Improve fractional second parser

ISO 8601 allows decimal fractions of at least one digit.
Since JS Date supports only milliseconds, we accept any
number of digits but we'll keep only up to three.

This way higher precision fractions will be accepted but
we'll only ever store 1-999 milliseconds (and no overflows).

See #48

src/edtf.ne

@@ -85,7 +85,7 @@ minutes -> d00_59 {% num %}
 seconds -> d00_59 {% num %}
 
 milliseconds -> null
-              | "." d3 {% data => num(data.slice(1)) %}
+              | "." d3s {% data => num(data.slice(1)) %}
 
 timezone -> "Z"                 {% zero %}
           | ("-"|"−") offset    {% data => -data[1] %}
@@ -296,6 +296,11 @@ d4 -> d2 d2       {% join %}
 d3 -> d2 digit    {% join %}
 d2 -> digit digit {% join %}
 
+d3s -> digit      {% id %}
+     | d2         {% id %}
+     | d3         {% id %}
+     | d3 digits  {% pick(0) %}
+
 d5+ -> positive_digit d3 digits {% num %}
 
 d1x -> [1-9X]  {% id %}

src/grammar.js

@@ -67,7 +67,7 @@ let ParserRules = [
     {"name": "minutes", "symbols": ["d00_59"], "postprocess": num},
     {"name": "seconds", "symbols": ["d00_59"], "postprocess": num},
     {"name": "milliseconds", "symbols": []},
-    {"name": "milliseconds", "symbols": [{"literal":"."}, "d3"], "postprocess": data => num(data.slice(1))},
+    {"name": "milliseconds", "symbols": [{"literal":"."}, "d3s"], "postprocess": data => num(data.slice(1))},
     {"name": "timezone", "symbols": [{"literal":"Z"}], "postprocess": zero},
     {"name": "timezone$subexpression$1", "symbols": [{"literal":"-"}]},
     {"name": "timezone$subexpression$1", "symbols": [{"literal":"−"}]},
@@ -295,6 +295,10 @@ let ParserRules = [
     {"name": "d4", "symbols": ["d2", "d2"], "postprocess": join},
     {"name": "d3", "symbols": ["d2", "digit"], "postprocess": join},
     {"name": "d2", "symbols": ["digit", "digit"], "postprocess": join},
+    {"name": "d3s", "symbols": ["digit"], "postprocess": id},
+    {"name": "d3s", "symbols": ["d2"], "postprocess": id},
+    {"name": "d3s", "symbols": ["d3"], "postprocess": id},
+    {"name": "d3s", "symbols": ["d3", "digits"], "postprocess": pick(0)},
     {"name": "d5+", "symbols": ["positive_digit", "d3", "digits"], "postprocess": num},
     {"name": "d1x", "symbols": [/[1-9X]/], "postprocess": id},
     {"name": "dx", "symbols": ["d1x"], "postprocess": id},

test/parser.js

@@ -66,6 +66,17 @@ describe('parser', () => {
       expect(p('2016-05-02T16:54:59.042'))
         .to.produce([2016, 4, 2, 16, 54, 59, 42]).at.level(0))
 
+    it('YYYY-MM-DDThh:mm:ss.sss+', () => {
+      expect(p('2016-05-02T16:54:59.04200000'))
+        .to.produce([2016, 4, 2, 16, 54, 59, 42]).at.level(0)
+      expect(p('2016-05-02T16:54:59.4'))
+        .to.produce([2016, 4, 2, 16, 54, 59, 4]).at.level(0)
+      expect(p('2016-05-02T16:54:59.42'))
+        .to.produce([2016, 4, 2, 16, 54, 59, 42]).at.level(0)
+      expect(p('2016-05-02T16:54:59.042123'))
+        .to.produce([2016, 4, 2, 16, 54, 59, 42]).at.level(0)
+    })
+
     it('YYYY-MM-DDThh:mm:ssZ', () => {
       expect(p('2016-05-02T16:54:59Z'))
         .to.produce([2016, 4, 2, 16, 54, 59]).at.level(0)