Node Express testing mock res.status(status).json(obj) - node.js

Question

I get the following error when trying to test my method:
TypeError: Cannot call method 'json' of undefined
Below is my code, i'd get the same error for 'status' if i remove res.status from the test method.
How do i define 'json' so i dont get an exception thrown at:
res.status(404).json(error);
when testing this function.
stores.js
{ //the get function declared above (removed to ease of reading)
// using a queryBuilder
var query = Stores.find();
query.sort('storeName');
query.exec(function (err, results) {
if (err)
res.send(err);
if (_.isEmpty(results)) {
var error = {
message: "No Results",
errorKey: "XXX"
}
res.status(404).json(error);
return;
}
return res.json(results);
});
}
storesTest.js
it('should on get call of stores, return a error', function () {
var mockFind = {
sort: function(sortOrder) {
return this;
},
exec: function (callback) {
callback('Error');
}
};
Stores.get.should.be.a["function"];
// Set up variables
var req,res;
req = {query: function(){}};
res = {
send: function(){},
json: function(err){
console.log("\n : " + err);
},
status: function(responseStatus) {
assert.equal(responseStatus, 404);
}
};
StoresModel.find = sinon.stub().returns(mockFind);
Stores.get(req,res);

Answer 1

The status method happens to be a chainable method. The convention for chainable methods is to always return this at the end. In your tests, you mock up the res.status method but forgot to return this;.
res = {
send: function(){ },
json: function(err){
console.log("\n : " + err);
},
status: function(responseStatus) {
assert.equal(responseStatus, 404);
// This next line makes it chainable
return this;
}
}