From 52c8ff858fa4191ccb088a2a521cf71fc21479b6 Mon Sep 17 00:00:00 2001
From: NullVoxPopuli <199018+NullVoxPopuli@users.noreply.github.com>
Date: Mon, 23 Feb 2026 15:55:04 -0500
Subject: [PATCH] Extract rule: template-no-input-tagname

---
 README.md                                    |  1 +
 docs/rules/template-no-input-tagname.md      | 30 +++++++++++
 lib/rules/template-no-input-tagname.js       | 38 ++++++++++++++
 tests/lib/rules/template-no-input-tagname.js | 55 ++++++++++++++++++++
 4 files changed, 124 insertions(+)
 create mode 100644 docs/rules/template-no-input-tagname.md
 create mode 100644 lib/rules/template-no-input-tagname.js
 create mode 100644 tests/lib/rules/template-no-input-tagname.js

diff --git a/README.md b/README.md
index ae2c7b3b6c..c6c0ce3c32 100644
--- a/README.md
+++ b/README.md
@@ -199,6 +199,7 @@ rules in templates can be disabled with eslint directives with mustache or html
 | [template-no-capital-arguments](docs/rules/template-no-capital-arguments.md)                           | disallow capital arguments (use lowercase @arg instead of @Arg) |    |    |    |
 | [template-no-debugger](docs/rules/template-no-debugger.md)                                             | disallow {{debugger}} in templates                              |    |    |    |
 | [template-no-element-event-actions](docs/rules/template-no-element-event-actions.md)                   | disallow element event actions (use {{on}} modifier instead)    |    |    |    |
+| [template-no-input-tagname](docs/rules/template-no-input-tagname.md)                                   | disallow tagName attribute on {{input}} helper                  |    |    |    |
 | [template-no-log](docs/rules/template-no-log.md)                                                       | disallow {{log}} in templates                                   |    |    |    |
 
 ### Components
diff --git a/docs/rules/template-no-input-tagname.md b/docs/rules/template-no-input-tagname.md
new file mode 100644
index 0000000000..8a630390a2
--- /dev/null
+++ b/docs/rules/template-no-input-tagname.md
@@ -0,0 +1,30 @@
+# ember/template-no-input-tagname
+
+<!-- end auto-generated rule header -->
+
+`{{input tagName=x}}` will result in obtuse errors. Typically, the input will simply fail to render, whether used in block form or inline. The only valid `tagName` for the input helper is `input`. For `textarea`, `button`, and other input-like elements, you should instead create a new component or better use the DOM!
+
+## Examples
+
+This rule **forbids** the following:
+
+```gjs
+<template>
+  {{input tagName='foo'}}
+  {{input tagName=X}}
+  {{component 'input' tagName='foo'}}
+  {{component 'input' tagName=X}}
+  {{yield (component 'input' tagName='foo')}}
+  {{yield (component 'input' tagName=X)}}
+</template>
+```
+
+## Related rules
+
+- [no-link-to-tagname](no-link-to-tagname.md)
+- [no-unknown-arguments-for-builtin-components](no-unknown-arguments-for-builtin-components.md)
+
+## References
+
+- [Ember api/input component](https://api.emberjs.com/ember/release/classes/Ember.Templates.components/methods/Input?anchor=Input)
+- [rfcs/built in components](https://emberjs.github.io/rfcs/0459-angle-bracket-built-in-components.html)
diff --git a/lib/rules/template-no-input-tagname.js b/lib/rules/template-no-input-tagname.js
new file mode 100644
index 0000000000..152f2c974c
--- /dev/null
+++ b/lib/rules/template-no-input-tagname.js
@@ -0,0 +1,38 @@
+/** @type {import('eslint').Rule.RuleModule} */
+module.exports = {
+  meta: {
+    type: 'problem',
+    docs: {
+      description: 'disallow tagName attribute on {{input}} helper',
+      category: 'Best Practices',
+      strictGjs: true,
+      strictGts: true,
+      url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-input-tagname.md',
+    },
+    schema: [],
+    messages: { unexpected: 'Unexpected tagName usage on input helper.' },
+  },
+  create(context) {
+    function check(node) {
+      if (!node.path) {
+        return;
+      }
+      const attrs = node.hash?.pairs || [];
+      const hasTagName = attrs.some((a) => a.key === 'tagName');
+
+      if (node.path.original === 'input' && hasTagName) {
+        context.report({ node, messageId: 'unexpected' });
+      } else if (
+        node.path.original === 'component' &&
+        node.params?.[0]?.original === 'input' &&
+        hasTagName
+      ) {
+        context.report({ node, messageId: 'unexpected' });
+      }
+    }
+    return {
+      GlimmerMustacheStatement: check,
+      GlimmerSubExpression: check,
+    };
+  },
+};
diff --git a/tests/lib/rules/template-no-input-tagname.js b/tests/lib/rules/template-no-input-tagname.js
new file mode 100644
index 0000000000..efd4c26eb6
--- /dev/null
+++ b/tests/lib/rules/template-no-input-tagname.js
@@ -0,0 +1,55 @@
+const rule = require('../../../lib/rules/template-no-input-tagname');
+const RuleTester = require('eslint').RuleTester;
+
+const ruleTester = new RuleTester({
+  parser: require.resolve('ember-eslint-parser'),
+  parserOptions: { ecmaVersion: 2022, sourceType: 'module' },
+});
+ruleTester.run('template-no-input-tagname', rule, {
+  valid: [
+    '<template>{{input value=this.foo}}</template>',
+    // Test cases ported from ember-template-lint
+    '<template>{{input type="text"}}</template>',
+    '<template>{{component "input" type="text"}}</template>',
+    '<template>{{yield (component "input" type="text")}}</template>',
+  ],
+  invalid: [
+    {
+      code: '<template>{{input tagName="span"}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+
+    // Test cases ported from ember-template-lint
+    {
+      code: '<template>{{input tagName="foo"}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+    {
+      code: '<template>{{input tagName=bar}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+    {
+      code: '<template>{{component "input" tagName="foo"}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+    {
+      code: '<template>{{component "input" tagName=bar}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+    {
+      code: '<template>{{yield (component "input" tagName="foo")}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+    {
+      code: '<template>{{yield (component "input" tagName=bar)}}</template>',
+      output: null,
+      errors: [{ messageId: 'unexpected' }],
+    },
+  ],
+});