diff --git a/_infrastructure/tests/_ref.d.ts b/_infrastructure/tests/_ref.d.ts
new file mode 100644
index 000000000..1743cad05
--- /dev/null
+++ b/_infrastructure/tests/_ref.d.ts
@@ -0,0 +1 @@
+/// <reference path='../../node/node.d.ts' />
diff --git a/_infrastructure/tests/runner.js b/_infrastructure/tests/runner.js
index f73c72a39..ee80513a2 100644
--- a/_infrastructure/tests/runner.js
+++ b/_infrastructure/tests/runner.js
@@ -44,6 +44,7 @@ var NodeExec = (function () {
 var Exec = function () {
     return new NodeExec();
 }();
+/// <reference path="../_ref.d.ts" />
 var DT;
 (function (DT) {
     var path = require('path');
@@ -85,9 +86,9 @@ var DT;
     })();
     DT.File = File;
 })(DT || (DT = {}));
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
-/// <reference path='host/exec.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
+/// <reference path="host/exec.ts" />
 var DT;
 (function (DT) {
     var fs = require('fs');
@@ -127,8 +128,8 @@ var DT;
     })();
     DT.Tsc = Tsc;
 })(DT || (DT = {}));
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
 var DT;
 (function (DT) {
     /////////////////////////////////
@@ -167,6 +168,7 @@ var DT;
     })();
     DT.Timer = Timer;
 })(DT || (DT = {}));
+/// <reference path="../_ref.d.ts" />
 var DT;
 (function (DT) {
     var referenceTagExp = /<reference[ \t]*path=["']?([\w\.\/_-]*)["']?[ \t]*\/>/g;
@@ -194,19 +196,19 @@ var DT;
     }
     DT.extractReferenceTags = extractReferenceTags;
 })(DT || (DT = {}));
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
-/// <reference path='util.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
+/// <reference path="util.ts" />
 var DT;
 (function (DT) {
     var fs = require('fs');
     var path = require('path');
 
-    var ReferenceIndex = (function () {
-        function ReferenceIndex(options) {
+    var FileIndex = (function () {
+        function FileIndex(options) {
             this.options = options;
         }
-        ReferenceIndex.prototype.collectReferences = function (files, callback) {
+        FileIndex.prototype.parseFiles = function (files, callback) {
             var _this = this;
             this.fileMap = Object.create(null);
             files.forEach(function (file) {
@@ -217,7 +219,7 @@ var DT;
             });
         };
 
-        ReferenceIndex.prototype.loadReferences = function (files, callback) {
+        FileIndex.prototype.loadReferences = function (files, callback) {
             var _this = this;
             var queue = files.slice(0);
             var active = [];
@@ -240,7 +242,7 @@ var DT;
             process.nextTick(next);
         };
 
-        ReferenceIndex.prototype.parseFile = function (file, callback) {
+        FileIndex.prototype.parseFile = function (file, callback) {
             var _this = this;
             fs.readFile(file.filePathWithName, {
                 encoding: 'utf8',
@@ -267,12 +269,49 @@ var DT;
                 callback(file);
             });
         };
-        return ReferenceIndex;
+        return FileIndex;
     })();
-    DT.ReferenceIndex = ReferenceIndex;
+    DT.FileIndex = FileIndex;
 })(DT || (DT = {}));
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
+/// <reference path="../_ref.d.ts" />
+var DT;
+(function (DT) {
+    var fs = require('fs');
+    var path = require('path');
+    var Git = require('git-wrapper');
+
+    var GitChanges = (function () {
+        function GitChanges(baseDir) {
+            this.baseDir = baseDir;
+            this.options = [];
+            var dir = path.join(baseDir, '.git');
+            if (!fs.existsSync(dir)) {
+                throw new Error('cannot locate git-dir: ' + dir);
+            }
+            this.options['git-dir'] = dir;
+        }
+        GitChanges.prototype.getChanges = function (callback) {
+            //git diff --name-only HEAD~1
+            var git = new Git(this.options);
+            var opts = {};
+            var args = ['--name-only HEAD~1'];
+            git.exec('diff', opts, args, function (err, msg) {
+                if (err) {
+                    callback(err, null);
+                    return;
+                }
+                var paths = msg.replace(/^\s+/, '').replace(/\s+$/, '').split(/\r?\n/g);
+
+                // console.log(paths);
+                callback(null, paths);
+            });
+        };
+        return GitChanges;
+    })();
+    DT.GitChanges = GitChanges;
+})(DT || (DT = {}));
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
 var DT;
 (function (DT) {
     /////////////////////////////////
@@ -387,6 +426,8 @@ var DT;
     })();
     DT.Print = Print;
 })(DT || (DT = {}));
+/// <reference path="../../_ref.d.ts" />
+/// <reference path="../printer.ts" />
 var DT;
 (function (DT) {
     
