diff --git a/internal_packages/composer/lib/composer-view.cjsx b/internal_packages/composer/lib/composer-view.cjsx
index 378222bdd..7af4aaf58 100644
--- a/internal_packages/composer/lib/composer-view.cjsx
+++ b/internal_packages/composer/lib/composer-view.cjsx
@@ -18,6 +18,7 @@ ParticipantsTextField = require './participants-text-field.cjsx'
 # simulate the effect of the parent re-rendering us
 module.exports =
 ComposerView = React.createClass
+  displayName: 'ComposerView'
 
   getInitialState: ->
     state = @getComponentRegistryState()
diff --git a/internal_packages/composer/spec/inbox-composer-view-spec.cjsx b/internal_packages/composer/spec/inbox-composer-view-spec.cjsx
index 9d688f3d7..7474622e0 100644
--- a/internal_packages/composer/spec/inbox-composer-view-spec.cjsx
+++ b/internal_packages/composer/spec/inbox-composer-view-spec.cjsx
@@ -29,7 +29,7 @@ textFieldStub = (className) ->
     focus: ->
 
 draftStoreProxyStub = (localId) ->
-  listen: -> # noop
+  listen: -> ->
   draft: -> new Message()
   changes:
     add: ->
diff --git a/internal_packages/message-list/lib/message-list.cjsx b/internal_packages/message-list/lib/message-list.cjsx
index c5825495a..a720800f5 100755
--- a/internal_packages/message-list/lib/message-list.cjsx
+++ b/internal_packages/message-list/lib/message-list.cjsx
@@ -2,8 +2,6 @@ _ = require 'underscore-plus'
 React = require 'react'
 MessageItem = require "./message-item.cjsx"
 
-ThreadParticipants = require "./thread-participants.cjsx"
-
 {Actions, ThreadStore, MessageStore, ComponentRegistry} = require("inbox-exports")
 
 module.exports =
@@ -80,13 +78,9 @@ MessageList = React.createClass
     <div className="message-list-headers">
       <h2>{@state.current_thread.subject}</h2>
 
-      {if Participants?
-        <Participants clickable={true}
-                      context={'primary'}
-                      participants={@_threadParticipants()}/>
-      else
-        <ThreadParticipants thread_participants={@_threadParticipants()} />
-      }
+      <Participants clickable={true}
+                    context={'primary'}
+                    participants={@_threadParticipants()}/>
 
       {for MessageListHeader in MessageListHeaders
         <MessageListHeader thread={@state.current_thread} />
diff --git a/internal_packages/message-list/lib/thread-participants.cjsx b/internal_packages/message-list/lib/thread-participants.cjsx
deleted file mode 100644
index d20abfc1b..000000000
--- a/internal_packages/message-list/lib/thread-participants.cjsx
+++ /dev/null
@@ -1,15 +0,0 @@
-_ = require 'underscore-plus'
-React = require "react"
-
-module.exports =
-ThreadParticipants = React.createClass
-  displayName: 'ThreadParticipants'
-  
-  render: ->
-    <div className="participants thread-participants">
-      {@_formattedParticipants()}
-    </div>
-
-  _formattedParticipants: ->
-    contacts = @props.thread_participants ? []
-    _.map(contacts, (c) -> c.displayName()).join(", ")
diff --git a/internal_packages/message-list/spec/message-list-spec.cjsx b/internal_packages/message-list/spec/message-list-spec.cjsx
index 1e141dd5e..1d98c0e2b 100644
--- a/internal_packages/message-list/spec/message-list-spec.cjsx
+++ b/internal_packages/message-list/spec/message-list-spec.cjsx
@@ -16,6 +16,18 @@ TestUtils = React.addons.TestUtils
  InboxTestUtils,
  ComponentRegistry} = require "inbox-exports"
 
