Turn on all of Microsoft's recommend lint rules

Biggest changes forced by this: alt tags for all images, resulting in
new strings added to messages.json, and a new i18n paramter/prop added
in a plot of places.

Another change of note is that there are two new tslint.json files under
ts/test and ts/styleguide to relax our rules a bit there. This required
a change to our package.json script, as manually specifying the config
file there made it ignore our tslint.json files in subdirectories

ts/styleguide/ConversationContext.tsx

@@ -1,5 +1,5 @@
 import React from 'react';
-import classnames from 'classnames';
+import classNames from 'classnames';
 
 interface Props {
   /**
@@ -13,13 +13,13 @@ interface Props {
  * Provides the parent elements necessary to allow the main Signal Desktop stylesheet to
  * apply (with no changes) to messages in the Style Guide.
  */
-export class ConversationContext extends React.Component<Props, {}> {
+export class ConversationContext extends React.Component<Props> {
   public render() {
     const { theme, type } = this.props;
 
     return (
       <div className={theme || 'android'}>
-        <div className={classnames('conversation', type || 'private')}>
+        <div className={classNames('conversation', type || 'private')}>
           <div className="discussion-container" style={{ padding: '0.5em' }}>
             <ul className="message-list">{this.props.children}</ul>
           </div>

ts/styleguide/StyleGuideUtil.ts

@@ -1,11 +1,10 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
-import { padStart, sample } from 'lodash';
+import { default as _, padStart, sample } from 'lodash';
 import libphonenumber from 'google-libphonenumber';
 
-import _ from 'lodash';
 import moment from 'moment';
-import qs from 'qs';
+import QueryString from 'qs';
 
 export { _ };
 
@@ -57,6 +56,7 @@ function makeObjectUrl(data: ArrayBuffer, contentType: string): string {
   const blob = new Blob([data], {
     type: contentType,
   });
+
   return URL.createObjectURL(blob);
 }
 
@@ -90,7 +90,7 @@ export {
 const parent = window as any;
 
 const query = window.location.search.replace(/^\?/, '');
-const urlOptions = qs.parse(query);
+const urlOptions = QueryString.parse(query);
 const theme = urlOptions.theme || 'android';
 const locale = urlOptions.locale || 'en';
 
@@ -99,11 +99,11 @@ import localeMessages from '../../_locales/en/messages.json';
 
 // @ts-ignore
 import { setup } from '../../js/modules/i18n';
-import filesize from 'filesize';
+import fileSize from 'filesize';
 
 const i18n = setup(locale, localeMessages);
 
-parent.filesize = filesize;
+parent.filesize = fileSize;
 
 parent.i18n = i18n;
 parent.React = React;
@@ -137,6 +137,7 @@ const Attachments = {
 parent.Signal = Signal.setup({
   Attachments,
   userDataPath: '/',
+  // tslint:disable-next-line:no-backbone-get-set-outside-model
   getRegionCode: () => parent.storage.get('regionCode'),
 });
 parent.SignalService = SignalService;

ts/styleguide/tslint.json

@@ -0,0 +1,11 @@
+{
+  "defaultSeverity": "error",
+  "extends": ["../../tslint.json"],
+  "rules": {
+    // To allow the use of devDependencies here
+    "no-implicit-dependencies": false,
+
+    // All tests use arrow functions, and they can be long
+    "max-func-body-length": false
+  }
+}