diff --git a/spec/parser/javascript_spec.js b/spec/parser/javascript_spec.js
deleted file mode 100644
index b0620f4..0000000
--- a/spec/parser/javascript_spec.js
+++ /dev/null
@@ -1,28 +0,0 @@
-import parser from 'src/js/parser/javascript.js';
-
-describe('parser/javascript.peg', function() {
-
-  describe('regular expression literals', function() {
-
-    describe('flags support', function() {
-
-      it('handles the ignore case flag', function() {
-        expect(parser.parse('/test/i').flags().ignore_case).toEqual(true);
-        expect(parser.parse('/test/').flags().ignore_case).toEqual(false);
-      });
-
-      it('handles the global flag', function() {
-        expect(parser.parse('/test/g').flags().global).toEqual(true);
-        expect(parser.parse('/test/').flags().global).toEqual(false);
-      });
-
-      it('handles the multiline flag', function() {
-        expect(parser.parse('/test/m').flags().multiline).toEqual(true);
-        expect(parser.parse('/test/').flags().multiline).toEqual(false);
-      });
-
-    });
-
-  });
-
-});
diff --git a/spec/regexper_spec.js b/spec/regexper_spec.js
new file mode 100644
index 0000000..f6a2cb5
--- /dev/null
+++ b/spec/regexper_spec.js
@@ -0,0 +1,333 @@
+import Regexper from 'src/js/regexper.js';
+import Q from 'q';
+
+describe('regexper.js', function() {
+
+  beforeEach(function() {
+    this.root = document.createElement('div');
+    this.root.innerHTML = [
+      '<form id="regexp-form" action="/"><input type="text" id="regexp-input" /></form>',
+      '<div id="error"></div>',
+      '<div><a href="#" data-glyph="link-intact"></a></div>',
+      '<div><a href="#" data-glyph="data-transfer-download"></a></div>',
+      '<div id="progress"><div></div></div>',
+      '<div id="regexp-render"><svg></svg></div>'
+    ].join('');
+
+    this.regexper = new Regexper(this.root);
+    spyOn(this.regexper, '_setHash');
+    spyOn(this.regexper, '_getHash').and.returnValue('example hash value');
+  });
+
+  describe('#keypressListener', function() {
+
+    beforeEach(function() {
+      this.event = document.createEvent('Event');
+      spyOn(this.event, 'preventDefault');
+      spyOn(this.regexper.form, 'dispatchEvent');
+    });
+
+    describe('when the shift key is not depressed', function() {
+
+      beforeEach(function() {
+        this.event.shiftKey = false;
+        this.event.keyCode = 13;
+      });
+
+      it('does not prevent the default action', function() {
+        this.regexper.keypressListener(this.event);
+        expect(this.event.returnValue).not.toEqual(false);
+        expect(this.event.preventDefault).not.toHaveBeenCalled();
+      });
+
+      it('does not trigger a submit event', function() {
+        this.regexper.keypressListener(this.event);
+        expect(this.regexper.form.dispatchEvent).not.toHaveBeenCalled();
+      });
+
+    });
+
+    describe('when the keyCode is not 13 (Enter)', function() {
+
+      beforeEach(function() {
+        this.event.shiftKey = true;
+        this.event.keyCode = 42;
+      });
+
+      it('does not prevent the default action', function() {
+        this.regexper.keypressListener(this.event);
+        expect(this.event.returnValue).not.toEqual(false);
+        expect(this.event.preventDefault).not.toHaveBeenCalled();
+      });
+
+      it('does not trigger a submit event', function() {
+        this.regexper.keypressListener(this.event);
+        expect(this.regexper.form.dispatchEvent).not.toHaveBeenCalled();
+      });
+
+    });
+
+    describe('when the shift key is depressed and the keyCode is 13 (Enter)', function() {
+
+      beforeEach(function() {
+        this.event.shiftKey = true;
+        this.event.keyCode = 13;
+      });
+
+      it('prevents the default action', function() {
+        this.regexper.keypressListener(this.event);
+        expect(this.event.returnValue).not.toEqual(true);
+        expect(this.event.preventDefault).toHaveBeenCalled();
+      });
+