@@ -608,27 +649,41 @@ var DT;
     })(DT.TestSuiteBase);
     DT.FindNotRequiredTscparams = FindNotRequiredTscparams;
 })(DT || (DT = {}));
-/// <reference path='../../node/node.d.ts' />
-/// <reference path='src/host/exec.ts' />
-/// <reference path='src/file.ts' />
-/// <reference path='src/tsc.ts' />
-/// <reference path='src/timer.ts' />
+/// <reference path="_ref.d.ts" />
+/// <reference path="src/host/exec.ts" />
+/// <reference path="src/file.ts" />
+/// <reference path="src/tsc.ts" />
+/// <reference path="src/timer.ts" />
 /// <reference path="src/util.ts" />
-/// <reference path="src/references.ts" />
-/// <reference path='src/printer.ts' />
-/// <reference path='src/reporter/reporter.ts' />
-/// <reference path='src/suite/suite.ts' />
-/// <reference path='src/suite/syntax.ts' />
-/// <reference path='src/suite/testEval.ts' />
-/// <reference path='src/suite/tscParams.ts' />
+/// <reference path="src/index.ts" />
+/// <reference path="src/changes.ts" />
+/// <reference path="src/printer.ts" />
+/// <reference path="src/reporter/reporter.ts" />
+/// <reference path="src/suite/suite.ts" />
+/// <reference path="src/suite/syntax.ts" />
+/// <reference path="src/suite/testEval.ts" />
+/// <reference path="src/suite/tscParams.ts" />
 var DT;
 (function (DT) {
-    require('source-map-support');
+    require('source-map-support').install();
 
     var fs = require('fs');
     var path = require('path');
     var glob = require('glob');
 
+    var tsExp = /\.ts$/;
+
+    // TOD0 remove this after dev!
+    var testNames = [
+        'async/',
+        'jquery/jquery.d',
+        'angularjs/angular.d',
+        'pixi/'
+    ];
+
+    /* if (process.env.TRAVIS) {
+    testNames = null;
+    } */
     DT.DEFAULT_TSC_VERSION = "0.9.1.1";
 
     var Test = (function () {
@@ -679,39 +734,36 @@ var DT;
     var TestRunner = (function () {
         function TestRunner(dtPath, options) {
             if (typeof options === "undefined") { options = { tscVersion: DT.DEFAULT_TSC_VERSION }; }
+            var _this = this;
+            this.dtPath = dtPath;
             this.options = options;
             this.suites = [];
             this.options.findNotRequiredTscparams = !!this.options.findNotRequiredTscparams;
 
-            // TOD0 remove this after dev!
-            var testNames = [
-                'async/',
-                'jquery/jquery.d',
-                'angularjs/angular.d',
-                'pixi/'
-            ];
-            if (process.env.TRAVIS) {
-                testNames = null;
-            }
+            this.index = new DT.FileIndex(this.options);
 
             // should be async
             // only includes .d.ts or -tests.ts or -test.ts or .ts
             var filesName = glob.sync('**/*.ts', { cwd: dtPath });
             this.files = filesName.filter(function (fileName) {
-                return fileName.indexOf('_infrastructure') < 0;
-            }).filter(function (fileName) {
-                return fileName.indexOf('node_modules/') < 0;
-            }).filter(function (fileName) {
-                // TOD0 remove this after dev!
-                return !testNames || testNames.some(function (pattern) {
-                    return fileName.indexOf(pattern) > -1;
-                });
-            }).filter(function (fileName) {
-                return /^[a-z]/i.test(fileName);
+                return _this.checkAcceptFile(fileName);
             }).sort().map(function (fileName) {
                 return new DT.File(dtPath, fileName);
             });
         }
+        TestRunner.prototype.checkAcceptFile = function (fileName) {
+            var ok = tsExp.test(fileName);
+            ok = ok && fileName.indexOf('_infrastructure') < 0;
+            ok = ok && fileName.indexOf('node_modules/') < 0;
+            ok = ok && /^[a-z]/i.test(fileName);
+
+            //TODO remove this dev code
+            ok = ok && (!testNames || testNames.some(function (pattern) {
+                return fileName.indexOf(pattern) > -1;
+            }));
+            return ok;
+        };
+
         TestRunner.prototype.addSuite = function (suite) {
             this.suites.push(suite);
         };
@@ -721,17 +773,38 @@ var DT;
             this.timer = new DT.Timer();
             this.timer.start();
 
