test conditions and notes

test.js

@@ -0,0 +1,133 @@
+var d = new Date("5/18/2019, 07:49:13");
+// Fri May 17 2019 17:49:13 GMT-0400 (Eastern Daylight Time)
+// utc should be Fri, 17 May 2019 21:49:13 GMT"
+// 
+console.log("d:" + d)
+console.log("tzUTC:" + tzUTC(d, 'Australia/Sydney'))
+
+d = new Date("5/17/2019, 14:53:21");
+console.log("d:" + d)
+
+// Fri May 17 2019 17:53:21 GMT-0400 (Eastern Daylight Time)
+// utc "Fri, 17 May 2019 21:53:21 GMT"
+
+console.log("tzUTC:" + tzUTC(d, 'America/Los_Angeles'))
+
+
+//////
+////// 9:01 twice
+//////
+
+var d = new Date("3/10/2019, 01:59:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 10 Mar 2019 08:59:00 GMT
+
+var d = new Date("3/10/2019, 02:01:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 10 Mar 2019 09:01:00 GMT
+
+var d = new Date("3/10/2019, 02:59:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 10 Mar 2019 09:59:00 GMT
+
+var d = new Date("3/10/2019, 03:01:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 10 Mar 2019 09:01:00 GMT
+
+//////
+////// 8:01 never
+//////
+
+var d = new Date("11/03/2019, 01:59:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 03 Nov 2019 07:59:00 GMT
+
+var d = new Date("11/03/2019, 02:01:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 03 Nov 2019 09:01:00 GMT
+
+var d = new Date("11/03/2019, 02:59:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+// tzUTC:Sun, 03 Nov 2019 09:59:00 GMT
+
+var d = new Date("11/03/2019, 03:01:00");
+console.log("tzUTC:" + tzUTC(d, 'America/Denver'));
+tzUTC:Sun, 03 Nov 2019 10:01:00 GMT
+
+
+/*
+Yes, that's a major use case. And one that can contact people according to their timezone. The daylight savings problem most likely won't affect us. But it could.
+As a failsafe is there a way that you could detect daylight savings time and report it? Perhaps create 3 times and check that the difference on either side is exactly 1.5 hours?
+*/
+
+/*
+But there's a second thing, more along the lines of a scheduler:
+
+Given a target date in local time, produce the same local time a week later.
+
+"I'm having lunch with John today at 12:30 pm. Schedule a lunch next week at 12:30pm."
+
+The naive approach that almost always works is to simply add (7 x 24 x 60 x 60 x 1000), but that won't work if the lunch happened on either of these days:
+
+var d = new Date("03/07/2019, 12:30:00"); // +  (7 * 24 * 60 * 60 * 1000)
+
+var d = new Date("11/01/2019, 12:30:00"); // +  (7 * 24 * 60 * 60 * 1000)
+
+In both instances my simple calendar would be off by an hour.
+*/
+
+/*
+I think the solution will be:
+
+srcMs = toMs(srcLocalDate)
+targetMs = srcMs + diffMs
+targetLocalDate = toLocal(targetMs)
+targetMs += toMsAsIfUtc(srcLocalDate) - (toMsAsIfUtc(targetLocalDate) - diffMs)
+return toLocalDate(targetMs)
+*/
+
+(function (exports) {
+'use strict';
+
+exports.TEST = function (myfn) {
+
+  var tests = [
+    { name: "normal date"
+    , input: { d: '5/18/2019, 8:59:48 AM', tz: "America/Denver" }
+    , expected: 1558191588007
+    }
+  ];
+
+  function next() {
+    var t = tests.shift();
+    var result;
+    if (!t) {
+      return true;
+    }
+    try {
+      result = Promise.resolve(myfn(t.input));
+    } catch(e) {
+      result = Promise.reject(e);
+    }
+
+    result.then(function (result) {
+      if (result === t.expected) {
+        return true;
+      }
+      throw new Error(t.name + ": result did not match expected: " + JSON.stringify(result) + " vs " + JSON.stringify(t.expected));
+    });
+  }
+
+  return next();
+};
+}('undefined' === typeof module ? window : module.exports));
+
+runner.js:
+(function (exports) {
+'use strict';
+
+var tzUtc = exports.tzUtc || require('./index.js').tzUtc;
+var tester = exports.TEST || require('./test.js').TEST;
+tester(tzUtc);
+
+}('undefined' === typeof module ? window : module.exports));