feat: Extend res.links() to allow adding multiple links with the same rel (closes #2729) (#4885)

Author: andvea

History.md

@@ -11,6 +11,7 @@ unreleased
 * Remove unused `depd` dependency
 * Add support for `Uint8Array` in `res.send`
 * Add support for ETag option in res.sendFile
+* Extend res.links() to allow adding multiple links with the same rel
 * deps: debug@^4.4.0
 * deps: body-parser@^2.1.0
 * deps: router@^2.1.0

lib/response.js

@@ -80,19 +80,30 @@ res.status = function status(code) {
  *
  * res.links({
  * next: 'http://api.example.com/users?page=2',
- * last: 'http://api.example.com/users?page=5'
+ * last: 'http://api.example.com/users?page=5',
+ * pages: [
+ * 'http://api.example.com/users?page=1',
+ * 'http://api.example.com/users?page=2'
+ * ]
  * });
  *
  * @param {Object} links
  * @return {ServerResponse}
  * @public
  */
 
-res.links = function(links){
+res.links = function(links) {
  var link = this.get('Link') || '';
  if (link) link += ', ';
- return this.set('Link', link + Object.keys(links).map(function(rel){
- return '<' + links[rel] + '>; rel="' + rel + '"';
+ return this.set('Link', link + Object.keys(links).map(function(rel) {
+ // Allow multiple links if links[rel] is an array
+ if (Array.isArray(links[rel])) {
+ return links[rel].map(function (singleLink) {
+ return `<${singleLink}>; rel="${rel}"`;
+ }).join(', ');
+ } else {
+ return `<${links[rel]}>; rel="${rel}"`;
+ }
  }).join(', '));
 };
 

test/res.links.js

@@ -43,5 +43,23 @@ describe('res', function(){
  .expect('Link', '<http://api.example.com/users?page=2>; rel="next", <http://api.example.com/users?page=5>; rel="last", <http://api.example.com/users?page=1>; rel="prev"')
  .expect(200, done);
  })
+
+ it('should set multiple links for single rel', function (done) {
+ var app = express();
+
+ app.use(function (req, res) {
+ res.links({
+ next: 'http://api.example.com/users?page=2',
+ last: ['http://api.example.com/users?page=5', 'http://api.example.com/users?page=1']
+ });
+
+ res.end();
+ });
+
+ request(app)
+ .get('/')
+ .expect('Link', '<http://api.example.com/users?page=2>; rel="next", <http://api.example.com/users?page=5>; rel="last", <http://api.example.com/users?page=1>; rel="last"')
+ .expect(200, done);
+ })
  })
 })