-            var index = new DT.ReferenceIndex(this.options);
-            index.collectReferences(this.files, function () {
+            this.index.parseFiles(this.files, function () {
+                console.log('files:');
+                console.log('---');
                 _this.files.forEach(function (file) {
                     console.log(file.filePathWithName);
                     file.references.forEach(function (file) {
                         console.log('  - %s', file.filePathWithName);
                     });
                 });
+                console.log('---');
+                _this.getChanges();
+            });
+        };
+
+        TestRunner.prototype.getChanges = function () {
+            var _this = this;
+            var changes = new DT.GitChanges(this.dtPath);
+            changes.getChanges(function (err, changes) {
+                if (err) {
+                    throw err;
+                }
+                console.log('changes:');
+                console.log('---');
+                changes.forEach(function (file) {
+                    console.log(file);
+                });
+                console.log('---');
+
                 _this.runTests();
             });
         };
+
         TestRunner.prototype.runTests = function () {
             var _this = this;
             var syntaxChecking = new DT.SyntaxChecking(this.options);
diff --git a/_infrastructure/tests/runner.ts b/_infrastructure/tests/runner.ts
index bf0502526..555ec54ab 100644
--- a/_infrastructure/tests/runner.ts
+++ b/_infrastructure/tests/runner.ts
@@ -1,28 +1,43 @@
-/// <reference path='../../node/node.d.ts' />
+/// <reference path="_ref.d.ts" />
 
-/// <reference path='src/host/exec.ts' />
+/// <reference path="src/host/exec.ts" />
 
-/// <reference path='src/file.ts' />
-/// <reference path='src/tsc.ts' />
-/// <reference path='src/timer.ts' />
+/// <reference path="src/file.ts" />
+/// <reference path="src/tsc.ts" />
+/// <reference path="src/timer.ts" />
 /// <reference path="src/util.ts" />
-/// <reference path="src/references.ts" />
 
-/// <reference path='src/printer.ts' />
-/// <reference path='src/reporter/reporter.ts' />
+/// <reference path="src/index.ts" />
+/// <reference path="src/changes.ts" />
 
-/// <reference path='src/suite/suite.ts' />
-/// <reference path='src/suite/syntax.ts' />
-/// <reference path='src/suite/testEval.ts' />
-/// <reference path='src/suite/tscParams.ts' />
+/// <reference path="src/printer.ts" />
+/// <reference path="src/reporter/reporter.ts" />
+
+/// <reference path="src/suite/suite.ts" />
+/// <reference path="src/suite/syntax.ts" />
+/// <reference path="src/suite/testEval.ts" />
+/// <reference path="src/suite/tscParams.ts" />
 
 module DT {
-    require('source-map-support');
+    require('source-map-support').install();
 
     var fs = require('fs');
     var path = require('path');
     var glob = require('glob');
 
+    var tsExp = /\.ts$/;
+
+    // TOD0 remove this after dev!
+    var testNames = [
+        'async/',
+        'jquery/jquery.d',
+        'angularjs/angular.d',
+        'pixi/'
+    ];
+    /* if (process.env.TRAVIS) {
+        testNames = null;
+    } */
+
     export var DEFAULT_TSC_VERSION = "0.9.1.1";
 
     export class Test {
@@ -72,40 +87,21 @@ module DT {
         files: File[];
         timer: Timer;
         suites: ITestSuite[] = [];
+        private index: FileIndex;
         private print: Print;
 
-        constructor(dtPath: string, public options: ITestRunnerOptions = {tscVersion: DT.DEFAULT_TSC_VERSION}) {
+        constructor(public dtPath: string, public options: ITestRunnerOptions = {tscVersion: DT.DEFAULT_TSC_VERSION}) {
             this.options.findNotRequiredTscparams = !!this.options.findNotRequiredTscparams;
 
