Flow for all the files

.eslintrc

@@ -3,16 +3,34 @@
   "extends": [
     "react-app",
     "plugin:import/errors",
-    "plugin:import/warnings"
+    "plugin:import/warnings",
+    "plugin:flowtype/recommended"
   ],
   "plugins": [
-    "prettier"
+    "prettier",
+    "flowtype",
   ],
   "rules": {
     "import/order": "warn",
     // Prettier automatically uses the least amount of parens possible, so this
     // does more harm than good.
     "no-mixed-operators": "off",
+    // Flow
+    "flowtype/require-valid-file-annotation": [
+      2,
+      "always",
+      {
+        "annotationStyle": "line"
+      }
+    ],
+    "flowtype/space-after-type-colon": [
+      2,
+      "always"
+    ],
+    "flowtype/space-before-type-colon": [
+      2,
+      "never"
+    ],
     // Enforce that code is formatted with prettier.
     "prettier/prettier": [
       "error",
@@ -23,7 +41,10 @@
     ]
   },
   "settings": {
-    "import/resolver": "webpack"
+    "import/resolver": "webpack",
+    "flowtype": {
+      "onlyFilesWithFlowAnnotation": false
+    }
   },
   "env": {
     "jest": true
@@ -33,6 +54,7 @@
     "SLACK_KEY": true,
     "SLACK_REDIRECT_URI": true,
     "DEPLOYMENT": true,
+    "BASE_URL": true,
     "afterAll": true
   }
 }

.flowconfig

@@ -1,7 +1,11 @@
+[include]
+.*/frontend/.*
+
 [ignore]
 .*/node_modules/styled-components/.*
 .*/node_modules/react-side-effect/.*
 .*/node_modules/fbjs/.*
+.*/node_modules/config-chain/.*
 
 [libs]
 
@@ -12,8 +16,11 @@ module.system.node.resolve_dirname=node_modules
 module.system.node.resolve_dirname=frontend
 
 module.name_mapper='^\(.*\)\.s?css$' -> 'empty/object'
+module.name_mapper='^\(.*\)\.md$' -> 'empty/object'
 module.file_ext=.js
 module.file_ext=.scss
+module.file_ext=.md
+module.file_ext=.json
 
 esproposal.decorators=ignore
 esproposal.class_static_fields=enable

.githooks/pre-commit/flow.sh

@@ -1 +0,0 @@
-yarn flow

flow-typed/globals.js

@@ -0,0 +1,6 @@
+// @flow
+declare var __DEV__: string;
+declare var SLACK_REDIRECT_URI: string;
+declare var SLACK_KEY: string;
+declare var BASE_URL: string;
+declare var DEPLOYMENT: string;

frontend/components/Alert/Alert.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 import { Flex } from 'reflexbox';
 import classNames from 'classnames/bind';

frontend/components/Alert/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Alert from './Alert';
 export default Alert;

frontend/components/AtlasPreview/AtlasPreview.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 import Link from 'react-router/lib/Link';

frontend/components/AtlasPreview/components/DocumentLink/DocumentLink.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 

frontend/components/AtlasPreview/components/DocumentLink/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentLink from './DocumentLink';
 export default DocumentLink;

frontend/components/AtlasPreview/index.js

@@ -1,2 +1,3 @@
+// @flow
 import AtlasPreview from './AtlasPreview';
 export default AtlasPreview;

frontend/components/AtlasPreviewLoading/AtlasPreviewLoading.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import ReactCSSTransitionGroup from 'react-addons-css-transition-group';
 import styled, { keyframes } from 'styled-components';

frontend/components/AtlasPreviewLoading/index.js

@@ -1,2 +1,3 @@
+// @flow
 import AtlasPreviewLoading from './AtlasPreviewLoading';
 export default AtlasPreviewLoading;

frontend/components/Button/index.js

@@ -1,2 +0,0 @@
-import Button from './Button';
-export default Button;

frontend/components/CenteredContent/CenteredContent.js

@@ -3,9 +3,9 @@ import React from 'react';
 import styles from './CenteredContent.scss';
 
 type Props = {
-  children: any,
-  style: Object,
-  maxWidth: string,
+  children?: React.Element<any>,
+  style?: Object,
+  maxWidth?: string,
 };
 
 const CenteredContent = (props: Props) => {

frontend/components/CenteredContent/index.js

@@ -1,2 +1,3 @@
+// @flow
 import CenteredContent from './CenteredContent';
 export default CenteredContent;

frontend/components/Divider/Divider.js

@@ -1,8 +1,9 @@
+// @flow
 import React from 'react';
 
 import styles from './Divider.scss';
 
-const Divider = props => {
+const Divider = () => {
   return <div className={styles.divider}><span /></div>;
 };
 

frontend/components/Divider/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Divider from './Divider';
 export default Divider;

frontend/components/Document/components/DocumentHtml/DocumentHtml.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 import ReactDOM from 'react-dom';
 import { observer } from 'mobx-react';
@@ -18,9 +19,11 @@ import styles from './DocumentHtml.scss';
   };
 
   setExternalLinks = () => {
+    // $FlowFixMe
     const links = ReactDOM.findDOMNode(this).querySelectorAll('a');
     links.forEach(link => {
       if (link.hostname !== window.location.hostname) {
+        // $FlowFixMe
         link.target = '_blank'; // eslint-disable-line no-param-reassign
       }
     });

frontend/components/Document/components/DocumentHtml/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentHtml from './DocumentHtml';
 export default DocumentHtml;

frontend/components/Document/index.js

@@ -1,3 +1,4 @@
+// @flow
 import Document from './Document';
 import DocumentHtml from './components/DocumentHtml';
 

frontend/components/DocumentList/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentList from './DocumentList';
 export default DocumentList;

frontend/components/DocumentPreview/DocumentPreview.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { toJS } from 'mobx';
 import { Link } from 'react-router';

frontend/components/DocumentPreview/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentPreview from './DocumentPreview';
 export default DocumentPreview;

frontend/components/DropdownMenu/DropdownMenu.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { browserHistory } from 'react-router';
 

frontend/components/DropdownMenu/components/MoreIcon/MoreIcon.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 
 import styles from './MoreIcon.scss';

frontend/components/DropdownMenu/components/MoreIcon/index.js

@@ -1,2 +1,3 @@
+// @flow
 import MoreIcon from './MoreIcon';
 export default MoreIcon;

frontend/components/DropdownMenu/index.js

@@ -1,3 +1,4 @@
+// @flow
 import DropdownMenu, { MenuItem } from './DropdownMenu';
 import MoreIcon from './components/MoreIcon';
 export default DropdownMenu;

frontend/components/Layout/Layout.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { browserHistory, Link } from 'react-router';
 import Helmet from 'react-helmet';
@@ -10,24 +11,25 @@ import { Flex } from 'reflexbox';
 import DropdownMenu, { MenuItem } from 'components/DropdownMenu';
 
 import LoadingIndicator from 'components/LoadingIndicator';
+import UserStore from 'stores/UserStore';
 
 import styles from './Layout.scss';
 import classNames from 'classnames/bind';
 const cx = classNames.bind(styles);
 
