From: Jukka Kurkela <jukka.kurkela@gmail.com>
Date: Sat, 14 Nov 2020 19:38:38 +0000 (+0200)
Subject: Chart.register: preserve existing defaults (#8052)
X-Git-Tag: v3.0.0-beta.7~42
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fde84f272acf441fbfb8d51931c2484e1d34c805;p=thirdparty%2FChart.js.git

Chart.register: preserve existing defaults (#8052)
---

diff --git a/src/core/core.typedRegistry.js b/src/core/core.typedRegistry.js
index 7e70cb112..187a3d161 100644
--- a/src/core/core.typedRegistry.js
+++ b/src/core/core.typedRegistry.js
@@ -42,10 +42,6 @@ export default class TypedRegistry {
 			return scope;
 		}
 
-		if (Object.keys(defaults.get(scope)).length) {
-			throw new Error('Can not register "' + id + '", because "defaults.' + scope + '" would collide with existing defaults');
-		}
-
 		items[id] = item;
 		registerDefaults(item, scope, parentScope);
 
@@ -81,10 +77,13 @@ export default class TypedRegistry {
 }
 
 function registerDefaults(item, scope, parentScope) {
-	// Inherit the parent's defaults
-	const itemDefaults = parentScope
-		? Object.assign({}, defaults.get(parentScope), item.defaults)
-		: item.defaults;
+	// Inherit the parent's defaults and keep existing defaults
+	const itemDefaults = Object.assign(
+		Object.create(null),
+		parentScope && defaults.get(parentScope),
+		item.defaults,
+		defaults.get(scope)
+	);
 
 	defaults.set(scope, itemDefaults);
 
diff --git a/test/specs/core.registry.tests.js b/test/specs/core.registry.tests.js
index 8c349ab70..e93207dc0 100644
--- a/test/specs/core.registry.tests.js
+++ b/test/specs/core.registry.tests.js
@@ -284,14 +284,18 @@ describe('Chart.registry', function() {
 		expect(afterUnregisterCount).withContext('afterUnregister').toBe(4);
 	});
 
-	it('should not register anything that would collide with existing defaults', function() {
-		Chart.defaults.controllers.test = {test: true};
+	it('should preserve existing defaults', function() {
+		Chart.defaults.controllers.test = {test1: true};
+
 		class testController extends Chart.DatasetController {}
 		testController.id = 'test';
-		expect(function() {
-			Chart.register(testController);
-		}).toThrow(new Error('Can not register "test", because "defaults.controllers.test" would collide with existing defaults'));
-		delete Chart.defaults.controllers.test;
+		testController.defaults = {test1: false, test2: true};
+
+		Chart.register(testController);
+		expect(Chart.defaults.controllers.test).toEqual({test1: true, test2: true});
+
+		Chart.unregister(testController);
+		expect(Chart.defaults.controllers.test).not.toBeDefined();
 	});
 
 	describe('should handle multiple items', function() {