diff --git a/.travis.yml b/.travis.yml
index 56718cfcfc..56ba281685 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,7 @@
 language: node_js
 node_js:
 - stable
-script: npm run lint && npm run build
+script: npm run lint && npm run test && npm run build
 addons:
   sauce_connect:
     username: "chriseth"
diff --git a/package.json b/package.json
index 07fa048f07..ee3d46f471 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "version": "1.0.0",
   "description": "Minimalistic browser-based Solidity IDE",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1",
+    "test": "node test/index.js",
     "build": "mkdir -p build; browserify src/index.js -o build/app.js",
     "lint": "semistandard"
   },
@@ -19,6 +19,7 @@
     "jquery": "^2.2.0",
     "js-base64": "^2.1.9",
     "semistandard": "^7.0.0",
+    "tape": "^4.5.1",
     "web3": "^0.15.3",
     "webworkify": "^1.2.1"
   },
diff --git a/src/app.js b/src/app.js
index 5297cdbd28..d8aaeba334 100644
--- a/src/app.js
+++ b/src/app.js
@@ -3,12 +3,16 @@
 var $ = require('jquery');
 
 var utils = require('./app/utils');
-var queryParams = require('./app/query-params');
-var gistHandler = require('./app/gist-handler');
+var QueryParams = require('./app/query-params');
+var queryParams = new QueryParams();
+var GistHandler = require('./app/gist-handler');
+var gistHandler = new GistHandler();
 
 var StorageHandler = require('./app/storage-handler');
 var Editor = require('./app/editor');
+var Renderer = require('./app/renderer');
 var Compiler = require('./app/compiler');
+var ExecutionContext = require('./app/execution-context');
 
 // The event listener needs to be registered as early as possible, because the
 // parent will send the message upon the "load" event.
@@ -61,7 +65,7 @@ var run = function () {
 
   // ------------------ gist load ----------------
 
-  var loadingFromGist = gistHandler.handleLoad(function (gistId) {
+  var loadingFromGist = gistHandler.handleLoad(queryParams.get(), function (gistId) {
     $.ajax({
       url: 'https://api.github.com/gists/' + gistId,
       jsonp: 'callback',
@@ -421,7 +425,10 @@ var run = function () {
     return $.getJSON('https://api.github.com/repos/' + root + '/contents/' + path, cb);
   }
 
-  var compiler = new Compiler(editor, handleGithubCall, $('#output'), getHidingRHP, updateFiles);
+  var executionContext = new ExecutionContext();
+  var renderer = new Renderer(editor, executionContext, updateFiles);
+  var compiler = new Compiler(editor, renderer, queryParams, handleGithubCall, $('#output'), getHidingRHP, updateFiles);
+  executionContext.setCompiler(compiler);
 
   function setVersionText (text) {
     $('#version').text(text);
diff --git a/src/app/compiler.js b/src/app/compiler.js
index b47dfbebe7..0121136a4d 100644
--- a/src/app/compiler.js
+++ b/src/app/compiler.js
@@ -1,18 +1,13 @@
 var webworkify = require('webworkify');
-var queryParams = require('./query-params');
 var utils = require('./utils');
-var Renderer = require('./renderer');
 
 var Base64 = require('js-base64').Base64;
 
-function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles) {
-  var renderer = new Renderer(editor, this, updateFiles);
-
+function Compiler (editor, renderer, queryParams, handleGithubCall, outputField, hidingRHP, updateFiles) {
   var compileJSON;
   var compilerAcceptsMultipleFiles;
 
   var previousInput = '';
-  var sourceAnnotations = [];
 
   var cachedRemoteFiles = {};
   var worker = null;
@@ -39,7 +34,6 @@ function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles
 
   var compile = function (missingInputs) {
     editor.clearAnnotations();
-    sourceAnnotations = [];
     outputField.empty();
     var input = editor.getValue();
     editor.setCacheFileContent(input);
@@ -58,10 +52,10 @@ function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles
   };
   this.compile = compile;
 
