0].callback;
+      const callback = expected[0].callback;
       expected.shift();
       callback && callback();
     }
   });
 
-  var childClosed = false;
+  let childClosed = false;
   child.on('close', function(code) {
     assert(!code);
     childClosed = true;
   });
 
-  var quitCalled = false;
+  let quitCalled = false;
   quit = function() {
     if (quitCalled || childClosed) return;
     quitCalled = true;
@@ -60,7 +60,7 @@ function startDebugger(scriptToDebug) {
 
   setTimeout(function() {
     console.error('dying badly buffer=%j', buffer);
-    var err = 'Timeout';
+    let err = 'Timeout';
     if (expected.length > 0 && expected[0].lines) {
       err = err + '. Expected: ' + expected[0].lines.shift();
     }
@@ -95,7 +95,7 @@ function addTest(input, output) {
       child.stdin.write(expected[0].input + '\n');
 
       if (!expected[0].lines) {
-        var callback = expected[0].callback;
+        const callback = expected[0].callback;
         expected.shift();
 
         callback && callback();
@@ -107,17 +107,17 @@ function addTest(input, output) {
   expected.push({input: input, lines: output, callback: next});
 }
 
-var handshakeLines = [
+const handshakeLines = [
   /listening on /,
   /connecting.* ok/
 ];
 
-var initialBreakLines = [
+const initialBreakLines = [
   /break in .*:1/,
   /1/, /2/, /3/
 ];
 
-var initialLines = handshakeLines.concat(initialBreakLines);
+const initialLines = handshakeLines.concat(initialBreakLines);
 
 // Process initial lines
 addTest(null, initialLines);

test/debugger/test-debugger-repl-restart.js

@@ -3,13 +3,13 @@ require('../common');
 const repl = require('./helper-debugger-repl.js');
 
 repl.startDebugger('breakpoints.js');
-var linesWithBreakpoint = [
+const linesWithBreakpoint = [
   /1/, /2/, /3/, /4/, /5/, /\* 6/
 ];
 // We slice here, because addTest will change the given array.
 repl.addTest('sb(6)', linesWithBreakpoint.slice());
 
-var initialLines = repl.initialLines.slice();
+const initialLines = repl.initialLines.slice();
 initialLines.splice(2, 0, /Restoring/, /Warning/);
 
 // Restart the debugged script

test/debugger/test-debugger-repl-term.js

@@ -6,7 +6,7 @@ const repl = require('./helper-debugger-repl.js');
 
 repl.startDebugger('breakpoints.js');
 
-var addTest = repl.addTest;
+const addTest = repl.addTest;
 
 // next
 addTest('n', [

test/debugger/test-debugger-repl-utf8.js

@@ -1,6 +1,6 @@
 'use strict';
 const common = require('../common');
-var script = common.fixturesDir + '/breakpoints_utf8.js';
+const script = common.fixturesDir + '/breakpoints_utf8.js';
 process.env.NODE_DEBUGGER_TEST_SCRIPT = script;
 
 require('./test-debugger-repl.js');

test/debugger/test-debugger-repl.js

@@ -4,7 +4,7 @@ const repl = require('./helper-debugger-repl.js');
 
 repl.startDebugger('breakpoints.js');
 
-var addTest = repl.addTest;
+const addTest = repl.addTest;
 
 // Next
 addTest('n', [

test/gc/test-http-client-connaborted.js

@@ -18,7 +18,7 @@ let countGC = 0;
 
 console.log('We should do ' + todo + ' requests');
 
-var server = http.createServer(serverHandler);
+const server = http.createServer(serverHandler);
 server.listen(0, getall);
 
 function getall() {
@@ -31,7 +31,7 @@ function getall() {
       statusLater();
     }
 
-    var req = http.get({
+    const req = http.get({
       hostname: 'localhost',
       pathname: '/',
       port: server.address().port
@@ -44,14 +44,14 @@ function getall() {
   setImmediate(getall);
 }
 
-for (var i = 0; i < 10; i++)
+for (let i = 0; i < 10; i++)
   getall();
 
 function afterGC() {
   countGC++;
 }
 
-var timer;
+let timer;
 function statusLater() {
   global.gc();
   if (timer) clearTimeout(timer);