chore(i18n): fix parser for currency patterns without fraction digits

Previously, it was assumed that all currency pattern would have fraction digits.
However, in [closure-library@b9155d5][1] the `agq_CM` locale was modified to
have such a pattern (namely `#,##0\u00A4`).
This commit modifies the parser implementation to account for pattern without a
decimal point (and thus no fraction digits).

[1]: google/closure-library@b9155d5#diff-02793124214ad0470ccea6f86b90d786R711

Author: gkalpak

i18n/spec/parserSpec.js

@@ -1,6 +1,43 @@
 'use strict';
 
-var parsePattern = require('../src/parser.js').parsePattern;
+var parser = require('../src/parser');
+var ensureDecimalSep = parser.ensureDecimalSep;
+var parsePattern = parser.parsePattern;
+
+describe('ensureDecimalSep', function() {
+  it('should leave patterns with DECIMAL_SEP untouched', function() {
+    [
+      '#,##0.00',
+      '$#,##0.00',
+      '#,##0.00$',
+      '$0.00',
+      '0.00$',
+      '0.0',
+      '#,##0.',
+      '0.'
+    ].forEach(function(pattern) {
+      expect(ensureDecimalSep(pattern)).toBe(pattern);
+    });
+  });
+
+  it('should add a DECIMAL_SEP in patterns that don\'t have one (after the last ZERO)', function() {
+    var patterns = {
+      '#,##000': '#,##000.',
+      '$#,#0#00': '$#,#0#00.',
+      '#,##000$': '#,##000.$',
+      '$000': '$000.',
+      '000$': '000.$',
+      '00': '00.',
+      '#,##0': '#,##0.',
+      '0': '0.'
+    };
+
+    Object.keys(patterns).forEach(function(input) {
+      var output = patterns[input];
+      expect(ensureDecimalSep(input)).toBe(output);
+    });
+  });
+});
 
 describe('parsePattern', function() {
   function parseAndExpect(pattern, pp, np, ps, ns, mii, mif, maf, g, lg) {
@@ -28,6 +65,11 @@ describe('parsePattern', function() {
         '', '\u202A-', '', '\u202C', 1, 0, 3, 3, 3);
     parseAndExpect('#0.###;#0.###-', '', '', '', '-', 1, 0, 3, 0, 0);
 
+    // Even patterns without a DECIMAL_SEP
+    parseAndExpect('#,##0', '', '-', '', '', 1, 0, 0, 3, 3);
+    parseAndExpect('+#,##0', '+', '-+', '', '', 1, 0, 0, 3, 3);
+    parseAndExpect('#,#0;+#,#0', '', '+', '', '', 1, 0, 0, 2, 2);
+    parseAndExpect('#,##,##0+;(#,##,##0)', '', '(', '+', ')', 1, 0, 0, 2, 3);
   });
 
   it('should parse CURRENCY patterns', function() {
@@ -51,5 +93,11 @@ describe('parsePattern', function() {
     parseAndExpect('\u00A4 #,##0.00;\u00A4 #,##0.00-',
                    '\u00A4 ', '\u00A4 ', '', '-', 1, 2, 2, 3, 3);
     parseAndExpect('\u00A4 #,##,##0.00', '\u00A4 ', '-\u00A4 ', '', '', 1, 2, 2, 2, 3);
+
+    // Even patterns without a DECIMAL_SEP
+    parseAndExpect('#,##0 \u00A4', '', '-', ' \u00A4', ' \u00A4', 1, 0, 0, 3, 3);
+    parseAndExpect('\u00A4 #,##0', '\u00A4 ', '-\u00A4 ', '', '', 1, 0, 0, 3, 3);
+    parseAndExpect('#,#0 \u00A4;+#,#0\u00A4', '', '+', ' \u00A4', '\u00A4', 1, 0, 0, 2, 2);
+    parseAndExpect('\u00A4 #,##,##0;(\u00A4 #,##,##0)', '\u00A4 ', '(\u00A4 ', '', ')', 1, 0, 0, 2, 3);
   });
 });

i18n/src/parser.js

@@ -4,13 +4,26 @@
 * A simple parser to parse a number format into a pattern object
 */
 
+exports.ensureDecimalSep = ensureDecimalSep;
 exports.parsePattern = parsePattern;
 
-var PATTERN_SEP = ';',
-    DECIMAL_SEP = '.',
-    GROUP_SEP   = ',',
-    ZERO        = '0',
-    DIGIT       = '#';
+var PATTERN_SEP  = ';',
+    DECIMAL_SEP  = '.',
+    GROUP_SEP    = ',',
+    DIGIT        = '#',
+    ZERO         = '0',
+    LAST_ZERO_RE = /^(.*0)(?!0)(.*)$/;
+
+/**
+ * Helper function for parser.
+ * Ensures that `pattern` (e.g #,##0.###) contains a DECIMAL_SEP, which is necessary for further
+ * parsing. If a pattern does not include one, it is added after the last ZERO (which is the last
+ * thing before the `posSuf` - if any).
+ */
+function ensureDecimalSep(pattern) {
+  return (pattern.indexOf(DECIMAL_SEP) !== -1)
+      ? pattern : pattern.replace(LAST_ZERO_RE, '$1' + DECIMAL_SEP + '$2');
+}
 
 /**
  * main function for parser
@@ -33,7 +46,16 @@ function parsePattern(pattern) {
       positive = patternParts[0],
       negative = patternParts[1];
 
-  var positiveParts = positive.split(DECIMAL_SEP),
+  // The parsing logic further below assumes that there will always be a DECIMAL_SEP in the pattern.
+  // However, some locales (e.g. agq_CM) do not have one, thus we add one after the last ZERO
+  // (which is the last thing before the `posSuf` - if any). Since there will be no ZEROs or DIGITs
+  // after DECIMAL_SEP, `min/maxFrac` will remain 0 (which is accurate - no fraction digits) and
+  // `posSuf` will be processed correctly.
+  // For example `#,##0$` would be converted to `#,##0.$`, which would (correctly) result in:
+  // `minFrac: 0`, `maxFrac: 0`, `posSuf: '$'`
+  // Note: We shouldn't modify `positive` directly, because it is used to parse the negative part.)
+  var positiveWithDecimalSep = ensureDecimalSep(positive),
+      positiveParts = positiveWithDecimalSep.split(DECIMAL_SEP),
       integer = positiveParts[0],
       fraction = positiveParts[1];