I am looking for a solution to test Meteor Methods with mocha. I am using Velocity and the Mocha package.
This is an example method I am trying to test.
Meteor.methods({
addPoints: function(userId, points) {
return Players.update(userId, { $inc: { score: +points } });
}
});
This is, in a round about way how I would call it using node, I want to call the methods with arguments and assert that in this case, it returns 1 for updating the mongo document
if (!(typeof MochaWeb === 'undefined')){
MochaWeb.testOnly(function(){
describe("Meteor Method: Upldating a player", function(){
// define the handler as the method we are testing
// May be this needs to be a before each.
var handler = Meteor.call("addPoints");
var userId = "1";
var points = 5;
describe("Updating a player", function() {
it("Should Add a point", function(done){
handler(userId, points, function() {
assert(handler.calledOnce);
// a way here of asserting the callback is what we expect,
// in this case we expect a return of 1
done();
});
});
});
});
});
}
Thanks
Assuming your tests run on the server, you should avoid sending a callback to the method call. This way, the Meteor method will run "synchronously" (in the fibers sense).
I would re-write the describe section as follows:
describe('Updating a player', function () {
beforeEach(function() {
handler(userId, points)
})
it('Should Add a point', function () {
assert(handler.calledOnce)
})
})
Related
How can I use mocks to count function calls made via call or apply
// mylib.js
module.exports = {
requestInfo: function(model, id) {
return `The information for ${model} with ID ${id} is foobar`;
},
execute: function(name) {
return this[name] && this[name].apply(this, [].slice.call(arguments, 1));
},
};
// mylib.test.js
jest.mock('./mylib.js');
var myLib = require('./mylib.js');
test('', () => {
myLib.execute('requestInfo', 'Ferrari', '14523');
expect(myLib.execute.mock.calls.length).toBe(1); // Success!
expect(myLib.requestInfo.mock.calls.length).toBe(1); // FAIL
});
If I explicitly call myLib.requestInfo, the second expectation succeeds.
Is there a way to watch module mock calls whose functions were called via apply or call?
From the jest.mock doc:
Mocks a module with an auto-mocked version when it is being required.
The docs could probably be improved with a better description of what "auto-mocked version" means, but what happens is that Jest keeps the API surface of the module the same while replacing the implementation with empty mock functions.
So in this case execute is getting called but it has been replaced by an empty mock function so requestInfo never gets called which causes the test to fail.
To keep the implementation of execute intact you will want to avoid auto-mocking the entire module and instead spy on the original function with something like jest.spyOn:
var myLib = require('./mylib.js');
test('', () => {
jest.spyOn(myLib, 'execute'); // spy on execute
jest.spyOn(myLib, 'requestInfo') // spy on requestInfo...
.mockImplementation(() => {}); // ...and optionally replace the implementation
myLib.execute('requestInfo', 'Ferrari', '14523');
expect(myLib.execute.mock.calls.length).toBe(1); // SUCCESS
expect(myLib.requestInfo.mock.calls.length).toBe(1); // SUCCESS
});
I have the following files:-
target.js
var target = function(repository, logger) {
return {
addTarget : function(target) {
repository.add(target).then(
function (newTarget) {
console.log("added");
logger.info("added");
},
function (err) {
console.log("error");
logger.info("error");
}
);
}
};
};
module.exports = target;
targetTest.js
var chai = require("chai"),
expect = chai.expect,
sinon = require("sinon"),
Promise = require("bluebird"),
baseTarget = require("../target");
describe("target", function(){
it("should log error when it occurs", function() {
var mockRepository = {
add : sinon.stub().returns(Promise.reject(new Error()))
};
var mockLogger = {
info : sinon.spy()
};
var target = baseTarget(mockRepository, mockLogger);
target.addTarget("target");
expect(mockLogger.info.calledWith("error")).to.be.true;
});
});
The issue I have is that expect(mockLogger.info.calledWith("error")).to.be.true; returns false because add method on the repository is async and so hasn't executed yet. Is there a pattern for doing this properly.
This is really more of a question about 'how Promises work' than how they work within test frameworks - the answer to which is that their behaviour remains exactly the same.
Is there a pattern for doing this properly.
