## Follow Redirects
Drop-in replacement for Node's `http` and `https` modules that automatically follows redirects.
[](https://www.npmjs.com/package/follow-redirects)
[](https://github.com/follow-redirects/follow-redirects/actions)
[](https://coveralls.io/r/follow-redirects/follow-redirects?branch=master)
[](https://www.npmjs.com/package/follow-redirects)
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`follow-redirects` provides [request](https://nodejs.org/api/http.html#http_http_request_options_callback) and [get](https://nodejs.org/api/http.html#http_http_get_options_callback)
methods that behave identically to those found on the native [http](https://nodejs.org/api/http.html#http_http_request_options_callback) and [https](https://nodejs.org/api/https.html#https_https_request_options_callback)
modules, with the exception that they will seamlessly follow redirects.
```javascript
const { http, https } = require('follow-redirects');
http.get('http://bit.ly/900913', response => {
response.on('data', chunk => {
console.log(chunk);
});
}).on('error', err => {
console.error(err);
});
```
You can inspect the final redirected URL through the `responseUrl` property on the `response`.
If no redirection happened, `responseUrl` is the original request URL.
```javascript
const request = https.request({
host: 'bitly.com',
path: '/UHfDGO',
}, response => {
console.log(response.responseUrl);
// 'http://duckduckgo.com/robots.txt'
});
request.end();
```
## Options
### Global options
Global options are set directly on the `follow-redirects` module:
```javascript
const followRedirects = require('follow-redirects');
followRedirects.maxRedirects = 10;
followRedirects.maxBodyLength = 20 * 1024 * 1024; // 20 MB
```
The following global options are supported:
- `maxRedirects` (default: `21`) – sets the maximum number of allowed redirects; if exceeded, an error will be emitted.
- `maxBodyLength` (default: 10MB) – sets the maximum size of the request body; if exceeded, an error will be emitted.
### Per-request options
Per-request options are set by passing an `options` object:
```javascript
const url = require('url');
const { http, https } = require('follow-redirects');
const options = url.parse('http://bit.ly/900913');
options.maxRedirects = 10;
options.beforeRedirect = (options, response, request) => {
// Use this to adjust the request options upon redirecting,
// to inspect the latest response headers,
// or to cancel the request by throwing an error
// response.headers = the redirect response headers
// response.statusCode = the redirect response code (eg. 301, 307, etc.)
// request.url = the requested URL that resulted in a redirect
// request.headers = the headers in the request that resulted in a redirect
// request.method = the method of the request that resulted in a redirect
if (options.hostname === "example.com") {
options.auth = "user:password";
}
};
http.request(options);
```
In addition to the [standard HTTP](https://nodejs.org/api/http.html#http_http_request_options_callback) and [HTTPS options](https://nodejs.org/api/https.html#https_https_request_options_callback),
the following per-request options are supported:
- `followRedirects` (default: `true`) – whether redirects should be followed.
- `maxRedirects` (default: `21`) – sets the maximum number of allowed redirects; if exceeded, an error will be emitted.
- `maxBodyLength` (default: 10MB) – sets the maximum size of the request body; if exceeded, an error will be emitted.
- `beforeRedirect` (default: `undefined`) – optionally change the request `options` on redirects, or abort the request by throwing an error.
- `agents` (default: `undefined`) – sets the `agent` option per protocol, since HTTP and HTTPS use different agents. Example value: `{ http: new http.Agent(), https: new https.Agent() }`
- `trackRedirects` (default: `false`) – whether to store the redirected response details into the `redirects` array on the response object.
### Advanced usage
By default, `follow-redirects` will use the Node.js default implementations
of [`http`](https://nodejs.org/api/http.html)
and [`https`](https://nodejs.org/api/https.html).
To enable features such as caching and/or intermediate request tracking,
you might instead want to wrap `follow-redirects` around custom protocol implementations:
```javascript
const { http, https } = require('follow-redirects').wrap({
http: require('your-custom-http'),
https: require('your-custom-https'),
});
```
Such custom protocols only need an implementation of the `request` method.
## Browser Usage
Due to the way the browser works,
the `http` and `https` browser equivalents perform redirects by default.
By requiring `follow-redirects` this way:
```javascript
const http = require('follow-redirects/http');
const https = require('follow-redirects/https');
```
you can easily tell webpack and friends to replace
`follow-redirect` by the built-in versions:
```json
{
"follow-redirects/http" : "http",
"follow-redirects/https" : "https"
}
```
## Contributing
Pull Requests are always welcome. Please [file an issue](https://github.com/follow-redirects/follow-redirects/issues)
detailing your proposal before you invest your valuable time. Additional features and bug fixes should be accompanied
by tests. You can run the test suite locally with a simple `npm test` command.
## Debug Logging
`follow-redirects` uses the excellent [debug](https://www.npmjs.com/package/debug) for logging. To turn on logging
set the environment variable `DEBUG=follow-redirects` for debug output from just this module. When running the test
suite it is sometimes advantageous to set `DEBUG=*` to see output from the express server as well.
## Authors
- [Ruben Verborgh](https://ruben.verborgh.org/)
- [Olivier Lalonde](mailto:olalonde@gmail.com)
- [James Talmage](mailto:james@talmage.io)
## License
[MIT License](https://github.com/follow-redirects/follow-redirects/blob/master/LICENSE)
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