-  this.addAnnotation = function (annotation) {
-    sourceAnnotations[sourceAnnotations.length] = annotation;
-    editor.setAnnotations(sourceAnnotations);
-  };
+  function setCompileJSON (_compileJSON) {
+    compileJSON = _compileJSON;
+  }
+  this.setCompileJSON = setCompileJSON; // this is exposed for testing
 
   function onCompilerLoaded (setVersionText, version) {
     setVersionText(version);
@@ -91,14 +85,14 @@ function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles
         compilerAcceptsMultipleFiles = false;
         compile = Module.cwrap('compileJSON', 'string', [ 'string', 'number' ]);
       }
-      compileJSON = function (source, optimize, cb) {
+      setCompileJSON(function (source, optimize, cb) {
         try {
           var result = compile(source, optimize);
         } catch (exception) {
           result = JSON.stringify({ error: 'Uncaught JavaScript exception:\n' + exception });
         }
         compilationFinished(result, missingInputs);
-      };
+      });
       onCompilerLoaded(setVersionText, Module.cwrap('version', 'string', [])());
     }
   }
@@ -149,7 +143,7 @@ function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles
   function loadInternal (url, setVersionText) {
     delete window.Module;
     // Set a safe fallback until the new one is loaded
-    compileJSON = function (source, optimize) { compilationFinished('{}'); };
+    setCompileJSON(function (source, optimize) { compilationFinished('{}'); });
 
     var newScript = document.createElement('script');
     newScript.type = 'text/javascript';
@@ -183,9 +177,9 @@ function Compiler (editor, handleGithubCall, outputField, hidingRHP, updateFiles
     });
     worker.onerror = function (msg) { console.log(msg.data); };
     worker.addEventListener('error', function (msg) { console.log(msg.data); });
-    compileJSON = function (source, optimize) {
+    setCompileJSON(function (source, optimize) {
       worker.postMessage({cmd: 'compile', source: source, optimize: optimize});
-    };
+    });
     worker.postMessage({cmd: 'loadVersion', data: url});
   }
 
diff --git a/src/app/editor.js b/src/app/editor.js
index 7742b0fb08..e8dc95f906 100644
--- a/src/app/editor.js
+++ b/src/app/editor.js
@@ -6,6 +6,15 @@ var ace = require('brace');
 require('../mode-solidity.js');
 
 function Editor (loadingFromGist) {
+  var SOL_CACHE_UNTITLED = utils.getCacheFilePrefix() + 'Untitled';
+  var SOL_CACHE_FILE = null;
+
+  var editor = ace.edit('input');
+  var sessions = {};
+  var sourceAnnotations = [];
+
+  setupStuff(getFiles());
+
   this.newFile = function () {
     var untitledCount = '';
     while (window.localStorage[SOL_CACHE_UNTITLED + untitledCount]) {
@@ -58,7 +67,7 @@ function Editor (loadingFromGist) {
     return this.getFiles().indexOf(utils.fileKey(name)) !== -1;
   };
 
-  this.getFiles = function () {
+  function getFiles () {
     var files = [];
     for (var f in window.localStorage) {
       if (f.indexOf(utils.getCacheFilePrefix(), 0) === 0) {
@@ -67,7 +76,8 @@ function Editor (loadingFromGist) {
       }
     }
     return files;
-  };
+  }
+  this.getFiles = getFiles;
 
   this.packageFiles = function () {
     var files = {};
@@ -100,9 +110,15 @@ function Editor (loadingFromGist) {
   };
 
   this.clearAnnotations = function () {
+    sourceAnnotations = [];
     editor.getSession().clearAnnotations();
   };
 
+  this.addAnnotation = function (annotation) {
+    sourceAnnotations[sourceAnnotations.length] = annotation;
+    this.setAnnotations(sourceAnnotations);
+  };
+
   this.setAnnotations = function (sourceAnnotations) {
     editor.getSession().setAnnotations(sourceAnnotations);
   };
@@ -152,14 +168,6 @@ function Editor (loadingFromGist) {
     editor.setSession(sessions[SOL_CACHE_FILE]);
     editor.resize(true);
   }
-
-  var SOL_CACHE_UNTITLED = utils.getCacheFilePrefix() + 'Untitled';
-  var SOL_CACHE_FILE = null;
-
-  var editor = ace.edit('input');
-  var sessions = {};
-
-  setupStuff(this.getFiles());
 }
 
 module.exports = Editor;
diff --git a/src/app/execution-context.js b/src/app/execution-context.js
index 4627a8634e..db67897a80 100644
--- a/src/app/execution-context.js
+++ b/src/app/execution-context.js
@@ -13,9 +13,14 @@ if (typeof window.web3 !== 'undefined') {
   web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
 }
 
-function ExecutionContext (compiler) {
+function ExecutionContext () {
+  var compiler;
   var executionContext = injectedProvider ? 'injected' : 'vm';
 
+  this.setCompiler = function (_compiler) {
+    compiler = _compiler;
+  };
+
   this.isVM = function () {
     return executionContext === 'vm';
   };
diff --git a/src/app/gist-handler.js b/src/app/gist-handler.js
index 7d07651512..b69cbac4fc 100644
--- a/src/app/gist-handler.js
+++ b/src/app/gist-handler.js
@@ -1,14 +1,12 @@
-/* global prompt */
+// Allowing window to be overriden for testing
+function GistHandler (_window) {
+  if (_window === undefined) _window = window;
 