It is not so much a pattern as it is what Promises are built to do. Each success handler of a then is executed in sequence on success of the last. In your code we can return the Promise created by calling repository#add as you would if you wanted to use its result or perform some external dependent operation outside of addTarget:
addTarget: function (target) {
return repository
// ^^^^^^
.add(target)
.then(function (newTarget) {
console.log("added");
logger.info("added");
}, function (err) {
console.log("error");
logger.info("error");
});
}
Then place your expectation inside a then that will be executed on success of all members of the Promise chain created in addTarget:
target.addTarget("target").then(function () {
expect(mockLogger.info.calledWith("error")).to.be.true;
cb();
});
Asynchronous Tests
You will notice in the example above that there is also a call to a function cb. Due to your test being asynchronous you need to 'tell' the test framework when the test has completed. This is most often done by declaring your it function with a parameter, from which the framework will infer that the test is asynchronous and pass in a callback:
describe("target", function () {
it("should log error when it occurs", function (cb) {
// ^^^^
});
});
Given a data structure that satisfies some invariants, I would like to test the state of an instance of the data structure after various operations. What is the best way to do this?
describe('data-structure', function() {
var x;
beforeEach(function() {
x = getDataStructure();
});
describe('satisfies invariants', function() {
// run tests on 'fresh' x
it('should ...', function() {
// ...
});
// ...
});
describe('operation 1', function() {
it('should preserve invariants', function() {
x.doSomething();
// run 'satisfies invariants' tests on modified x
});
});
});
I thought about using an afterEach hook, but I do not think x is preserved there?
afterEach(function() {
// somehow run 'satisfies invariants' test
});
It maybe be that I can refactor 'satisfies invariants' into a method, but it would be nice if mocha could report which invariant-tests failed for each operation, e.g.
data-structure
satisfies invariants
should satisfy invariant 1 ...
...
operation 1
should satisfy invariant 1 ...
...
operation 2
should satisfy invariant 1 ...
...
Edit
Using the structure
describe('data-structure', function() {
var x;
describe('satisfies invariants', function() {
afterEach(function() {
it('should satisfy invariant 1', function() {
// x.value === a again
// ...
});
// ...
});
it('should work after operation 1', function() {
x = getDataStructure(); // x.value === a
x.operation1(); // x.value === b
});
it('should work after operation 2', function() {
x = getDataStructure();
x.operation2();
});
// ...
});
});
does not seem to preserve the changes to x.
It follows an example, let me know if I forget something of what we have discussed:
var assert = require('assert');
describe('data-structure', function() {
var x;
beforeEach(function() {
// freshly created data structure for each describe block below
x = getDataStructure;
});
describe('satisfies invariants', function() {
after(function() {
// it executes those tests only once after all the it block below
assert(x); // put your tests here
});
it('op 1.1', function() {
do_something_on(x);
});
it('op 1.2', function() {
// keep in mind that x is the same instance of the previous test
do_something_else_on(x);
});
// so on
});
describe('satisfies something else', function() {
// here you have a new instance of x, because of the outer beforeeach
after(function() {
// it executes those tests only once after all the it block within this describe block
assert(x); // put your tests here
});
it('op 2.1', function() {
do_something_on(x);
});
it('op 2.2', function() {
// keep in mind that x is the same instance of the previous test, but not the one used in 1.2
do_something_else_on(x);
});
// so on
});
// so on
});
This piece of code should give you an idea of which instance is accessible and where.
If it lacks something, let me know and I'll have a go to fix it.
The Problem
Mocha does not support putting it inside a hook like you do in your last snippet. (afterEach is a hook). In some trivial cases you may get the desired behavior but that's just luck. Once you move on to more complicated test suites, you won't get the behavior your expect.
Moreover, I suggest that afterEach is the wrong place for that kind of test. You should use the hooks only to setup and tear down your test environment and not for performing assertions on the state of your code. Mocha treats any failure in a hook as "the test suite is broken, abort!!" rather than as a test failure. Look at this example, for instance:
var assert = require('assert');
describe("test", function () {
var x;
beforeEach(function () {
x = { foo: 'something' };
});
afterEach(function () {
assert(x.foo === 'something');
});
it("one", function () {});
it("two", function () {
x.foo = 'something else';
});
it("three", function () {});
});
In theory there's no reason test three should not run but when the failure occurs in the afterEach hook after test two is run, Mocha will just stop running tests there. The output (omitting the final stack trace) is:
test
✓ one
✓ two
1) "after each" hook
2 passing (14ms)
1 failing
Note how two is marked as passing but the hook failed. And note how three is never even attempted. As soon as there is a failure in a hook, Mocha stops right there.
The Solution
You should just create a function that you call from each test to test your invariants. For instance:
var assert = require('assert');
describe("test", function () {
var x;
beforeEach(function () {
x = { foo: 'something' };
});
function testInvariant() {
assert(x.foo === 'something');
}
it("one", function () {
testInvariant();
});
it("two", function () {
x.foo = 'something else';
testInvariant();
});
it("three", function () {
testInvariant();
});
});
If you run Mocha on the code above, you'll get (again, omitting the final stack trace):
test
✓ one
1) two
✓ three
2 passing (10ms)
1 failing
two was marked as failed and Mocha moved on to run three, which was successful.
