Is there a way to test roblox games? - testing

Question

As I started to understand a little bit more about Roblox, I was wondering if there is any possible way to automate the testing. As a first step only on the Lua scripting, but ideally also simulating the game and interactions.
Is there any way of doing such a thing?
Also if there are already best practices on doing testing on Roblox(this includes Lua scripting) I would like to know more about them.

Answer 1

Unit Testing
For lua modules, I would recommend the library TestEZ. It was developed in-house by Roblox engineers to allow for behavior driven tests. It allows you to specify a location where test files exist and will gives you pretty detailed output as to how your tests did.
This example will run in RobloxStudio, but you can pair it with other libraries like Lemur for command-line and continuous integration workflows. Anyways, follow these steps :
1. Get the TestEZ Library into Roblox Studio
Download Rojo. This program allows you to convert project directories into .rbxm (Roblox model object) files.
Download the TestEZ source code.
Open a Powershell or Terminal window and navigate into the downloaded TestEZ directory.
Build the TestEZ library with this command rojo build --output TestEZ.rbxm .
Make sure that it generated a new file called TestEZ.rbxm in that directory.
Open RobloxStudio to your place.
Drag the newly created TestEZ.rbxm file into the world. It will unpack the library into a ModuleScript with the same name.
Move this ModuleScript somewhere like ReplicatedStorage.
2. Create unit tests
In this step we need to create ModuleScripts with names ending in `.spec` and write tests for our source code.
A common way to structure code is with your code classes in ModuleScripts and their tests right next to them. So let's say you have a simple utility class in a ModuleScript called MathUtil
local MathUtil = {}
function MathUtil.add(a, b)
assert(type(a) == "number")
assert(type(b) == "number")
return a + b
end
return MathUtil
To create tests for this file, create a ModuleScript next to it and call it MathUtil.spec. This naming convention is important, as it allows TestEZ to discover the tests.
return function()
local MathUtil = require(script.parent.MathUtil)
describe("add", function()
it("should verify input", function()
expect(function()
local result = MathUtil.add("1", 2)
end).to.throw()
end)
it("should properly add positive numbers", function()
local result = MathUtil.add(1, 2)
expect(result).to.equal(3)
end)
it("should properly add negative numbers", function()
local result = MathUtil.add(-1, -2)
expect(result).to.equal(-3)
end)
end)
end
For a full breakdown on writing tests with TestEZ, please take a look at the official documentation.
3. Create a test runner
In this step, we need to tell TestEZ where to find our tests. So create a Script in ServerScriptService with this :
local TestEZ = require(game.ReplicatedStorage.TestEZ)
-- add any other root directory folders here that might have tests
local testLocations = {
game.ServerStorage,
}
local reporter = TestEZ.TextReporter
--local reporter = TestEZ.TextReporterQuiet -- use this one if you only want to see failing tests
TestEZ.TestBootstrap:run(testLocations, reporter)
4. Run your tests
Now we can run the game and check the Output window. We should see our tests output :
Test results:
[+] ServerStorage
[+] MathUtil
[+] add
[+] should properly add negative numbers
[+] should properly add positive numbers
[+] should verify input
3 passed, 0 failed, 0 skipped - TextReporter:87
Automation Testing
Unfortunately, there does not exist a way to fully automate the testing of your game.
You can use TestService to create tests that automate the testing of some interactions, like a player touching a kill block or checking bullet paths from guns. But there isn't a publicly exposed way to start your game, record inputs, and validate the game state.
There's an internal service for this, and a non-scriptable service for mocking inputs but without overriding CoreScripts, it's really not possible at this moment in time.