Add some more argument validation

src/source.ts

@@ -15,24 +15,28 @@ export abstract class Source {
 }
 
 /** @public */
-export class ArrayBufferSource extends Source {
+export class BufferSource extends Source {
 	/** @internal */
-	_buffer: ArrayBuffer;
+	_bytes: Uint8Array;
+
+	constructor(buffer: ArrayBuffer | Uint8Array) {
+		if (!(buffer instanceof ArrayBuffer) && !(buffer instanceof Uint8Array)) {
+			throw new TypeError('buffer must be an ArrayBuffer or Uint8Array.');
+		}
 
-	constructor(buffer: ArrayBuffer) {
 		super();
 
-		this._buffer = buffer;
+		this._bytes = buffer instanceof Uint8Array ? buffer : new Uint8Array(buffer);
 	}
 
 	/** @internal */
 	override async _read(start: number, end: number) {
-		return new Uint8Array(this._buffer, start, end - start);
+		return this._bytes.subarray(start, end);
 	}
 
 	/** @internal */
 	override async _retrieveSize() {
-		return this._buffer.byteLength;
+		return this._bytes.byteLength;
 	}
 }
 
@@ -42,6 +46,10 @@ export class BlobSource extends Source {
 	_blob: Blob;
 
 	constructor(blob: Blob) {
+		if (!(blob instanceof Blob)) {
+			throw new TypeError('blob must be a Blob.');
+		}
+
 		super();
 
 		this._blob = blob;