Port autofix for template-no-redundant-fn

Author: johanrd

README.md

@@ -258,7 +258,7 @@ rules in templates can be disabled with eslint directives with mustache or html
 | [template-no-passed-in-event-handlers](docs/rules/template-no-passed-in-event-handlers.md)                         | disallow passing event handlers directly as component arguments              |    |    |    |
 | [template-no-positional-data-test-selectors](docs/rules/template-no-positional-data-test-selectors.md)             | disallow positional data-test-* params in curly invocations                  |    |    |    |
 | [template-no-potential-path-strings](docs/rules/template-no-potential-path-strings.md)                             | disallow potential path strings in attribute values                          |    |    |    |
-| [template-no-redundant-fn](docs/rules/template-no-redundant-fn.md)                                                 | disallow unnecessary usage of (fn) helper                                    |    |    |    |
+| [template-no-redundant-fn](docs/rules/template-no-redundant-fn.md)                                                 | disallow unnecessary usage of (fn) helper                                    |    | 🔧 |    |
 | [template-no-restricted-invocations](docs/rules/template-no-restricted-invocations.md)                             | disallow certain components, helpers or modifiers from being used            |    |    |    |
 | [template-no-splattributes-with-class](docs/rules/template-no-splattributes-with-class.md)                         | disallow splattributes with class attribute                                  |    |    |    |
 | [template-no-this-in-template-only-components](docs/rules/template-no-this-in-template-only-components.md)         | disallow this in template-only components (gjs/gts)                          |    | 🔧 |    |

docs/rules/template-no-redundant-fn.md

@@ -1,5 +1,7 @@
 # ember/template-no-redundant-fn
 
+🔧 This rule is automatically fixable by the [`--fix` CLI option](https://eslint.org/docs/latest/user-guide/command-line-interface#--fix).
+
 <!-- end auto-generated rule header -->
 
 The `fn` helper can be used to bind arguments to another function. Using it without any arguments is redundant because then the inner function could just be used directly.

lib/rules/template-no-redundant-fn.js

@@ -8,7 +8,7 @@ module.exports = {
       url: 'https://github.com/ember-cli/eslint-plugin-ember/tree/master/docs/rules/template-no-redundant-fn.md',
       templateMode: 'both',
     },
-    fixable: null,
+    fixable: 'code',
     schema: [],
     messages: {
       redundant:
@@ -66,6 +66,13 @@ module.exports = {
           data: {
             suggestion: paramText,
           },
+          fix(fixer) {
+            if (node.type === 'GlimmerMustacheStatement') {
+              return fixer.replaceTextRange(node.range, `{{${paramText}}}`);
+            }
+            // GlimmerSubExpression: (fn this.handleClick) → this.handleClick
+            return fixer.replaceTextRange(node.range, paramText);
+          },
         });
       }
     }

tests/lib/rules/template-no-redundant-fn.js

@@ -51,7 +51,9 @@ ruleTester.run('template-no-redundant-fn', rule, {
       code: `<template>
         <button {{on "click" (fn this.handleClick)}}>Click</button>
       </template>`,
-      output: null,
+      output: `<template>
+        <button {{on "click" this.handleClick}}>Click</button>
+      </template>`,
       errors: [
         {
           message:
@@ -64,7 +66,9 @@ ruleTester.run('template-no-redundant-fn', rule, {
       code: `<template>
         <Component @action={{fn this.save}} />
       </template>`,
-      output: null,
+      output: `<template>
+        <Component @action={{this.save}} />
+      </template>`,
       errors: [
         {
           message: 'Unnecessary use of (fn) helper. Pass the function directly instead: this.save',
@@ -75,7 +79,7 @@ ruleTester.run('template-no-redundant-fn', rule, {
 
     {
       code: '<template><button {{on "click" (fn this.handleClick)}}>Click Me</button></template>',
-      output: null,
+      output: '<template><button {{on "click" this.handleClick}}>Click Me</button></template>',
       errors: [
         {
           message:
@@ -85,7 +89,7 @@ ruleTester.run('template-no-redundant-fn', rule, {
     },
     {
       code: '<template><SomeComponent @onClick={{fn this.handleClick}} /></template>',
-      output: null,
+      output: '<template><SomeComponent @onClick={{this.handleClick}} /></template>',
       errors: [
         {
           message:
@@ -95,7 +99,7 @@ ruleTester.run('template-no-redundant-fn', rule, {
     },
     {
       code: '<template>{{foo bar=(fn this.handleClick)}}></template>',
-      output: null,
+      output: '<template>{{foo bar=this.handleClick}}></template>',
       errors: [
         {
           message:
@@ -126,7 +130,7 @@ hbsRuleTester.run('template-no-redundant-fn', rule, {
   invalid: [
     {
       code: '<button {{on "click" (fn this.handleClick)}}>Click Me</button>',
-      output: null,
+      output: '<button {{on "click" this.handleClick}}>Click Me</button>',
       errors: [
         {
           message:
@@ -136,7 +140,7 @@ hbsRuleTester.run('template-no-redundant-fn', rule, {
     },
     {
       code: '<SomeComponent @onClick={{fn this.handleClick}} />',
-      output: null,
+      output: '<SomeComponent @onClick={{this.handleClick}} />',
       errors: [
         {
           message:
@@ -146,7 +150,7 @@ hbsRuleTester.run('template-no-redundant-fn', rule, {
     },
     {
       code: '{{foo bar=(fn this.handleClick)}}>',
-      output: null,
+      output: '{{foo bar=this.handleClick}}>',
       errors: [
         {
           message: