Refactored lib code to let/const

- this was supported from Node v6 and we support Node v10 so there
  shouldn't be a problem there

Author: daniellockyer

lib/sqlite3-binding.js

@@ -1,5 +1,5 @@
-var binary = require('@mapbox/node-pre-gyp');
-var path = require('path');
-var binding_path = binary.find(path.resolve(path.join(__dirname,'../package.json')));
-var binding = require(binding_path);
+const binary = require('@mapbox/node-pre-gyp');
+const path = require('path');
+const binding_path = binary.find(path.resolve(path.join(__dirname,'../package.json')));
+const binding = require(binding_path);
 module.exports = exports = binding;

lib/sqlite3.js

@@ -1,27 +1,28 @@
-var path = require('path');
-var sqlite3 = require('./sqlite3-binding.js');
-var EventEmitter = require('events').EventEmitter;
+const path = require('path');
+const sqlite3 = require('./sqlite3-binding.js');
+const EventEmitter = require('events').EventEmitter;
 module.exports = exports = sqlite3;
 
 function normalizeMethod (fn) {
     return function (sql) {
-        var errBack;
-        var args = Array.prototype.slice.call(arguments, 1);
+        let errBack;
+        const args = Array.prototype.slice.call(arguments, 1);
+
         if (typeof args[args.length - 1] === 'function') {
-            var callback = args[args.length - 1];
+            const callback = args[args.length - 1];
             errBack = function(err) {
                 if (err) {
                     callback(err);
                 }
             };
         }
-        var statement = new Statement(this, sql, errBack);
+        const statement = new Statement(this, sql, errBack);
         return fn.call(this, statement, args);
     };
 }
 
 function inherits(target, source) {
-    for (var k in source.prototype)
+    for (const k in source.prototype)
         target.prototype[k] = source.prototype[k];
 }
 
@@ -32,18 +33,18 @@ sqlite3.cached = {
             return new Database(file, a, b);
         }
 
-        var db;
+        let db;
         file = path.resolve(file);
-        function cb() { callback.call(db, null); }
 
         if (!sqlite3.cached.objects[file]) {
             db = sqlite3.cached.objects[file] = new Database(file, a, b);
         }
         else {
             // Make sure the callback is called.
             db = sqlite3.cached.objects[file];
-            var callback = (typeof a === 'number') ? b : a;
+            const callback = (typeof a === 'number') ? b : a;
             if (typeof callback === 'function') {
+                function cb() { callback.call(db, null); }
                 if (db.open) process.nextTick(cb);
                 else db.once('open', cb);
             }
@@ -55,9 +56,9 @@ sqlite3.cached = {
 };
 
 
-var Database = sqlite3.Database;
-var Statement = sqlite3.Statement;
-var Backup = sqlite3.Backup;
+const Database = sqlite3.Database;
+const Statement = sqlite3.Statement;
+const Backup = sqlite3.Backup;
 
 inherits(Database, EventEmitter);
 inherits(Statement, EventEmitter);
@@ -102,7 +103,7 @@ Database.prototype.map = normalizeMethod(function(statement, params) {
 // Database#backup(filename, [callback])
 // Database#backup(filename, destName, sourceName, filenameIsDest, [callback])
 Database.prototype.backup = function() {
-    var backup;
+    let backup;
     if (arguments.length <= 2) {
         // By default, we write the main database out to the main database of the named file.
         // This is the most likely use of the backup api.
@@ -117,22 +118,23 @@ Database.prototype.backup = function() {
 };
 
 Statement.prototype.map = function() {
-    var params = Array.prototype.slice.call(arguments);
-    var callback = params.pop();
+    const params = Array.prototype.slice.call(arguments);
+    const callback = params.pop();
     params.push(function(err, rows) {
         if (err) return callback(err);
-        var result = {};
+        const result = {};
         if (rows.length) {
-            var keys = Object.keys(rows[0]), key = keys[0];
+            const keys = Object.keys(rows[0]);
+            const key = keys[0];
             if (keys.length > 2) {
                 // Value is an object
-                for (var i = 0; i < rows.length; i++) {
+                for (let i = 0; i < rows.length; i++) {
                     result[rows[i][key]] = rows[i];
                 }
             } else {
-                var value = keys[1];
+                const value = keys[1];
                 // Value is a plain value
-                for (i = 0; i < rows.length; i++) {
+                for (let i = 0; i < rows.length; i++) {
                     result[rows[i][key]] = rows[i][value];
                 }
             }
@@ -142,28 +144,28 @@ Statement.prototype.map = function() {
     return this.all.apply(this, params);
 };
 
-var isVerbose = false;
+let isVerbose = false;
 
-var supportedEvents = [ 'trace', 'profile', 'insert', 'update', 'delete' ];
+const supportedEvents = [ 'trace', 'profile', 'insert', 'update', 'delete' ];
 
 Database.prototype.addListener = Database.prototype.on = function(type) {
-    var val = EventEmitter.prototype.addListener.apply(this, arguments);
+    const val = EventEmitter.prototype.addListener.apply(this, arguments);
     if (supportedEvents.indexOf(type) >= 0) {
         this.configure(type, true);
     }
     return val;
 };
 
 Database.prototype.removeListener = function(type) {
-    var val = EventEmitter.prototype.removeListener.apply(this, arguments);
+    const val = EventEmitter.prototype.removeListener.apply(this, arguments);
     if (supportedEvents.indexOf(type) >= 0 && !this._events[type]) {
         this.configure(type, false);
     }
     return val;
 };
 
 Database.prototype.removeAllListeners = function(type) {
-    var val = EventEmitter.prototype.removeAllListeners.apply(this, arguments);
+    const val = EventEmitter.prototype.removeAllListeners.apply(this, arguments);
     if (supportedEvents.indexOf(type) >= 0) {
         this.configure(type, false);
     }
@@ -173,7 +175,7 @@ Database.prototype.removeAllListeners = function(type) {
 // Save the stack trace over EIO callbacks.
 sqlite3.verbose = function() {
     if (!isVerbose) {
-        var trace = require('./trace');
+        const trace = require('./trace');
         [
             'prepare',
             'get',

lib/trace.js

@@ -1,21 +1,21 @@
 // Inspired by https://github.com/tlrobinson/long-stack-traces
-var util = require('util');
+const util = require('util');
 
 function extendTrace(object, property, pos) {
-    var old = object[property];
+    const old = object[property];
     object[property] = function() {
-        var error = new Error();
-        var name = object.constructor.name + '#' + property + '(' + 
+        const error = new Error();
+        const name = object.constructor.name + '#' + property + '(' +
             Array.prototype.slice.call(arguments).map(function(el) {
                 return util.inspect(el, false, 0);
             }).join(', ') + ')';
 
         if (typeof pos === 'undefined') pos = -1;
         if (pos < 0) pos += arguments.length;
-        var cb = arguments[pos];
+        const cb = arguments[pos];
         if (typeof arguments[pos] === 'function') {
             arguments[pos] = function replacement() {
-                var err = arguments[0];
+                const err = arguments[0];
                 if (err && err.stack && !err.__augmented) {
                     err.stack = filter(err).join('\n');
                     err.stack += '\n--> in ' + name;