feat: type guards isViewModel isViewModelClass; fix: useViewModel

Author: js2me

.changeset/clear-forks-take.md

@@ -0,0 +1,5 @@
+---
+"mobx-view-model": minor
+---
+
+added type guards `isViewModel` and `isViewModelClass`

.changeset/clever-times-eat.md

@@ -0,0 +1,5 @@
+---
+"mobx-view-model": patch
+---
+
+fix missing throwing exception in `useViewModel` hook

src/hooks/use-create-view-model.ts

@@ -13,6 +13,7 @@ import { ViewModelsContext } from '../contexts/view-models-context.js';
 import { useIsomorphicLayoutEffect } from '../lib/hooks/use-isomorphic-layout-effect.js';
 import { useValue } from '../lib/hooks/use-value.js';
 import { generateVmId } from '../utils/generate-vm-id.js';
+import { isViewModelClass } from '../utils/typeguards.js';
 import { ViewModelSimple } from '../view-model/view-model-simple.js';
 import { ViewModelCreateConfig } from '../view-model/view-model.store.types.js';
 import {
@@ -83,7 +84,7 @@ export function useCreateViewModel(
   payload?: any,
   config?: any,
 ) {
-  if ('payloadChanged' in VM.prototype) {
+  if (isViewModelClass(VM)) {
     // scenario for ViewModelBase
     return useCreateViewModelBase(VM, payload, config);
   }

src/hooks/use-view-model.ts

@@ -41,7 +41,7 @@ export const useViewModel = <T extends AnyViewModel | AnyViewModelSimple>(
 
     if (!activeViewModel) {
       if (process.env.NODE_ENV !== 'production') {
-        console.error(
+        throw new Error(
           'Active ViewModel not found.\n' +
             'This happened because "vmLookup" for hook "useViewModel" is not provided and hook trying to lookup active view model using ActiveViewModelContext which works only with using "withViewModel" HOC.\n' +
             'Please provide "vmLookup" (first argument for "useViewModel" hook) or use "withViewModel" HOC.\n' +

src/index.ts

@@ -5,5 +5,6 @@ export * from './hoc/index.js';
 export * from './hooks/index.js';
 export * from './config/index.js';
 export * from './components/index.js';
+export * from './utils/index.js';
 
 export const ViewModelsProvider = ViewModelsContext.Provider;

src/utils/generate-vm-id.ts

@@ -1,12 +1,14 @@
 import { createCounter } from 'yummies/complex';
 
+import { GenerateViewModelIdFn } from '../config/index.js';
+
 import { AnyObject } from './types.js';
 
 declare const process: { env: { NODE_ENV?: string } };
 
 const staticCounter = createCounter((counter) => counter.toString(16));
 
-export const generateVmId = (ctx: AnyObject) => {
+export const generateVmId: GenerateViewModelIdFn = (ctx: AnyObject) => {
   if (!ctx.generateId) {
     const staticId = staticCounter();
     const counter = createCounter((counter) =>

src/utils/index.ts

@@ -1 +1,2 @@
 export * from './generate-vm-id.js';
+export * from './typeguards.js';

src/utils/typeguards.ts

@@ -0,0 +1,12 @@
+/* eslint-disable @typescript-eslint/ban-types */
+import { ViewModel } from '../view-model/view-model.js';
+
+import { AnyObject, Class, EmptyObject } from './types.js';
+
+export const isViewModel = <TPayload extends AnyObject = EmptyObject>(
+  value: AnyObject,
+): value is ViewModel<TPayload> => 'payloadChanged' in value;
+
+export const isViewModelClass = <TPayload extends AnyObject = EmptyObject>(
+  value: Function,
+): value is Class<ViewModel<TPayload>> => 'payloadChanged' in value.constructor;