[MIRROR] Unit Test rework & Master/Ticker update (#11372)

Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>
Co-authored-by: C.L. <killer65311@gmail.com>

code/modules/unit_tests/subsystem_init.dm

@@ -0,0 +1,22 @@
+/// Tests that all subsystems that need to properly initialize.
+/datum/unit_test/subsystem_init
+
+/datum/unit_test/subsystem_init/Run()
+	for(var/datum/controller/subsystem/subsystem as anything in Master.subsystems)
+		if(subsystem.flags & SS_NO_INIT)
+			continue
+		if(subsystem.initialized)
+			continue
+
+		var/should_fail = !(subsystem.flags & SS_OK_TO_FAIL_INIT)
+		var/list/message_strings = list("[subsystem] ([subsystem.type]) is a subsystem meant to initialize but could not get initialized.")
+
+		if(!isnull(subsystem.initialization_failure_message))
+			message_strings += "The subsystem reported the following: [subsystem.initialization_failure_message]"
+
+		if(should_fail)
+			TEST_FAIL(jointext(message_strings, "\n"))
+			continue
+
+		message_strings += "This subsystem is marked as SS_OK_TO_FAIL_INIT. This is still a bug, but it is non-blocking."
+		TEST_NOTICE(src, jointext(message_strings, "\n"))