diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..3c3629e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+node_modules
diff --git a/package.json b/package.json
index 5f679c9..57dd498 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "Tools for manipulating semver strings and objects",
   "main": "semver-utils.js",
   "scripts": {
-    "test": "node semver-utils-test.js"
+    "test": "mocha"
   },
   "repository": {
     "type": "git",
@@ -18,5 +18,9 @@
   ],
   "author": "AJ ONeal",
   "license": "APACHEv2",
-  "readmeFilename": "README.md"
+  "readmeFilename": "README.md",
+  "devDependencies": {
+    "chai": "^3.0.0",
+    "mocha": "^2.2.5"
+  }
 }
diff --git a/semver-utils-test.js b/semver-utils-test.js
deleted file mode 100644
index 9bfa0a2..0000000
--- a/semver-utils-test.js
+++ /dev/null
@@ -1,131 +0,0 @@
-(function () {
-  var semverutils = require('./semver-utils')
-    ;
-
-  function testParseRange() {
-    console.info('testParseRange');
-    var good =
-        [ 'v1.0.0'
-        , '< v2.0.0'
-        , '~v2.0.0'
-        , '~1.0.0'
-        , '~1.0.0 || >= 1.1.7 < 2.0.0+build.1848'
-        , '~1.0.0 || >= 1.1.7 < 2.0.0+build.1848 || v1.1.3'
-        , '~1.0.0 || >= 1.1.7 < 2.0.0+build.1848 || v1.1.3 || 2.0.1-alpha.1227'
-        , '~1.0.0 || >= 1.1.7 < 2.0.0+build.1848 || v1.1.3 || 2.0.1-alpha.1227 || 1.0.0 - 1.0.x'
-        , '~1.0.0 || >= 1.1.7 < 2.0.0+build.1848 || v1.1.3 || 2.0.1-alpha.1227 || 1.0.0 - 1.0.x || 1.*'
-        ]
-      ;
-
-    good.every(function (range) {
-      var result = semverutils.parseRange(range)
-        ;
-   
-      if (!result || 0 === result.length) {
-        throw new Error("didn't parse something that should be parseable: " + range);
-      }
-   
-      return true;
-    });
-
-    console.log(good[good.length - 1]);
-    console.log(semverutils.stringifyRange(semverutils.parseRange(good[good.length - 1])));
-  }
-
-  function testParse() {
-    console.info('testParse');
-    var good
-      , bad
-      ;
-   
-    good = [
-        "1.0.8"
-      , "1.23.7"
-      , "2.0.0-alpha.123.abc"
-      , "2.0.0-alpha.123.abc+build.acebfde1284"
-      , "1.0.0-alpha"
-      , "1.0.0-alpha.1"
-      , "1.0.0-0.3.7"
-      , "1.0.0-x.7.z.92"
-      , "1.0.0-alpha"
-      , "1.0.0-alpha.1"
-      , "1.0.0-beta.2"
-      , "1.0.0-beta.11"
-      , "1.0.0-rc.1"
-      , "1.0.0-rc.1+build.1"
-      , "1.0.0-rc.1+build.1-b"
-      , "1.0.0"
-      , "1.0.0+0.3.7"
-      , "1.3.7+build"
-      , "1.3.7+build.2.b8f12d7"
-      , "1.3.7+build.11.e0f985a"
-      , "1.3.7+build.11.e0f9-85a"
-      , "1.0.0+build-acbe"
-      , "2.0.0+build.acebfde1284-alpha.123.abc"
-    ];
-   
-    bad = [
-      //  "v1.0.0" now allows optional 'v'
-      , "a.b.c"
-      , "1"
-      , "1.0.0b"
-      , "1.0"
-      , "1.0.0+b[\\]^_`uild" // [,\,],^,_,` are between A-z, but not A-Za-z
-      , "1.0.0+build-acbe." // trailing period
-      , "1.0.0+build.!@#$%"
-    ];
-   
-    good.every(function (version) {
-      var result = semverutils.parse(version)
-        ;
-   
-      if (!result) {
-        throw new Error("didn't parse something that should be parseable: " + version);
-      }
-   
-      return true;
-    });
-   
-    bad.every(function (version) {
-      var result = semverutils.parse(version)
-        ;
-   
-      if (result) {
-        throw new Error("parsed something that should not be parseable: " + version);
-      }
-   
-      return true;
-    });
-   
-    console.log(semverutils.parse("a.b.c")); // null
