Extract rule: template-splat-attributes-only

Author: NullVoxPopuli

README.md

@@ -245,6 +245,7 @@ rules in templates can be disabled with eslint directives with mustache or html
 | [template-no-obsolete-elements](docs/rules/template-no-obsolete-elements.md)                                 | disallow obsolete HTML elements                                              |    |    |    |
 | [template-no-outlet-outside-routes](docs/rules/template-no-outlet-outside-routes.md)                         | disallow {{outlet}} outside of route templates                               |    |    |    |
 | [template-no-page-title-component](docs/rules/template-no-page-title-component.md)                           | disallow usage of ember-page-title component                                 |    |    |    |
+| [template-splat-attributes-only](docs/rules/template-splat-attributes-only.md)                               | disallow ...spread other than ...attributes                                  |    |    |    |
 | [template-style-concatenation](docs/rules/template-style-concatenation.md)                                   | disallow string concatenation in inline styles                               |    |    |    |
 
 ### Components

docs/rules/template-splat-attributes-only.md

@@ -0,0 +1,32 @@
+# ember/template-splat-attributes-only
+
+<!-- end auto-generated rule header -->
+
+It is easy to introduce typos when typing out `...attributes` or to use e.g.
+`...arguments` instead. Unfortunately, that leads to a cryptic runtime error,
+but does not fail the build.
+
+This rule warns you when you use an attribute starting with `...` that is **not**
+`...attributes`.
+
+## Examples
+
+This rule **forbids** the following:
+
+```gjs
+<template><div ...atributes></div></template>
+```
+
+```gjs
+<template><div ...arguments></div></template>
+```
+
+This rule **allows** the following:
+
+```gjs
+<template><div ...attributes></div></template>
+```
+
+## References
+
+- [Ember 3.11 release](https://blog.emberjs.com/2019/07/15/ember-3-11-released.html)

lib/rules/template-splat-attributes-only.js

@@ -0,0 +1,31 @@
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'disallow ...spread other than ...attributes',
+      category: 'Best Practices',
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-splat-attributes-only.md',
+      templateMode: 'both',
+    },
+    schema: [],
+    messages: {
+      onlyAttributes: 'Only `...attributes` can be applied to elements',
+    },
+    originallyFrom: {
+      name: 'ember-template-lint',
+      rule: 'lib/rules/splat-attributes-only.js',
+      docs: 'docs/rule/splat-attributes-only.md',
+      tests: 'test/unit/rules/splat-attributes-only-test.js',
+    },
+  },
+  create(context) {
+    return {
+      GlimmerAttrNode(node) {
+        if (node.name?.startsWith('...') && node.name !== '...attributes') {
+          context.report({ node, messageId: 'onlyAttributes' });
+        }
+      },
+    };
+  },
+};

tests/lib/rules/template-splat-attributes-only.js

@@ -0,0 +1,55 @@
+const rule = require('../../../lib/rules/template-splat-attributes-only');
+const RuleTester = require('eslint').RuleTester;
+
+const ruleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+
+ruleTester.run('template-splat-attributes-only', rule, {
+  valid: [
+    '<template><div ...attributes></div></template>',
+    '<template><MyComponent ...attributes /></template>',
+
+    '<template><div attributes></div></template>',
+    '<template><div arguments></div></template>',
+    '<template><div><div ...attributes></div></div></template>',
+  ],
+  invalid: [
+    {
+      code: '<template><div ...props></div></template>',
+      output: null,
+      errors: [{ messageId: 'onlyAttributes' }],
+    },
+
+    {
+      code: '<template><div ...arguments></div></template>',
+      output: null,
+      errors: [{ messageId: 'onlyAttributes' }],
+    },
+  ],
+});
+
+const hbsRuleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser/hbs'),
+  parserOptions: {
+    ecmaVersion: 2022,
+    sourceType: 'module',
+  },
+});
+
+hbsRuleTester.run('template-splat-attributes-only', rule, {
+  valid: [
+    '<div ...attributes></div>',
+    '<div attributes></div>',
+    '<div arguments></div>',
+    '<div><div ...attributes></div></div>',
+  ],
+  invalid: [
+    {
+      code: '<div ...arguments></div>',
+      output: null,
+      errors: [{ message: 'Only `...attributes` can be applied to elements' }],
+    },
+  ],
+});