resolve typescript buffer-to-uint8array type mismatches

[Mohit-Davar]

Description

This PR resolves three TypeScript compilation errors in src/utils/event.ts caused by incompatibility between Buffer and the stricter Uint8Array<ArrayBuffer> requirements in modern TypeScript environments.

The fix explicitly wraps Buffer instances using new Uint8Array() or introduces type-safe checks to ensure compatibility with cryptographic functions used by noble-secp256k1 and Node.js crypto APIs.

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Related Issue

Fixes #444

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Motivation and Context

Modern TypeScript definitions enforce stricter typing for Uint8Array, often requiring a strict ArrayBuffer backing. Although Node.js Buffer extends Uint8Array, it internally relies on ArrayBufferLike (which may include SharedArrayBuffer), leading to "is not assignable" errors under strict type checking.

This change ensures:

• Full TypeScript compatibility
• Type safety in cryptographic operations
• Successful project compilation in newer TypeScript and Node.js environments

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How Has This Been Tested?

• Verified that the TypeScript compiler no longer reports errors in src/utils/event.ts
• Confirmed no runtime behavior changes

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Screenshots (if appropriate)

N/A

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Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

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Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have read the CONTRIBUTING document
• I have added tests to cover my code changes
• All new and existing tests passed

[cameri]

@Mohit-Davar we use commitlint with Conventional Commits in this repository, do you mind ensuring your commits adhere to it? Otherwise ci checks will fail

[Copilot]

Pull request overview

This PR addresses TypeScript compile errors in src/utils/event.ts caused by stricter Uint8Array<ArrayBuffer> typing expectations when passing Node.js Buffer values into noble-secp256k1 and Node crypto APIs (Fixes #444).

Changes:

• Wraps event-serialization bytes in a Uint8Array before hashing with secp256k1.utils.sha256.
• Ensures getSharedSecret receives a type-compatible private key by converting Buffer inputs to Uint8Array.
• Passes a Uint8Array key into createCipheriv to satisfy stricter CipherKey typing.

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[Copilot]

new Uint8Array(key) copies the 32-byte shared secret before passing it into createCipheriv. If the goal is only to satisfy stricter typings, consider reusing the existing bytes with a view/type-narrowing approach (or a small helper used across this file) to avoid the extra allocation.

Suggested change

	new Uint8Array(key),
	key,

[Copilot]

new Uint8Array(Buffer.from(...)) creates a full copy of the serialized event bytes. If getEventHash is on a hot path and events can be large, consider using a zero-copy Uint8Array view over the Buffer’s underlying ArrayBuffer when it’s an ArrayBuffer (and only fall back to copying when the backing buffer is a SharedArrayBuffer). This preserves the type fix while avoiding an extra allocation/copy.

Suggested change

	const id = await secp256k1.utils.sha256(new Uint8Array(Buffer.from(JSON.stringify(serializeEvent(event)))))
	const serializedEvent = Buffer.from(JSON.stringify(serializeEvent(event)))
	const serializedEventBytes =
	serializedEvent.buffer instanceof SharedArrayBuffer
	? new Uint8Array(serializedEvent)
	: new Uint8Array(
	serializedEvent.buffer,
	serializedEvent.byteOffset,
	serializedEvent.byteLength,
	)
	const id = await secp256k1.utils.sha256(serializedEventBytes)

[cameri]

@Mohit-Davar Agree with Copilot here.