Functional First TypeScript Doodle

gistfile1.ts

// really more a struct/interface
class DataStore {
   store: (object: any) => string;
   get: (key: string) => any;
}

class JsonDataStore: DataStore {
   getRawJson: () => string;
   
   static create(fileWriter: FileWriter): JsonDataStore {
      return {
         get: function(key: string): any {
            return JSON.parse(fileWriter.readAll())[key];
         },
         store: function(object: any): string {
            var allData = JSON.parse(fileWriter.readAll())[key];
            allData[key] = object;
            fileWriter.writeAll(JSON.stringify(allData);
         },
         getRawJson: function() {
            return fileWriter.readAll();
         }
      }
   }
}

var store = JsonDataStore.create(someRandomFileWriter);
store.store(myRandomObject);