-@inject('user')
-@observer
-class Layout extends React.Component {
-  static propTypes = {
-    children: React.PropTypes.node,
-    actions: React.PropTypes.node,
-    title: React.PropTypes.node,
-    titleText: React.PropTypes.node,
-    loading: React.PropTypes.bool,
-    user: React.PropTypes.object.isRequired,
-    search: React.PropTypes.bool,
-    notifications: React.PropTypes.node,
-  };
+type Props = {
+  children?: ?React.Element<any>,
+  actions?: ?React.Element<any>,
+  title?: ?React.Element<any>,
+  titleText?: string,
+  loading?: boolean,
+  user: UserStore,
+  search: ?boolean,
+  notifications?: React.Element<any>,
+};
+
+@observer class Layout extends React.Component {
+  props: Props;
 
   static defaultProps = {
     search: true,
@@ -114,4 +116,4 @@ const Avatar = styled.img`
   border-radius: 50%;
 `;
 
-export default Layout;
+export default inject('user')(Layout);

frontend/components/Layout/components/HeaderAction/HeaderAction.js

@@ -1,8 +1,11 @@
+// @flow
 import React from 'react';
 
 import styles from './HeaderAction.scss';
 
-const HeaderAction = props => {
+type Props = { onClick?: ?Function, children?: ?React.Element<any> };
+
+const HeaderAction = (props: Props) => {
   return (
     <div onClick={props.onClick} className={styles.container}>
       {props.children}
@@ -10,8 +13,4 @@ const HeaderAction = props => {
   );
 };
 
-HeaderAction.propTypes = {
-  onClick: React.PropTypes.func,
-};
-
 export default HeaderAction;

frontend/components/Layout/components/HeaderAction/index.js

@@ -1,2 +1,3 @@
+// @flow
 import HeaderAction from './HeaderAction';
 export default HeaderAction;

frontend/components/Layout/components/SaveAction/SaveAction.js

@@ -1,14 +1,17 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 
-@observer class SaveAction extends React.Component {
-  static propTypes = {
-    onClick: React.PropTypes.func.isRequired,
-    disabled: React.PropTypes.bool,
-    isNew: React.PropTypes.bool,
-  };
+type Props = {
+  onClick: Function,
+  disabled?: boolean,
+  isNew?: boolean,
+};
 
-  onClick = event => {
+@observer class SaveAction extends React.Component {
+  props: Props;
+
+  onClick = (event: MouseEvent) => {
     if (this.props.disabled) return;
 
     event.preventDefault();

frontend/components/Layout/components/SaveAction/index.js

@@ -1,2 +1,3 @@
+// @flow
 import SaveAction from './SaveAction';
 export default SaveAction;

frontend/components/Layout/components/Title/Title.js

@@ -4,9 +4,9 @@ import _ from 'lodash';
 import styled from 'styled-components';
 
 type Props = {
-  children: string,
+  content: string,
   truncate?: number,
-  placeholder: string,
+  placeholder?: ?string,
 };
 
 class Title extends React.Component {
@@ -15,9 +15,9 @@ class Title extends React.Component {
   render() {
     let title;
     if (this.props.truncate) {
-      title = _.truncate(this.props.children, this.props.truncate);
+      title = _.truncate(this.props.content, this.props.truncate);
     } else {
-      title = this.props.children;
+      title = this.props.content;
     }
 
     let usePlaceholder;
@@ -29,7 +29,7 @@ class Title extends React.Component {
     return (
       <span>
         {title && <span>&nbsp;/&nbsp;</span>}
-        <TitleText title={this.props.children} untitled={usePlaceholder}>
+        <TitleText title={this.props.content} untitled={usePlaceholder}>
           {title}
         </TitleText>
       </span>

frontend/components/Layout/index.js

@@ -1,3 +1,4 @@
+// @flow
 import Layout from './Layout';
 import Title from './components/Title';
 import HeaderAction from './components/HeaderAction';

frontend/components/LoadingIndicator/LoadingIndicator.js

@@ -1,8 +1,9 @@
+// @flow
 import React from 'react';
 
 import styles from './LoadingIndicator.scss';
 
-const LoadingIndicator = props => {
+const LoadingIndicator = () => {
   return (
     <div className={styles.loading}>
       <div className={styles.loader} />

frontend/components/LoadingIndicator/index.js

@@ -1,2 +1,3 @@
+// @flow
 import LoadingIndicator from './LoadingIndicator';
 export default LoadingIndicator;

frontend/components/MarkdownEditor/MarkdownEditor.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 import Codemirror from 'react-codemirror';
@@ -28,13 +29,13 @@ import { client } from 'utils/ApiClient';
     toggleUploadingIndicator: React.PropTypes.func,
   };
 
-  onChange = newText => {
+  onChange = (newText: string) => {
     if (newText !== this.props.text) {
       this.props.onChange(newText);
     }
   };
 
-  onDropAccepted = files => {
+  onDropAccepted = (files: Object[]) => {
     const file = files[0];
     const editor = this.getEditorInstance();
 
@@ -62,6 +63,7 @@ import { client } from 'utils/ApiClient';
         filename: file.name,
       })
       .then(response => {
+        // $FlowFixMe need to augment ApiClient
         const data = response.data;
         // Upload using FormData API
         const formData = new FormData();
@@ -77,7 +79,7 @@ import { client } from 'utils/ApiClient';
         }
 
         fetch(data.uploadUrl, {
-          method: 'post',
+          method: 'POST',
           body: formData,
         })
           .then(_s3Response => {

frontend/components/MarkdownEditor/components/ClickablePadding/ClickablePadding.js

@@ -1,8 +1,9 @@
+// @flow
 import React from 'react';
 
 import styles from './ClickablePadding.scss';
 
-const ClickablePadding = props => {
+const ClickablePadding = (props: { onClick: Function }) => {
   return <div className={styles.container} onClick={props.onClick}>&nbsp;</div>;
 };
 

frontend/components/MarkdownEditor/components/ClickablePadding/index.js

@@ -1,2 +1,3 @@
+// @flow
 import ClickablePadding from './ClickablePadding';
 export default ClickablePadding;

frontend/components/MarkdownEditor/index.js

@@ -1,2 +1,3 @@
+// @flow
 import MarkdownEditor from './MarkdownEditor';
 export default MarkdownEditor;

frontend/components/PublishingInfo/PublishingInfo.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 import moment from 'moment';
 import styled from 'styled-components';

frontend/components/PublishingInfo/index.js

@@ -1,2 +1,3 @@
+// @flow
 import PublishingInfo from './PublishingInfo';
 export default PublishingInfo;

frontend/components/SlackAuthLink/SlackAuthLink.js

@@ -3,15 +3,15 @@ import React from 'react';
 import { observer, inject } from 'mobx-react';
 import UserStore from 'stores/UserStore';
 
