Fixes incapacitating sleep test failure, general test touch ups. (#55196)

Fixes the random incapacitating sleep test failure
Tests now provide the option to use a custom turf, by default uses plasteel tiles instead of space
Tests now reserve turf instead of just using a corner in CentCom (which had unaccounted for tiles)

code/modules/unit_tests/machine_disassembly.dm

@@ -3,7 +3,6 @@
 	var/obj/machinery/freezer = allocate(/obj/machinery/atmospherics/components/unary/thermomachine/freezer)
 
 	var/turf/freezer_location = freezer.loc
-	freezer_location.ChangeTurf(/turf/open/floor/plasteel)
 	freezer.deconstruct()
 
 	// Check that the components are created

code/modules/unit_tests/reagent_mod_expose.dm

@@ -11,6 +11,9 @@
 		target.health = 80
 
 /datum/unit_test/reagent_mob_expose/Run()
+	// Life() is handled just by tests
+	SSmobs.pause()
+
 	var/mob/living/carbon/human/human = allocate(/mob/living/carbon/human)
 	var/obj/item/reagent_containers/dropper/dropper = allocate(/obj/item/reagent_containers/dropper)
 	var/obj/item/reagent_containers/food/drinks/drink = allocate(/obj/item/reagent_containers/food/drinks/bottle)
@@ -23,7 +26,7 @@
 	drink.attack(human, human)
 	TEST_ASSERT_EQUAL(human.fire_stacks, 1, "Human does not have fire stacks after taking phlogiston")
 	human.Life()
-	TEST_ASSERT_EQUAL(human.fire_stacks, 2, "Human fire stacks did not increase after life tick")
+	TEST_ASSERT(human.fire_stacks > 1, "Human fire stacks did not increase after life tick")
 
 	// TOUCH
 	dropper.reagents.add_reagent(/datum/reagent/water, 1)
@@ -50,3 +53,6 @@
 	syringe.mode = SYRINGE_INJECT
 	syringe.afterattack(human, human, TRUE)
 	TEST_ASSERT_EQUAL(human.health, 80, "Human health did not update after injection from syringe")
+
+/datum/unit_test/reagent_mob_expose/Destroy()
+	SSmobs.ignite()

code/modules/unit_tests/unit_test.dm

@@ -19,20 +19,33 @@ GLOBAL_VAR(test_log)
 	//Bit of metadata for the future maybe
 	var/list/procs_tested
 
-	//usable vars
+	/// The bottom left turf of the testing zone
 	var/turf/run_loc_bottom_left
+
+	/// The top right turf of the testing zone
 	var/turf/run_loc_top_right
 
+	/// The type of turf to allocate for the testing zone
+	var/test_turf_type = /turf/open/floor/plasteel
+
 	//internal shit
 	var/focus = FALSE
 	var/succeeded = TRUE
 	var/list/allocated
 	var/list/fail_reasons
 
+	var/static/datum/turf_reservation/turf_reservation
+
 /datum/unit_test/New()
+	if (isnull(turf_reservation))
+		turf_reservation = SSmapping.RequestBlockReservation(5, 5)
+
+	for (var/turf/reserved_turf in turf_reservation.reserved_turfs)
+		reserved_turf.ChangeTurf(test_turf_type)
+
 	allocated = new
-	run_loc_bottom_left = locate(1, 1, 1)
-	run_loc_top_right = locate(5, 5, 1)
+	run_loc_bottom_left = locate(turf_reservation.bottom_left_coords[1], turf_reservation.bottom_left_coords[2], turf_reservation.bottom_left_coords[3])
+	run_loc_top_right = locate(turf_reservation.top_right_coords[1], turf_reservation.top_right_coords[2], turf_reservation.top_right_coords[3])
 
 /datum/unit_test/Destroy()
 	//clear the test area