+      it('triggers a submit event', function() {
+        var event;
+
+        this.regexper.keypressListener(this.event);
+        expect(this.regexper.form.dispatchEvent).toHaveBeenCalled();
+
+        event = this.regexper.form.dispatchEvent.calls.mostRecent().args[0];
+        expect(event.type).toEqual('submit');
+      });
+
+    });
+
+  });
+
+  describe('#submitListener', function() {
+
+    beforeEach(function() {
+      this.event = document.createEvent('Event');
+      spyOn(this.event, 'preventDefault');
+
+      this.regexper.field.value = 'example value';
+    });
+
+    it('prevents the default action', function() {
+      this.regexper.submitListener(this.event);
+      expect(this.event.returnValue).not.toEqual(true);
+      expect(this.event.preventDefault).toHaveBeenCalled();
+    });
+
+    it('sets the location.hash', function() {
+      this.regexper.submitListener(this.event);
+      expect(this.regexper._setHash).toHaveBeenCalledWith('example value');
+    });
+
+    describe('when setting location.hash fails', function() {
+
+      beforeEach(function() {
+        this.regexper._setHash.and.throwError('hash failure');
+      });
+
+      it('disables the permalink', function() {
+        this.regexper.submitListener(this.event);
+        expect(this.regexper.permalinkEnabled).toEqual(false);
+      });
+
+      it('shows the expression directly', function() {
+        spyOn(this.regexper, 'showExpression');
+        this.regexper.submitListener(this.event);
+        expect(this.regexper.showExpression).toHaveBeenCalledWith('example value');
+      });
+
+    });
+
+  });
+
+  describe('#hashchangeListener', function() {
+
+    it('enables the permalink', function() {
+      this.regexper.hashchangeListener();
+      expect(this.regexper.permalinkEnabled).toEqual(true);
+    });
+
+    it('shows the expression from the hash', function() {
+      spyOn(this.regexper, 'showExpression');
+      this.regexper.hashchangeListener();
+      expect(this.regexper.showExpression).toHaveBeenCalledWith('example hash value');
+    });
+
+  });
+
+  describe('#updatePercentage', function() {
+
+    beforeEach(function() {
+      this.event = document.createEvent('Event');
+      this.event.detail = { percentage: 0.42 };
+    });
+
+    it('sets the width of the progress bar', function() {
+      this.regexper.updatePercentage(this.event);
+      expect(this.regexper.percentage.style.width).toEqual('42%');
+    });
+
+  });
+
+  describe('#bindListeners', function() {
+
+    it('binds #keypressListener to keypress on the text field', function() {
+      spyOn(this.regexper.field, 'addEventListener');
+      spyOn(this.regexper, 'keypressListener');
+      this.regexper.bindListeners();
+      expect(this.regexper.field.addEventListener).toHaveBeenCalledWith('keypress', jasmine.any(Function));
+
+      this.regexper.field.addEventListener.calls.mostRecent().args[1]();
+      expect(this.regexper.keypressListener).toHaveBeenCalled();
+    });
+
+    it('binds #submitListener to submit on the form', function() {
+      spyOn(this.regexper.form, 'addEventListener');
+      spyOn(this.regexper, 'submitListener');
+      this.regexper.bindListeners();
+      expect(this.regexper.form.addEventListener).toHaveBeenCalledWith('submit', jasmine.any(Function));
+
+      this.regexper.form.addEventListener.calls.mostRecent().args[1]();
+      expect(this.regexper.submitListener).toHaveBeenCalled();
+    });
+
+    it('binds #updatePercentage to updateStatus on the root', function() {
+      spyOn(this.regexper.root, 'addEventListener');
+      spyOn(this.regexper, 'updatePercentage');
+      this.regexper.bindListeners();
+      expect(this.regexper.root.addEventListener).toHaveBeenCalledWith('updateStatus', jasmine.any(Function));
+
+      this.regexper.root.addEventListener.calls.mostRecent().args[1]();
+      expect(this.regexper.updatePercentage).toHaveBeenCalled();
+    });
+
