[ui] Bugfix: reinstate the "this variable will be accessible by $job/$group/$task" notification (#14741)

* When we isolated the variable form path to within its component for isolation reasons, we lost the model-level checks for related entites at type-time

* Be a little more functionally pure

* Use Ember.set to appease mirage

ui/app/components/variable-form.hbs

@@ -40,6 +40,7 @@
         @value={{this.path}}
         placeholder="nomad/jobs/my-job/my-group/my-task"
         class="input path-input {{if this.duplicatePathWarning "error"}}"
+        {{on "input" this.setModelPath}}
         disabled={{not @model.isNew}}
         {{autofocus}}
         data-test-path-input

ui/app/components/variable-form.js

@@ -168,6 +168,14 @@ export default class VariableFormComponent extends Component {
     this.save(e, true);
   }
 
+  /**
+   *
+   * @param {KeyboardEvent} e
+   */
+  @action setModelPath(e) {
+    set(this.args.model, 'path', e.target.value);
+  }
+
   @action
   async save(e, overwrite = false) {
     if (e.type === 'submit') {

ui/tests/acceptance/variables-test.js

@@ -145,7 +145,7 @@ module('Acceptance | variables', function (hooks) {
   });
 
   test('variables prefixed with nomad/jobs/ correctly link to entities', async function (assert) {
-    assert.expect(23);
+    assert.expect(29);
     allScenarios.variableTestCluster(server);
     const variablesToken = server.db.tokens.find(VARIABLE_TOKEN_ID);
 
@@ -313,6 +313,45 @@ module('Acceptance | variables', function (hooks) {
     assert
       .dom('[data-test-task-stat="variables"]')
       .doesNotExist('Link from Variable-less Job to Variable does not exist');
+
+    // Related Entities during the Variable creation process
+    await Variables.visitNew();
+    assert
+      .dom('.related-entities.notification')
+      .doesNotExist('Related Entities notification is not present by default');
+    await typeIn('[data-test-path-input]', 'foo/bar');
+    assert
+      .dom('.related-entities.notification')
+      .doesNotExist(
+        'Related Entities notification is not present when path is generic'
+      );
+    document.querySelector('[data-test-path-input]').value = ''; // clear path input
+    await typeIn('[data-test-path-input]', 'nomad/jobs/abc');
+    assert
+      .dom('.related-entities.notification')
+      .exists(
+        'Related Entities notification is present when path is job-oriented'
+      );
+    assert
+      .dom('.related-entities.notification')
+      .containsText(
+        'This variable will be accessible by job',
+        'Related Entities notification is job-oriented'
+      );
+    await typeIn('[data-test-path-input]', '/def');
+    assert
+      .dom('.related-entities.notification')
+      .containsText(
+        'This variable will be accessible by group',
+        'Related Entities notification is group-oriented'
+      );
+    await typeIn('[data-test-path-input]', '/ghi');
+    assert
+      .dom('.related-entities.notification')
+      .containsText(
+        'This variable will be accessible by task',
+        'Related Entities notification is task-oriented'
+      );
   });
 
   test('it does not allow you to save if you lack Items', async function (assert) {