[MIRROR] Water will now make you wet (#72844) (#18888)

Water will now make you wet (#72844)

Water, when exposed to a mob either via `TOUCH` or `VAPOR` application,
will now apply wet stacks to said mob according to the amount of water
used. For touch application, the ratio is 0.5 wet stack per unit of
water, whereas for vapor application (so for foam and sprays), that
ratio is lowered to 0.1 wet stack per unit of water. Yes, that would
mean that you could now put someone out by spraying enough water at them
with a spray bottle (usually around 50-150u), and I think that is quite
simply hilarious.

I also updated the unit test of water's `expose_mob()` proc, to check
that wet stacks were being applied properly, hopefully making sure that
there's no regression on that part in the future.

code/modules/unit_tests/_unit_tests.dm

@@ -168,7 +168,7 @@
 #include "range_return.dm"
 #include "rcd.dm"
 #include "reagent_id_typos.dm"
-#include "reagent_mod_expose.dm"
+#include "reagent_mob_expose.dm"
 #include "reagent_mod_procs.dm"
 #include "reagent_names.dm"
 #include "reagent_recipe_collisions.dm"

code/modules/unit_tests/reagent_mob_expose.dm

@@ -29,9 +29,9 @@
 	TEST_ASSERT(human.fire_stacks > 1, "Human fire stacks did not increase after life tick")
 
 	// TOUCH
-	dropper.reagents.add_reagent(/datum/reagent/water, 1)
+	dropper.reagents.add_reagent(/datum/reagent/water, 5)
 	dropper.afterattack(human, human, TRUE)
-	TEST_ASSERT_EQUAL(human.fire_stacks, 0, "Human still has fire stacks after touching water")
+	TEST_ASSERT(human.fire_stacks < 0, "Human still has fire stacks after touching water")
 
 	// VAPOR
 	TEST_ASSERT_NULL(human.has_status_effect(/datum/status_effect/drowsiness), "Human is drowsy at the start of testing")
@@ -39,6 +39,11 @@
 	drink.reagents.add_reagent(/datum/reagent/nitrous_oxide, 10)
 	drink.reagents.trans_to(human, 10, methods = VAPOR)
 	TEST_ASSERT_NOTNULL(human.has_status_effect(/datum/status_effect/drowsiness), "Human is not drowsy after exposure to vapors")
+	drink.reagents.clear_reagents()
+	drink.reagents.add_reagent(/datum/reagent/water, 10)
+	var/old_fire_stacks = human.fire_stacks
+	drink.reagents.trans_to(human, 10, methods = VAPOR)
+	TEST_ASSERT(human.fire_stacks < old_fire_stacks, "Human does not get wetter after being exposed to water by vapors")
 
 	// PATCH
 	human.health = 100