+    it('binds #hashchangeListener to hashchange on the window', function() {
+      spyOn(window, 'addEventListener');
+      spyOn(this.regexper, 'hashchangeListener');
+      this.regexper.bindListeners();
+      expect(window.addEventListener).toHaveBeenCalledWith('hashchange', jasmine.any(Function));
+
+      window.addEventListener.calls.mostRecent().args[1]();
+      expect(this.regexper.hashchangeListener).toHaveBeenCalled();
+    });
+
+  });
+
+  describe('#showExpression', function() {
+
+    beforeEach(function() {
+      this.renderPromise = Q.defer();
+      spyOn(this.regexper, 'renderRegexp').and.returnValue(this.renderPromise.promise);
+    });
+
+    it('sets the text field value', function() {
+      this.regexper.showExpression('example expression');
+      expect(this.regexper.field.value).toEqual('example expression');
+    });
+
+    describe('when the expression is blank', function() {
+
+      it('clears the state', function() {
+        this.regexper.showExpression('');
+        expect(this.regexper.state).toEqual('');
+      });
+
+    });
+
+    describe('when the expression is not blank', function() {
+
+      it('sets the state to "is-loading"', function() {
+        this.regexper.showExpression('example expression');
+        expect(this.regexper.state).toEqual('is-loading');
+      });
+
+      it('renders the expression', function() {
+        this.regexper.showExpression('example expression');
+        expect(this.regexper.renderRegexp).toHaveBeenCalledWith('example expression');
+      });
+
+      describe('when the expression finishes rendering', function() {
+
+        beforeEach(function(done) {
+          spyOn(this.regexper, 'updateLinks');
+          this.regexper.showExpression('example expression');
+          this.renderPromise.resolve();
+          setTimeout(done, 100);
+        });
+
+        it('sets the state to "has-results"', function() {
+          expect(this.regexper.state).toEqual('has-results');
+        });
+
+        it('updates the links', function() {
+          expect(this.regexper.updateLinks).toHaveBeenCalled();
+        });
+
+      });
+
+    });
+
+  });
+
+  describe('#updateLinks', function() {
+
+    beforeEach(function() {
+      spyOn(this.regexper, 'buildBlobURL');
+    });
+
+    describe('when blob URLs are supported', function() {
+
+      beforeEach(function() {
+        this.regexper.buildBlobURL.and.returnValue('http://example.com/blob');
+      });
+
+      it('sets the download link href', function() {
+        this.regexper.updateLinks();
+        expect(this.regexper.download.href).toEqual('http://example.com/blob');
+      });
+
+    });
+
+    describe('when blob URLs are not supported', function() {
+
+      beforeEach(function() {
+        this.regexper.buildBlobURL.and.throwError('blob failure');
+      });
+
+      it('hides the download link', function() {
+        this.regexper.updateLinks();
+        expect(this.regexper.download.parentNode.style.display).toEqual('none');
+      });
+
+    });
+
+    describe('when the permalink is enabled', function() {
+
+      beforeEach(function() {
+        this.regexper.permalinkEnabled = true;
+      });
+
+      it('sets the permalink href', function() {
+        this.regexper.updateLinks();
+        expect(this.regexper.permalink.href).toEqual(location.toString());
+      });
+
+    });
+
+    describe('when the permalink is disabled', function() {
+
+      beforeEach(function() {
+        this.regexper.permalinkEnabled = false;
+      });
+
+      it('hides the permalink', function() {
+        this.regexper.updateLinks();
+        expect(this.regexper.permalink.parentNode.style.display).toEqual('none');
+      });
+
+    });
+
+  });
+
+  describe('#renderRegexp', function() {
+
+
+
+  });
+
+});
diff --git a/src/js/regexper.js b/src/js/regexper.js
index 04db34a..9d96629 100644
--- a/src/js/regexper.js
+++ b/src/js/regexper.js
@@ -33,40 +33,25 @@ export default class Regexper {
   }
 