-@inject('user')
-@observer
-class SlackAuthLink extends React.Component {
-  props: {
-    children: any,
-    scopes: Array<string>,
-    user: UserStore,
-    redirectUri: string,
-  };
+type Props = {
+  children: React.Element<any>,
+  scopes?: Array<string>,
+  user: UserStore,
+  redirectUri: string,
+};
+
+@observer class SlackAuthLink extends React.Component {
+  props: Props;
 
   static defaultProps = {
     scopes: [
@@ -25,10 +25,8 @@ class SlackAuthLink extends React.Component {
   slackUrl = () => {
     const baseUrl = 'https://slack.com/oauth/authorize';
     const params = {
-      // $FlowIssue global variable
       client_id: SLACK_KEY,
-      scope: this.props.scopes.join(' '),
-      // $FlowIssue global variable
+      scope: this.props.scopes ? this.props.scopes.join(' ') : '',
       redirect_uri: this.props.redirectUri || SLACK_REDIRECT_URI,
       state: this.props.user.getOauthState(),
     };
@@ -47,4 +45,4 @@ class SlackAuthLink extends React.Component {
   }
 }
 
-export default SlackAuthLink;
+export default inject('user')(SlackAuthLink);

frontend/components/SlackAuthLink/index.js

@@ -1,2 +1,3 @@
+// @flow
 import SlackAuthLink from './SlackAuthLink';
 export default SlackAuthLink;

frontend/components/Tree/Node.js

@@ -1,3 +1,4 @@
+/* eslint-disable */
 import React from 'react';
 import history from 'utils/History';
 

frontend/components/Tree/Tree.js

@@ -1,3 +1,4 @@
+/* eslint-disable */
 const Tree = require('js-tree');
 const proto = Tree.prototype;
 

frontend/components/Tree/UiTree.js

@@ -1,3 +1,4 @@
+/* eslint-disable */
 const React = require('react');
 const Tree = require('./Tree');
 const Node = require('./Node');

frontend/components/Tree/index.js

@@ -1,2 +1,3 @@
+// @flow
 import UiTree from './UiTree';
 export default UiTree;

frontend/index.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { render } from 'react-dom';
 import { Provider } from 'mobx-react';
@@ -115,7 +116,7 @@ render(
         </Route>
       </Router>
     </Provider>
-    {__DEV__ && <DevTools position={{ bottom: 0, right: 0 }} />}
+    {DevTools && <DevTools position={{ bottom: 0, right: 0 }} />}
   </div>,
   document.getElementById('root')
 );

frontend/scenes/Application.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 import Helmet from 'react-helmet';

frontend/scenes/Atlas/Atlas.js

@@ -1,10 +1,12 @@
-import React, { PropTypes } from 'react';
+// @flow
+import React from 'react';
 import { observer } from 'mobx-react';
 import { browserHistory } from 'react-router';
 import keydown from 'react-keydown';
 import ReactCSSTransitionGroup from 'react-addons-css-transition-group';
 import _ from 'lodash';
 
+// TODO move here argh
 import store from './AtlasStore';
 
 import Layout, { Title } from 'components/Layout';
@@ -17,12 +19,15 @@ import { Flex } from 'reflexbox';
 
 import styles from './Atlas.scss';
 
+type Props = {
+  params: Object,
+  keydown: Object,
+};
+
 @keydown(['c'])
 @observer
 class Atlas extends React.Component {
-  static propTypes = {
-    params: PropTypes.object.isRequired,
-  };
+  props: Props;
 
   componentDidMount = () => {
     const { id } = this.props.params;
@@ -34,7 +39,7 @@ class Atlas extends React.Component {
     });
   };
 
-  componentWillReceiveProps = nextProps => {
+  componentWillReceiveProps = (nextProps: Props) => {
     const key = nextProps.keydown.event;
     if (key) {
       if (key.key === 'c') {
@@ -43,9 +48,9 @@ class Atlas extends React.Component {
     }
   };
 
-  onCreate = event => {
+  onCreate = (event: Event) => {
     if (event) event.preventDefault();
-    browserHistory.push(`${store.collection.url}/new`);
+    store.collection && browserHistory.push(`${store.collection.url}/new`);
   };
 
   render() {
@@ -65,7 +70,7 @@ class Atlas extends React.Component {
           </DropdownMenu>
         </Flex>
       );
-      title = <Title>{collection.name}</Title>;
+      title = <Title content={collection.name} />;
       titleText = collection.name;
     }
 
@@ -81,21 +86,22 @@ class Atlas extends React.Component {
           >
             {store.isFetching
               ? <AtlasPreviewLoading />
-              : <div className={styles.container}>
-                  <div className={styles.atlasDetails}>
-                    <h2>{collection.name}</h2>
-                    <blockquote>
-                      {collection.description}
-                    </blockquote>
-                  </div>
+              : collection &&
+                  <div className={styles.container}>
+                    <div className={styles.atlasDetails}>
+                      <h2>{collection.name}</h2>
+                      <blockquote>
+                        {collection.description}
+                      </blockquote>
+                    </div>
 
-                  <Divider />
+                    <Divider />
 
-                  <DocumentList
-                    documents={collection.recentDocuments}
-                    preview
-                  />
-                </div>}
+                    <DocumentList
+                      documents={collection.recentDocuments}
+                      preview
+                    />
+                  </div>}
           </ReactCSSTransitionGroup>
         </CenteredContent>
       </Layout>

frontend/scenes/Atlas/AtlasStore.js

@@ -1,19 +1,29 @@
-import { observable, action } from 'mobx';
+// @flow
+import { observable, action, computed } from 'mobx';
+import invariant from 'invariant';
 import { client } from 'utils/ApiClient';
+import type { Collection } from 'types';
 
 const store = new class AtlasStore {
-  @observable collection;
+  @observable collection: ?(Collection & { recentDocuments?: Object[] });
 
   @observable isFetching = true;
 
+  /* Computed */
+
+  @computed get isLoaded(): boolean {
+    return !this.isFetching && !!this.collection;
+  }
+
   /* Actions */
 
-  @action fetchCollection = async (id, successCallback) => {
+  @action fetchCollection = async (id: string, successCallback: Function) => {
     this.isFetching = true;
     this.collection = null;
 
     try {
       const res = await client.get('/collections.info', { id });
+      invariant(res && res.data, 'Data should be available');
       const { data } = res;
       this.collection = data;
       successCallback(data);

frontend/scenes/Atlas/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Atlas from './Atlas';
 export default Atlas;

frontend/scenes/Dashboard/DashboardStore.js

@@ -1,5 +1,6 @@
 // @flow
 import { observable, action, runInAction } from 'mobx';
+import invariant from 'invariant';
 import { client } from 'utils/ApiClient';
 import type { Pagination, Collection } from 'types';
 
