feat(entities): added a function getEntityByPredicate (#465)

* feat: add function getEntityByPredicate * feat(entities): some fix * feat(queries): removed console.log from test file --------- Co-authored-by: Sergey Rogachev <[email protected]>
ngneat · Jul 7, 2023 · df17064 · df17064
1 parent c539add
commit df17064
Show file tree

Hide file tree

Showing 4 changed files with 79 additions and 0 deletions.
diff --git a/docs/docs/features/entities-management/entities.mdx b/docs/docs/features/entities-management/entities.mdx
@@ -229,6 +229,16 @@ import { getEntity } from '@ngneat/elf-entities';
 const todo = todosStore.query(getEntity(id));
 ```
 
+### `getEntityByPredicate`
+
+Get first entity from the store by predicate:
+
+```ts
+import { getEntityByPredicate } from '@ngneat/elf-entities';
+
+const todo = todosStore.query(getEntityByPredicate(({ title }) => title = 'Elf'));
+```
+
 ### `hasEntity`
 
 Returns whether an entity exists:

diff --git a/packages/entities/src/index.ts b/packages/entities/src/index.ts
@@ -45,6 +45,7 @@ export { unionEntitiesAsMap as unionEntitiesAsMap } from './lib/union-entities-a
 export * from './lib/active/active';
 export {
   getEntity,
+  getEntityByPredicate,
   hasEntity,
   getAllEntities,
   getAllEntitiesApply,

diff --git a/packages/entities/src/lib/queries.spec.ts b/packages/entities/src/lib/queries.spec.ts
@@ -11,6 +11,7 @@ import {
   getEntity,
   hasEntity,
   getEntitiesIds,
+  getEntityByPredicate,
 } from './queries';
 import { addEntities } from './add.mutation';
 import { UIEntitiesRef } from './entity.state';
@@ -56,6 +57,25 @@ describe('queries', () => {
       expect(store.query(getEntity(1))).toEqual(todo);
     });
 
+    it('should return an entity by predicate', () => {
+      const store = createEntitiesStore();
+
+      store.update(
+        addEntities([
+          createTodo(1),
+          {
+            id: 4,
+            title: `todo 2`,
+            completed: false,
+          },
+          createTodo(3),
+        ])
+      );
+      expect(
+        store.query(getEntityByPredicate((el) => el.title === `todo 2`))?.id
+      ).toEqual(4);
+    });
+
     it('should work with ref', () => {
       const store = createUIEntityStore();
       expect(store.query(getEntity(1, { ref: UIEntitiesRef }))).toEqual(
@@ -66,6 +86,26 @@ describe('queries', () => {
       store.update(addEntities(todo, { ref: UIEntitiesRef }));
       expect(store.query(getEntity(1, { ref: UIEntitiesRef }))).toEqual(todo);
     });
+
+    it('should find by predicate with ref', () => {
+      const store = createUIEntityStore();
+      expect(
+        store.query(
+          getEntityByPredicate((el) => el.id === 1, { ref: UIEntitiesRef })
+        )
+      ).toEqual(undefined);
+
+      store.update(
+        addEntities([createUITodo(1), createUITodo(2), createUITodo(3)], {
+          ref: UIEntitiesRef,
+        })
+      );
+      expect(
+        store.query(
+          getEntityByPredicate((el) => el.id === 2, { ref: UIEntitiesRef })
+        )?.id
+      ).toEqual(2);
+    });
   });
 
   describe('hasEntity', () => {

diff --git a/packages/entities/src/lib/queries.ts b/packages/entities/src/lib/queries.ts
@@ -6,6 +6,7 @@ import {
   EntitiesState,
   getEntityType,
   getIdType,
+  ItemPredicate,
 } from './entity.state';
 import { Query } from '@ngneat/elf';
 
@@ -92,6 +93,33 @@ export function getEntity<
   };
 }
 
+/**
+ *
+ * Get first entity by predicate
+ *
+ * @example
+ *
+ * store.query(getEntityByPredicate(({ title }) => title === 'Elf'))
+ *
+ */
+export function getEntityByPredicate<
+  S extends EntitiesState<Ref>,
+  Ref extends EntitiesRef = DefaultEntitiesRef
+>(
+  predicate: ItemPredicate<getEntityType<S, Ref>>,
+  options: BaseEntityOptions<Ref> = {}
+): Query<S, getEntityType<S, Ref> | undefined> {
+    return function (state) {
+    const { ref: { entitiesKey, idsKey } = defaultEntitiesRef } = options;
+    const entities = state[entitiesKey];
+    const id = state[idsKey].find((id: getIdType<S, Ref>) => {
+      return predicate(entities[id]);
+    });
+
+    return entities[id];
+  };
+}
+
 /**
  *
  * Check whether the entity exist