Extract owner-scoped WeakMap into service

packages/util/addon/index.js

@@ -1,4 +1,4 @@
-import { deprecate } from '@ember/debug';
+import { assert, deprecate } from '@ember/debug';
 import { getOwner } from '@ember/application';
 import { isCurriedComponentDefinition, lookupCurriedComponentDefinition } from './ember-private-api';
 import Helper from '@ember/component/helper';
@@ -39,22 +39,11 @@ function handleString(name, thingWithOwner) {
   return lookupCurriedComponentDefinition(name, owner);
 }
 
-const classNoncesForOwner = new WeakMap();
-let nonceCounter = 0;
-
 function ensureRegistered(klass, owner) {
-  let classNonces = classNoncesForOwner.get(owner);
-  if (!classNonces) {
-    classNonces = new WeakMap();
-    classNoncesForOwner.set(owner, classNonces);
-  }
-  let nonce = classNonces.get(klass);
-  if (nonce == null) {
-    nonce = `-ensure${nonceCounter++}`;
-    classNonces.set(klass, nonce);
-    owner.register(`component:${nonce}`, klass);
-  }
-  return nonce;
+  let service = owner.lookup('service:-ensure-registered');
+  assert('Could not lookup private -ensure-registered service', service);
+
+  return service.register(klass, owner);
 }
 
 function handleClass(klass, thingWithOwner) {

packages/util/addon/services/ensure-registered.js

@@ -0,0 +1,17 @@
+import Service from '@ember/service';
+import { getOwner } from '@ember/application';
+
+export default class EnsureRegisteredService extends Service {
+  classNonces = new WeakMap();
+  nonceCounter = 0;
+
+  register(klass, owner = getOwner(this)) {
+    let nonce = this.classNonces.get(klass);
+    if (nonce == null) {
+      nonce = `-ensure${this.nonceCounter++}`;
+      this.classNonces.set(klass, nonce);
+      owner.register(`component:${nonce}`, klass);
+    }
+    return nonce;
+  }
+}

packages/util/app/services/-ensure-registered.js

@@ -0,0 +1 @@
+export { default } from '@embroider/util/services/ensure-registered';

packages/util/tests/unit/services/ensure-registered-test.js

@@ -0,0 +1,33 @@
+import { module, test } from 'qunit';
+import { setupTest } from 'ember-qunit';
+import EmberComponent from '@ember/component';
+
+module('Unit | Service | ensure-registered', function (hooks) {
+  setupTest(hooks);
+
+  const Klass1 = EmberComponent.extend();
+  const Klass2 = EmberComponent.extend();
+
+  test('it returns nonce for class', function (assert) {
+    let service = this.owner.lookup('service:-ensure-registered');
+    assert.equal(service.register(Klass1), '-ensure0');
+  });
+
+  test('it returns different nonce for different class', function (assert) {
+    let service = this.owner.lookup('service:-ensure-registered');
+    assert.equal(service.register(Klass1), '-ensure0');
+    assert.equal(service.register(Klass2), '-ensure1');
+  });
+
+  test('it returns same nonce for same class', function (assert) {
+    let service = this.owner.lookup('service:-ensure-registered');
+    assert.equal(service.register(Klass1), '-ensure0');
+    assert.equal(service.register(Klass1), '-ensure0');
+  });
+
+  test('it registers component', function (assert) {
+    let service = this.owner.lookup('service:-ensure-registered');
+    assert.equal(service.register(Klass1), '-ensure0');
+    assert.ok(this.owner.hasRegistration('component:-ensure0'));
+  });
+});