From 0da1107858493b7ccf320e9b3c1d79e627adc998 Mon Sep 17 00:00:00 2001
From: Jonny Burger <jonathanburger11@gmail.com>
Date: Mon, 15 Jun 2026 16:25:02 +0200
Subject: [PATCH] [AI-generated] Fix unhandled rejection when disposing invalid
 input (#413)

* Fix input dispose rejection handling

* Move input disposal regression test
---
 src/input.ts            |  8 ++++++--
 test/node/input.test.ts | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)
 create mode 100644 test/node/input.test.ts

diff --git a/src/input.ts b/src/input.ts
index 747d3f4..211478c 100644
--- a/src/input.ts
+++ b/src/input.ts
@@ -527,8 +527,12 @@ export class Input<S extends Source = Source> extends EventEmitter<InputEvents>
 		}
 		this._sourceRefs.length = 0;
 
-		void this._demuxerPromise
-			?.then(demuxer => demuxer.dispose());
+		if (this._demuxerPromise) {
+			// The demuxer promise may already be rejected after failed format detection.
+			void this._demuxerPromise
+				.then(demuxer => demuxer.dispose())
+				.catch(() => {});
+		}
 	}
 
 	/**
diff --git a/test/node/input.test.ts b/test/node/input.test.ts
new file mode 100644
index 0000000..5e923af
--- /dev/null
+++ b/test/node/input.test.ts
@@ -0,0 +1,28 @@
+import { expect, test } from 'vitest';
+import { Input, UnsupportedInputFormatError } from '../../src/input.js';
+import { ALL_FORMATS } from '../../src/input-format.js';
+import { BufferSource } from '../../src/source.js';
+
+test('Disposing after failed format detection does not emit an unhandled rejection', async () => {
+	const input = new Input({
+		source: new BufferSource(new Uint8Array([1, 2, 3, 4])),
+		formats: ALL_FORMATS,
+	});
+
+	await expect(input.getFormat()).rejects.toThrow(UnsupportedInputFormatError);
+
+	const unhandledRejections: unknown[] = [];
+	const onUnhandledRejection = (reason: unknown) => {
+		unhandledRejections.push(reason);
+	};
+
+	process.on('unhandledRejection', onUnhandledRejection);
+	try {
+		input.dispose();
+		await new Promise(resolve => setTimeout(resolve, 0));
+	} finally {
+		process.off('unhandledRejection', onUnhandledRejection);
+	}
+
+	expect(unhandledRejections).toEqual([]);
+});