Fix injected services becoming public by mistake (#209513)

* Fix injected services becoming public by mistake

Fixes cases of `@IFooService readonly foo: IFooService`. This makes the service public, which is likely not expected and also means we can't mangle it

* Fix name

* Remove unused props

.eslintplugin/code-parameter-properties-must-have-explicit-accessibility.ts

@@ -0,0 +1,41 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as eslint from 'eslint';
+import { TSESTree } from '@typescript-eslint/experimental-utils';
+
+/**
+ * Enforces that all parameter properties have an explicit access modifier (public, protected, private).
+ *
+ * This catches a common bug where a service is accidentally made public by simply writing: `readonly prop: Foo`
+ */
+export = new class implements eslint.Rule.RuleModule {
+
+	create(context: eslint.Rule.RuleContext): eslint.Rule.RuleListener {
+		function check(inNode: any) {
+			const node: TSESTree.TSParameterProperty = inNode;
+
+			// For now, only apply to injected services
+			const firstDecorator = node.decorators?.at(0);
+			if (
+				firstDecorator?.expression.type !== 'Identifier'
+				|| !firstDecorator.expression.name.endsWith('Service')
+			) {
+				return;
+			}
+
+			if (!node.accessibility) {
+				context.report({
+					node: inNode,
+					message: 'Parameter properties must have an explicit access modifier.'
+				});
+			}
+		}
+
+		return {
+			['TSParameterProperty']: check,
+		};
+	}
+};