From a0e71d5adde315bc071d954b7029ae0dbcded00e Mon Sep 17 00:00:00 2001
From: sid <48153483+siddsriv@users.noreply.github.com>
Date: Thu, 2 Jan 2025 17:35:47 -0500
Subject: [PATCH] fix(smithy-client): remove support for instanceof operator in
 ServiceException (#1486)

* fix(smithy-client): remove support for instanceof operator in ServiceException

* chore(smithy-client): add changeset
---
 .changeset/curvy-cups-fly.md                  |  5 +++++
 packages/smithy-client/src/exceptions.spec.ts | 14 --------------
 packages/smithy-client/src/exceptions.ts      |  4 ----
 3 files changed, 5 insertions(+), 18 deletions(-)
 create mode 100644 .changeset/curvy-cups-fly.md

diff --git a/.changeset/curvy-cups-fly.md b/.changeset/curvy-cups-fly.md
new file mode 100644
index 00000000000..5e934c90817
--- /dev/null
+++ b/.changeset/curvy-cups-fly.md
@@ -0,0 +1,5 @@
+---
+"@smithy/smithy-client": minor
+---
+
+fix(smithy-client): remove support for instanceof operator
diff --git a/packages/smithy-client/src/exceptions.spec.ts b/packages/smithy-client/src/exceptions.spec.ts
index fc591f96a3e..5aecb9553db 100644
--- a/packages/smithy-client/src/exceptions.spec.ts
+++ b/packages/smithy-client/src/exceptions.spec.ts
@@ -69,20 +69,6 @@ describe("ServiceException type checking", () => {
       expect(ServiceException.isInstance({ $metadata: {} })).toBe(false);
     });
   });
-
-  describe("instanceof", () => {
-    it("should return true for ServiceException instances", () => {
-      expect(error instanceof ServiceException).toBe(true);
-    });
-
-    it("should return true for duck-typed objects", () => {
-      expect(duckTyped instanceof ServiceException).toBe(true);
-    });
-
-    it("should return false for invalid objects", () => {
-      expect({} instanceof ServiceException).toBe(false);
-    });
-  });
 });
 
 describe("decorateServiceException", () => {
diff --git a/packages/smithy-client/src/exceptions.ts b/packages/smithy-client/src/exceptions.ts
index 298fd40a65a..922c230f229 100644
--- a/packages/smithy-client/src/exceptions.ts
+++ b/packages/smithy-client/src/exceptions.ts
@@ -50,10 +50,6 @@ export class ServiceException extends Error implements SmithyException, Metadata
       (candidate.$fault === "client" || candidate.$fault === "server")
     );
   }
-
-  public static [Symbol.hasInstance](instance: unknown) {
-    return ServiceException.isInstance(instance);
-  }
 }
 
 /**