From 02c44c0ed18a52852a85a8831ef595f3aa05b44d Mon Sep 17 00:00:00 2001
From: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Date: Thu, 19 Feb 2026 16:30:24 -0500
Subject: [PATCH] Extract rule: template-no-action-modifiers

---
 README.md                                     |  1 +
 docs/rules/template-no-action-modifiers.md    | 64 +++++++++++++++++++
 lib/rules/template-no-action-modifiers.js     | 42 ++++++++++++
 .../lib/rules/template-no-action-modifiers.js | 51 +++++++++++++++
 4 files changed, 158 insertions(+)
 create mode 100644 docs/rules/template-no-action-modifiers.md
 create mode 100644 lib/rules/template-no-action-modifiers.js
 create mode 100644 tests/lib/rules/template-no-action-modifiers.js

diff --git a/README.md b/README.md
index 384e45ca98..330bed0756 100644
--- a/README.md
+++ b/README.md
@@ -190,6 +190,7 @@ 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-action-modifiers](docs/rules/template-no-action-modifiers.md)                       | disallow usage of {{action}} modifiers                    |    |    |    |
 | [template-no-arguments-for-html-elements](docs/rules/template-no-arguments-for-html-elements.md) | disallow @arguments on HTML elements                      |    |    |    |
 | [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                             |    |    |    |
diff --git a/docs/rules/template-no-action-modifiers.md b/docs/rules/template-no-action-modifiers.md
new file mode 100644
index 0000000000..d62ca80549
--- /dev/null
+++ b/docs/rules/template-no-action-modifiers.md
@@ -0,0 +1,64 @@
+# ember/template-no-action-modifiers
+
+<!-- end auto-generated rule header -->
+
+💼 This rule is enabled in the following [configs](https://github.com/ember-cli/eslint-plugin-ember#-configurations): `strict-gjs`, `strict-gts`.
+
+Disallow usage of `{{action}}` modifiers in templates.
+
+The `{{action}}` modifier has been deprecated in favor of the `{{on}}` modifier. The `{{on}}` modifier provides a more explicit and flexible way to handle events.
+
+## Rule Details
+
+This rule disallows using `{{action}}` as an element modifier.
+
+## Examples
+
+### Incorrect ❌
+
+```gjs
+<template>
+  <button {{action "save"}}>Save</button>
+</template>
+```
+
+```gjs
+<template>
+  <div {{action "onClick"}}>Click me</div>
+</template>
+```
+
+```gjs
+<template>
+  <form {{action "submit" on="submit"}}>Submit</form>
+</template>
+```
+
+### Correct ✅
+
+```gjs
+<template>
+  <button {{on "click" this.handleClick}}>Save</button>
+</template>
+```
+
+```gjs
+<template>
+  <div {{on "click" this.onClick}}>Click me</div>
+</template>
+```
+
+```gjs
+<template>
+  <form {{on "submit" this.handleSubmit}}>Submit</form>
+</template>
+```
+
+## Related Rules
+
+- [template-no-action](./template-no-action.md)
+
+## References
+
+- [Ember Octane Guide - Element Modifiers](https://guides.emberjs.com/release/components/template-lifecycle-dom-and-modifiers/)
+- [eslint-plugin-ember template-no-action](https://github.com/ember-cli/eslint-plugin-ember/blob/master/docs/rules/template-no-action.md)
diff --git a/lib/rules/template-no-action-modifiers.js b/lib/rules/template-no-action-modifiers.js
new file mode 100644
index 0000000000..5aa37f74be
--- /dev/null
+++ b/lib/rules/template-no-action-modifiers.js
@@ -0,0 +1,42 @@
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'suggestion',
+    docs: {
+      description: 'disallow usage of {{action}} modifiers',
+      category: 'Best Practices',
+      strictGjs: true,
+      strictGts: true,
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-action-modifiers.md',
+    },
+    fixable: null,
+    schema: [],
+    messages: {
+      noActionModifier: 'Do not use action modifiers. Use on modifier with a function instead.',
+    },
+  },
+
+  create(context) {
+    function checkForActionModifier(node) {
+      // Check if this is an action modifier (not action helper in mustache)
+      if (
+        node.path &&
+        node.path.type === 'GlimmerPathExpression' &&
+        node.path.original === 'action' &&
+        node.path.head?.type !== 'AtHead' &&
+        node.path.head?.type !== 'ThisHead'
+      ) {
+        context.report({
+          node,
+          messageId: 'noActionModifier',
+        });
+      }
+    }
+
+    return {
+      GlimmerElementModifierStatement(node) {
+        checkForActionModifier(node);
+      },
+    };
+  },
+};
diff --git a/tests/lib/rules/template-no-action-modifiers.js b/tests/lib/rules/template-no-action-modifiers.js
new file mode 100644
index 0000000000..ad9debaa67
--- /dev/null
+++ b/tests/lib/rules/template-no-action-modifiers.js
@@ -0,0 +1,51 @@
+const rule = require('../../../lib/rules/template-no-action-modifiers');
+const RuleTester = require('eslint').RuleTester;
+
+const ruleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+
+ruleTester.run('template-no-action-modifiers', rule, {
+  valid: [
+    '<template><button {{on "click" this.handleClick}}>Click</button></template>',
+    '<template><div {{on "mouseenter" this.onHover}}>Hover</div></template>',
+    '<template><form {{on "submit" this.handleSubmit}}>Submit</form></template>',
+    '<template>{{action "myAction"}}</template>',
+    '<template>{{this.action}}</template>',
+    '<template>{{@action}}</template>',
+  ],
+
+  invalid: [
+    {
+      code: '<template><button {{action "save"}}>Save</button></template>',
+      output: null,
+      errors: [
+        {
+          message: 'Do not use action modifiers. Use on modifier with a function instead.',
+          type: 'GlimmerElementModifierStatement',
+        },
+      ],
+    },
+    {
+      code: '<template><div {{action "onClick"}}>Click me</div></template>',
+      output: null,
+      errors: [
+        {
+          message: 'Do not use action modifiers. Use on modifier with a function instead.',
+          type: 'GlimmerElementModifierStatement',
+        },
+      ],
+    },
+    {
+      code: '<template><form {{action "submit" on="submit"}}>Submit</form></template>',
+      output: null,
+      errors: [
+        {
+          message: 'Do not use action modifiers. Use on modifier with a function instead.',
+          type: 'GlimmerElementModifierStatement',
+        },
+      ],
+    },
+  ],
+});