performing tasks on relative time at timezone

src/node-cron.js

@@ -14,8 +14,8 @@ module.exports = (function() {
    * @param {boolean} immediateStart - whether to start the task immediately.
    * @returns {ScheduledTask} update function.
    */
-  function createTask(expression, func, immediateStart) {
-    var task = new Task(expression, func);
+  function createTask(expression, func, immediateStart, timezone) {
+    var task = new Task(expression, func, timezone);
 
     return new ScheduledTask(task, immediateStart);
   }

src/task.js

@@ -2,6 +2,7 @@
 
 var convertExpression = require('./convert-expression');
 var validatePattern = require('./pattern-validation');
+var tz = require('./timezone/timezone-converter');
 
 module.exports = (function(){
   function matchPattern(pattern, value){
@@ -13,6 +14,9 @@ module.exports = (function(){
   }
 
   function mustRun(task, date){
+    if(task.timezone)
+      date = tz.atTimezone(date, task.timezone);
+
     var runInSecond = matchPattern(task.expressions[0], date.getSeconds());
     var runOnMinute = matchPattern(task.expressions[1], date.getMinutes());
     var runOnHour = matchPattern(task.expressions[2], date.getHours());
@@ -34,8 +38,9 @@ module.exports = (function(){
     return runInSecond && runOnMinute && runOnHour && runOnDay && runOnMonth;
   }
 
-  function Task(pattern, execution){
+  function Task(pattern, execution, timezone){
     validatePattern(pattern);
+    this.timezone = timezone;
     this.initialPattern = pattern.split(' ');
     this.pattern = convertExpression(pattern);
     this.execution = execution;

src/timezone/timezone-converter.js

@@ -0,0 +1,26 @@
+'use strict';
+var tz = require('./timezones');
+
+module.exports = (function(){
+    /**
+     *
+     */
+
+    function getUTCTime(date){
+        var currentOffset = date.getTimezoneOffset() * 60000;
+        if(currentOffset > 0) {
+            return date.getTime() + currentOffset;
+        } 
+        return date.getTime() - currentOffset;
+    }
+
+    function atTimezone(date, timezoneName){
+        var utcTime = getUTCTime(date);
+        var time = utcTime + tz.getOffset(timezoneName);
+        return new Date(time);
+    }
+
+    return {
+        atTimezone: atTimezone
+    }
+})();

src/timezone/timezones.js

@@ -0,0 +1,20 @@
+'use strict';
+var timezones = require('../../timezones');
+
+module.exports = (function(){
+
+    var tz = {};
+
+    for(var key in timezones){
+        var value = timezones[key];
+        tz[key.toLowerCase()] = value; 
+    }
+
+    function getOffset(tzName){
+        return tz[tzName.toLowerCase()] / 100 * 60 * 60000;
+    }
+
+    return {
+        getOffset: getOffset
+    }
+})();

test/convert-expression/step-values-conversion-test.js

@@ -7,7 +7,6 @@ describe('step-values-conversion.js', function() {
   it('shuld convert step values', function() {
     var expressions = '1,2,3,4,5,6,7,8,9,10/2 0,1,2,3,4,5,6,7,8,9/5 * * * *'.split(' ');
     expressions = conversion(expressions);
-    console.log(expressions);
     expect(expressions[0]).to.equal('2,4,6,8,10');
     expect(expressions[1]).to.equal('0,5');
   });

test/timezone/task-with-timezone-test.js

@@ -0,0 +1,51 @@
+'use strict';
+
+var expect = require('expect.js');
+var sinon = require('sinon');
+var Task = require('../../src/task');
+var cron = require('../../src/node-cron');
+var tz = require('../../src/timezone/timezone-converter')
+
+describe('task at timezone', function () {
+    it('should should perform at timezone', function () {
+        var task = new Task('* 4 * * *', function () {
+            this.executed += 1;
+        }, "America/Virgin");
+        task.executed = 0;
+        var date = new Date('August 19, 2018 00:00:00 GMT-03:00');
+        date.setHours(date.getHours() + 1);
+        task.update(date);
+        date.setHours(date.getHours() + 3);
+        task.update(date);
+        date.setHours(date.getHours() + 1);
+        task.update(date);
+        expect(1).to.equal(task.executed);
+    });
+
+    describe('by node-cron', function () {
+        beforeEach(function () {
+            this.now = new Date('August 19, 2018 03:00:00 GMT-04:00');
+            this.clock = sinon.useFakeTimers(this.now);
+        });
+
+        afterEach(function () {
+            this.clock.restore();
+        });
+
+        it('should perform at timezone', function () {
+            var executed = 0;
+            var executedAt = null;
+            var executedAt2 = null;
+            var task = cron.schedule('* 4 * * *', function () {
+                executed++;
+                executedAt = new Date();
+            }, true, "America/Virgin");
+
+            this.clock.tick(60 * 60 * 1000);
+            this.now.setHours(this.now.getHours() + 1);
+
+            expect(executedAt.getHours()).to.equal(this.now.getHours());
+        });
+
+    });
+});

test/timezone/timezone-converter-test.js

@@ -0,0 +1,34 @@
+'use strict';
+
+var expect = require('expect.js');
+var timezone = require('../../src/timezone/timezone-converter');
+
+describe('convert timezone', function() {
+
+  it('should convert a date to greenwich timezone', function() {
+    var date = new Date('August 19, 2018 23:00:00 GMT-03:00');
+    var relativeDate = timezone.atTimezone(date, "Greenwich");
+    expect(relativeDate.getDate()).to.equal(20);
+    expect(relativeDate.getHours()).to.equal(2);
+  });
+
+  it('should convert a date to greenwich timezone', function() {
+    var date = new Date('August 19, 2018 00:00:00 GMT-03:00');
+    var relativeDate = timezone.atTimezone(date, "Greenwich");
+    expect(relativeDate.getDate()).to.equal(19);
+    expect(relativeDate.getHours()).to.equal(3);
+  });
+
+  it('should convert a date to Sydney timezone', function() {
+    var date = new Date('August 19, 2018 14:00:00 GMT+11:00');
+    var relativeDate = timezone.atTimezone(date, "Greenwich");
+    expect(relativeDate.getHours()).to.equal(3);
+  });
+
+
+  it('should convert a date to America/Virgin timezone', function() {
+    var date = new Date('August 19, 2018 10:00:00 GMT-03:00');
+    var relativeDate = timezone.atTimezone(date, "America/Virgin")
+    expect(relativeDate.getHours()).to.equal(9);
+  });  
+});