-var queryParams = require('./query-params');
-
-function handleLoad (cb) {
-  var params = queryParams.get();
-  var loadingFromGist = false;
-  if (typeof params['gist'] !== undefined) {
+  this.handleLoad = function (params, cb) {
+    var loadingFromGist = false;
     var gistId;
     if (params['gist'] === '') {
-      var str = prompt('Enter the URL or ID of the Gist you would like to load.');
+      var str = _window.prompt('Enter the URL or ID of the Gist you would like to load.');
       if (str !== '') {
         gistId = getGistId(str);
         loadingFromGist = !!gistId;
@@ -20,16 +18,14 @@ function handleLoad (cb) {
     if (loadingFromGist) {
       cb(gistId);
     }
-  }
-  return loadingFromGist;
-}
+    return loadingFromGist;
+  };
 
-function getGistId (str) {
-  var idr = /[0-9A-Fa-f]{8,}/;
-  var match = idr.exec(str);
-  return match ? match[0] : null;
+  function getGistId (str) {
+    var idr = /[0-9A-Fa-f]{8,}/;
+    var match = idr.exec(str);
+    return match ? match[0] : null;
+  }
 }
 
-module.exports = {
-  handleLoad: handleLoad
-};
+module.exports = GistHandler;
diff --git a/src/app/query-params.js b/src/app/query-params.js
index 391a242195..0b11eac34f 100644
--- a/src/app/query-params.js
+++ b/src/app/query-params.js
@@ -1,38 +1,40 @@
-function getQueryParams () {
-  var qs = window.location.hash.substr(1);
+// Allowing window to be overriden for testing
+function QueryParams (_window) {
+  if (_window === undefined) _window = window;
 
-  if (window.location.search.length > 0) {
-    // use legacy query params instead of hash
-    window.location.hash = window.location.search.substr(1);
-    window.location.search = '';
-  }
+  this.get = function () {
+    var qs = _window.location.hash.substr(1);
 
-  var params = {};
-  var parts = qs.split('&');
-  for (var x in parts) {
-    var keyValue = parts[x].split('=');
-    if (keyValue[0] !== '') {
-      params[keyValue[0]] = keyValue[1];
+    if (_window.location.search.length > 0) {
+      // use legacy query params instead of hash
+      _window.location.hash = _window.location.search.substr(1);
+      _window.location.search = '';
     }
-  }
-  return params;
-}
 
-function updateQueryParams (params) {
-  var currentParams = getQueryParams();
-  var keys = Object.keys(params);
-  for (var x in keys) {
-    currentParams[keys[x]] = params[keys[x]];
-  }
-  var queryString = '#';
-  var updatedKeys = Object.keys(currentParams);
-  for (var y in updatedKeys) {
-    queryString += updatedKeys[y] + '=' + currentParams[updatedKeys[y]] + '&';
-  }
-  window.location.hash = queryString.slice(0, -1);
+    var params = {};
+    var parts = qs.split('&');
+    for (var x in parts) {
+      var keyValue = parts[x].split('=');
+      if (keyValue[0] !== '') {
+        params[keyValue[0]] = keyValue[1];
+      }
+    }
+    return params;
+  };
+
+  this.update = function (params) {
+    var currentParams = this.get();
+    var keys = Object.keys(params);
+    for (var x in keys) {
+      currentParams[keys[x]] = params[keys[x]];
+    }
+    var queryString = '#';
+    var updatedKeys = Object.keys(currentParams);
+    for (var y in updatedKeys) {
+      queryString += updatedKeys[y] + '=' + currentParams[updatedKeys[y]] + '&';
+    }
+    _window.location.hash = queryString.slice(0, -1);
+  };
 }
 
-module.exports = {
-  get: getQueryParams,
-  update: updateQueryParams
-};
+module.exports = QueryParams;
diff --git a/src/app/renderer.js b/src/app/renderer.js
index 811ec9b44d..21229e68f0 100644
--- a/src/app/renderer.js
+++ b/src/app/renderer.js
@@ -3,11 +3,9 @@ var $ = require('jquery');
 var UniversalDApp = require('../universal-dapp.js');
 
 var utils = require('./utils');
-var ExecutionContext = require('./execution-context');
 
