dev: add eslint rule for annotation checks

Inversify >=6.1 requires to annotate all constructor parameters of
injectable classes. To avoid runtime errors we add a new eslint rule to
check for this at lint time.

configs/errors.eslintrc.json

@@ -135,6 +135,7 @@
         }
       }
     ],
+    "@theia/annotation-check": "error",
     "@theia/localization-check": "error",
     "@theia/no-src-import": "error",
     "@theia/runtime-import-check": "error",

dev-packages/private-eslint-plugin/README.md

@@ -17,6 +17,11 @@ The plugin helps identify problems during development through static analysis in
 
 ## Rules
 
+### `annotation-check`:
+
+Inversify >=6.1 requires to annotate all constructor parameters of injectable classes as otherwise runtime errors are thrown.
+The rule checks that all constructor parameters of injectable classes are annotated with `@inject`, `@unmanaged` or `@multiInject`.
+
 ### `localization-check`:
 
 The rule prevents the following localization related issues:

dev-packages/private-eslint-plugin/index.js

@@ -17,6 +17,7 @@
 
 /** @type {{[ruleId: string]: import('eslint').Rule.RuleModule}} */
 exports.rules = {
+    "annotation-check": require('./rules/annotation-check'),
     "localization-check": require('./rules/localization-check'),
     "no-src-import": require('./rules/no-src-import'),
     "runtime-import-check": require('./rules/runtime-import-check'),

dev-packages/private-eslint-plugin/rules/annotation-check.js

@@ -0,0 +1,103 @@
+// @ts-check
+// *****************************************************************************
+// Copyright (C) 2024 EclipseSource and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0.
+//
+// This Source Code may also be made available under the following Secondary
+// Licenses when the conditions for such availability set forth in the Eclipse
+// Public License v. 2.0 are satisfied: GNU General Public License, version 2
+// with the GNU Classpath Exception which is available at
+// https://www.gnu.org/software/classpath/license.html.
+//
+// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-only WITH Classpath-exception-2.0
+// *****************************************************************************
+
+/**
+ * @typedef {import('@typescript-eslint/utils').TSESTree.ClassDeclaration} ClassDeclaration
+ * @typedef {import('@typescript-eslint/utils').TSESTree.ClassElement} ClassElement
+ * @typedef {import('@typescript-eslint/utils').TSESTree.Decorator} Decorator
+ * @typedef {import('@typescript-eslint/utils').TSESTree.MethodDefinition} MethodDefinition
+ * @typedef {import('@typescript-eslint/utils').TSESTree.Parameter} Parameter
+ * @typedef {import('estree').Node} Node
+ * @typedef {import('eslint').Rule.RuleModule} RuleModule
+ */
+
+/**
+ * Type guard to check if a ClassElement is a MethodDefinition.
+ * @param {ClassElement} element
+ * @returns {element is MethodDefinition}
+ */
+function isMethodDefinition(element) {
+    return element.type === 'MethodDefinition';
+}
+
+/** @type {RuleModule} */
+module.exports = {
+    meta: {
+        type: 'problem',
+        docs: {
+            description:
+                'Ensure @injectable classes have annotated constructor parameters',
+        },
+        messages: {
+            missingAnnotation: 'Constructor parameters in an @injectable class must be annotated with @inject, @unmanaged or @multiInject',
+        },
+    },
+    create(context) {
+        return {
+            /**
+             * @param {ClassDeclaration} node
+             */
+            ClassDeclaration(node) {
+                // Check if the class has a decorator named `injectable`
+                const hasInjectableDecorator = node.decorators?.some(
+                    (/** @type {Decorator} */ decorator) =>
+                        decorator.expression.type === 'CallExpression' &&
+                        decorator.expression.callee.type === 'Identifier' &&
+                        decorator.expression.callee.name === 'injectable'
+                );
+
+                if (hasInjectableDecorator) {
+                    // Find the constructor method within the class body
+                    const constructor = node.body.body.find(
+                        member =>
+                            isMethodDefinition(member) &&
+                            member.kind === 'constructor'
+                    );
+
+                    if (
+                        constructor &&
+                        // We need to re-apply 'isMethodDefinition' here because the type guard is not properly preserved
+                        isMethodDefinition(constructor) &&
+                        constructor.value &&
+                        constructor.value.params.length > 0
+                    ) {
+                        constructor.value.params.forEach(
+                            /** @type {Parameter} */ param => {
+                                // Check if each constructor parameter has a decorator
+                                const hasAnnotation = param.decorators?.some(
+                                    (/** @type {Decorator} */ decorator) =>
+                                        decorator.expression.type === 'CallExpression' &&
+                                        decorator.expression.callee.type === 'Identifier' &&
+                                        (decorator.expression.callee.name === 'inject' ||
+                                            decorator.expression.callee.name === 'unmanaged' ||
+                                            decorator.expression.callee.name === 'multiInject')
+                                );
+
+                                if (!hasAnnotation) {
+                                    context.report({
+                                        node: /** @type Node */ (param),
+                                        messageId: 'missingAnnotation',
+                                    });
+                                }
+                            }
+                        );
+                    }
+                }
+            },
+        };
+    },
+};