If you don't want to write testInvariant() in each test you could create a function that adds it for you. For instance:
var assert = require('assert');
describe("test", function () {
var x;
beforeEach(function () {
x = { foo: 'something' };
});
function makeTest(name, fn) {
it(name, function () {
fn();
assert(x.foo === 'something');
});
}
makeTest("one", function () {
});
makeTest("two", function () {
x.foo = 'something else';
});
makeTest("three", function () {
});
});
This produces the same output as the previous code snippet.
I am using a database library that its callback-based interface looks like this:
var DB = {
insert: function(options, callback) {
}
}
I want to implement a wrapper around this database to convert its callback style API to a promise based API. To do this I have defined the following class:
var DatabaseWrapper = {
init: function(db) {
this.db = db;
},
insert: function(options) {
return Q.denodeify(this.db.insert.bind(this.db))(options);
}
}
I want to write a unit test to ensure that when I call DatabaseWrapper.insert it calls DB.insert. So far my test looks like this:
describe('DatabaseWrapper', function () {
var wrapper, insertSpy, bindStub;
beforeEach(function () {
wrapper = Object.create(DatabaseWrapper);
insertSpy = sinon.spy(function () {
console.log('insertSpy got called');
});
bindStub = sinon.stub();
wrapper.db = {
insert: function (options, callback) {
}
};
sinon.stub(wrapper.db.insert, 'bind').returns(insertSpy);
});
describe('#insert', function () {
it('should delegate to db.insert', function (done) {
wrapper.insert({herp: 'derp'});
expect(wrapper.db.insert.bind).to.have.been.calledOnce;
// This fails but I expect it to succeed
expect(promise).to.have.been.calledOnce;
})
});
});
The DB instance's insert method is actually getting called as after the test fails, as the 'insertSpy got called' message is printed in the console.
But apparently it gets called after the test has failed.
As far as I know, this is due to the way Node's process.nextTick works. So the call to the callback happens after the test fails. Is there a way I can fix this test without relying on third-party libraries (e.g. q-flush)?
You're performing an asynchronous action so it's best to perform an asynchronous test. Adding a setTimeout still leaves you prone to race conditions.
describe('#insert', function () {
it('should delegate to db.insert', function () { // no done here
// note the return here to signal to mocha this is a promise test
return wrapper.insert({herp: 'derp'}).then(function(){
// add expects here, rest of asserts should happen here
expect(wrapper.db.insert.bind).to.have.been.calledOnce;
});
})
});
});
I'm trying to create a module that will fill in form inputs when functional testing, and I'd like to be able to call it from multiple test suites.
Pseudo code for the helper file (helper.js)
module.exports = {
fillForm: function() {
this.findByCssSelector('#firstname')
.click()
.pressKeys('John')
.end()
},
anotherFunction: function() {
// more code
}
}
In the spec for the functional test, I load that module as helper and I can see it execute. However, it seems I can't use this syntax and guarantee that the chained steps execute in the defined order:
'Test filling form data': function() {
return this.remote
.get(require(toUrl(url))
// should happen first
.then(helper.fillForm)
// should happen second
.then(helper.anotherFunction)
// only after the above should the click happen
.findByCsSelector('#submit')
// click evt should show the #someElement element
.click()
.findByCssSelector('#someElement')
.getComputedStyle('display')
.then(style) {
// assertions here
}
It seems that the promise chaining allows the click event to happen before the then callbacks have executed. Is this sort of flow possible with intern?
UPDATE:
For the moment, working around this with this sort of code:
var remote = initTest.call(this, url);
return helpers.fillForm1Data.call(remote)
.otherChainedMethodsHere()
.moreChainedMethods()
.then() {
// assertion code here
where the initTest method does url fetching, window sizing, clearing data, and the fillForm1Data does as you'd expect. But the syntax is pretty ugly this way.
Your helper is not returning any value so it is treated as a synchronous callback and the next thing in the chain is executed immediately. You also cannot return this from a promise helper or it will cause a deadlock (because the Command promise will be waiting for itself to resolve—Intern will throw an error instead if you try to do this), so you need to create a new Command and return that if you want to use the chained Command interface within your helper:
module.exports = {
fillForm: function() {
return new this.constructor(this.session)
.findByCssSelector('#firstname')
.click()
.pressKeys('John');
},
anotherFunction: function() {
// more code
}
};
You can also just return from this.session instead if you don’t care about the convenience of the Command API and can deal with normal promise callback chains:
module.exports = {
fillForm: function() {
var session = this.session;
return session.findByCssSelector('#firstname')
.then(function (element) {
return element.click();
})
.then(function () {
return session.pressKeys('John');
});
},
anotherFunction: function() {
// more code
}
};