-            // TOD0 remove this after dev!
-            var testNames = [
-                'async/',
-                'jquery/jquery.d',
-                'angularjs/angular.d',
-                'pixi/'
-            ];
-            if (process.env.TRAVIS) {
-                testNames = null;
-            }
+
+            this.index = new FileIndex(this.options);
 
             // should be async
             // only includes .d.ts or -tests.ts or -test.ts or .ts
             var filesName = glob.sync('**/*.ts', { cwd: dtPath });
             this.files = filesName
                 .filter((fileName) => {
-                    return fileName.indexOf('_infrastructure') < 0;
-                })
-                .filter((fileName) => {
-                    return fileName.indexOf('node_modules/') < 0;
-                })
-                .filter((fileName) => {
-                    // TOD0 remove this after dev!
-                    return !testNames || testNames.some((pattern) => {
-                        return fileName.indexOf(pattern) > -1;
-                    });
-                })
-                .filter((fileName) => {
-                    return /^[a-z]/i.test(fileName);
+                    return this.checkAcceptFile(fileName);
                 })
                 .sort()
                 .map((fileName) => {
@@ -113,26 +109,59 @@ module DT {
                 });
         }
 
-        public addSuite(suite: ITestSuite) {
+        public checkAcceptFile(fileName: string): boolean {
+            var ok = tsExp.test(fileName);
+            ok = ok && fileName.indexOf('_infrastructure') < 0;
+            ok = ok && fileName.indexOf('node_modules/') < 0;
+            ok = ok && /^[a-z]/i.test(fileName);
+
+            //TODO remove this dev code
+            ok = ok && (!testNames || testNames.some((pattern) => {
+                return fileName.indexOf(pattern) > -1;
+            }));
+            return ok;
+        }
+
+        public addSuite(suite: ITestSuite):void {
             this.suites.push(suite);
         }
 
-        public run() {
+        public run():void {
             this.timer = new Timer();
             this.timer.start();
 
-            var index = new ReferenceIndex(this.options);
-            index.collectReferences(this.files, () => {
+            this.index.parseFiles(this.files, () => {
+                console.log('files:');
+                console.log('---');
                 this.files.forEach((file) => {
                     console.log(file.filePathWithName);
                     file.references.forEach((file) => {
-                       console.log('  - %s', file.filePathWithName);
+                        console.log('  - %s', file.filePathWithName);
                     });
                 });
+                console.log('---');
+                this.getChanges();
+            });
+        }
+
+        public getChanges():void {
+            var changes = new GitChanges(this.dtPath);
+            changes.getChanges((err, changes: string[]) => {
+                if (err) {
+                    throw err;
+                }
+                console.log('changes:');
+                console.log('---');
+                changes.forEach((file) => {
+                    console.log(file);
+                });
+                console.log('---');
+
                 this.runTests();
             });
         }
-        public runTests() {
+
+        public runTests():void {
 
             var syntaxChecking = new SyntaxChecking(this.options);
             var testEval = new TestEval(this.options);
diff --git a/_infrastructure/tests/src/changes.ts b/_infrastructure/tests/src/changes.ts
index e69de29bb..5f28f24c5 100644
--- a/_infrastructure/tests/src/changes.ts
+++ b/_infrastructure/tests/src/changes.ts
@@ -0,0 +1,37 @@
+/// <reference path="../_ref.d.ts" />
+
+module DT {
+
+    var fs = require('fs');
+    var path = require('path');
+    var Git = require('git-wrapper');
+
+    export class GitChanges {
+
+        options = [];
+
+        constructor(public baseDir: string) {
+            var dir = path.join(baseDir, '.git');
+            if (!fs.existsSync(dir)) {
+                throw new Error('cannot locate git-dir: ' + dir);
+            }
+            this.options['git-dir'] = dir;
+        }
+
+        getChanges(callback: (err, paths: string[]) => void): void {
+            //git diff --name-only HEAD~1
+            var git = new Git(this.options);
+            var opts = {};
+            var args = ['--name-only HEAD~1'];
+            git.exec('diff', opts, args, (err, msg: string) => {
+                if (err) {
+                    callback(err, null);
+                    return;
+                }
+                var paths = msg.replace(/^\s+/, '').replace(/\s+$/, '').split(/\r?\n/g);
+                // console.log(paths);
+                callback(null, paths);
+            });
+        }
+    }
+}
diff --git a/_infrastructure/tests/src/file.ts b/_infrastructure/tests/src/file.ts
index c1a8d1f51..bd7f62dc8 100644
--- a/_infrastructure/tests/src/file.ts
+++ b/_infrastructure/tests/src/file.ts
@@ -1,3 +1,5 @@
+/// <reference path="../_ref.d.ts" />
+
 module DT {
     var path = require('path');
 
