Extract rule: template-no-args-paths

README.md

@@ -189,6 +189,7 @@ rules in templates can be disabled with eslint directives with mustache or html
 | Name                                                                                       | Description                                               | 💼 | 🔧 | 💡 |
 | :----------------------------------------------------------------------------------------- | :-------------------------------------------------------- | :- | :- | :- |
 | [template-builtin-component-arguments](docs/rules/template-builtin-component-arguments.md) | disallow setting certain attributes on builtin components |    |    |    |
+| [template-no-args-paths](docs/rules/template-no-args-paths.md)                             | disallow @args in paths                                   |    |    |    |
 | [template-no-debugger](docs/rules/template-no-debugger.md)                                 | disallow {{debugger}} in templates                        |    |    |    |
 | [template-no-log](docs/rules/template-no-log.md)                                           | disallow {{log}} in templates                             |    |    |    |
 

docs/rules/template-no-args-paths.md

@@ -0,0 +1,68 @@
+# ember/template-no-args-paths
+
+<!-- end auto-generated rule header -->
+
+✅ The `extends: 'recommended'` property in a configuration file enables this rule.
+
+Arguments that are passed to components are prefixed with the `@` symbol in Angle bracket syntax.
+Ember Octane leverages this in the component's templates by allowing users to directly refer to an argument using the same prefix:
+
+```hbs
+<!-- todo-list.hbs -->
+<ul>
+  {{#each @todos as |todo index|}}
+    <li>
+      {{yield (todo-item-component todo=todo) index}}
+    </li>
+  {{/each}}
+</ul>
+```
+
+We can immediately tell now by looking at this template that `@todos` is an argument that was passed to the component externally. This is in fact _always true_ - there is no way to modify the value referenced by `@todos` from the component class, it is the original, unmodified value.
+
+## Examples
+
+This rule **forbids** the following:
+
+```hbs
+{{this.args.foo}}
+{{args.foo}}
+```
+
+```hbs
+{{my-helper this.args.foo}}
+{{my-helper (hash value=this.args.foo)}}
+```
+
+```hbs
+<MyComponent @value={{this.args.foo}} />
+<div {{my-modifier this.args.foo}}></div>
+```
+
+This rule **allows** the following:
+
+```hbs
+{{my-helper this.args}}
+{{my-helper (hash value=this.args)}}
+```
+
+```hbs
+{{@foo}}
+<MyComponent @value={{@foo}} />
+<div {{my-modifier @foo}}></div>
+```
+
+## Migration
+
+- find in templates `this.args.` replace to `@`
+
+## Related Rules
+
+- [no-curly-component-invocation](no-curly-component-invocation.md)
+
+## References
+
+- [RFC #276](https://github.com/emberjs/rfcs/blob/master/text/0276-named-args.md)
+- [Coming Soon in Ember Octane - Part 2: Named Argument Syntax](https://www.pzuraq.com/blog/coming-soon-in-ember-octane-part-2-angle-brackets-and-named-arguments/#namedargumentsyntax)
+- [Named arguments in Ember.js](https://www.balinterdi.com/blog/named-arguments-in-ember-js/)
+- [ember-named-arguments-polyfill](https://github.com/rwjblue/ember-named-arguments-polyfill)

lib/rules/template-no-args-paths.js

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+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'disallow @args in paths',
+      category: 'Best Practices',
+      strictGjs: true,
+      strictGts: true,
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-args-paths.md',
+    },
+    schema: [],
+    messages: { argsPath: 'Do not use paths with @args, use @argName directly instead.' },
+  },
+  create(context) {
+    return {
+      GlimmerPathExpression(node) {
+        if (node.original?.startsWith('@args.')) {
+          context.report({ node, messageId: 'argsPath' });
+        }
+      },
+    };
+  },
+};

tests/lib/rules/template-no-args-paths.js

@@ -0,0 +1,17 @@
+const rule = require('../../../lib/rules/template-no-args-paths');
+const RuleTester = require('eslint').RuleTester;
+
+const ruleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+ruleTester.run('template-no-args-paths', rule, {
+  valid: ['<template>{{@foo}}</template>'],
+  invalid: [
+    {
+      code: '<template>{{@args.foo}}</template>',
+      output: null,
+      errors: [{ messageId: 'argsPath' }],
+    },
+  ],
+});