+ComposerItem = React.createClass
+  render: -> <div></div>
+  focus: ->
+
+AttachmentItem = React.createClass
+  render: -> <div></div>
+  focus: ->
+
+ParticipantsItem = React.createClass
+  render: -> <div></div>
+  focus: ->
+
 MessageItem = proxyquire("../lib/message-item.cjsx", {
   "./email-frame": React.createClass({render: -> <div></div>})
 })
@@ -24,15 +36,7 @@ MessageList = proxyquire("../lib/message-list.cjsx", {
   "./message-item.cjsx": MessageItem
 })
 
-ComposerItem = React.createClass
-  render: -> <div></div>
-  focus: ->
-ComponentRegistry.register
-  name: 'Composer'
-  view: ComposerItem
-
 MessageParticipants = require "../lib/message-participants.cjsx"
-ThreadParticipants = require "../lib/thread-participants.cjsx"
 
 me = new Namespace(
   "name": "User One",
@@ -175,14 +179,22 @@ test_thread = (new Thread).fromJSON({
 })
 
 describe "MessageList", ->
-  _resetMessageStore = ->
+  beforeEach ->
+    ComponentRegistry.register
+      name: 'Composer'
+      view: ComposerItem
+    ComponentRegistry.register
+      name: 'Participants'
+      view: ParticipantsItem
+    ComponentRegistry.register
+      name: 'AttachmentComponent'
+      view: AttachmentItem
+
     MessageStore._items = []
     MessageStore._threadId = null
     spyOn(MessageStore, "itemLocalIds").andCallFake ->
       {"666": "666"}
 
-  beforeEach ->
-    _resetMessageStore()
     @message_list = TestUtils.renderIntoDocument(<MessageList />)
     @message_list_node = @message_list.getDOMNode()
 
@@ -218,7 +230,7 @@ describe "MessageList", ->
 
     it "displays the thread participants on the page", ->
       items = TestUtils.scryRenderedComponentsWithType(@message_list,
-              ThreadParticipants)
+              ParticipantsItem)
       expect(items.length).toBe 1
 
     it "focuses new composers when a draft is added", ->
diff --git a/internal_packages/thread-list/spec/thread-list-spec.cjsx b/internal_packages/thread-list/spec/thread-list-spec.cjsx
index 3177296ed..9114c9191 100644
--- a/internal_packages/thread-list/spec/thread-list-spec.cjsx
+++ b/internal_packages/thread-list/spec/thread-list-spec.cjsx
@@ -11,7 +11,8 @@ ReactTestUtils = _.extend ReactTestUtils, require("jasmine-react-helpers")
  ThreadStore,
  DatabaseStore,
  InboxTestUtils,
- NamespaceStore} = require "inbox-exports"
+ NamespaceStore,
+ ComponentRegistry} = require "inbox-exports"
 
 ThreadListColumn = require("../lib/thread-list-column")
 
@@ -21,6 +22,9 @@ ThreadListNarrowItem = require("../lib/thread-list-narrow-item.cjsx")
 ThreadListTabular = require("../lib/thread-list-tabular.cjsx")
 ThreadListTabularItem = require("../lib/thread-list-tabular-item.cjsx")
 
+ParticipantsItem = React.createClass
+  render: -> <div></div>
+
 me = new Namespace(
   "name": "User One",
   "email": "user1@inboxapp.com"
@@ -218,6 +222,10 @@ describe "ThreadListTabular", ->
 
     ThreadStore._resetInstanceVars()
 
+    ComponentRegistry.register
+      name: 'Participants'
+      view: ParticipantsItem
+
     @thread_list = ReactTestUtils.renderIntoDocument(
       <ThreadListTabular />
     )
@@ -300,6 +308,10 @@ describe "ThreadListNarrow", ->
       new Promise (resolve, reject) -> resolve(test_threads())
     ThreadStore._resetInstanceVars()
 
+    ComponentRegistry.register
+      name: 'Participants'
+      view: ParticipantsItem
+
     @thread_list = ReactTestUtils.renderIntoDocument(
       <ThreadListNarrow />
     )
diff --git a/spec-inbox/models/model-spec.coffee b/spec-inbox/models/model-spec.coffee
index 07b00adbe..1453507e1 100644
--- a/spec-inbox/models/model-spec.coffee
+++ b/spec-inbox/models/model-spec.coffee
@@ -3,7 +3,7 @@ Attributes = require '../../src/flux/attributes'
 {isTempId} = require '../../src/flux/models/utils'
 _ = require 'underscore-plus'
 
