chore: use es6 arrows function

.eslintrc

@@ -14,7 +14,12 @@
     "node": true
   },
   "rules": {
+    "no-invalid-this": "error",
+    "consistent-this": "error",
+    "prefer-arrow-callback": "error",
     "prefer-const": "error",
+    "arrow-parens": ["error", "as-needed"],
+    "arrow-body-style": ["error", "as-needed"],
     "no-var": "error",
     "no-use-before-define": "error",
     "strict": ["error", "global"]

benchmarks/FB/hello.js

@@ -9,7 +9,7 @@ if (cluster.isMaster) {
     cluster.fork();
   }
 
-  cluster.on('exit', function(worker) {
+  cluster.on('exit', worker => {
     console.log('worker ' + worker.pid + ' died');
   });
 
@@ -58,7 +58,7 @@ function getRandomNumber() {
 }
 
 function sequelizeQuery(callback) {
-  World.findById(getRandomNumber(), function(err, world) {
+  World.findById(getRandomNumber(), (err, world) => {
     callback(null, world);
   });
 }
@@ -71,7 +71,7 @@ function handlePrepared(req, res) {
     mysql2conn.execute(
       'SELECT * FROM world WHERE id = ?',
       [getRandomNumber()],
-      function(err, rows) {
+      (err, rows) => {
         results.push(rows[0]);
         if (results.length == queries) res.end(JSON.stringify(results));
       }
@@ -89,7 +89,7 @@ function handleMysqlIsh(conn, req, res) {
     mysql2conn.query(
       'SELECT * FROM world WHERE id = ?',
       [getRandomNumber()],
-      function(err, rows) {
+      (err, rows) => {
         results.push(rows[0]);
         if (results.length == queries) res.end(JSON.stringify(results));
       }
@@ -103,10 +103,10 @@ function handleMysqlIshPool(pool, req, res) {
   const queries = values.query.queries || 1;
   const results = [];
   for (let i = 0; i < queries; ++i) {
-    pool.getConnection(function() {
+    pool.getConnection(() => {
       mysql2conn.query(
         'SELECT * FROM world WHERE id = ' + getRandomNumber(),
-        function(err, rows) {
+        (err, rows) => {
           results.push(rows[0]);
           if (results.length == queries) res.end(JSON.stringify(results));
         }
@@ -122,8 +122,8 @@ function handleMaria(req, res) {
   for (let i = 0; i < queries; ++i) {
     mariaconn
       .query('SELECT * FROM world WHERE id = :id', { id: getRandomNumber() })
-      .on('result', function(dbres) {
-        dbres.on('row', function(row) {
+      .on('result', dbres => {
+        dbres.on('row', row => {
           results.push(row);
           if (results.length == queries) res.end(JSON.stringify(results));
         });
@@ -137,7 +137,7 @@ function sortFortunes(a, b) {
 
 function fortuneMysql(conn, res) {
   res.writeHead(200, { 'Content-Type': 'text/html' });
-  conn.query('select * from Fortune', function(err, fortunes) {
+  conn.query('select * from Fortune', (err, fortunes) => {
     fortunes.push({
       id: 0,
       message: 'Additional fortune added at request time.'
@@ -150,11 +150,11 @@ function fortuneMysql(conn, res) {
 function fortuneMaria(res) {
   const fortunes = [];
   res.writeHead(200, { 'Content-Type': 'text/html' });
-  mariaconn.query('SELECT * from Fortune').on('result', function(dbres) {
-    dbres.on('row', function(row) {
+  mariaconn.query('SELECT * from Fortune').on('result', dbres => {
+    dbres.on('row', row => {
       fortunes.push(row);
     });
-    dbres.on('end', function() {
+    dbres.on('end', () => {
       fortunes.push({
         id: 0,
         message: 'Additional fortune added at request time.'
@@ -166,7 +166,7 @@ function fortuneMaria(res) {
 }
 
 http
-  .createServer(function(req, res) {
+  .createServer((req, res) => {
     // JSON response object
     const hello = { message: 'Hello, world' };
 
@@ -197,7 +197,7 @@ http
 
         res.writeHead(200, { 'Content-Type': 'application/json' });
 
-        async.parallel(queryFunctions, function(err, results) {
+        async.parallel(queryFunctions, (err, results) => {
           res.end(JSON.stringify(results));
         });
         break;
@@ -208,12 +208,12 @@ http
         function libmysqlQuery2(callback) {
           libmysql.query(
             'SELECT * FROM world WHERE id = ' + getRandomNumber(),
-            function(err, res) {
+            (err, res) => {
               if (err) {
                 throw err;
               }
 
-              res.fetchAll(function(err, rows) {
+              res.fetchAll((err, rows) => {
                 if (err) {
                   throw err;
                 }
@@ -232,7 +232,7 @@ http
         for (let i = 0; i < queries; i += 1) {
           queryFunctions[i] = libmysqlQuery2;
         }
-        async.parallel(queryFunctions, function(err, results) {
+        async.parallel(queryFunctions, (err, results) => {
           if (err) {
             res.writeHead(500);
             return res.end('MYSQL CONNECTION ERROR.');
@@ -279,12 +279,12 @@ http
         function libmysqlQuery(callback) {
           libmysql.query(
             'SELECT * FROM world WHERE id = ' + getRandomNumber(),
-            function(err, res) {
+            (err, res) => {
               if (err) {
                 throw err;
               }
 
