bytebuffer.js

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Since all the 'static' functions (like concat, wrap, etc) use the ByteBuffer definition itself instead of "this", it's hard to subclass it. By using this.constructor and this (in static) instead of forcefully deriving from ByteBuffer, it can work. I can submit a patch, and I think it won't break anything, but will make it easier to add methods to the class without monkeypatching it

export class BB extends ByteBuffer {

    static allocate( capacity?: number, littleEndian?: number, noAssert?: boolean ): BB {
        var c: BB = <any>super.allocate(capacity, littleEndian, noAssert);
        c.readBytes = this.prototype.readBytes;
        c.refresh = this.prototype.refresh;
        return c;
    }

    static wrap( buffer: ByteBuffer | Buffer | ArrayBuffer | Uint8Array | string | Array<number>, enc?: string | boolean, littleEndian?: boolean, noAssert?: boolean ): BB {
        var c: BB = <any>super.wrap(buffer, enc, littleEndian, noAssert);
        c.readBytes = this.prototype.readBytes;
        c.refresh = this.prototype.refresh;
        return c;
    }

    static concat( buffers: Array<ByteBuffer | Buffer |  ArrayBuffer | Uint8Array | string>, encoding?: string | boolean, litteEndian?: boolean, noAssert?: boolean ): BB {
        var c: BB = <any>super.concat(buffers, encoding, litteEndian, noAssert);
        c.readBytes = this.prototype.readBytes;
        c.refresh = this.prototype.refresh;
        return c;
    }

}

So, what you are proposing basically is to change https://github.com/dcodeIO/bytebuffer.js/blob/master/src/methods/static/allocate.js#L12 and similar to:

return new this(capacity, littleEndian, noAssert);

Correct?

Yup, exactly that, so it can be inherited from without those hacks. and when instance methods like clone, copy that returns a new ByteBuffer, should be new this.constructor()

So, is this pattern safe to use across (not so modern) browsers?

Yup, you can check in built-in classes, like [].constructor, ({}).constructor, (0).constructor,(function(){}).constructor and so on, it's from the first version of JS (1.1ish I think)