diff --git a/_infrastructure/tests/src/references.ts b/_infrastructure/tests/src/index.ts
similarity index 90%
rename from _infrastructure/tests/src/references.ts
rename to _infrastructure/tests/src/index.ts
index c98f947c3..4a40f35d4 100644
--- a/_infrastructure/tests/src/references.ts
+++ b/_infrastructure/tests/src/index.ts
@@ -1,13 +1,12 @@
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
-
-/// <reference path='util.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
+/// <reference path="util.ts" />
 
 module DT {
     var fs = require('fs');
     var path = require('path');
 
-    export class ReferenceIndex {
+    export class FileIndex {
 
         fileMap: {[path:string]:File};
 
@@ -15,7 +14,7 @@ module DT {
 
         }
 
-        collectReferences(files: File[], callback: () => void): void {
+        parseFiles(files: File[], callback: () => void): void {
             this.fileMap = Object.create(null);
             files.forEach((file) => {
                 this.fileMap[file.fullPath] = file;
diff --git a/_infrastructure/tests/src/printer.ts b/_infrastructure/tests/src/printer.ts
index d1f0f952e..53274587a 100644
--- a/_infrastructure/tests/src/printer.ts
+++ b/_infrastructure/tests/src/printer.ts
@@ -1,5 +1,5 @@
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
 
 module DT {
     /////////////////////////////////
diff --git a/_infrastructure/tests/src/reporter/reporter.ts b/_infrastructure/tests/src/reporter/reporter.ts
index d4556e0cc..5f01c43ab 100644
--- a/_infrastructure/tests/src/reporter/reporter.ts
+++ b/_infrastructure/tests/src/reporter/reporter.ts
@@ -1,3 +1,6 @@
+/// <reference path="../../_ref.d.ts" />
+/// <reference path="../printer.ts" />
+
 module DT {
     /////////////////////////////////
     // Test reporter interface
diff --git a/_infrastructure/tests/src/timer.ts b/_infrastructure/tests/src/timer.ts
index e03a94166..446ea1b34 100644
--- a/_infrastructure/tests/src/timer.ts
+++ b/_infrastructure/tests/src/timer.ts
@@ -1,5 +1,5 @@
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
 
 module DT {
     /////////////////////////////////
diff --git a/_infrastructure/tests/src/tsc.ts b/_infrastructure/tests/src/tsc.ts
index 5a2c803c8..6bd3fb259 100644
--- a/_infrastructure/tests/src/tsc.ts
+++ b/_infrastructure/tests/src/tsc.ts
@@ -1,7 +1,6 @@
-/// <reference path='../../../node/node.d.ts' />
-/// <reference path='../runner.ts' />
-
-/// <reference path='host/exec.ts' />
+/// <reference path="../_ref.d.ts" />
+/// <reference path="../runner.ts" />
+/// <reference path="host/exec.ts" />
 
 module DT {
     var fs = require('fs');
diff --git a/_infrastructure/tests/src/util.ts b/_infrastructure/tests/src/util.ts
index 3b441991f..3d63ce142 100644
--- a/_infrastructure/tests/src/util.ts
+++ b/_infrastructure/tests/src/util.ts
@@ -1,3 +1,5 @@
+/// <reference path="../_ref.d.ts" />
+
 module DT {
 
     var referenceTagExp = /<reference[ \t]*path=["']?([\w\.\/_-]*)["']?[ \t]*\/>/g;
diff --git a/package.json b/package.json
index 0119109e9..bb4c816f6 100644
--- a/package.json
+++ b/package.json
@@ -1,8 +1,13 @@
 {
-	"private": true,
-	"name": "DefinitelyTyped",
-	"version": "0.0.0",
-	"scripts": {
-		"test": "node ./_infrastructure/tests/runner.js --tsc-version 0.9.7"
-	}
+  "private": true,
+  "name": "DefinitelyTyped",
+  "version": "0.0.0",
+  "scripts": {
+    "test": "node ./_infrastructure/tests/runner.js --tsc-version 0.9.7"
+  },
+  "dependencies": {
+    "git-wrapper": "~0.1.1",
+    "glob": "~3.2.9",
+    "source-map-support": "~0.2.5"
+  }
 }