accept 'now' as a time spec, especially useful for one-shot jobs

README.md

@@ -30,6 +30,11 @@ minutes.  The units must be one of 'd', 'h', 'm', or 's': days, hours, minutes,
 Numbers can be integers or simple decimals with a decimal point, (eg "1.5h" 90 minutes).
 Numbers without units are milliseconds, i.e. "1s 500" is 1500 ms.
 
+Jobs scheduled for a time offset not less than the milliseconds since 1/1/70 GMT will
+be scheduled to launch at the specified absolute runtime.  As a convenience, the special
+keyword `now` is recognized in timespecs as meaning the current datetime.  `now` is
+additive like the other time formats, so "now 20s" is 20 seconds from now.
+
 To pass call arguments or an object instance to a method call, use the `options` form of the
 call; see below.
 
@@ -111,6 +116,7 @@ for the same time the following day instead of letting them expire unrun.
 Changelog
 ---------
 
+- 0.5.0 - accept 'now' as a time spec, eg `at: 'now 10s'`
 - 0.4.0 - job pause/resume methods, fix timespec units in options object
 - 0.3.0 - allow units in timespec eg '2h 15m'
 - 0.2.0 - first release

cron.js

@@ -81,6 +81,7 @@ Cron.prototype.setTimeout = function setTimeout( func, ms, repeat ) {
 
 // given ms after midnight and ms between runs, find the next scheduled runtime in GMT
 Cron.prototype._findNextRuntime = function _findNextRuntime( nowDate, offset, interval ) {
+    if (offset >= nowDate) return offset;
     var midnight = nowDate - nowDate % Cron.msPerDay;
     var next = midnight + offset;
     if (!(interval > 0)) interval = Cron.msPerDay;  // pretend daily if missing
@@ -102,11 +103,12 @@ function parseMs( ms ) {
     if (typeof ms !== 'string') return ms;
 
     var at = 0, match;
-    while ((match = /((\s*[.]\d+|\s*\d+[.]\d*|\s*\d+)\s*([dhms]|))/g.exec(ms))) {
+    while ((match = /(\s*(now|[.]\d+|\d+[.]\d*|\d+)\s*([dhms]|))/g.exec(ms))) {
         ms = ms.slice(match[1].length);
-        at += +match[2] * unitScale[match[3]];
+        if (match[2] === 'now') at += new Date().getTime();
+        else at += +match[2] * unitScale[match[3]];
     }
-    if (ms.length > 0) throw new Error(ms + ': bad time format, expected number[dhms]');
+    if (ms.trim().length > 0) throw new Error(ms + ': bad time format, expected number[dhms]');
 
     return at;
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "qcron",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "description": "simple little call scheduler",
   "main": "cron.js",
   "license": "Apache-2.0",

test.js

@@ -47,14 +47,18 @@ module.exports = {
         job = cron.scheduleCall(noop, 0, '1000');
         t.equal(job._repeat, 1000);
         t.equal(cron.scheduleCall(noop, 0, '2h')._repeat, 7200000);
-        t.equal(cron.scheduleCall(noop, 0, '3m')._repeat, 180000);
-        t.equal(cron.scheduleCall(noop, 0, '4s')._repeat, 4000);
+        t.equal(cron.scheduleCall(noop, 0, ' 3m')._repeat, 180000);
+        t.equal(cron.scheduleCall(noop, 0, ' 4  s ')._repeat, 4000);
         t.equal(cron.scheduleCall(noop, 0, '4.5s')._repeat, 4500);
         t.equal(cron.scheduleCall(noop, 0, '.5s 4000')._repeat, 4500);
         t.equal(cron.scheduleCall(noop, 0, '4.5s 100')._repeat, 4600);
         t.equal(cron.scheduleCall(noop, 0, '1d 2 h 3m4s5')._repeat, 93784005);
         t.equal(cron.scheduleCall({ func: noop, at: 0, repeat: '2h' })._repeat, 7200000);
+        t.ok(cron.scheduleCall({ func: noop, at: 0, repeat: '2h' })._start > 0);
+        t.equal(cron.scheduleCall({ func: noop, at: '.05s now' })._start, 50 + new Date().getTime());
+        var now = Date.now();
         t.throws(function() { cron.scheduleCall(noop, 'x') }, /expected number/);
+        t.throws(function() { cron.scheduleCall(noop, '3s new') }, /bad time format/);
         t.done();
     },