Add unit tests for some surgeries, adds more APIs for unit tests to call (#52093)

* Add unit tests for medical related stuff

* Remove inaccurate assertion

code/modules/unit_tests/unit_test.dm

@@ -25,9 +25,11 @@ GLOBAL_VAR(test_log)
 
 	//internal shit
 	var/succeeded = TRUE
+	var/list/allocated
 	var/list/fail_reasons
 
 /datum/unit_test/New()
+	allocated = new
 	run_loc_bottom_left = locate(1, 1, 1)
 	run_loc_top_right = locate(5, 5, 1)
 
@@ -35,6 +37,7 @@ GLOBAL_VAR(test_log)
 	//clear the test area
 	for(var/atom/movable/AM in block(run_loc_bottom_left, run_loc_top_right))
 		qdel(AM)
+	QDEL_LIST(allocated)
 	return ..()
 
 /datum/unit_test/proc/Run()
@@ -48,6 +51,18 @@ GLOBAL_VAR(test_log)
 
 	LAZYADD(fail_reasons, reason)
 
+/// Allocates an instance of the provided type, and places it somewhere in an available loc
+/// Instances allocated through this proc will be destroyed when the test is over
+/datum/unit_test/proc/allocate(type, ...)
+	var/list/arguments = args.Copy(2)
+	if (!arguments.len)
+		arguments = list(run_loc_bottom_left)
+	else if (arguments[1] == null)
+		arguments[1] = run_loc_bottom_left
+	var/instance = new type(arglist(arguments))
+	allocated += instance
+	return instance
+
 /proc/RunUnitTests()
 	CHECK_TICK