Files
Bubberstation/code/modules/unit_tests
san7890 8400284868 Illusion Basic Mob Refactor (#93860)
## About The Pull Request

Another relatively simple simple_mob to basic mob refactor. I wish more
people were doing these since I was saving these for people to get their
feet wet, but I think it's better to pivot away from that and just have
only the gargantuan ones outstanding (since those ones are pretty much
their own framework).

I also delayed this one because we didn't actually have the AI framework
available 1-2 years ago for this to be seamless and easy, but now we
have easy fleeing functionality so that's an easy plug and play.

This rework contains the following:

* General code readability changes and standardization (i.e. removing
single letter vars, `SECONDS` defines)
* Moves more stuff to subtypes instead of having it be on parent
* Removes the necessity for define "attack modes", that's on subtypes
now
* Fixed instances where args weren't defined. I think cult apparitions
via the mirror shield have been much weaker than what they were
originally intended to, so I changed it to what I thought was correct. I
can change the health to be down but it really doesn't make sense as a
lot of the args were not standardized (ideally we would have more
subtypes). I can change this back to the original arg order, let me
know.
* Clones now replicate on damage taken as well as when they attack. I
wanted to tweak this around more but this was originally added since I
confused myself, but it gave a more realistic mitotic effect I liked
more for the replicating clones.
## Why It's Good For The Game

If we want more flamboyant mirage escapes or sneaky clone AI behavior,
it is now far easier to implement. It's very simplistic at the moment
but is pretty much fully featured and representative of the simple mob
version of illusions. They were already laden to the item/mob that was
spawning them in anyways, so this is really the most simple stuff we got
going on.

I tested this with the mirage grenade, reactive stealth armor, and the
mirror shield. I have no clue how the heretic stuff works but it appears
to be a really simple framework plug-and-play so no real worries there I
think.
## Changelog
🆑
refactor: The Cult of Nar'Sie realized that they were installing the
mirrors on their mirror shields the wrong way around, thus altering the
makeup of their mirror clones health, damage, and re-replicability.
refactor: In response to the recent updates in clone magic, Nanotrasen's
Stealth Reactive Armor should now generate more convincing clones.
/🆑
2025-11-26 13:02:00 +11:00
..
2025-10-07 20:08:57 +02:00
2025-10-28 12:49:18 -05:00
2025-09-07 09:24:34 +02:00
2025-06-25 17:36:10 -07:00

Unit Tests

What is unit testing?

Unit tests are automated code to verify that parts of the game work exactly as they should. For example, a test to make sure that the amputation surgery actually amputates the limb. These are ran every time a PR is made, and thus are very helpful for preventing bugs from cropping up in your code that would've otherwise gone unnoticed. For example, would you have thought to check that beach boys would still work the same after editing pizza? If you value your time, probably not.

On their most basic level, when UNIT_TESTS is defined, all subtypes of /datum/unit_test will have their Run proc executed. From here, if Fail is called at any point, then the tests will report as failed.

How do I write one?

  1. Find a relevant file.

All unit test related code is in code/modules/unit_tests. If you are adding a new test for a surgery, for example, then you'd open surgeries.dm. If a relevant file does not exist, simply create one in this folder, then #include it in _unit_tests.dm.

  1. Create the unit test.

To make a new unit test, you simply need to define a /datum/unit_test.

For example, let's suppose that we are creating a test to make sure a proc square correctly raises inputs to the power of two. We'd start with first:

/datum/unit_test/square/Run()

This defines our new unit test, /datum/unit_test/square. Inside this function, we're then going to run through whatever we want to check. Tests provide a few assertion functions to make this easy. For now, we're going to use TEST_ASSERT_EQUAL.

/datum/unit_test/square/Run()
    TEST_ASSERT_EQUAL(square(3), 9, "square(3) did not return 9")
    TEST_ASSERT_EQUAL(square(4), 16, "square(4) did not return 16")

As you can hopefully tell, we're simply checking if the output of square matches the output we are expecting. If the test fails, it'll report the error message given as well as whatever the actual output was.