-    console.log(semverutils.parse("1.0.3"));
-    /*
-    {
-        semver: 1.0.3
-      , major: 1
-      , minor: 0
-      , patch: 3
-    }
-    */
-   
-    console.log(semverutils.parse("1.0.3-rc.1+build.aef312"));
-    /*
-    {
-        semver: v1.0.3-rc.1+build.aef312
-      , major: 1
-      , minor: 0
-      , patch: 3
-      , build: build.aef312
-      , release: rc.1
-    }
-    */
-   
-    console.log(semverutils.parse("1.0.0-rc.1-1"));
-    console.log(semverutils.parse("1.0.0-rc.1+build.1-b"));
-    console.log(semverutils.parse("1.0.0-rc.1-1+build.1-b"));
-    console.log(semverutils.parse("2.0.0+build.acebfde1284-alpha.123.abc"));
-  }
-
-  testParse();
-  testParseRange(); 
-}());
diff --git a/semver-utils.js b/semver-utils.js
index 20b3fff..4307a12 100644
--- a/semver-utils.js
+++ b/semver-utils.js
@@ -8,9 +8,20 @@
   //               | |                    |                                        |optional build prefixed by '+'
   var reSemver = /^v?((\d+)\.(\d+)\.(\d+))(?:-([\dA-Za-z\-]+(?:\.[\dA-Za-z\-]+)*))?(?:\+([\dA-Za-z\-]+(?:\.[\dA-Za-z\-]+)*))?$/
     //, reSemverRange = /\s*((\|\||\-)|(([<>~]?=?)\s*(v)?([0-9]+)(\.(x|[0-9]+))?(\.(x|[0-9]+))?(([\-+])([a-zA-Z0-9\.]+))?))\s*/g
-    , reSemverRange = /\s*((\|\||\-)|(([<>~]?=?)\s*(v)?([0-9]+)(\.(x|\*|[0-9]+))?(\.(x|\*|[0-9]+))?(([\-+])([a-zA-Z0-9\.]+))?))\s*/g
+    , reSemverRange = /\s*((\|\||\-)|(([<>~^]?=?)\s*(v)?([0-9]+)(\.(x|\*|[0-9]+))?(\.(x|\*|[0-9]+))?(([\-+])([a-zA-Z0-9\.-]+))?))\s*/g
     ;
 
+  // Returns a new object with all of the undefined properties removed from the given object
+  function pruned(obj) {
+    var o = {};
+    for(var key in obj) {
+      if ('undefined' !== typeof obj[key]) {
+        o[key] = obj[key];
+      }
+    }
+    return o;
+  }
+
   function stringifySemver(obj) {
     var str = ''
       ;
@@ -43,7 +54,7 @@
     }
 
     arr.forEach(stringify);
-  
+
     return str.trim();
   }
 
@@ -86,7 +97,7 @@
     // https://github.com/isaacs/node-semver/issues/10
     // optional v
     var m = reSemver.exec(version) || []
-      , ver = new SemVer({
+      , ver = new SemVer(pruned({
             semver: m[0]
           , version: m[1]
           , major: m[2]
@@ -94,13 +105,13 @@
           , patch: m[4]
           , release: m[5]
           , build: m[6]
-        })
+        }))
       ;
- 
+
     if (0 === m.length) {
       ver = null;
     }
- 
+
     return ver;
   }
 
@@ -109,18 +120,9 @@
       , arr = []
       , obj
       ;
- 
-    function prune(key) {
-      if ('undefined' === typeof obj[key]) {
-        delete obj[key];
-      }
-    }
- 
-    while (true) {
-      m = reSemverRange.exec(str);
-      if (!m) {
-        break;
-      }
+
+
+    while (m = reSemverRange.exec(str)) {
       obj = {
           semver: m[3]
         , operator: m[4] || m[2]
@@ -134,11 +136,10 @@
       if ('-' === m[12]) {
         obj.release = m[13];
       }
-      Object.keys(obj).forEach(prune);
-      arr.push(new SemVer(obj));
+      arr.push(new SemVer(pruned(obj)));
       //console.log(m);
     }
- 
+
     //return new SemVerRange(arr);
     return arr;
   }
diff --git a/test/deepOwnEqual.js b/test/deepOwnEqual.js
new file mode 100644
index 0000000..b7dd276
--- /dev/null
+++ b/test/deepOwnEqual.js
@@ -0,0 +1,26 @@
+var assert = require('chai').assert;
+
+// we need to define our own deepEqual function that ignores properties that are not hasOwnProperty. Not supported in chai.assert.deepEqual as of v3.0.0.
