fix: format static private methods correctly with classPropertiesAllowed: true

Closes #46
Closes #47

Author: gurgunday

src/prefer-arrow-functions.spec.ts

@@ -481,6 +481,16 @@ const invalidAndHasBlockStatement = [
     output: 'class MyClass { render = (a, b) => { console.log(3); }; }',
     options: [{ classPropertiesAllowed: true }],
   },
+  {
+    code: 'class MyClass { #render(a, b) { console.log(3); } }',
+    output: 'class MyClass { #render = (a, b) => { console.log(3); }; }',
+    options: [{ classPropertiesAllowed: true }],
+  },
+  {
+    code: 'class MyClass { static #render(a, b) { console.log(3); } }',
+    output: 'class MyClass { static #render = (a, b) => { console.log(3); }; }',
+    options: [{ classPropertiesAllowed: true }],
+  },
   {
     code: 'class MyClass { static render(a, b) { console.log(3); } }',
     output: 'class MyClass { static render = (a, b) => { console.log(3); }; }',

src/prefer-arrow-functions.ts

@@ -280,7 +280,10 @@ export default {
       },
       ':matches(ClassProperty, MethodDefinition, Property)[key.name][value.type="FunctionExpression"][kind!=/^(get|set|constructor)$/]':
         (node) => {
-          const propName = node.key.name;
+          const propName =
+            node.key.type === 'PrivateIdentifier'
+              ? `#${node.key.name}`
+              : node.key.name;
           const functionNode = node.value;
           const staticModifier = node.static ? 'static ' : '';
           if (