feat: 🎸 add group custom methods for add/remove members

addons/api/addon/models/group.js

@@ -1,3 +1,89 @@
 import GeneratedGroupModel from '../generated/models/group';
+import { attr } from '@ember-data/model';
+import { computed } from '@ember/object';
 
-export default class GroupModel extends GeneratedGroupModel {}
+export default class GroupModel extends GeneratedGroupModel {
+
+  // =attributes
+
+  /**
+   * Members is read-only under normal circumstances.  But members can
+   * be persisted via calls to `addMembers()` or `removeMembers()`.
+   */
+  @attr( {readOnly: true}) member_ids;
+
+  /**
+   * An array of resolved user instances.
+   * Unresolvable instances are excluded from the array.
+   * @type {[UserModel]}
+   */
+  @computed('member_ids.[]')
+  get members() {
+    return this.member_ids
+      .map(id => this.store.peekRecord('user', id))
+      .filter(Boolean);
+  }
+
+  // =methods
+
+  /**
+   * Adds members via the `add-members` method.
+   * See serializer and adapter for more information.
+   * @param {[string]} memberIDs
+   * @param {object} options
+   * @param {object} options.adapterOptions
+   * @return {Promise}
+   */
+  addMembers(memberIDs, options={ adapterOptions: {} }) {
+    const defaultAdapterOptions = {
+      method: 'add-members',
+      memberIDs
+    };
+    // There is no "deep merge" in ES.
+    // All of this nonsense is here to ensure we get
+    // a decent merge of `adapterOptions`.
+    return this.save({
+      ...options,
+      adapterOptions: {
+        ...defaultAdapterOptions,
+        ...options.adapterOptions
+      }
+    });
+  }
+
+  /**
+   * Delete members via the `remove-members` method.
+   * See serializer and adapter for more information.
+   * @param {[string]} memberIDs
+   * @param {object} options
+   * @param {object} options.adapterOptions
+   * @return {Promise}
+   */
+  removeMembers(memberIDs, options={ adapterOptions: {} }) {
+    const defaultAdapterOptions = {
+      method: 'remove-members',
+      memberIDs
+    };
+    // There is no "deep merge" in ES.
+    // All of this nonsense is here to ensure we get
+    // a decent merge of `adapterOptions`.
+    return this.save({
+      ...options,
+      adapterOptions: {
+        ...defaultAdapterOptions,
+        ...options.adapterOptions
+      }
+    });
+  }
+
+  /**
+   * Delete a single member via the `remove-members` method.
+   * @param {number} memberID
+   * @param {object} options
+   * @return {Promise}
+   */
+  removeMember(memberID, options) {
+    return this.removeMembers([memberID], options);
+  }
+
+}