From b71a9fe3dee363200e10e4586a8156d5a7706424 Mon Sep 17 00:00:00 2001
From: Ronen Amiel <ronen.amiel@gmail.com>
Date: Tue, 4 Feb 2025 21:02:59 +0200
Subject: [PATCH 1/2] handle accessor property with prefer-return-this-type

---
 .../src/rules/prefer-return-this-type.ts      | 31 +++++++-------
 .../rules/prefer-return-this-type.test.ts     | 42 +++++++++++++++++++
 2 files changed, 59 insertions(+), 14 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/prefer-return-this-type.ts b/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
index 304f63dd1027..7834cebb6547 100644
--- a/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
+++ b/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
@@ -148,24 +148,27 @@ export default createRule({
       }
     }
 
+    function checkProperty(
+      node: TSESTree.AccessorProperty | TSESTree.PropertyDefinition,
+    ): void {
+      if (
+        !(
+          node.value?.type === AST_NODE_TYPES.FunctionExpression ||
+          node.value?.type === AST_NODE_TYPES.ArrowFunctionExpression
+        )
+      ) {
+        return;
+      }
+
+      checkFunction(node.value, node.parent.parent as ClassLikeDeclaration);
+    }
+
     return {
+      'ClassBody > AccessorProperty': checkProperty,
       'ClassBody > MethodDefinition'(node: TSESTree.MethodDefinition): void {
         checkFunction(node.value, node.parent.parent as ClassLikeDeclaration);
       },
-      'ClassBody > PropertyDefinition'(
-        node: TSESTree.PropertyDefinition,
-      ): void {
-        if (
-          !(
-            node.value?.type === AST_NODE_TYPES.FunctionExpression ||
-            node.value?.type === AST_NODE_TYPES.ArrowFunctionExpression
-          )
-        ) {
-          return;
-        }
-
-        checkFunction(node.value, node.parent.parent as ClassLikeDeclaration);
-      },
+      'ClassBody > PropertyDefinition': checkProperty,
     };
   },
 });
diff --git a/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts b/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
index 4a9262e92ce9..796909a7406b 100644
--- a/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
@@ -200,6 +200,48 @@ class Foo {
     },
     {
       code: `
+class Foo {
+  accessor f = (): Foo => {
+    return this;
+  };
+}
+      `,
+      errors: [
+        {
+          column: 20,
+          line: 3,
+          messageId: 'useThisType',
+        },
+      ],
+      output: `
+class Foo {
+  accessor f = (): this => {
+    return this;
+  };
+}
+      `,
+    },
+    {
+      code: `
+class Foo {
+  accessor f = (): Foo => this;
+}
+      `,
+      errors: [
+        {
+          column: 20,
+          line: 3,
+          messageId: 'useThisType',
+        },
+      ],
+      output: `
+class Foo {
+  accessor f = (): this => this;
+}
+      `,
+    },
+    {
+      code: `
 class Foo {
   f1(): Foo | undefined {
     return this;

From b463fe5e76ee371065905b71062671964e7dbb81 Mon Sep 17 00:00:00 2001
From: Ronen Amiel <ronen.amiel@gmail.com>
Date: Thu, 6 Feb 2025 15:04:18 +0200
Subject: [PATCH 2/2] refactor and add missing tests

---
 .../src/rules/prefer-return-this-type.ts      |  4 +-
 .../rules/prefer-return-this-type.test.ts     | 42 +++++++++++++++++++
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/prefer-return-this-type.ts b/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
index 7834cebb6547..fff92141fe12 100644
--- a/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
+++ b/packages/eslint-plugin/src/rules/prefer-return-this-type.ts
@@ -160,13 +160,13 @@ export default createRule({
         return;
       }
 
-      checkFunction(node.value, node.parent.parent as ClassLikeDeclaration);
+      checkFunction(node.value, node.parent.parent);
     }
 
     return {
       'ClassBody > AccessorProperty': checkProperty,
       'ClassBody > MethodDefinition'(node: TSESTree.MethodDefinition): void {
-        checkFunction(node.value, node.parent.parent as ClassLikeDeclaration);
+        checkFunction(node.value, node.parent.parent);
       },
       'ClassBody > PropertyDefinition': checkProperty,
     };
diff --git a/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts b/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
index 796909a7406b..5b372350059f 100644
--- a/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-return-this-type.test.ts
@@ -79,6 +79,25 @@ class Derived extends Base {
   f(): Base {
     return this;
   }
+}
+    `,
+    `
+class Foo {
+  accessor f = () => {
+    return this;
+  };
+}
+    `,
+    `
+class Foo {
+  accessor f = (): this => {
+    return this;
+  };
+}
+    `,
+    `
+class Foo {
+  f?: string;
 }
     `,
   ],
@@ -108,6 +127,29 @@ class Foo {
     },
     {
       code: `
+class Foo {
+  f = function (): Foo {
+    return this;
+  };
+}
+      `,
+      errors: [
+        {
+          column: 20,
+          line: 3,
+          messageId: 'useThisType',
+        },
+      ],
+      output: `
+class Foo {
+  f = function (): this {
+    return this;
+  };
+}
+      `,
+    },
+    {
+      code: `
 class Foo {
   f(): Foo {
     const self = this;