-fdescribe "Model", ->
+describe "Model", ->
   describe "constructor", ->
     it "should accept a hash of attributes and assign them to the new Model", ->
       attrs =
diff --git a/spec/spec-helper.coffee b/spec/spec-helper.coffee
index 867de523c..084b6c1fb 100644
--- a/spec/spec-helper.coffee
+++ b/spec/spec-helper.coffee
@@ -21,6 +21,7 @@ clipboard = require 'clipboard'
 
 NamespaceStore = require "../src/flux/stores/namespace-store"
 Contact = require '../src/flux/models/contact'
+{ComponentRegistry} = require "inbox-exports"
 
 atom.themes.loadBaseStylesheets()
 atom.themes.requireStylesheet '../static/jasmine'
@@ -65,8 +66,35 @@ if specDirectory
 
 isCoreSpec = specDirectory == fs.realpathSync(__dirname)
 
+# Override React.addons.TestUtils.renderIntoDocument so that
+# we can remove all the created elements after the test completes.
+React = require "react/addons"
+ReactTestUtils = React.addons.TestUtils
+ReactTestUtils.scryRenderedDOMComponentsWithAttr = (root, attrName, attrValue) ->
+  ReactTestUtils.findAllInRenderedTree root, (inst) ->
+    inst.props[attrName] and (!attrValue or inst.props[attrName] is attrValue)
+
+ReactTestUtils.findRenderedDOMComponentWithAttr = (root, attrName, attrValue) ->
+  all = ReactTestUtils.scryRenderedDOMComponentsWithAttr(root, attrName, attrValue)
+  if all.length is not 1
+    throw new Error("Did not find exactly one match for data attribute: #{attrName} with value: #{attrValue}")
+  all[0]
+
+ReactElementContainers = []
+ReactTestUtils.renderIntoDocument = (element) ->
+  container = document.createElement('div')
+  ReactElementContainers.push(container)
+  React.render(element, container)
+
+ReactTestUtils.unmountAll = ->
+  for container in ReactElementContainers
+    React.unmountComponentAtNode(container)
+  ReactElementContainers = []
+
 beforeEach ->
   Grim.clearDeprecations() if isCoreSpec
+  ComponentRegistry._clear()
+
   $.fx.off = true
   documentTitle = null
   atom.workspace = new Workspace()
@@ -146,6 +174,8 @@ afterEach ->
 
   $('#jasmine-content').empty() unless window.debugContent
 
+  ReactTestUtils.unmountAll()
+
   jasmine.unspy(atom, 'saveSync')
   ensureNoPathSubscriptions()
   waits(0) # yield to ui thread to make screen update more frequently
diff --git a/src/component-registry.coffee b/src/component-registry.coffee
index 5f3536595..e3e042659 100644
--- a/src/component-registry.coffee
+++ b/src/component-registry.coffee
@@ -16,17 +16,20 @@ getViewsByName = (components) ->
     [registered, requested] = component.split " as "
     requested ?= registered
     state[requested] = ComponentRegistry.findViewByName registered
+    if not state[requested]?
+      console.log("""Warning: No component found for #{requested} in
+        #{@constructor.displayName}. Loaded: #{Object.keys(registry)}""")
   state
 
 Mixin =
   getInitialState: ->
-    getViewsByName(@components)
+    getViewsByName.apply(@, [@components])
 
   componentWillMount: ->
-    @_componentUnlistener = ComponentRegistry.listen (event) =>
+    @_componentUnlistener = ComponentRegistry.listen =>
       @setState getViewsByName(@components)
 
-  componentDidUnmount: ->
+  componentWillUnmount: ->
     @_componentUnlistener()
 
 # Internal representation of components