feat: 🎸 add hostSets convenience field to resolve models

addons/api/addon/models/target.js

@@ -1,12 +1,32 @@
 import GeneratedTargetModel from '../generated/models/target';
 import { fragmentArray } from 'ember-data-model-fragments/attributes';
+import { computed } from '@ember/object';
 
 export default class TargetModel extends GeneratedTargetModel {
 
   // =attributes
 
+  /**
+   * @type {[FragmentHostSetModel]}
+   */
   @fragmentArray('fragment-host-set', {readOnly: true}) host_sets;
 
+  /**
+   * An array of resolved host set and host catalog instances.  Model instances
+   * must already be loaded into the store (this method will not load unloaded
+   * instances).  Unresolvable instances are excluded from the array.
+   * @type {[{model: HostSetModel, hostCatalog: HostCatalogModel}]}
+   */
+  @computed('host_sets.[]')
+  get hostSets() {
+    return this.host_sets
+      .map(({ host_set_id, host_catalog_id }) => ({
+        model: this.store.peekRecord('host-set', host_set_id),
+        hostCatalog: this.store.peekRecord('host-catalog', host_catalog_id)
+      }))
+      .filter(hostSetRef => hostSetRef.model !== null);
+  }
+
   // =methods
 
   /**
@@ -17,20 +37,17 @@ export default class TargetModel extends GeneratedTargetModel {
    * @return {Promise}
    */
   saveHostSets(options={ adapterOptions: {} }) {
-    const defaultOptions = {
-      adapterOptions: {
-        method: 'set-host-sets',
-        serializeHostSets: true
-      }
+    const defaultAdapterOptions = {
+      method: 'set-host-sets',
+      serializeHostSets: true
     };
     // 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({
-      ...defaultOptions,
       ...options,
       adapterOptions: {
-        ...defaultOptions.adapterOptions,
+        ...defaultAdapterOptions,
         ...options.adapterOptions
       }
     });

addons/api/tests/unit/models/target-test.js

@@ -6,10 +6,55 @@ module('Unit | Model | target', function (hooks) {
   setupTest(hooks);
   setupMirage(hooks);
 
-  test('it exists', function(assert) {
-    let store = this.owner.lookup('service:store');
-    let model = store.createRecord('target', {});
-    assert.ok(model);
+  test('it has a `hostSets` array of resolved model instances (if those instances are already in the store)', function(assert) {
+    assert.expect(6);
+    const store = this.owner.lookup('service:store');
+    store.push({
+      data: {
+        id: '123abc',
+        type: 'target',
+        attributes: {
+          host_sets: [
+            { host_set_id: '1', host_catalog_id: '2' },
+            { host_set_id: '3', host_catalog_id: '2' }
+          ]
+        }
+      }
+    });
+    const target = store.peekRecord('target', '123abc');
+    assert.equal(target.host_sets.length, 2, 'Target has two entires in host_sets');
+    assert.equal(target.hostSets.length, 0, 'Target has no resolved hostSets because they are not loaded yet');
+    store.push({
+      data: {
+        id: '1',
+        type: 'host-set',
+        attributes: {}
+      }
+    });
+    store.push({
+      data: {
+        id: '3',
+        type: 'host-set',
+        attributes: {}
+      }
+    });
+    // Since `hostSets` is computed on `host_sets`, not the store itself,
+    // it's necessary to do this assignment to kick-off the computed update.
+    // eslint-disable-next-line no-self-assign
+    target.host_sets = target.host_sets;
+    assert.equal(target.host_sets.length, 2, 'Target has two entires in host_sets');
+    assert.equal(target.hostSets.length, 2, 'Target has two resolved hostSets');
+    assert.notOk(target.hostSets[0].hostCatalog, 'Host catalog was not resolved because it is not loaded yet');
+    store.push({
+      data: {
+        id: '2',
+        type: 'host-catalog',
+        attributes: {}
+      }
+    });
+    // eslint-disable-next-line no-self-assign
+    target.host_sets = target.host_sets;
+    assert.ok(target.hostSets[0].hostCatalog, 'Host catalog is resolved');
   });
 
   test('it has a `saveHostSets` method that targets a specific POST API endpoint and serialization', async function (assert) {