Merge pull request #8126 from MistakeNot4892/chirp

Added unit test to ensure emote key uniqueness.

code/unit_tests/decl_tests.dm

@@ -0,0 +1,26 @@
+/datum/unit_test/emotes_shall_have_unique_keys
+	name = "DECLS: Emotes Shall Have Unique Keys"
+
+/datum/unit_test/emotes_shall_have_unique_keys/start_test()
+
+	var/list/keys = list()
+	var/list/duplicates = list()
+
+	var/list/all_emotes = decls_repository.get_decls_of_subtype(/decl/emote)
+	for(var/etype in all_emotes)
+		var/decl/emote/emote = all_emotes[etype]
+		if(!emote.key)
+			continue
+		if(emote.key in keys)
+			if(!duplicates[emote.key])
+				duplicates[emote.key] = list() 
+			duplicates[emote.key] += etype
+		else
+			keys += emote.key
+
+	if(length(duplicates))
+		fail("[length(duplicates)] emote\s had overlapping keys: [english_list(duplicates)].")
+	else
+		pass("All emotes had unique keys.")
+
+	return TRUE