fix(core): Fix type errors and typos in Smartstate class

ts/smartstate.classes.smartstate.ts

@@ -6,26 +6,26 @@ export type TInitMode = 'soft' | 'mandatory' | 'force' | 'persistent';
 /**
  * Smartstate takes care of providing state
  */
-export class Smartstate<StatePartNameType> {
-  public statePartMap: { [key: string]: StatePart<StatePartNameType, any> } = {};
+export class Smartstate<StatePartNameType extends string> {
+  public statePartMap: { [key in StatePartNameType]?: StatePart<StatePartNameType, any> } = {};
 
   constructor() {}
 
   /**
    * Allows getting and initializing a new statepart
    * initMode === 'soft' it will allow existing stateparts
-   * initMode === 'mandatory' will fail if there is an exiting statepart
+   * initMode === 'mandatory' will fail if there is an existing statepart
    * initMode === 'force' will overwrite any existing statepart
    * @param statePartNameArg
    * @param initialArg
    * @param initMode
    */
   public async getStatePart<PayloadType>(
-    statePartNameArg: string & StatePartNameType,
+    statePartNameArg: StatePartNameType,
     initialArg?: PayloadType,
     initMode?: TInitMode
   ): Promise<StatePart<StatePartNameType, PayloadType>> {
-    if (this.statePartMap[statePartNameArg as any]) {
+    if (this.statePartMap[statePartNameArg]) {
       if (initialArg && (!initMode || initMode !== 'soft')) {
         throw new Error(
           `${statePartNameArg} already exists, yet you try to set an initial state again`
@@ -43,7 +43,7 @@ export class Smartstate<StatePartNameType> {
   }
 
   /**
-   * creates a statepart
+   * Creates a statepart
    * @param statePartName
    * @param initialPayloadArg
    */
@@ -54,10 +54,12 @@ export class Smartstate<StatePartNameType> {
   ): Promise<StatePart<StatePartNameType, PayloadType>> {
     const newState = new StatePart<StatePartNameType, PayloadType>(
       statePartName,
-      initMode === 'persistent' ? {
-        dbName: 'smartstate',
-        storeName: statePartName as any,
-      } : null
+      initMode === 'persistent'
+        ? {
+            dbName: 'smartstate',
+            storeName: statePartName,
+          }
+        : null
     );
     await newState.init();
     const currentState = newState.getState();
@@ -65,7 +67,7 @@ export class Smartstate<StatePartNameType> {
       ...initialPayloadArg,
       ...currentState,
     });
-    this.statePartMap[statePartName as any] = newState;
+    this.statePartMap[statePartName] = newState;
     return newState;
   }
-}
+}