fix(selectvalue): should be typed

Author: NetanelBasal

README.md

@@ -279,6 +279,34 @@ export class HomeComponent {
 }
 ```
 
+## NgFormsManager Generic Type
+
+`NgFormsManager` can take a generic type where you can define the forms shape. For example:
+
+```ts
+export interface AppForms = {
+  onboarding: {
+    name: string;
+    age: number;
+    city: string;
+  }
+}
+```
+
+This will make sure that the queries are typed, and you don't make any mistakes in the form name.
+
+```ts
+export class OnboardingComponent {
+  constructor(private formsManager: NgFormsManager<AppForms>, private builder: FormBuilder) {}
+
+  ngOnInit() {
+    this.formsManager.selectValue('onboarding').subscribe(value => {
+      // value now typed as AppForms['onboarding']
+    });
+  }
+}
+```
+
 ## NgFormsManager Config
 
 You can override the default config by passing the `NG_FORMS_MANAGER_CONFIG` provider:

projects/ngneat/forms-manager/src/lib/forms-manager.ts

@@ -30,12 +30,12 @@ export class NgFormsManager<FormsState = any> {
     return this.selectControl(formName, path).pipe(map(control => control.disabled));
   }
 
-  selectValue<T = any>(formName: keyof FormsState, path?: string): Observable<T> {
+  selectValue<T extends keyof FormsState>(formName: T, path?: string): Observable<FormsState[T]> {
     return this.selectControl(formName, path).pipe(map(control => control.value));
   }
 
-  selectErrors(formName: keyof FormsState, path?: string): Observable<any> {
-    return this.selectControl(formName, path).pipe(map(control => control.errors));
+  selectErrors<T = any>(formName: keyof FormsState, path?: string): Observable<T> {
+    return this.selectControl(formName, path).pipe(map(control => control.errors as T));
   }
 
   /**
@@ -55,6 +55,7 @@ export class NgFormsManager<FormsState = any> {
       );
   }
 
+  // TODO: _AbstractControl should take a generic that should type the `value` property
   getControl(formName: keyof FormsState, path?: string): _AbstractControl {
     if (!path) {
       return this.getForm(formName);
@@ -68,6 +69,7 @@ export class NgFormsManager<FormsState = any> {
     return null;
   }
 
+  // TODO: _AbstractControl should take a generic that should type the `value` property
   selectForm(
     formName: keyof FormsState,
     options: { filterNil: true } = { filterNil: true }