From baf6cf6a147f89af28dc2a6814f2acfdb1b47480 Mon Sep 17 00:00:00 2001
From: Patrick Steele-Idem <pnidem@gmail.com>
Date: Wed, 8 Feb 2017 22:53:46 -0800
Subject: [PATCH] Reject class with extends for single file UI components

---
 .../render/error-component-class-extends/expected.html      | 0
 .../render/error-component-class-extends/template.marko     | 6 ++++++
 test/autotests/render/error-component-class-extends/test.js | 6 ++++++
 widgets/taglib/TransformHelper/handleRootNodes.js           | 6 ++++++
 4 files changed, 18 insertions(+)
 create mode 100644 test/autotests/render/error-component-class-extends/expected.html
 create mode 100644 test/autotests/render/error-component-class-extends/template.marko
 create mode 100644 test/autotests/render/error-component-class-extends/test.js

diff --git a/test/autotests/render/error-component-class-extends/expected.html b/test/autotests/render/error-component-class-extends/expected.html
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/autotests/render/error-component-class-extends/template.marko b/test/autotests/render/error-component-class-extends/template.marko
new file mode 100644
index 000000000..c8a684809
--- /dev/null
+++ b/test/autotests/render/error-component-class-extends/template.marko
@@ -0,0 +1,6 @@
+class Foo extends Bar {
+
+}
+
+<div>
+</div>
\ No newline at end of file
diff --git a/test/autotests/render/error-component-class-extends/test.js b/test/autotests/render/error-component-class-extends/test.js
new file mode 100644
index 000000000..5b9d164f1
--- /dev/null
+++ b/test/autotests/render/error-component-class-extends/test.js
@@ -0,0 +1,6 @@
+var expect = require('chai').expect;
+
+exports.checkError = function(e) {
+    expect(e.toString()).to.contain('A component class is not allowed to use `extends`');
+    expect(e.toString()).to.contain('https://github.com/marko-js/marko/wiki/Error:-Component-class-with-extends');
+};
\ No newline at end of file
diff --git a/widgets/taglib/TransformHelper/handleRootNodes.js b/widgets/taglib/TransformHelper/handleRootNodes.js
index 689d96632..b8a98ac73 100644
--- a/widgets/taglib/TransformHelper/handleRootNodes.js
+++ b/widgets/taglib/TransformHelper/handleRootNodes.js
@@ -207,6 +207,12 @@ function handleClassDeclaration(classEl, transformHelper) {
         return;
     }
     let expression = tree.body[0].expression;
+
+    if (expression.superClass && expression.superClass.name) {
+        transformHelper.context.addError(classEl, 'A component class is not allowed to use `extends`. See: https://github.com/marko-js/marko/wiki/Error:-Component-class-with-extends');
+        return;
+    }
+
     let object = classToObject(expression);
     let componentVar = transformHelper.context.addStaticVar('marko_component', escodegen.generate(object));