feat: Add useCollection hook

Author: oliverroick

src/hooks/useCollection.test.ts

@@ -0,0 +1,30 @@
+import fetch from 'jest-fetch-mock';
+import { renderHook } from '@testing-library/react-hooks';
+import useCollection from './useCollection';
+import wrapper from './wrapper';
+
+describe('useCollection' ,() => {
+  beforeEach(() => {
+    fetch.resetMocks();
+  });
+
+  it('queries collection', async () => {
+    fetch
+      .mockResponseOnce(JSON.stringify({ links: [] }), { url: 'https://fake-stac-api.net' })
+      .mockResponseOnce(JSON.stringify({ 
+        collections: [
+          {id: 'abc', title: 'Collection A'},
+          {id: 'def', title: 'Collection B'}
+        ]  
+      }));
+
+    const { result, waitForNextUpdate } = renderHook(
+      () => useCollection('abc'),
+      { wrapper }
+    );
+    await waitForNextUpdate();
+    await waitForNextUpdate();
+    expect(result.current.collection).toEqual({id: 'abc', title: 'Collection A'});
+    expect(result.current.state).toEqual('IDLE');
+  });
+});

src/hooks/useCollection.ts

@@ -0,0 +1,26 @@
+import { useMemo } from 'react';
+
+import type { LoadingState } from '../types';
+import type { Collection } from '../types/stac';
+import useCollections from './useCollections';
+
+type StacCollectionHook = {
+  collection?: Collection,
+  state: LoadingState
+};
+
+function useCollection(collectionId: string): StacCollectionHook {
+  const { collections, state } = useCollections();
+
+  const collection = useMemo(
+    () => collections?.collections.find(({ id }) => id === collectionId),
+    [collectionId, collections]
+  );
+
+  return {
+    collection,
+    state
+  };
+}
+
+export default useCollection;