fix: parsing issue with numeric character in group of options (#19)

BREAKING CHANGE:

subtle change to how values are parsed in a group of single-character arguments.

index.js

@@ -213,8 +213,9 @@ function parse (args, opts) {
           continue
         }
 
+        // current letter is an alphabetic character and next value is a number
         if (/[A-Za-z]/.test(letters[j]) &&
-          /-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
+          /^-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
           setArg(letters[j], next)
           broken = true
           break

test/yargs-parser.js

@@ -879,6 +879,29 @@ describe('yargs-parser', function () {
       argv.should.have.property('n', 123)
     })
 
+    it('should set n to the numeric value 123, with n at the end of a group', function () {
+      var argv = parser([ '-ab5n123' ])
+      argv.should.have.property('a', true)
+      argv.should.have.property('b', true)
+      argv.should.have.property('5', true)
+      argv.should.have.property('n', 123)
+      argv.should.have.property('_').with.length(0)
+    })
+
+    it('should set n to the numeric value 123, with = as separator', function () {
+      var argv = parser([ '-n=123' ])
+      argv.should.have.property('n', 123)
+    })
+
+    it('should set n to the numeric value 123, with n at the end of a group and = as separator', function () {
+      var argv = parser([ '-ab5n=123' ])
+      argv.should.have.property('a', true)
+      argv.should.have.property('b', true)
+      argv.should.have.property('5', true)
+      argv.should.have.property('n', 123)
+      argv.should.have.property('_').with.length(0)
+    })
+
     it('should set option "1" to true, option "2" to true, and option "3" to numeric value 456', function () {
       var argv = parser([ '-123', '456' ])
       argv.should.have.property('1', true)