@@ -23,6 +24,10 @@ class DashboardStore {
 
     try {
       const res = await client.post('/collections.list', { id: this.team.id });
+      invariant(
+        res && res.data && res.pagination,
+        'API response should be available'
+      );
       const { data, pagination } = res;
       runInAction('fetchCollections', () => {
         this.collections = data;

frontend/scenes/Dashboard/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Dashboard from './Dashboard';
 export default Dashboard;

frontend/scenes/DocumentEdit/DocumentEdit.js

@@ -1,21 +1,29 @@
+// @flow
 import React, { Component } from 'react';
 import { observer } from 'mobx-react';
 import { browserHistory, withRouter } from 'react-router';
 import keydown from 'react-keydown';
+import { Flex } from 'reflexbox';
 
 import DocumentEditStore, { DOCUMENT_EDIT_SETTINGS } from './DocumentEditStore';
+import EditorLoader from './components/EditorLoader';
 
 import Layout, { Title, HeaderAction, SaveAction } from 'components/Layout';
-import { Flex } from 'reflexbox';
+
 import AtlasPreviewLoading from 'components/AtlasPreviewLoading';
 import CenteredContent from 'components/CenteredContent';
 import DropdownMenu, { MenuItem, MoreIcon } from 'components/DropdownMenu';
 
-import EditorLoader from './components/EditorLoader';
-
 const DISREGARD_CHANGES = `You have unsaved changes.
 Are you sure you want to disgard them?`;
 
+type Props = {
+  route: Object,
+  router: Object,
+  params: Object,
+  keydown: Object,
+};
+
 @keydown([
   'cmd+enter',
   'ctrl+enter',
@@ -27,13 +35,10 @@ Are you sure you want to disgard them?`;
 @withRouter
 @observer
 class DocumentEdit extends Component {
-  static propTypes = {
-    route: React.PropTypes.object.isRequired,
-    router: React.PropTypes.object.isRequired,
-    params: React.PropTypes.object,
-  };
+  store: DocumentEditStore;
+  props: Props;
 
-  constructor(props) {
+  constructor(props: Props) {
     super(props);
     this.store = new DocumentEditStore(
       JSON.parse(localStorage[DOCUMENT_EDIT_SETTINGS] || '{}')
@@ -60,6 +65,7 @@ class DocumentEdit extends Component {
 
     // Load editor async
     EditorLoader().then(({ Editor }) => {
+      // $FlowIssue we can remove after moving to new editor
       this.setState({ Editor });
     });
 
@@ -72,7 +78,7 @@ class DocumentEdit extends Component {
     });
   };
 
-  componentWillReceiveProps = nextProps => {
+  componentWillReceiveProps = (nextProps: Props) => {
     const key = nextProps.keydown.event;
 
     if (key) {
@@ -109,7 +115,7 @@ class DocumentEdit extends Component {
     browserHistory.goBack();
   };
 
-  onScroll = scrollTop => {
+  onScroll = (scrollTop: number) => {
     this.setState({
       scrollTop,
     });
@@ -119,10 +125,9 @@ class DocumentEdit extends Component {
     const title = (
       <Title
         truncate={60}
-        placeholder={!this.store.isFetching && 'Untitled document'}
-      >
-        {this.store.title}
-      </Title>
+        placeholder={!this.store.isFetching ? 'Untitled document' : null}
+        content={this.store.title}
+      />
     );
 
     const titleText = this.store.title;

frontend/scenes/DocumentEdit/DocumentEditStore.js

@@ -1,7 +1,10 @@
+// @flow
 import { observable, action, toJS, autorun } from 'mobx';
-import { client } from 'utils/ApiClient';
 import { browserHistory } from 'react-router';
+import invariant from 'invariant';
+import { client } from 'utils/ApiClient';
 import emojify from 'utils/emojify';
+import type { Document } from 'types';
 
 const DOCUMENT_EDIT_SETTINGS = 'DOCUMENT_EDIT_SETTINGS';
 
@@ -22,17 +25,17 @@ const parseHeader = text => {
 class DocumentEditStore {
   @observable documentId = null;
   @observable collectionId = null;
-  @observable parentDocument;
-  @observable title;
-  @observable text;
+  @observable parentDocument: ?Document;
+  @observable title: string;
+  @observable text: string;
   @observable hasPendingChanges = false;
-  @observable newDocument;
-  @observable newChildDocument;
+  @observable newDocument: ?boolean;
+  @observable newChildDocument: ?boolean;
 
-  @observable preview;
-  @observable isFetching;
-  @observable isSaving;
-  @observable isUploading;
+  @observable preview: ?boolean = false;
+  @observable isFetching: boolean = false;
+  @observable isSaving: boolean = false;
+  @observable isUploading: boolean = false;
 
   /* Actions */
 
@@ -40,17 +43,18 @@ class DocumentEditStore {
     this.isFetching = true;
 
     try {
-      const data = await client.get(
+      const res = await client.get(
         '/documents.info',
         {
           id: this.documentId,
         },
         { cache: true }
       );
+      invariant(res && res.data, 'Data shoule be available');
       if (this.newChildDocument) {
-        this.parentDocument = data.data;
+        this.parentDocument = res.data;
       } else {
-        const { title, text } = data.data;
+        const { title, text } = res.data;
         this.title = title;
         this.text = text;
       }
@@ -66,17 +70,19 @@ class DocumentEditStore {
     this.isSaving = true;
 
     try {
-      const data = await client.post(
+      const res = await client.post(
         '/documents.create',
         {
           parentDocument: this.parentDocument && this.parentDocument.id,
+          // $FlowFixMe this logic will probably get rewritten soon anyway
           collection: this.collectionId || this.parentDocument.collection.id,
           title: this.title || 'Untitled document',
           text: this.text,
         },
         { cache: true }
       );
-      const { url } = data.data;
+      invariant(res && res.data, 'Data shoule be available');
+      const { url } = res.data;
 
       this.hasPendingChanges = false;
       browserHistory.push(url);
@@ -92,7 +98,7 @@ class DocumentEditStore {
     this.isSaving = true;
 
     try {
-      const data = await client.post(
+      const res = await client.post(
         '/documents.update',
         {
           id: this.documentId,
@@ -101,7 +107,8 @@ class DocumentEditStore {
         },
         { cache: true }
       );
-      const { url } = data.data;
+      invariant(res && res.data, 'Data shoule be available');
+      const { url } = res.data;
 
       this.hasPendingChanges = false;
       browserHistory.push(url);
@@ -111,17 +118,17 @@ class DocumentEditStore {
     this.isSaving = false;
   };
 
-  @action updateText = text => {
+  @action updateText = (text: string) => {
     this.text = text;
     this.title = parseHeader(text);
     this.hasPendingChanges = true;
   };
 
-  @action updateTitle = title => {
+  @action updateTitle = (title: string) => {
     this.title = title;
   };
 
-  @action replaceText = args => {
+  @action replaceText = (args: { original: string, new: string }) => {
     this.text = this.text.replace(args.original, args.new);
     this.hasPendingChanges = true;
   };
@@ -147,7 +154,7 @@ class DocumentEditStore {
     });
   };
 
