ad111f4950
## About The Pull Request This PR significantly enhances how zero-g movement works. Its no longer locked to one of 8 directions, everything now has inertia and is affected by weight. This means that throwing a piece of wire will no longer completely reverse your movement direction, and that being thrown out of mass driver no longer will slow you down to a halt at some point. This leads to following gameplay changes: * Guns now accelerate you. Ballistics have higher acceleration than lasers, and higher calibers have higher acceleration than smaller ones. This means that firing full-auto weapons in zero-g will make you drift and accelerate significantly. While this can be a hilarious way to travel in space, it makes using them trickier. * Impacting a wall or an object while moving at high speeds will cause you to violently crash into it as if you were thrown. Careful when exploring! * Jetpacks now have inertia. Changes introduced in #84712 have been mostly reverted, although speed buff has been reduced to 0.3 instead of 0.5 (although this is compensated by new movement mechanics, so overall speed should be roughly equal). All MODsuit jetpacks now possess the speed boost. Advanced MODsuit jets (which has also been added back) and captain's jetpack instead have higher acceleration and stabilization power, providing much more precise control over your movement. * Firing guns while moving on a jetpack will partially negate your pack's acceleration, slowing you down. Non-advanced jetpacks' stabilization is not enough to compensate for heavy caliber weaponry as sniper rifles, shotguns or rocket launchers. * You no longer instantly decelerate upon sliding along a wall. Instead, it may take a few tiles if you are moving at extreme speeds. Passing over lattices still allows you to grab onto them! As space movement is angle-based instead of dir-based now, its much more smooth than before due to using new movement logic. Example of jetpack stabilization in action: https://github.com/tgstation/tgstation/assets/44720187/6761a4fd-b7de-4523-97ea-38144b8aab41 And, of course, you can do this now.  **This pull request requires extensive gameplay testing before merging**, as a large amount of numbers have been picked arbitrarily in an attempt to keep consistency with previous behavior (guns and normal-sized items applying 1 drift force, which is equal to what everything applied before this PR). Jetpacks and impacts may also require adjustments as to not be frustrating to use. Closes #85165 ## Why It's Good For The Game Zero-G refactor - currently our zero-g movement is rather ugly and can be uncomfortable to work with. A piece of cable being able to accelerate you the same as a duffelbag full of items when thrown makes no sense, and so does instantly changing directions. Inertia-based version is smoother and more intuitive. This also makes being thrown into space more of a hazard (possibly opening the door for explosive decompressions?) Jetpack inertia and gun changes - this is mostly a consequence of inertia-based movement. However, zero-g combat being preferred during modes like warops was an issue due to it negatively affecting everyone without jetpacks which are in limited supply onboard. This reverts the mobility changes which severely impacted space exploration, while making zero-g combat more dangerous and having it require more skill to be a viable option. ## What's left - [x] Refactor moth wings to use jetpack code - [x] Refactor functional wings to use jetpack code - [x] Locate and fix a recursion runtime that sometimes occurs upon splattering against a wall - [x] Add craftable tethers and modify engineering MOD tethers to use the same system ## Changelog 🆑 add: You can now craft tether anchors, which can be secured with a wrench and attached to with right click. They won't let you drift into space and you can adjust tether length/cut it via lmb/rmb/ctrl click on the wire. add: MOD tethers now remotely place and connect to tether anchors instead of throwing you at where they landed. balance: MOD tethers can now be used in gravity balance: Jetpacks are now inertia-based. balance: Guns can accelerate you significantly in zero-g. balance: All jetpacks now give you equal speed buff, however advanced MOD ion jets and captain's jetpack have higher acceleration/deceleration values. refactor: Refactored zero-g movement to be inertia-based and utilize angles instead of directions. /🆑
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?
- 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.
- 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.
- 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
Then, 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!
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.