Fix Trying to unregister a portal assertion when immediately unrendering portal

ember-stargate/src/services/-portal.ts

@@ -56,6 +56,7 @@ export default class PortalService extends Service {
 
   unregisterTarget(name: string): void {
     this.#targets.delete(name);
+    this.#portalCount.delete(name);
   }
 
   registerPortal(name: string): void {
@@ -70,11 +71,11 @@ export default class PortalService extends Service {
   }
 
   unregisterPortal(name: string): void {
-    let count = this.#portalCount.get(name) ?? 0;
-    assert(
-      `Trying to unregister a portal "${name}" that hasn't been registered before`,
-      count > 0
-    );
+    let count = this.#portalCount.get(name);
+    if (count === undefined) {
+      return;
+    }
+
     count--;
     this.#portalCount.set(name, count);
     const target = this.#targets.get(name);

test-app/ember-cli-build.js

@@ -4,7 +4,9 @@ const EmberApp = require('ember-cli/lib/broccoli/ember-app');
 
 module.exports = function (defaults) {
   let app = new EmberApp(defaults, {
-    // Add options here
+    autoImport: {
+      watchDependencies: ['ember-stargate'],
+    },
   });
 
   // Use `app.import` to add additional libraries to the generated

test-app/tests/integration/components/portal-test.ts

@@ -1,6 +1,6 @@
 import { module, test } from 'qunit';
 import { setupRenderingTest } from 'ember-qunit';
-import { render, settled } from '@ember/test-helpers';
+import { render, rerender, settled } from '@ember/test-helpers';
 import { hbs } from 'ember-cli-htmlbars';
 import sinon from 'sinon';
 
@@ -316,4 +316,25 @@ module('Integration | Component | portal', function (hooks) {
     assert.ok(action.calledWithExactly(2));
     assert.strictEqual(action.callCount, 2);
   });
+
+  test('portal can be immediately unrendered', async function (assert) {
+    assert.expect(0);
+
+    this.set('show', true);
+    const promise = render(hbs`
+      {{#if this.show}}
+      xxx
+      <PortalTarget @name="main" />
+      <Portal @target="main">
+        foo
+      </Portal>
+      {{/if}}
+    `);
+
+    await rerender();
+
+    this.set('show', false);
+
+    await promise;
+  });
 });