-              res.fetchAll(function(err, rows) {
+              res.fetchAll((err, rows) => {
                 if (err) {
                   throw err;
                 }
@@ -297,7 +297,7 @@ http
                     rows[0].randomNumber +
                     ' WHERE id = ' +
                     rows[0]['id'],
-                  function(err) {
+                  err => {
                     if (err) {
                       throw err;
                     }
@@ -316,7 +316,7 @@ http
         for (let i = 0; i < queries; i += 1) {
           queryFunctions[i] = libmysqlQuery;
         }
-        async.parallel(queryFunctions, function(err, results) {
+        async.parallel(queryFunctions, (err, results) => {
           if (err) {
             res.writeHead(500);
             return res.end('MYSQL CONNECTION ERROR.');

benchmarks/bench-fake-server-maria.js

@@ -15,16 +15,16 @@ connection.connect({
 function benchmarkSelect(numLeft, callback) {
   let numRows = 0;
   const q = connection.query('select 1+1 as qqq');
-  q.on('result', function(res) {
+  q.on('result', res => {
     //console.log("result!");
     //console.log(res);
 
-    res.on('row', function() {
+    res.on('row', () => {
       //console.log(r);
       numRows++;
     });
 
-    res.on('end', function() {
+    res.on('end', () => {
       if (numLeft > 1) benchmarkSelect(numLeft - 1, callback);
       else callback(numRows);
     });
@@ -34,7 +34,7 @@ function benchmarkSelect(numLeft, callback) {
 function benchmarkSelects(n, cb) {
   const numSelects = 100;
   const start = process.hrtime();
-  benchmarkSelect(numSelects, function(rowsPerQuery) {
+  benchmarkSelect(numSelects, rowsPerQuery => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log(
@@ -52,7 +52,7 @@ function benchmarkSelects(n, cb) {
 module.exports = function(done) {
   console.log('connected');
   const testStart = process.hrtime();
-  benchmarkSelects(5, function() {
+  benchmarkSelects(5, () => {
     const testEnd = process.hrtime();
     console.log('total time: ', common.hrdiff(testStart, testEnd) / 1e9);
     connection.end();

benchmarks/bench-fake-server.js

@@ -23,10 +23,10 @@ function benchmarkSelect(numLeft, callback) {
 
   let rows = 0;
   const q = connection.query('query from fake server fixture');
-  q.on('result', function() {
+  q.on('result', () => {
     rows++;
   });
-  q.on('end', function() {
+  q.on('end', () => {
     if (numLeft > 1) benchmarkSelect(numLeft - 1, callback);
     else callback(rows);
   });
@@ -35,7 +35,7 @@ function benchmarkSelect(numLeft, callback) {
 function benchmarkSelects(n, cb) {
   const numSelects = 100000;
   const start = process.hrtime();
-  benchmarkSelect(numSelects, function(rowsPerQuery) {
+  benchmarkSelect(numSelects, rowsPerQuery => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log(
@@ -52,7 +52,7 @@ function benchmarkSelects(n, cb) {
 
 module.exports = function(done) {
   const testStart = process.hrtime();
-  benchmarkSelects(5, function() {
+  benchmarkSelects(5, () => {
     const testEnd = process.hrtime();
     console.log('total time: ', common.hrdiff(testStart, testEnd) / 1e9);
     connection.end();

benchmarks/bench-insert-select-parallel.js

@@ -6,7 +6,7 @@ const connection = common.createConnection();
 const table = 'insert_test';
 //const text = "本日は晴天なり";
 const text = 'test abc xyz';
-connection.query('drop table ' + table).on('error', function() {});
+connection.query('drop table ' + table).on('error', () => {});
 connection.query(
   [
     'CREATE TABLE `' + table + '` (',
@@ -20,7 +20,7 @@ connection.query(
 function benchmarkInsert(numLeft, callback) {
   connection.query(
     'INSERT INTO ' + table + ' SET title="' + text + '"',
-    function(err) {
+    err => {
       if (err) throw err;
       if (numLeft > 1) benchmarkInsert(numLeft - 1, callback);
       else callback();
@@ -31,7 +31,7 @@ function benchmarkInsert(numLeft, callback) {
 function benchmarkInserts(n, cb) {
   const numInsert = 50000;
   const start = process.hrtime();
-  benchmarkInsert(numInsert, function() {
+  benchmarkInsert(numInsert, () => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log((numInsert * 1e9) / diff + ' inserts/sec');
@@ -75,8 +75,8 @@ function benchmarkParallelSelects(n, size, cb) {
 