-  constructor(settings) {
+  constructor(settings: { preview: ?boolean }) {
     // Rehydrate settings
     this.preview = settings.preview;
 

frontend/scenes/DocumentEdit/components/Editor.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer } from 'mobx-react';
 import { convertToMarkdown } from 'utils/markdown';

frontend/scenes/DocumentEdit/components/EditorLoader.js

@@ -1,5 +1,7 @@
+// @flow
 export default () => {
   return new Promise(resolve => {
+    // $FlowIssue this is available with webpack
     require.ensure([], () => {
       resolve({
         Editor: require('./Editor').default,

frontend/scenes/DocumentEdit/components/EditorPane.js

@@ -1,18 +1,21 @@
+// @flow
 import React from 'react';
 
 import styles from '../DocumentEdit.scss';
 import classNames from 'classnames/bind';
 const cx = classNames.bind(styles);
 
-class EditorPane extends React.Component {
-  static propTypes = {
-    children: React.PropTypes.node.isRequired,
-    onScroll: React.PropTypes.func.isRequired,
-    scrollTop: React.PropTypes.number,
-    fullWidth: React.PropTypes.bool,
-  };
+type Props = {
+  children?: ?React.Element<any>,
+  onScroll?: Function,
+  scrollTop?: ?number,
+  fullWidth?: ?boolean,
+};
 
-  componentWillReceiveProps = nextProps => {
+class EditorPane extends React.Component {
+  props: Props;
+
+  componentWillReceiveProps = (nextProps: Props) => {
     if (nextProps.scrollTop) {
       this.scrollToPosition(nextProps.scrollTop);
     }
@@ -26,15 +29,16 @@ class EditorPane extends React.Component {
     this.refs.pane.removeEventListener('scroll', this.handleScroll);
   };
 
-  handleScroll = e => {
+  handleScroll = (e: Event) => {
     setTimeout(() => {
       const element = this.refs.pane;
       const contentEl = this.refs.content;
-      this.props.onScroll(element.scrollTop / contentEl.offsetHeight);
+      this.props.onScroll &&
+        this.props.onScroll(element.scrollTop / contentEl.offsetHeight);
     }, 50);
   };
 
-  scrollToPosition = percentage => {
+  scrollToPosition = (percentage: number) => {
     const contentEl = this.refs.content;
 
     // Push to edges

frontend/scenes/DocumentEdit/components/Preview/Preview.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 
 import { DocumentHtml } from 'components/Document';
@@ -6,7 +7,11 @@ import styles from './Preview.scss';
 import classNames from 'classnames/bind';
 const cx = classNames.bind(styles);
 
-const Preview = props => {
+type Props = {
+  html: ?string,
+};
+
+const Preview = (props: Props) => {
   return (
     <div className={cx(styles.container)}>
       <DocumentHtml html={props.html} />
@@ -14,8 +19,4 @@ const Preview = props => {
   );
 };
 
-Preview.propTypes = {
-  html: React.PropTypes.string.isRequired,
-};
-
 export default Preview;

frontend/scenes/DocumentEdit/components/Preview/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Preview from './Preview';
 export default Preview;

frontend/scenes/DocumentEdit/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentEdit from './DocumentEdit';
 export default DocumentEdit;

frontend/scenes/DocumentScene/DocumentScene.js

@@ -1,4 +1,6 @@
+// @flow
 import React, { PropTypes } from 'react';
+import invariant from 'invariant';
 import { Link, browserHistory } from 'react-router';
 import { observer, inject } from 'mobx-react';
 import { toJS } from 'mobx';
@@ -6,6 +8,7 @@ import keydown from 'react-keydown';
 import _ from 'lodash';
 
 import DocumentSceneStore, { DOCUMENT_PREFERENCES } from './DocumentSceneStore';
+import UiStore from 'stores/UiStore';
 
 import Layout from 'components/Layout';
 import AtlasPreviewLoading from 'components/AtlasPreviewLoading';
@@ -16,13 +19,20 @@ import { Flex } from 'reflexbox';
 import Sidebar from './components/Sidebar';
 
 import styles from './DocumentScene.scss';
-// import classNames from 'classnames/bind';
-// const cx = classNames.bind(styles);
+
+type Props = {
+  ui: UiStore,
+  routeParams: Object,
+  params: Object,
+  location: Object,
+  keydown: Object,
+};
 
 @keydown(['cmd+/', 'ctrl+/', 'c', 'e'])
 @inject('ui')
 @observer
 class DocumentScene extends React.Component {
+  store: DocumentSceneStore;
   static propTypes = {
     ui: PropTypes.object.isRequired,
     routeParams: PropTypes.object,
@@ -30,7 +40,7 @@ class DocumentScene extends React.Component {
     location: PropTypes.object.isRequired,
   };
 
-  constructor(props) {
+  constructor(props: Props) {
     super(props);
     this.store = new DocumentSceneStore(
       JSON.parse(localStorage[DOCUMENT_PREFERENCES] || '{}')
@@ -41,15 +51,16 @@ class DocumentScene extends React.Component {
     didScroll: false,
   };
 
-  componentDidMount = async () => {
+  componentDidMount = () => {
     const { id } = this.props.routeParams;
-    await this.store.fetchDocument(id, {
-      replaceUrl: !this.props.location.hash,
-    });
-    this.scrollTohash();
+    this.store
+      .fetchDocument(id, {
+        replaceUrl: !this.props.location.hash,
+      })
+      .then(() => this.scrollTohash());
   };
 
-  componentWillReceiveProps = async nextProps => {
+  componentWillReceiveProps = (nextProps: Props) => {
     const key = nextProps.keydown.event;
     if (key) {
       if (key.key === '/' && (key.metaKey || key.ctrl.Key)) {
@@ -57,7 +68,7 @@ class DocumentScene extends React.Component {
       }
 
       if (key.key === 'c') {
-        _.defer(this.onCreate);
+        _.defer(this.onCreateDocument);
       }
 
       if (key.key === 'e') {
@@ -69,31 +80,38 @@ class DocumentScene extends React.Component {
     const oldId = this.props.params.id;
     const newId = nextProps.params.id;
     if (oldId !== newId) {
-      await this.store.fetchDocument(newId, {
-        softLoad: true,
-        replaceUrl: !this.props.location.hash,
-      });
+      this.store
+        .fetchDocument(newId, {
+          softLoad: true,
+          replaceUrl: !this.props.location.hash,
+        })
+        .then(() => this.scrollTohash());
     }
-
-    this.scrollTohash();
   };
 
   onEdit = () => {
+    invariant(this.store.document, 'Document is not available');
     const url = `${this.store.document.url}/edit`;
     browserHistory.push(url);
   };
 
   onCreateDocument = () => {
+    invariant(this.store.collectionTree, 'collectionTree is not available');
     browserHistory.push(`${this.store.collectionTree.url}/new`);
   };
 
   onCreateChild = () => {
+    invariant(this.store.document, 'Document is not available');
     browserHistory.push(`${this.store.document.url}/new`);
   };
 
   onDelete = () => {
     let msg;
-    if (this.store.document.collection.type === 'atlas') {
+    if (
+      this.store.document &&
+      this.store.document.collection &&
+      this.store.document.collection.type === 'atlas'
+    ) {
       msg =
         "Are you sure you want to delete this document and all it's child documents (if any)?";
     } else {
@@ -107,11 +125,13 @@ class DocumentScene extends React.Component {
 