+function deepOwnEqual(a, b) {
+
+  // if arrays of objects, recurse down to the objects
+  if(Array.isArray(a) && Array.isArray(b)) {
+    assert.deepEqual(a.length, b.length, 'Arrays have different lengths')
+    for(var i=0; i<a.length; i++) {
+      deepOwnEqual(a[i], b[i])
+    }
+  }
+  // compare all the object properties
+  else {
+    var aKeys = Object.keys(a);
+    var bKeys = Object.keys(b);
+
+    assert.deepEqual(aKeys, bKeys, 'Objects have different keys');
+
+    aKeys.forEach(function(key) {
+      assert.deepEqual(a[key], b[key], 'Expected values of "' + key + '" property to be equal in each object')
+    });
+  }
+}
+
+module.exports = deepOwnEqual
\ No newline at end of file
diff --git a/test/spec.js b/test/spec.js
new file mode 100644
index 0000000..4017b11
--- /dev/null
+++ b/test/spec.js
@@ -0,0 +1,192 @@
+var assert = require('chai').assert;
+var semverutils = require('../semver-utils');
+var deepOwnEqual = require('./deepOwnEqual');
+
+describe('parse', function() {
+
+  it('should parse a simple 3-part version', function() {
+    deepOwnEqual(semverutils.parse('1.0.0'), {
+      semver: '1.0.0',
+      version: '1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    });
+  });
+
+  it('should parse pre-release versions', function() {
+    deepOwnEqual(semverutils.parse('1.0.0-alpha1'), {
+      semver: '1.0.0-alpha1',
+      version: '1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0',
+      release: 'alpha1'
+    });
+  });
+
+  it('should parse build numbers', function() {
+    deepOwnEqual(semverutils.parse('1.0.0+build-123'), {
+      semver: '1.0.0+build-123',
+      version: '1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0',
+      build: 'build-123'
+    });
+  });
+
+  it('should not parse invalid versions', function() {
+    assert.equal(semverutils.parse('a.b.c'), null);
+    assert.equal(semverutils.parse('1'), null);
+    assert.equal(semverutils.parse('1.0'), null);
+    assert.equal(semverutils.parse('1.0.0b'), null);
+    assert.equal(semverutils.parse('1.0.0+build-abc.'), null, 'trailing period');
+  });
+
+});
+
+describe('parseRange', function() {
+
+  it('should parse an exact version as a range', function() {
+
+    deepOwnEqual(semverutils.parseRange('1.0.0'), [{
+      semver: '1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should ignore the v- prefix', function() {
+
+    deepOwnEqual(semverutils.parseRange('v1.0.0'), [{
+      semver: 'v1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse a comparison operator', function() {
+    deepOwnEqual(semverutils.parseRange('< v2.0.0'), [{
+      semver: '< v2.0.0',
+      operator: '<',
+      major: '2',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse tilde', function() {
+    deepOwnEqual(semverutils.parseRange('~1.0.0'), [{
+      semver: '~1.0.0',
+      operator: '~',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse caret', function() {
+    deepOwnEqual(semverutils.parseRange('^1.0.0'), [{
+      semver: '^1.0.0',
+      operator: '^',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse tilde and v- prefix', function() {
+    deepOwnEqual(semverutils.parseRange('~v1.0.0'), [{
+      semver: '~v1.0.0',
+      operator: '~',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse ||', function() {
+    deepOwnEqual(semverutils.parseRange('~1.0.0 || ~2.0.0'), [{
+      semver: '~1.0.0',
+      operator: '~',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }, {
+      operator: '||'
+    }, {
+      semver: '~2.0.0',
+      operator: '~',
+      major: '2',
+      minor: '0',
+      patch: '0'
+    }]);
+  });
+
+  it('should parse build numbers', function() {
+    deepOwnEqual(semverutils.parseRange('2.0.0+build.1848'), [{
+      semver: '2.0.0+build.1848',
+      major: '2',
+      minor: '0',
+      patch: '0',
+      build: 'build.1848'
+    }]);
+  });
+
+  it('should parse pre-release versions', function() {
+    deepOwnEqual(semverutils.parseRange('1.0.0-rc1'), [{
+      semver: '1.0.0-rc1',
+      major: '1',
+      minor: '0',
+      patch: '0',
+      release: 'rc1'
+    }]);
+  });
+
+  it('should parse pre-release versions with hyphens', function() {
+
+    deepOwnEqual(semverutils.parseRange('1.0.0-rc-2'), [{
+      semver: '1.0.0-rc-2',
+      major: '1',
+      minor: '0',
+      patch: '0',
+      release: 'rc-2'
+    }]);
+  });
+
+  it('should parse hyphen ranges', function() {
+    deepOwnEqual(semverutils.parseRange('1.0.0 - 1.0.x'), [{
+      semver: '1.0.0',
+      major: '1',
+      minor: '0',
+      patch: '0'
+    }, {
+      operator: '-'
+    }, {
+      semver: '1.0.x',
+      major: '1',
+      minor: '0',
+      patch: 'x'
+    }]);
+  });
+
+  it('should parse constrained * ranges', function() {
+    deepOwnEqual(semverutils.parseRange('1.*'), [{
+      semver: '1.*',
+      major: '1',
+      minor: '*',
+    }]);
+  });
+
+  it('should parse constrained .x', function() {
+    deepOwnEqual(semverutils.parseRange('1.x'), [{
+      semver: '1.x',
+      major: '1',
+      minor: 'x',
+    }]);
+  });
+
+});
\ No newline at end of file