-function Renderer (editor, compiler, updateFiles) {
+function Renderer (editor, executionContext, updateFiles) {
   var detailsOpen = {};
-  var executionContext = new ExecutionContext(compiler);
 
   function renderError (message) {
     var type = utils.errortype(message);
@@ -20,7 +18,7 @@ function Renderer (editor, compiler, updateFiles) {
       var errLine = parseInt(err[2], 10) - 1;
       var errCol = err[4] ? parseInt(err[4], 10) : 0;
       if (errFile === '' || errFile === utils.fileNameFromKey(editor.getCacheFile())) {
-        compiler.addAnnotation({
+        editor.addAnnotation({
           row: errLine,
           column: errCol,
           text: message,
diff --git a/test/compiler-test.js b/test/compiler-test.js
new file mode 100644
index 0000000000..80f803208e
--- /dev/null
+++ b/test/compiler-test.js
@@ -0,0 +1,17 @@
+var test = require('tape');
+
+var Compiler = require('../src/app/compiler');
+
+test('compiler.compile smoke', function (t) {
+  t.plan(1);
+
+  var noop = function () {};
+  var getCacheFile = function () { return 'fakeCacheFile'; };
+  var fakeEditor = {onChangeSetup: noop, clearAnnotations: noop, getValue: noop, setCacheFileContent: noop, getCacheFile: getCacheFile};
+  var fakeOutputField = {empty: noop};
+  var fakeQueryParams = {get: function () { return {}; }};
+  var compiler = new Compiler(fakeEditor, null, fakeQueryParams, null, fakeOutputField);
+  compiler.setCompileJSON(noop);
+  compiler.compile();
+  t.ok(compiler);
+});
diff --git a/test/gist-handler-test.js b/test/gist-handler-test.js
new file mode 100644
index 0000000000..d260310aac
--- /dev/null
+++ b/test/gist-handler-test.js
@@ -0,0 +1,69 @@
+var test = require('tape');
+
+var GistHandler = require('../src/app/gist-handler');
+
+test('gistHandler.handleLoad with no gist param', function (t) {
+  t.plan(1);
+
+  var gistHandler = new GistHandler({});
+
+  var params = {};
+  var result = gistHandler.handleLoad(params, null);
+
+  t.equal(result, false);
+});
+
+test('gistHandler.handleLoad with blank gist param, and invalid user input', function (t) {
+  t.plan(3);
+
+  var fakeWindow = {prompt: function (message) {
+    t.ok(message);
+    t.ok(message.match(/gist/i));
+    return 'invalid';
+  }};
+
+  var gistHandler = new GistHandler(fakeWindow);
+
+  var params = {'gist': ''};
+  var result = gistHandler.handleLoad(params, null);
+
+  t.equal(result, false);
+});
+
+test('gistHandler.handleLoad with blank gist param, and valid user input', function (t) {
+  t.plan(4);
+
+  var fakeWindow = {prompt: function (message) {
+    t.ok(message);
+    t.ok(message.match(/gist/i));
+    return 'Beef1234';
+  }};
+
+  var cb = function (gistId) {
+    t.equal(gistId, 'Beef1234');
+  };
+
+  var gistHandler = new GistHandler(fakeWindow);
+
+  var params = {'gist': ''};
+  var result = gistHandler.handleLoad(params, cb);
+
+  t.equal(result, true);
+});
+
+test('gistHandler.handleLoad with gist param', function (t) {
+  t.plan(2);
+
+  var gistHandler = new GistHandler({});
+
+  var params = {'gist': 'abc'};
+
+  var cb = function (gistId) {
+    t.equal(gistId, 'abc');
+  };
+
+  var result = gistHandler.handleLoad(params, cb);
+
+  t.equal(result, true);
+});
+
diff --git a/test/index.js b/test/index.js
new file mode 100644
index 0000000000..db15b90e82
--- /dev/null
+++ b/test/index.js
@@ -0,0 +1,3 @@
+require('./compiler-test');
+require('./gist-handler-test');
+require('./query-params-test');
diff --git a/test/query-params-test.js b/test/query-params-test.js
new file mode 100644
index 0000000000..e3cff5c546
--- /dev/null
+++ b/test/query-params-test.js
@@ -0,0 +1,21 @@
+var test = require('tape');
+
+var QueryParams = require('../src/app/query-params');
+
+test('queryParams.get', function (t) {
+  t.plan(2);
+
+  var fakeWindow = {location: {hash: '#wat=sup&foo=bar', search: ''}};
+  var params = new QueryParams(fakeWindow).get();
+  t.equal(params.wat, 'sup');
+  t.equal(params.foo, 'bar');
+});
+
+test('queryParams.update', function (t) {
+  t.plan(1);
+
+  var fakeWindow = {location: {hash: '#wat=sup', search: ''}};
+  var qp = new QueryParams(fakeWindow);
+  qp.update({foo: 'bar'});
+  t.equal(fakeWindow.location.hash, '#wat=sup&foo=bar');
+});