Explicit Error classes

[floatdrop]

Before major release happen - maybe we should subclass error a little bit more, than GotError? For example we have parsing errors, http request errors, maxredirects errors, etc...

Sometimes it is useful to differentiate them by class, not by message.

One more concern is internal structure of errors - should we mimic error properties from Node 0.12 by default?

//cc @sindresorhus @kevva @julien-f

---

Related http://dailyjs.com/2014/01/30/exception-error/

[floatdrop]

Something like this:

diff --git a/index.js b/index.js
index 44f453a..b4bafb6 100644
--- a/index.js
+++ b/index.js
@@ -41,7 +32,7 @@ function requestAsEventEmitter(opts) {
                res.resume();

                if (++redirectCount > 10) {
-                   ee.emit('error', new GotError('Redirected 10 times. Aborting.'), undefined, res);
+                   ee.emit('error', new MaxRedirectsError(statusCode, {url: url}), undefined, res);
                    return;
                }

@@ -70,7 +61,7 @@ function requestAsEventEmitter(opts) {

            ee.emit('response', res);
        }).once('error', function (err) {
-           ee.emit('error', new GotError('Request to ' + url + ' failed', err));
+           ee.emit('error', new RequestError(err.message, {url: url, method: opts.method}));
        });

        if (opts.timeout) {
@@ -101,22 +92,21 @@ function asCallback(opts, cb) {
    ee.on('response', function (res) {
        readAllStream(res, opts.encoding, function (err, data) {
            if (err) {
-               cb(new GotError('Reading ' + url + ' response failed', err), null, res);
+               cb(new ReadError(err.message, {url: url}), null, res);
                return;
            }

            var statusCode = res.statusCode;

            if (statusCode < 200 || statusCode > 299) {
-               err = new GotError(opts.method + ' ' + url + ' response code is ' + statusCode + ' (' + http.STATUS_CODES[statusCode] + ')', err);
-               err.code = statusCode;
+               err = new HTTPError(statusCode, {url: url, method: opts.method});
            }

            if (opts.json && statusCode !== 204) {
                try {
                    data = JSON.parse(data);
                } catch (e) {
-                   err = new GotError('Parsing ' + url + ' response failed', new GotError(e.message, err));
+                   err = new ParseError(err.message, {url: url});
                }
            }

[sindresorhus]

👍

[kevva]

Yup, I like it too. +1 for more clarity.

[floatdrop]

Done in 1fe1e9a - please review 😃

[floatdrop]

There is one question, that's bothers me: should we store statusCode as code property? It was discussed in #9, but in other places people tend to use statusCode ((https://github.com/trentm/node-bunyan#log-record-fields, https://github.com/jshttp/http-errors).

[sindresorhus]

I prefer statusCode as it's a clearer intent.

[sindresorhus]

@floatdrop What happened to floatdrop@58bfb20 in the 4.0.0 PR? Did you back out of it?

[floatdrop]

@sindresorhus yup, I will send a PR with this soon.