   onExport = () => {
     const doc = this.store.document;
-    const a = document.createElement('a');
-    a.textContent = 'download';
-    a.download = `${doc.title}.md`;
-    a.href = `data:text/markdown;charset=UTF-8,${encodeURIComponent(doc.text)}`;
-    a.click();
+    if (doc) {
+      const a = document.createElement('a');
+      a.textContent = 'download';
+      a.download = `${doc.title}.md`;
+      a.href = `data:text/markdown;charset=UTF-8,${encodeURIComponent(doc.text)}`;
+      a.click();
+    }
   };
 
   scrollTohash = () => {
@@ -130,6 +150,7 @@ class DocumentScene extends React.Component {
     const { sidebar } = this.props.ui;
 
     const doc = this.store.document;
+    if (!doc) return;
     const allowDelete =
       doc &&
       doc.collection.type === 'atlas' &&

frontend/scenes/DocumentScene/DocumentSceneStore.js

@@ -1,5 +1,7 @@
+// @flow
 import _ from 'lodash';
 import { browserHistory } from 'react-router';
+import invariant from 'invariant';
 import {
   observable,
   action,
@@ -9,26 +11,36 @@ import {
   autorunAsync,
 } from 'mobx';
 import { client } from 'utils/ApiClient';
+import type { Document as DocumentType, Collection } from 'types';
 
 const DOCUMENT_PREFERENCES = 'DOCUMENT_PREFERENCES';
 
-class DocumentSceneStore {
-  @observable document;
-  @observable collapsedNodes = [];
+type Document = {
+  collection: Collection,
+} & DocumentType;
 
-  @observable isFetching = true;
-  @observable updatingContent = false;
-  @observable updatingStructure = false;
-  @observable isDeleting;
+class DocumentSceneStore {
+  @observable document: ?Document;
+  @observable collapsedNodes: string[] = [];
+
+  @observable isFetching: boolean = true;
+  @observable updatingContent: boolean = false;
+  @observable updatingStructure: boolean = false;
+  @observable isDeleting: boolean = false;
 
   /* Computed */
 
-  @computed get isCollection() {
-    return this.document && this.document.collection.type === 'atlas';
+  @computed get isCollection(): boolean {
+    return !!this.document && this.document.collection.type === 'atlas';
   }
 
-  @computed get collectionTree() {
-    if (!this.document || this.document.collection.type !== 'atlas') return;
+  @computed get collectionTree(): ?Object {
+    if (
+      !this.document ||
+      this.document.collection ||
+      this.document.collection.type !== 'atlas'
+    )
+      return;
     const tree = this.document.collection.navigationTree;
 
     const collapseNodes = node => {
@@ -45,7 +57,10 @@ class DocumentSceneStore {
 
   /* Actions */
 
-  @action fetchDocument = async (id, options = {}) => {
+  @action fetchDocument = async (
+    id: string,
+    options: { softLoad?: boolean, replaceUrl?: boolean } = {}
+  ) => {
     options = {
       softLoad: false,
       replaceUrl: true,
@@ -57,6 +72,7 @@ class DocumentSceneStore {
 
     try {
       const res = await client.get('/documents.info', { id });
+      invariant(res && res.data, 'data should be available');
       const { data } = res;
       runInAction('fetchDocument', () => {
         this.document = data;
@@ -70,10 +86,12 @@ class DocumentSceneStore {
   };
 
   @action deleteDocument = async () => {
+    if (!this.document) return;
     this.isFetching = true;
 
     try {
       await client.post('/documents.delete', { id: this.document.id });
+      // $FlowFixMe don't be stupid
       browserHistory.push(this.document.collection.url);
     } catch (e) {
       console.error('Something went wrong');
@@ -81,8 +99,9 @@ class DocumentSceneStore {
     this.isFetching = false;
   };
 
-  @action updateNavigationTree = async tree => {
+  @action updateNavigationTree = async (tree: Object) => {
     // Only update when tree changes
+    // $FlowFixMe don't be stupid
     if (_.isEqual(toJS(tree), toJS(this.document.collection.navigationTree))) {
       return true;
     }
@@ -91,11 +110,14 @@ class DocumentSceneStore {
 
     try {
       const res = await client.post('/collections.updateNavigationTree', {
+        // $FlowFixMe don't be stupid
         id: this.document.collection.id,
         tree,
       });
+      invariant(res && res.data, 'data should be available');
       runInAction('updateNavigationTree', () => {
         const { data } = res;
+        // $FlowFixMe don't be stupid
         this.document.collection = data;
       });
     } catch (e) {
@@ -104,7 +126,7 @@ class DocumentSceneStore {
     this.updatingStructure = false;
   };
 
-  @action onNodeCollapse = nodeId => {
+  @action onNodeCollapse = (nodeId: string) => {
     if (_.indexOf(this.collapsedNodes, nodeId) >= 0) {
       this.collapsedNodes = _.without(this.collapsedNodes, nodeId);
     } else {
@@ -120,7 +142,7 @@ class DocumentSceneStore {
     });
   };
 
-  constructor(settings, options) {
+  constructor(settings: { collapsedNodes: string[] }) {
     // Rehydrate settings
     this.collapsedNodes = settings.collapsedNodes || [];
 

frontend/scenes/DocumentScene/components/Sidebar/Sidebar.js

@@ -1,4 +1,5 @@
-import React, { PropTypes } from 'react';
+// @flow
+import React from 'react';
 import { observer } from 'mobx-react';
 
 import { Flex } from 'reflexbox';
@@ -11,22 +12,25 @@ const cx = classNames.bind(styles);
 
 import SidebarStore from './SidebarStore';
 
-@observer class Sidebar extends React.Component {
-  static propTypes = {
-    open: PropTypes.bool,
-    onToggle: PropTypes.func.isRequired,
-    navigationTree: PropTypes.object.isRequired,
-    onNavigationUpdate: PropTypes.func.isRequired,
-    onNodeCollapse: PropTypes.func.isRequired,
-  };
+type Props = {
+  open?: boolean,
+  onToggle: Function,
+  navigationTree: Object,
+  onNavigationUpdate: Function,
+  onNodeCollapse: Function,
+};
 
