From fe8e6a9f85dcdf561a8910dfa9bc36db4263caf6 Mon Sep 17 00:00:00 2001
From: armano2 <armano2@users.noreply.github.com>
Date: Sat, 14 May 2022 21:35:54 +0200
Subject: [PATCH 1/2] fix(eslint-plugin): [prefer-readonly] correct issue with
 anonymus functions #2590

---
 packages/eslint-plugin/src/rules/prefer-readonly.ts |  8 ++++++--
 .../tests/rules/prefer-readonly.test.ts             | 13 +++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/packages/eslint-plugin/src/rules/prefer-readonly.ts b/packages/eslint-plugin/src/rules/prefer-readonly.ts
index 19597264bbc..816a79371fb 100644
--- a/packages/eslint-plugin/src/rules/prefer-readonly.ts
+++ b/packages/eslint-plugin/src/rules/prefer-readonly.ts
@@ -270,8 +270,12 @@ class ClassScope {
     classNode: ts.ClassLikeDeclaration,
     private readonly onlyInlineLambdas?: boolean,
   ) {
-    this.checker = checker;
-    this.classType = checker.getTypeAtLocation(classNode);
+    const classType = checker.getTypeAtLocation(classNode);
+    if (tsutils.isIntersectionType(classType)) {
+      this.classType = classType.types[0];
+    } else {
+      this.classType = classType;
+    }
 
     for (const member of classNode.members) {
       if (ts.isPropertyDeclaration(member)) {
diff --git a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
index c1602f01913..e0f1c73c74d 100644
--- a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
@@ -292,6 +292,19 @@ class Foo {
     },
     {
       code: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private _name: string;
+
+    public test(value: string) {
+      this._name = value;
+    }
+  };
+}
+      `,
+    },
+    {
+      code: `
 class Foo {
   private value: Record<string, number> = {};
 

From e59b087a5ea6069099e9c01c9eb59d4ebccb6b86 Mon Sep 17 00:00:00 2001
From: armano2 <armano2@users.noreply.github.com>
Date: Sat, 14 May 2022 22:14:07 +0200
Subject: [PATCH 2/2] test(eslint-plugin): add missing invalid case

---
 .../tests/rules/prefer-readonly.test.ts       | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
index e0f1c73c74d..91e8213da57 100644
--- a/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
+++ b/packages/eslint-plugin/tests/rules/prefer-readonly.test.ts
@@ -717,5 +717,30 @@ class Foo {
         }
       `,
     },
+    {
+      code: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private _name: string;
+  };
+}
+      `,
+      output: `
+function ClassWithName<TBase extends new (...args: any[]) => {}>(Base: TBase) {
+  return class extends Base {
+    private readonly _name: string;
+  };
+}
+      `,
+      errors: [
+        {
+          data: {
+            name: '_name',
+          },
+          line: 4,
+          messageId: 'preferReadonly',
+        },
+      ],
+    },
   ],
 });