Improve error with invalid arguments to req.get()

fixes #2993

History.md

@@ -4,6 +4,7 @@ unreleased
   * Add `options` argument to `req.range`
     - Includes the `combine` option
   * Fix Windows absolute path check using forward slashes
+  * Improve error with invalid arguments to `req.get()`
   * Improve performance for `res.json`/`res.jsonp` in most cases
   * deps: accepts@~1.3.3
     - Fix including type extensions in parameters in `Accept` parsing

lib/request.js

@@ -57,6 +57,14 @@ var req = exports = module.exports = {
 
 req.get =
 req.header = function header(name) {
+  if (!name) {
+    throw new TypeError('name argument is required to req.get');
+  }
+
+  if (typeof name !== 'string') {
+    throw new TypeError('name must be a string to req.get');
+  }
+
   var lc = name.toLowerCase();
 
   switch (lc) {

test/req.get.js

@@ -31,5 +31,29 @@ describe('req', function(){
       .set('Referrer', 'http://foobar.com')
       .expect('http://foobar.com', done);
     })
+
+    it('should throw missing header name', function (done) {
+      var app = express()
+
+      app.use(function (req, res) {
+        res.end(req.get())
+      })
+
+      request(app)
+      .get('/')
+      .expect(500, /TypeError: name argument is required to req.get/, done)
+    })
+
+    it('should throw for non-string header name', function (done) {
+      var app = express()
+
+      app.use(function (req, res) {
+        res.end(req.get(42))
+      })
+
+      request(app)
+      .get('/')
+      .expect(500, /TypeError: name must be a string to req.get/, done)
+    })
   })
-})
+})