From d8637d69836f1483c705821a63ac3dd4530c6538 Mon Sep 17 00:00:00 2001
From: Gil Pedersen <git@gpost.dk>
Date: Sat, 26 Oct 2024 14:25:40 +0200
Subject: [PATCH] Improve boomify typings

---
 lib/index.d.ts | 7 +++----
 test/index.ts  | 5 +++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/index.d.ts b/lib/index.d.ts
index 1947522..3ed9367 100755
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -156,10 +156,9 @@ export function isBoom(obj: unknown, statusCode?: number): obj is Boom;
 *
 * @returns A boom object
 */
-export function boomify<Data, Decoration>(err: Boom<Data>, options?: BoomifyOptions<Data> & { decorate: Decoration }): Boom<Data> & Decoration;
-export function boomify<Data, Decoration>(err: unknown, options?: BoomifyOptions<Data> & { decorate: Decoration }): Boom<Data> & Decoration;
-export function boomify<Data extends object>(err: Boom<Data>, options?: BoomifyOptions<Data>): Boom<Data>;
-export function boomify<Data>(err: unknown, options?: BoomifyOptions<Data>): Boom<Data>;
+export function boomify<Terr, Data, Decoration>(err: Terr, options: BoomifyOptions<Data> & { decorate: Decoration, data: Data }): (Terr extends Boom ? Terr : Boom<Data>) & Omit<Decoration, 'data'>;
+export function boomify<Terr, Data, Decoration>(err: Terr, options: BoomifyOptions<Data> & { decorate: Decoration }): (Terr extends Boom ? Terr : Boom<Data>) & Decoration;
+export function boomify<Terr, Data = any>(err: Terr, options?: BoomifyOptions<Data>): Terr extends Boom ? Terr : Boom<Data>;
 
 // 4xx Errors
 
diff --git a/test/index.ts b/test/index.ts
index 387e0d9..b4cbd48 100755
--- a/test/index.ts
+++ b/test/index.ts
@@ -50,12 +50,17 @@ expect.type<Boom.Output['headers']>(boom.output.headers);
 // boomify()
 
 const error = new Error('Unexpected input');
+class BadaBoom extends Boom.Boom {}
 
 expect.type<Boom.Boom>(Boom.boomify(error, { statusCode: 400 }));
 expect.type<Boom.Boom>(Boom.boomify(error, { statusCode: 400, message: 'Unexpected Input', override: false }));
 expect.type<number>(Boom.boomify(error, { decorate }).x);
 expect.type<Boom.Boom>(Boom.boomify('error'));
 expect.type<Boom.Boom<{ foo: 'bar' }>>(Boom.boomify(new Boom.Boom<{ foo: 'bar' }>()));
+expect.type<number>(Boom.boomify(error, { decorate: { data: 1 } }).data);
+expect.type<string>(Boom.boomify(error, { decorate: { data: 1 }, data: 'bla' }).data);
+expect.type<string>(Boom.boomify(error, { data: 'bla' }).data);
+expect.type<BadaBoom>(Boom.boomify(new BadaBoom(), { statusCode: 400 }));
 
 expect.error(Boom.boomify(error, { statusCode: '400' }));
 expect.error(Boom.boomify(error, { statusCode: 400, message: true }));