From f4172f1f311c40d47b3086b1ee0cf216aaf14d67 Mon Sep 17 00:00:00 2001
From: yeonjuan <yeonjuan93@naver.com>
Date: Fri, 26 Apr 2024 21:41:40 +0900
Subject: [PATCH] fix(eslint-plugin): [no-unsafe-return] handle union types

---
 .../src/rules/no-unsafe-return.ts             |  2 +-
 .../tests/rules/no-unsafe-return.test.ts      | 22 +++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/packages/eslint-plugin/src/rules/no-unsafe-return.ts b/packages/eslint-plugin/src/rules/no-unsafe-return.ts
index fa301bafa65..ef308450bd8 100644
--- a/packages/eslint-plugin/src/rules/no-unsafe-return.ts
+++ b/packages/eslint-plugin/src/rules/no-unsafe-return.ts
@@ -104,7 +104,7 @@ export default createRule({
       // If there is an explicit type annotation *and* that type matches the actual
       // function return type, we shouldn't complain (it's intentional, even if unsafe)
       if (functionTSNode.type) {
-        for (const signature of functionType.getCallSignatures()) {
+        for (const signature of tsutils.getCallSignaturesOfType(functionType)) {
           if (
             returnNodeType === signature.getReturnType() ||
             isTypeFlagSet(
diff --git a/packages/eslint-plugin/tests/rules/no-unsafe-return.test.ts b/packages/eslint-plugin/tests/rules/no-unsafe-return.test.ts
index 42a798ffe11..36c6103bbc2 100644
--- a/packages/eslint-plugin/tests/rules/no-unsafe-return.test.ts
+++ b/packages/eslint-plugin/tests/rules/no-unsafe-return.test.ts
@@ -45,6 +45,14 @@ function foo() {
 function foo(): any {
   return {} as any;
 }
+    `,
+    `
+declare function foo(arg: () => any): void;
+foo((): any => 'foo' as any);
+    `,
+    `
+declare function foo(arg: null | (() => any)): void;
+foo((): any => 'foo' as any);
     `,
     // explicit any array return type is allowed, if you want to be unsafe like that
     `
@@ -408,5 +416,19 @@ function bar() {
         },
       ],
     },
+    {
+      code: `
+declare function foo(arg: null | (() => any)): void;
+foo(() => 'foo' as any);
+      `,
+      errors: [
+        {
+          messageId: 'unsafeReturn',
+          line: 3,
+          column: 11,
+          endColumn: 23,
+        },
+      ],
+    },
   ],
 });