Fix linting errors

src/utils/BlobCache.ts

@@ -2,7 +2,7 @@
 const blobCache: { [hash: string]: string } = {};
 
 export class BlobCache {
-  static get(hash: string) {
+  static get(hash: string): string {
     return blobCache[hash];
   }
 
@@ -11,7 +11,7 @@ export class BlobCache {
     blobCache[hash] = value;
   }
 
-  static removeByValue(value: string) {
+  static removeByValue(value: string): void {
     const keys = Object.keys(blobCache).filter((key) => blobCache[key] === value);
     keys.forEach((key) => delete blobCache[key]);
   }

src/utils/ImportCache.ts

@@ -3,7 +3,7 @@ import { ScriptUrl } from "../Script/ScriptUrl";
 const importCache: { [hash: string]: ScriptUrl[] } = {};
 
 export class ImportCache {
-  static get(hash: string) {
+  static get(hash: string): ScriptUrl[] {
     return importCache[hash];
   }
 

src/utils/helpers/computeHash.ts

@@ -6,7 +6,7 @@ import { sha256 } from "js-sha256";
  * @returns The SHA-256 hash in hex
  */
 export function computeHash(message: string): string {
-  var hash = sha256.create();
+  const hash = sha256.create();
   hash.update(message);
   return hash.hex();
 }