Make BaseStore abstract (#1431)

* make BaseStore abstract so that implementers are forced to decide how to store data

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/common/base-store.ts

@@ -15,7 +15,10 @@ export interface BaseStoreParams<T = any> extends ConfOptions<T> {
   syncOptions?: IReactionOptions;
 }
 
-export class BaseStore<T = any> extends Singleton {
+/**
+ * Note: T should only contain base JSON serializable types.
+ */
+export abstract class BaseStore<T = any> extends Singleton {
   protected storeConfig: Config<T>;
   protected syncDisposers: Function[] = [];
 
@@ -146,16 +149,19 @@ export class BaseStore<T = any> extends Singleton {
     }
   }
 
-  @action
-  protected fromStore(data: T) {
-    if (!data) return;
-    this.data = data;
-  }
+  /**
+   * fromStore is called internally when a child class syncs with the file
+   * system.
+   * @param data the parsed information read from the stored JSON file
+   */
+  protected abstract fromStore(data: T): void;
 
-  // todo: use "serializr" ?
-  toJSON(): T {
-    return toJS(this.data, {
-      recurseEverything: true,
-    })
-  }
+  /**
+   * toJSON is called when syncing the store to the filesystem. It should
+   * produce a JSON serializable object representaion of the current state.
+   *
+   * It is recommended that a round trip is valid. Namely, calling
+   * `this.fromStore(this.toJSON())` shouldn't change the state.
+   */
+  abstract toJSON(): T;
 }