from-node-stream/src/readable/attach-handlers.js

"use strict";

const debug = require("debug")("promistream:from-node-stream:readable:attach-handlers");

const objectID = require("../object-id");

module.exports = function attachReadableStreamHandlers({ stream, onClose, onError, onData }) {
	function detachEventHandlers() {
		debug(`[#${objectID(stream)}] Detaching event handlers`);
		stream.removeListener("end", onCloseWrapper);
		stream.removeListener("close", onCloseWrapper);
		stream.removeListener("error", onErrorWrapper);
		stream.removeListener("data", onData);
	}

	function attachEventHandlers() {
		debug(`[#${objectID(stream)}] Attaching event handlers`);
		stream.on("end", onCloseWrapper);
		stream.on("close", onCloseWrapper);
		stream.on("error", onErrorWrapper);
		stream.on("data", onData);
	}

	function onCloseWrapper() {
		debug(`[#${objectID(stream)}] onCloseWrapper called`);
		onClose();
		detachEventHandlers();
	}

	function onErrorWrapper(error) {
		debug(`[#${objectID(stream)}] onErrorWrapper called`);
		onError(error);
		detachEventHandlers();
	}

	attachEventHandlers();
};