-  constructor(props) {
+@observer class Sidebar extends React.Component {
+  props: Props;
+  store: SidebarStore;
+
+  constructor(props: Props) {
     super(props);
 
     this.store = new SidebarStore();
   }
 
-  toggleEdit = e => {
+  toggleEdit = (e: MouseEvent) => {
     e.preventDefault();
     this.store.toggleEdit();
   };

frontend/scenes/DocumentScene/components/Sidebar/SidebarStore.js

@@ -1,3 +1,4 @@
+// @flow
 import { observable, action } from 'mobx';
 
 class SidebarStore {

frontend/scenes/DocumentScene/components/Sidebar/components/Separator/Separator.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 
 import styles from './Separator.scss';

frontend/scenes/DocumentScene/components/Sidebar/components/Separator/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Separator from './Separator';
 export default Separator;

frontend/scenes/DocumentScene/components/Sidebar/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Sidebar from './Sidebar';
 export default Sidebar;

frontend/scenes/DocumentScene/index.js

@@ -1,2 +1,3 @@
+// @flow
 import DocumentScene from './DocumentScene';
 export default DocumentScene;

frontend/scenes/Error404/Error404.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { Link } from 'react-router';
 

frontend/scenes/Error404/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Error404 from './Error404';
 export default Error404;

frontend/scenes/ErrorAuth/ErrorAuth.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { Link } from 'react-router';
 

frontend/scenes/ErrorAuth/index.js

@@ -1,2 +1,3 @@
+// @flow
 import ErrorAuth from './ErrorAuth';
 export default ErrorAuth;

frontend/scenes/Flatpage/Flatpage.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 import { observer } from 'mobx-react';
 
@@ -16,7 +17,11 @@ import { convertToMarkdown } from 'utils/markdown';
     const { title, content } = this.props.route;
 
     return (
-      <Layout title={<Title>{title}</Title>} titleText={title} search={false}>
+      <Layout
+        title={<Title content={title} />}
+        titleText={title}
+        search={false}
+      >
         <CenteredContent>
           <DocumentHtml html={convertToMarkdown(content)} />
         </CenteredContent>

frontend/scenes/Flatpage/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Flatpage from './Flatpage';
 export default Flatpage;

frontend/scenes/Home/Home.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer, inject } from 'mobx-react';
 import { browserHistory } from 'react-router';
@@ -24,7 +25,7 @@ export default class Home extends React.Component {
     }
   };
 
-  get notifications() {
+  get notifications(): React.Element<any>[] {
     const notifications = [];
     const { state } = this.props.location;
 
@@ -54,7 +55,7 @@ export default class Home extends React.Component {
                 </p>
               </div>}
             <div className={styles.action}>
-              <SlackAuthLink redirectUri={`${URL}/auth/slack`}>
+              <SlackAuthLink redirectUri={`${BASE_URL}/auth/slack`}>
                 <img
                   alt="Sign in with Slack"
                   height="40"

frontend/scenes/Home/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Home from './Home';
 export default Home;

frontend/scenes/Search/Search.js

@@ -1,4 +1,5 @@
-import React, { PropTypes } from 'react';
+// @flow
+import React from 'react';
 import { observer } from 'mobx-react';
 import _ from 'lodash';
 import { Flex } from 'reflexbox';
@@ -11,13 +12,16 @@ import Layout, { Title } from 'components/Layout';
 import CenteredContent from 'components/CenteredContent';
 import DocumentPreview from 'components/DocumentPreview';
 
-@observer class Search extends React.Component {
-  static propTypes = {
-    route: PropTypes.object.isRequired,
-    routeParams: PropTypes.object.isRequired,
-  };
+type Props = {
+  route: Object,
+  routeParams: Object,
+};
 
-  constructor(props) {
+@observer class Search extends React.Component {
+  props: Props;
+  store: SearchStore;
+
+  constructor(props: Props) {
     super(props);
     this.store = new SearchStore();
   }
@@ -31,7 +35,7 @@ import DocumentPreview from 'components/DocumentPreview';
     }
   };
 
-  get viewNotFound() {
+  get viewNotFound(): boolean {
     const { sceneType } = this.props.route;
     return sceneType === 'notFound';
   }
@@ -40,11 +44,7 @@ import DocumentPreview from 'components/DocumentPreview';
     const search = _.debounce(searchTerm => {
       this.store.search(searchTerm);
     }, 250);
-    const title = (
-      <Title>
-        Search
-      </Title>
-    );
+    const title = <Title content="Search" />;
 
     return (
       <Layout

frontend/scenes/Search/SearchStore.js

@@ -1,23 +1,26 @@
+// @flow
 import { observable, action, runInAction } from 'mobx';
+import invariant from 'invariant';
 import { client } from 'utils/ApiClient';
+import type { Pagination, Document } from 'types';
 
 class SearchStore {
-  @observable documents;
-  @observable pagination;
-  @observable selectedDocument;
-  @observable searchTerm;
+  @observable documents: ?(Document[]);
+  @observable pagination: Pagination;
+  @observable searchTerm: ?string = null;
 
   @observable isFetching = false;
 
   /* Actions */
 
-  @action search = async query => {
+  @action search = async (query: string) => {
     this.searchTerm = query;
     this.isFetching = true;
 
     if (query) {
       try {
         const res = await client.get('/documents.search', { query });
+        invariant(res && res.data && res.pagination, 'API response');
         const { data, pagination } = res;
         runInAction('search document', () => {
           this.documents = data;

frontend/scenes/Search/components/SearchField/SearchField.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 import { observer } from 'mobx-react';
 
@@ -8,8 +9,8 @@ import styles from './SearchField.scss';
     onChange: PropTypes.func,
   };
 
-  onChange = event => {
-    this.props.onChange(event.currentTarget.value);
+  onChange = (event: SyntheticEvent) => {
+    event.currentTarget.value && this.props.onChange(event.currentTarget.value);
   };
 
   render() {

frontend/scenes/Search/components/SearchField/index.js

@@ -1,2 +1,3 @@
+// @flow
 import SearchField from './SearchField';
 export default SearchField;

frontend/scenes/Search/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Search from './Search';
 export default Search;

frontend/scenes/Settings/Settings.js

@@ -13,7 +13,7 @@ import CenteredContent from 'components/CenteredContent';
 import SlackAuthLink from 'components/SlackAuthLink';
 
 @observer class Settings extends React.Component {
-  store = SettingsStore;
+  store: SettingsStore;
 
   constructor() {
     super();
@@ -21,13 +21,7 @@ import SlackAuthLink from 'components/SlackAuthLink';
   }
 
   render() {
-    const title = (
-      <Title>
-        Settings
-      </Title>
-    );
-
-    // $FlowIssue global variable
+    const title = <Title content="Settings" />;
     const showSlackSettings = DEPLOYMENT === 'hosted';
 
     return (
@@ -48,8 +42,7 @@ import SlackAuthLink from 'components/SlackAuthLink';
 
               <SlackAuthLink
                 scopes={['commands']}
-                redirectUri={// $FlowIssue URL is a global variable
-                `${URL}/auth/slack/commands`}
+                redirectUri={`${BASE_URL}/auth/slack/commands`}
               >
                 <img
                   alt="Add to Slack"
@@ -71,15 +64,16 @@ import SlackAuthLink from 'components/SlackAuthLink';
             {this.store.apiKeys &&
               <table className={styles.apiKeyTable}>
                 <tbody>
-                  {this.store.apiKeys.map(key => (
-                    <ApiKeyRow
-                      id={key.id}
-                      key={key.id}
-                      name={key.name}
-                      secret={key.secret}
-                      onDelete={this.store.deleteApiKey}
-                    />
-                  ))}
+                  {this.store.apiKeys &&
+                    this.store.apiKeys.map(key => (
+                      <ApiKeyRow
+                        id={key.id}
+                        key={key.id}
+                        name={key.name}
+                        secret={key.secret}
+                        onDelete={this.store.deleteApiKey}
+                      />
+                    ))}
                 </tbody>
               </table>}
 