   submitListener(event) {
-    event.preventDefault();
+    event.returnValue = false;
+    if (event.preventDefault) {
+      event.preventDefault();
+    }
 
     try {
-      this.disablePermalink = false;
-      location.hash = this.field.value;
+      this._setHash(this.field.value);
     }
     catch(e) {
       // Most likely failed to set the URL has (probably because the expression
       // is too long). Turn off the permalink and just show the expression
-      this.disablePermalink = true;
+      this.permalinkEnabled = false;
       this.showExpression(this.field.value);
     }
   }
 
   hashchangeListener() {
-    var expression = decodeURIComponent(location.hash.slice(1));
-
-    this.showExpression(expression);
-  }
-
-  showExpression(expression) {
-    this.field.value = expression;
-    this.state = '';
-
-    if (expression !== '') {
-      this.state = 'is-loading';
-
-      this.renderRegexp(expression.replace(/\n/g, '\\n'))
-        .then(() => {
-          this.state = 'has-results';
-          this.updateLinks();
-        })
-        .done();
-    }
+    this.permalinkEnabled = true;
+    this.showExpression(this._getHash());
   }
 
   updatePercentage(event) {
@@ -80,27 +65,50 @@ export default class Regexper {
     window.addEventListener('hashchange', this.hashchangeListener.bind(this));
   }
 
+  _setHash(hash) {
+    location.hash = encodeURIComponent(hash);
+  }
+
+  _getHash() {
+    return decodeURIComponent(location.hash.slice(1));
+  }
+
   set state(state) {
     this.root.className = state;
   }
 
-  showError(message) {
-    this.state = 'has-error';
-    this.error.innerHTML = '';
-    this.error.appendChild(document.createTextNode(message));
+  get state() {
+    return this.root.className;
+  }
 
-    throw message;
+  showExpression(expression) {
+    this.field.value = expression;
+    this.state = '';
+
+    if (expression !== '') {
+      this.state = 'is-loading';
+
+      this.renderRegexp(expression)
+        .then(() => {
+          this.state = 'has-results';
+          this.updateLinks();
+        })
+        .done();
+    }
+  }
+
+  buildBlobURL(content) {
+    blob = new Blob([content], { type: 'image/svg+xml' });
+    window.blob = blob; // Blob object has to stick around for IE
+    return URL.createObjectURL(blob);
   }
 
   updateLinks() {
     var blob, url;
 
     try {
-      blob = new Blob([this.svg.parentNode.innerHTML], { type: 'image/svg+xml' });
-      url = URL.createObjectURL(blob);
-      window.blob = blob; // Blob object has to stick around for IE
-
-      this.download.setAttribute('href', url);
+      this.download.parentNode.style.display = null;
+      this.download.href = this.buildBlobURL(this.svg.parentNode.innerHTML);
     }
     catch(e) {
       // Blobs or URLs created from them don't work here.
@@ -108,11 +116,11 @@ export default class Regexper {
       this.download.parentNode.style.display = 'none';
     }
 
-    if (this.disablePermalink) {
-      this.permalink.parentNode.style.display = 'none';
-    } else {
+    if (this.permalinkEnabled) {
       this.permalink.parentNode.style.display = null;
-      this.permalink.setAttribute('href', location.toString());
+      this.permalink.href = location.toString();
+    } else {
+      this.permalink.parentNode.style.display = 'none';
     }
   }
 
@@ -123,8 +131,14 @@ export default class Regexper {
 
     parser.resetGroupCounter();
 
-    return Q.fcall(parser.parse.bind(parser), expression)
-      .then(null, this.showError.bind(this))
+    return Q.fcall(parser.parse.bind(parser), expression.replace(/\n/g, '\\n'))
+      .then(null, message => {
+        this.state = 'has-error';
+        this.error.innerHTML = '';
+        this.error.appendChild(document.createTextNode(message));
+
+        throw message;
+      })
       .invoke('render', snap.group())
       .then(result => {
         var box;