Add more files to strict compile. Update CONTRIBUTING.md (#63)

* Add more files to strict compile. Update CONTRIBUTING.md to recommend FluentUI use

* Remove eslint-disable and use non-null assertion

src/Shared/StorageUtility.ts

@@ -5,7 +5,7 @@ export class LocalStorageUtility {
     return !!localStorage.getItem(StorageKey[key]);
   }
 
-  public static getEntryString(key: StorageKey): string {
+  public static getEntryString(key: StorageKey): string | null {
     return localStorage.getItem(StorageKey[key]);
   }
 
@@ -39,7 +39,7 @@ export class SessionStorageUtility {
     return !!sessionStorage.getItem(StorageKey[key]);
   }
 
-  public static getEntryString(key: StorageKey): string {
+  public static getEntryString(key: StorageKey): string | null {
     return sessionStorage.getItem(StorageKey[key]);
   }
 

src/Shared/StringUtility.ts

@@ -1,9 +1,9 @@
 export class StringUtility {
-  public static toNumber(num: string): number {
+  public static toNumber(num: string | null): number {
     return Number(num);
   }
 
-  public static toBoolean(valueStr: string): boolean {
+  public static toBoolean(valueStr: string | null): boolean {
     return valueStr === "true";
   }
 }

src/Shared/Telemetry/TelemetryProcessor.ts

@@ -82,33 +82,35 @@ export default class TelemetryProcessor {
   }
 
   public static traceOpen(action: Action, data?: any, timestamp?: number): number {
+    const validTimestamp = timestamp || Date.now();
     MessageHandler.sendMessage({
       type: MessageTypes.TelemetryInfo,
       data: {
         action: Action[action],
         actionModifier: ActionModifiers.Open,
-        timestamp: timestamp || Date.now(),
+        timestamp: validTimestamp,
         data: JSON.stringify(data)
       }
     });
 
     appInsights.startTrackEvent(Action[action]);
-    return timestamp;
+    return validTimestamp;
   }
 
   public static traceMark(action: Action, data?: any, timestamp?: number): number {
+    const validTimestamp = timestamp || Date.now();
     MessageHandler.sendMessage({
       type: MessageTypes.TelemetryInfo,
       data: {
         action: Action[action],
         actionModifier: ActionModifiers.Mark,
-        timestamp: timestamp || Date.now(),
+        timestamp: validTimestamp,
         data: JSON.stringify(data)
       }
     });
 
     appInsights.startTrackEvent(Action[action]);
-    return timestamp;
+    return validTimestamp;
   }
 
   private static getData(data?: any): any {