Allow writable store as subject in getResource

Author: Polleps

src/stores/getResource.test.ts

@@ -1,9 +1,10 @@
 import { Store, urls } from '@tomic/lib';
 import { describe, it, expect, beforeEach } from 'vitest';
 import { getResource, initStore, store } from '~/index';
-import { get } from 'svelte/store';
+import { get, writable } from 'svelte/store';
 
 const resource1Subject = 'https://resource1';
+const resource2Subject = 'https://resource2';
 
 describe('getResource', () => {
   beforeEach(() => {
@@ -44,4 +45,16 @@ describe('getResource', () => {
 
     expect(resourceSecond.get(urls.properties.name)).toBe('Resource 1');
   });
+
+  it('should update when subject is writable and changes', async () => {
+    const writableSubject = writable(resource1Subject);
+
+    const resource = getResource(writableSubject, { newResource: true });
+
+    expect(get(resource).getSubject()).toBe(resource1Subject);
+
+    writableSubject.set(resource2Subject);
+
+    expect(get(resource).getSubject()).toBe(resource2Subject);
+  });
 });

src/stores/getResource.ts

@@ -1,27 +1,56 @@
-import { type FetchOpts, Resource } from '@tomic/lib';
+import { type FetchOpts, Resource, Store } from '@tomic/lib';
 
-import { type Readable, get, readable } from 'svelte/store';
+import { type Readable, get, readable, Subscriber } from 'svelte/store';
 import { store } from './store';
 
-export const getResource = (
+const subscribeToADStore = (
+  adStore: Store,
   subject: string,
+  set: Subscriber<Resource>,
+  opts?: FetchOpts,
+) => {
+  set(adStore.getResourceLoading(subject, opts));
+
+  const subscriber = (changedResource: Resource) => {
+    set(changedResource);
+  };
+
+  adStore.subscribe(subject, subscriber);
+
+  return () => {
+    adStore.unsubscribe(subject, subscriber);
+  };
+};
+
+export const getResource = (
+  subject: string | Readable<string>,
   opts?: FetchOpts,
 ): Readable<Resource> => {
   const adStore = get(store);
 
+  const subjectValue = typeof subject === 'string' ? subject : get(subject);
+
   // eslint-disable-next-line prefer-const
   let resource = readable<Resource>(
-    adStore.getResourceLoading(subject, opts),
+    adStore.getResourceLoading(subjectValue, opts),
     set => {
-      set(adStore.getResourceLoading(subject, opts));
+      if (typeof subject !== 'string') {
+        let atomicUnsubscriber: () => void;
 
-      const subscriber = (changedResource: Resource) => {
-        set(changedResource);
-      };
+        const subjectUnsubscriber = subject.subscribe(value => {
+          atomicUnsubscriber?.();
 
-      adStore.subscribe(subject, subscriber);
+          set(adStore.getResourceLoading(value, opts));
+          atomicUnsubscriber = subscribeToADStore(adStore, value, set, opts);
+        });
 
-      return () => adStore.unsubscribe(subject, subscriber);
+        return () => {
+          subjectUnsubscriber();
+          atomicUnsubscriber?.();
+        };
+      } else {
+        return subscribeToADStore(adStore, subject, set, opts);
+      }
     },
   );