Screenshot tests (#67679)

Adds screenshot visual testing workflow and scripts.

code/modules/unit_tests/_unit_tests.dm

@@ -129,6 +129,9 @@
 #include "reagent_recipe_collisions.dm"
 #include "resist.dm"
 #include "say.dm"
+#include "screenshot_antag_icons.dm"
+#include "screenshot_basic.dm"
+#include "screenshot_humanoids.dm"
 #include "security_officer_distribution.dm"
 #include "serving_tray.dm"
 #include "siunit.dm"

code/modules/unit_tests/screenshot_antag_icons.dm

@@ -0,0 +1,12 @@
+/// A screenshot test to make sure every antag icon in the preferences menu is consistent
+/datum/unit_test/screenshot_antag_icons
+
+/datum/unit_test/screenshot_antag_icons/Run()
+	var/datum/asset/spritesheet/antagonists/antagonists = get_asset_datum(/datum/asset/spritesheet/antagonists)
+
+	for (var/antag_icon_key in antagonists.antag_icons)
+		var/icon/reference_icon = antagonists.antag_icons[antag_icon_key]
+
+		var/icon/icon = new()
+		icon.Insert(reference_icon, null, SOUTH, 1)
+		test_screenshot(antag_icon_key, icon)

code/modules/unit_tests/screenshot_basic.dm

@@ -0,0 +1,8 @@
+/// This is an example for screenshot tests, and a meta-test to make sure they work in the success case.
+/// It creates a picture that is red on the left side, green on the other.
+/datum/unit_test/screenshot_basic
+
+/datum/unit_test/screenshot_basic/Run()
+	var/icon/red = icon('icons/blanks/32x32.dmi', "nothing")
+	red.Blend(COLOR_RED, ICON_OVERLAY)
+	test_screenshot("red", red)

code/modules/unit_tests/screenshot_humanoids.dm

@@ -0,0 +1,44 @@
+/// A screenshot test for every humanoid species with a handful of jobs.
+/datum/unit_test/screenshot_humanoids
+
+/datum/unit_test/screenshot_humanoids/Run()
+	// Test lizards as their own thing so we can get more coverage on their features
+	var/mob/living/carbon/human/lizard = allocate(/mob/living/carbon/human/dummy/consistent)
+	lizard.dna.features["mcolor"] = "#099"
+	lizard.dna.features["tail_lizard"] = "Light Tiger"
+	lizard.dna.features["snout"] = "Sharp + Light"
+	lizard.dna.features["horns"] = "Simple"
+	lizard.dna.features["frills"] = "Aquatic"
+	lizard.dna.features["legs"] = "Normal Legs"
+	lizard.set_species(/datum/species/lizard)
+	lizard.equipOutfit(/datum/outfit/job/engineer)
+	test_screenshot("[/datum/species/lizard]", get_flat_icon_for_all_directions(lizard))
+
+	// let me have this
+	var/mob/living/carbon/human/moth = allocate(/mob/living/carbon/human/dummy/consistent)
+	moth.dna.features["moth_antennae"] = "Firewatch"
+	moth.dna.features["moth_markings"] = "None"
+	moth.dna.features["moth_wings"] = "Firewatch"
+	moth.set_species(/datum/species/moth)
+	moth.equipOutfit(/datum/outfit/job/cmo, visualsOnly = TRUE)
+	test_screenshot("[/datum/species/moth]", get_flat_icon_for_all_directions(moth))
+
+	// The rest of the species
+	for (var/datum/species/species_type as anything in subtypesof(/datum/species) - /datum/species/moth - /datum/species/lizard)
+		test_screenshot("[species_type]", get_flat_icon_for_all_directions(make_dummy(species_type, /datum/outfit/job/assistant/consistent)))
+
+/datum/unit_test/screenshot_humanoids/proc/get_flat_icon_for_all_directions(atom/thing)
+	var/icon/output = icon('icons/effects/effects.dmi', "nothing")
+	COMPILE_OVERLAYS(thing)
+
+	for (var/direction in GLOB.cardinals)
+		var/icon/partial = getFlatIcon(thing, defdir = direction, no_anim = TRUE)
+		output.Insert(partial, dir = direction)
+
+	return output
+
+/datum/unit_test/screenshot_humanoids/proc/make_dummy(species, job_outfit)
+	var/mob/living/carbon/human/dummy/consistent/dummy = allocate(/mob/living/carbon/human/dummy/consistent)
+	dummy.set_species(species)
+	dummy.equipOutfit(job_outfit, visualsOnly = TRUE)
+	return dummy

code/modules/unit_tests/screenshots/README.md

@@ -0,0 +1,18 @@
+This folder contains the results for screenshot tests. Screenshot tests make sure an icon looks the same as it did before a change to prevent regressions.
+
+You can create one by simply using the `test_screenshot` proc.
+
+This example test screenshots a red image and keeps it.
+
+```dm
+/// This is an example for screenshot tests, and a meta-test to make sure they work in the success case.
+/// It creates a picture that is red on the left side, green on the other.
+/datum/unit_test/screenshot_basic
+
+/datum/unit_test/screenshot_basic/Run()
+	var/icon/red = icon('icons/blanks/32x32.dmi', "nothing")
+	red.Blend(COLOR_RED, ICON_OVERLAY)
+	test_screenshot("red", red)
+```
+
+Unfortunately, screenshot tests are sanest to test through a pull request directly, due to limitations with both DM and GitHub.

code/modules/unit_tests/unit_test.dm

@@ -84,6 +84,30 @@ GLOBAL_LIST_EMPTY(unit_test_mapping_logs)
 	allocated += instance
 	return instance
 
+/datum/unit_test/proc/test_screenshot(name, icon/icon)
+	if (!istype(icon))
+		TEST_FAIL("[icon] is not an icon.")
+		return
+
+	var/path_prefix = replacetext(replacetext("[type]", "/datum/unit_test/", ""), "/", "_")
+	name = replacetext(name, "/", "_")
+
+	var/filename = "code/modules/unit_tests/screenshots/[path_prefix]_[name].png"
+
+	if (fexists(filename))
+		var/data_filename = "data/screenshots/[path_prefix]_[name].png"
+		fcopy(icon, data_filename)
+		log_test("[path_prefix]_[name] was found, putting in data/screenshots")
+	else if (fexists("code"))
+		// We are probably running in a local build
+		fcopy(icon, filename)
+		TEST_FAIL("Screenshot for [name] did not exist. One has been created.")
+	else
+		// We are probably running in real CI, so just pretend it worked and move on
+		fcopy(icon, "data/screenshots_new/[path_prefix]_[name].png")
+
+		log_test("[path_prefix]_[name] was put in data/screenshots_new")
+
 /proc/RunUnitTest(test_path, list/test_results)
 	var/datum/unit_test/test = new test_path