  1. Run the unit test

Open code/_compile_options.dm and uncomment the following line.

//#define UNIT_TESTS			//If this is uncommented, we do a single run though of the game setup and tear down process with unit tests in between

There are 3 ways to run unit tests

  • Run tgstation.dmb in Dream Daemon. Don't bother trying to connect, you won't need to. You'll be able to see the outputs of all the tests. You'll get to see which tests failed and for what reason. If they all pass, you're set!

  • Launch game from VS Code. Launch the game as normal & you will see the output of your unit tests in your fancy chat window. This is preferred as you can use the debugger to step through each line of your unit test & can use the games inbuilt debugging tools to further aid in testing

  • Use VS Code Tgstation Test Explorer Extension. This allows you to run tests without launching the game & can also run focused tests(either a single or a selected group)

How to think about tests

Unit tests exist to prevent bugs that would happen in a real game. Thus, they should attempt to emulate the game world wherever possible. For example, the quick swap sanity test emulates a real scenario of the bug it fixed occurring by creating a character and giving it real items. The unrecommended alternative would be to create special test-only items. This isn't a hard rule, the reagent method exposure tests create a test-only reagent for example, but do keep it in mind.

Unit tests should also be just that--testing units of code. For example, instead of having one massive test for reagents, there are instead several smaller tests for testing exposure, metabolization, etc.

The unit testing API

You can find more information about all of these from their respective doc comments, but for a brief overview:

/datum/unit_test - The base for all tests to be ran. Subtypes must override Run(). New() and Destroy() can be used for setup and teardown. To fail, use TEST_FAIL(reason).

/datum/unit_test/proc/allocate(type, ...) - Allocates an instance of the provided type with the given arguments. Is automatically destroyed when the test is over. Commonly seen in the form of var/mob/living/carbon/human/human = allocate(/mob/living/carbon/human/consistent).

TEST_FAIL(reason) - Marks a failure at this location, but does not stop the test.

TEST_ASSERT(assertion, reason) - Stops the unit test and fails if the assertion is not met. For example: TEST_ASSERT(powered(), "Machine is not powered").

TEST_ASSERT_NOTNULL(a, message) - Same as TEST_ASSERT, but checks if !isnull(a). For example: TEST_ASSERT_NOTNULL(myatom, "My atom was never set!").

TEST_ASSERT_NULL(a, message) - Same as TEST_ASSERT, but checks if isnull(a). If not, gives a helpful message showing what a was. For example: TEST_ASSERT_NULL(delme, "Delme was never cleaned up!").

TEST_ASSERT_EQUAL(a, b, message) - Same as TEST_ASSERT, but checks if a == b. If not, gives a helpful message showing what both a and b were. For example: TEST_ASSERT_EQUAL(2 + 2, 4, "The universe is falling apart before our eyes!").

TEST_ASSERT_NOTEQUAL(a, b, message) - Same as TEST_ASSERT_EQUAL, but reversed.

TEST_FOCUS(test_path) - Only run the test provided within the parameters. Useful for reducing noise. For example, if we only want to run our example square test, we can add TEST_FOCUS(/datum/unit_test/square). Should never be pushed in a pull request--you will be laughed at.

Final Notes

  • Writing tests before you attempt to fix the bug can actually speed up development a lot! It means you don't have to go in game and folllow the same exact steps manually every time. This process is known as "TDD" (test driven development). Write the test first, make sure it fails, then start work on the fix/feature, and you'll know you're done when your tests pass. If you do try this, do make sure to confirm in a non-testing environment just to double check.
  • Make sure that your tests don't accidentally call RNG functions like prob. Since RNG is seeded during tests, you may not realize you have until someone else makes a PR and the tests fail!
  • Do your best not to change the behavior of non-testing code during tests. While it may sometimes be necessary in the case of situations such as the above, it is still a slippery slope that can lead to the code you're testing being too different from the production environment to be useful.