From 0ee530c63df77fd9cf458d67571b18dd621d66a9 Mon Sep 17 00:00:00 2001
From: Jeremias Peier <jeremias.peier@sbb.ch>
Date: Tue, 12 Dec 2023 16:12:18 +0100
Subject: [PATCH] build: add eslint rule for custom element class name

---
 .../eslint/custom-element-class-name-rule.ts  | 61 +++++++++++++++++++
 tools/eslint/index.ts                         |  3 +
 2 files changed, 64 insertions(+)
 create mode 100644 tools/eslint/custom-element-class-name-rule.ts

diff --git a/tools/eslint/custom-element-class-name-rule.ts b/tools/eslint/custom-element-class-name-rule.ts
new file mode 100644
index 0000000000..a5ace4a6c4
--- /dev/null
+++ b/tools/eslint/custom-element-class-name-rule.ts
@@ -0,0 +1,61 @@
+/* eslint-disable @typescript-eslint/naming-convention */
+import { ESLintUtils, TSESLint, TSESTree, AST_NODE_TYPES } from '@typescript-eslint/utils';
+
+const createRule = ESLintUtils.RuleCreator(
+  (name) =>
+    `https://github.com/lyne-design-system/lyne-components/blob/main/tools/eslint/${name}.ts`,
+);
+
+type MessageIds = 'customElementClassName';
+
+export const name = 'custom-element-class-name-rule';
+export const rule: TSESLint.RuleModule<'customElementClassName', never[]> = createRule<
+  never[],
+  MessageIds
+>({
+  create(context) {
+    return {
+      ['ClassDeclaration > Decorator[expression.callee.name="customElement"]'](
+        node: TSESTree.Decorator,
+      ) {
+        const isClassDeclaration = (node: TSESTree.Node): node is TSESTree.ClassDeclaration => {
+          return node.type === AST_NODE_TYPES.ClassDeclaration;
+        };
+
+        const getClassName = (node: TSESTree.Node): string | undefined => {
+          if (isClassDeclaration(node)) {
+            return node.id?.name;
+          }
+          if (node.parent) {
+            return getClassName(node.parent);
+          }
+          return undefined;
+        };
+
+        const classParent = node.parent as TSESTree.ClassDeclaration;
+        const className = getClassName(classParent);
+
+        if (!className || !className.startsWith('Sbb') || !className.endsWith('Element')) {
+          context.report({
+            node: classParent.id ? classParent.id : classParent,
+            messageId: 'customElementClassName',
+          });
+        }
+      },
+    };
+  },
+  name,
+  meta: {
+    docs: {
+      description: 'Components class name should start with `Sbb` and end with `Element`',
+      recommended: 'error',
+    },
+    messages: {
+      customElementClassName:
+        'Components class name should start with `Sbb` and end with `Element`',
+    },
+    type: 'problem',
+    schema: [],
+  },
+  defaultOptions: [],
+});
diff --git a/tools/eslint/index.ts b/tools/eslint/index.ts
index bde04c19b5..d8a54db92f 100644
--- a/tools/eslint/index.ts
+++ b/tools/eslint/index.ts
@@ -1,14 +1,17 @@
+import * as customElementClassName from './custom-element-class-name-rule';
 import * as missingComponentDocumentation from './missing-component-documentation-rule';
 
 export default {
   rules: {
     [missingComponentDocumentation.name]: missingComponentDocumentation.rule,
+    [customElementClassName.name]: customElementClassName.rule,
   },
   configs: {
     all: {
       plugins: ['lyne'],
       rules: {
         [`lyne/${missingComponentDocumentation.name}`]: 'error',
+        [`lyne/${customElementClassName.name}`]: 'error',
       },
     },
   },