 module.exports = function(done) {
   const testStart = process.hrtime();
-  benchmarkInserts(1, function() {
-    benchmarkParallelSelects(8, 50000, function() {
+  benchmarkInserts(1, () => {
+    benchmarkParallelSelects(8, 50000, () => {
       const testEnd = process.hrtime();
       console.log('total time: ', common.hrdiff(testStart, testEnd) / 1e9);
       if (done) done();

benchmarks/bench-insert-select-prepared.js

@@ -20,7 +20,7 @@ function benchmarkInsert(numLeft, callback) {
   connection.execute(
     'INSERT INTO ' + table + ' SET title="' + text + '"',
     [],
-    function(err) {
+    err => {
       if (err) throw err;
       if (numLeft > 1) benchmarkInsert(numLeft - 1, callback);
       else callback();
@@ -31,7 +31,7 @@ function benchmarkInsert(numLeft, callback) {
 function benchmarkInserts(n, cb) {
   const numInsert = 10000;
   const start = process.hrtime();
-  benchmarkInsert(numInsert, function() {
+  benchmarkInsert(numInsert, () => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log((numInsert * 1e9) / diff + ' inserts/sec');
@@ -44,7 +44,7 @@ function benchmarkSelect(numLeft, numSelect, callback) {
   connection.execute(
     'select * from ' + table + ' limit ' + numSelect,
     [],
-    function(err) {
+    err => {
       if (err) throw err;
       if (numLeft > 1) benchmarkSelect(numLeft - 1, numSelect, callback);
       else callback();
@@ -55,7 +55,7 @@ function benchmarkSelect(numLeft, numSelect, callback) {
 function benchmarkSelects(n, size, cb) {
   const numSelects = 100;
   const start = process.hrtime();
-  benchmarkSelect(numSelects, size, function() {
+  benchmarkSelect(numSelects, size, () => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log(
@@ -73,10 +73,10 @@ function benchmarkSelects(n, size, cb) {
 
 module.exports = function(done) {
   const testStart = process.hrtime();
-  benchmarkInserts(1, function() {
-    benchmarkSelects(5, 100, function() {
-      benchmarkSelects(10, 1000, function() {
-        benchmarkSelects(2, 50000, function() {
+  benchmarkInserts(1, () => {
+    benchmarkSelects(5, 100, () => {
+      benchmarkSelects(10, 1000, () => {
+        benchmarkSelects(2, 50000, () => {
           const testEnd = process.hrtime();
           console.log('total time: ', common.hrdiff(testStart, testEnd) / 1e9);
           connection.end();

benchmarks/bench-insert-select.js

@@ -18,7 +18,7 @@ connection.query(
 function benchmarkInsert(numLeft, callback) {
   connection.query(
     'INSERT INTO ' + table + ' SET title="' + text + '"',
-    function(err) {
+    err => {
       if (err) throw err;
       if (numLeft > 1) benchmarkInsert(numLeft - 1, callback);
       else callback();
@@ -29,7 +29,7 @@ function benchmarkInsert(numLeft, callback) {
 function benchmarkInserts(n, cb) {
   const numInsert = 10000;
   const start = process.hrtime();
-  benchmarkInsert(numInsert, function() {
+  benchmarkInsert(numInsert, () => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log((numInsert * 1e9) / diff + ' inserts/sec');
@@ -39,9 +39,7 @@ function benchmarkInserts(n, cb) {
 }
 
 function benchmarkSelect(numLeft, numSelect, callback) {
-  connection.query('select * from ' + table + ' limit ' + numSelect, function(
-    err
-  ) {
+  connection.query('select * from ' + table + ' limit ' + numSelect, err => {
     if (err) throw err;
     if (numLeft > 1) benchmarkSelect(numLeft - 1, numSelect, callback);
     else callback();
@@ -51,7 +49,7 @@ function benchmarkSelect(numLeft, numSelect, callback) {
 function benchmarkSelects(n, size, cb) {
   const numSelects = 100;
   const start = process.hrtime();
-  benchmarkSelect(numSelects, size, function() {
+  benchmarkSelect(numSelects, size, () => {
     const end = process.hrtime();
     const diff = common.hrdiff(start, end);
     console.log(
@@ -69,10 +67,10 @@ function benchmarkSelects(n, size, cb) {
 
 module.exports = function(done) {
   const testStart = process.hrtime();
-  benchmarkInserts(5, function() {
-    benchmarkSelects(5, 10000, function() {
-      benchmarkSelects(10, 1000, function() {
-        benchmarkSelects(2, 50000, function() {
+  benchmarkInserts(5, () => {
+    benchmarkSelects(5, 10000, () => {
+      benchmarkSelects(10, 1000, () => {
+        benchmarkSelects(2, 50000, () => {
           const testEnd = process.hrtime();
           console.log('total time: ', common.hrdiff(testStart, testEnd) / 1e9);
           connection.end();

benchmarks/benchmark-query.js

@@ -11,7 +11,7 @@ const sql = process.argv[2];
   const start = Date.now();
   let prev1000 = start;
   function bench() {
-    db.query(sql).on('end', function() {
+    db.query(sql).on('end', () => {
       left--;
       if (left % 1000 === 0) {
         const curTime = Date.now();