@@ -106,10 +100,10 @@ class InlineForm extends React.Component {
     placeholder: string,
     buttonLabel: string,
     name: string,
-    value: string,
+    value: ?string,
     onChange: Function,
     onSubmit: Function,
-    disabled?: boolean,
+    disabled?: ?boolean,
   };
   validationTimeout: number;
 

frontend/scenes/Settings/SettingsStore.js

@@ -1,18 +1,23 @@
+// @flow
 import { observable, action, runInAction } from 'mobx';
+import invariant from 'invariant';
 import { client } from 'utils/ApiClient';
+import type { ApiKey } from 'types';
 
 class SearchStore {
-  @observable apiKeys = [];
-  @observable keyName;
+  @observable apiKeys: ApiKey[] = [];
+  @observable keyName: ?string;
 
-  @observable isFetching;
+  @observable isFetching: boolean = false;
 
   @action fetchApiKeys = async () => {
     this.isFetching = true;
 
     try {
       const res = await client.post('/apiKeys.list');
+      invariant(res && res.data, 'Data shoule be available');
       const { data } = res;
+
       runInAction('fetchApiKeys', () => {
         this.apiKeys = data;
       });
@@ -27,8 +32,9 @@ class SearchStore {
 
     try {
       const res = await client.post('/apiKeys.create', {
-        name: `${this.keyName}` || 'Untitled key',
+        name: this.keyName ? this.keyName : 'Untitled key',
       });
+      invariant(res && res.data, 'Data shoule be available');
       const { data } = res;
       runInAction('createApiKey', () => {
         this.apiKeys.push(data);
@@ -40,7 +46,7 @@ class SearchStore {
     this.isFetching = false;
   };
 
-  @action deleteApiKey = async id => {
+  @action deleteApiKey = async (id: string) => {
     this.isFetching = true;
 
     try {
@@ -56,7 +62,7 @@ class SearchStore {
     this.isFetching = false;
   };
 
-  @action setKeyName = value => {
+  @action setKeyName = (value: SyntheticInputEvent) => {
     this.keyName = value.target.value;
   };
 

frontend/scenes/Settings/components/ApiKeyRow/ApiKeyRow.js

@@ -1,3 +1,4 @@
+// @flow
 import React, { PropTypes } from 'react';
 
 import styles from './ApiKeyRow.scss';

frontend/scenes/Settings/components/ApiKeyRow/index.js

@@ -1,2 +1,3 @@
+// @flow
 import ApiKeyRow from './ApiKeyRow';
 export default ApiKeyRow;

frontend/scenes/Settings/index.js

@@ -1,2 +1,3 @@
+// @flow
 import Settings from './Settings';
 export default Settings;

frontend/scenes/SlackAuth/SlackAuth.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import { observer, inject } from 'mobx-react';
 import { browserHistory } from 'react-router';
@@ -12,6 +13,7 @@ class SlackAuth extends React.Component {
     route: React.PropTypes.object.isRequired,
   };
 
+  // $FlowIssue wtf
   componentDidMount = async () => {
     const { error, code, state } = this.props.location.query;
 
@@ -22,6 +24,7 @@ class SlackAuth extends React.Component {
       } else {
         browserHistory.push('/auth/error');
       }
+      // $FlowIssue wtf
       return;
     }
 

frontend/scenes/SlackAuth/index.js

@@ -1,2 +1,3 @@
+// @flow
 import SlackAuth from './SlackAuth';
 export default SlackAuth;

frontend/static/flatpages/index.js

@@ -1,5 +1,6 @@
-import api from './api.markdown';
-import keyboard from './keyboard.markdown';
+// @flow
+import api from './api.md';
+import keyboard from './keyboard.md';
 
 export default {
   api,

frontend/stores/UiStore.js

@@ -1,13 +1,14 @@
+// @flow
 import { observable, action, computed } from 'mobx';
 
 const UI_STORE = 'UI_STORE';
 
 class UiStore {
-  @observable sidebar;
+  @observable sidebar: boolean = false;
 
   /* Computed */
 
-  @computed get asJson() {
+  @computed get asJson(): string {
     return JSON.stringify({
       sidebar: this.sidebar,
     });
@@ -15,7 +16,7 @@ class UiStore {
 
   /* Actions */
 
-  @action toggleSidebar = () => {
+  @action toggleSidebar = (): void => {
     this.sidebar = !this.sidebar;
   };
 

frontend/stores/UserStore.js

@@ -1,25 +1,28 @@
+// @flow
 import { observable, action, computed } from 'mobx';
+import invariant from 'invariant';
 import { browserHistory } from 'react-router';
 import { client } from 'utils/ApiClient';
+import type { User, Team } from 'types';
 
 const USER_STORE = 'USER_STORE';
 
 class UserStore {
-  @observable user;
-  @observable team;
+  @observable user: ?User;
+  @observable team: ?Team;
 
-  @observable token;
-  @observable oauthState;
+  @observable token: ?string;
+  @observable oauthState: string;
 
-  @observable isLoading;
+  @observable isLoading: boolean = false;
 
   /* Computed */
 
-  @computed get authenticated() {
+  @computed get authenticated(): boolean {
     return !!this.token;
   }
 
-  @computed get asJson() {
+  @computed get asJson(): string {
     return JSON.stringify({
       user: this.user,
       team: this.team,
@@ -42,7 +45,11 @@ class UserStore {
     return this.oauthState;
   };
 
-  @action authWithSlack = async (code, state, redirectTo) => {
+  @action authWithSlack = async (
+    code: string,
+    state: string,
+    redirectTo: ?string
+  ) => {
     if (state !== this.oauthState) {
       browserHistory.push('/auth-error');
       return;
@@ -56,6 +63,10 @@ class UserStore {
       return;
     }
 
+    invariant(
+      res && res.data && res.data.user && res.data.team && res.data.accessToken,
+      'All values should be available'
+    );
     this.user = res.data.user;
     this.team = res.data.team;
     this.token = res.data.accessToken;

frontend/stores/index.js

@@ -1,3 +1,4 @@
+// @flow
 import { autorunAsync } from 'mobx';
 import UserStore, { USER_STORE } from './UserStore';
 import UiStore, { UI_STORE } from './UiStore';

frontend/types/index.js

@@ -6,12 +6,18 @@ export type User = {
   username: string,
 };
 
+export type Team = {
+  id: string,
+  name: string,
+};
+
 export type Collection = {
   createdAt: string,
   description: ?string,
   id: string,
   name: string,
   type: 'atlas' | 'journal',
+  navigationTree: Object, // TODO
   updatedAt: string,
   url: string,
 };
@@ -37,3 +43,9 @@ export type Pagination = {
   nextPath: string,
   offset: number,
 };
+
+export type ApiKey = {
+  id: string,
+  name: ?string,
+  secret: string,
+};