From 6ea25b819435cc85a8a060f7dd1cba4d29b9cdcf Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 20 Jun 2021 19:55:31 +0300
Subject: [PATCH] engine: add simple unit-testing (v3?)

---
 engine/common/host.c  | 32 +++++++++++++++++++++++++++++++-
 engine/common/tests.h | 28 ++++++++++++++++++++++++++++
 engine/wscript        | 14 ++++++++++++--
 3 files changed, 71 insertions(+), 3 deletions(-)
 create mode 100644 engine/common/tests.h

diff --git a/engine/common/host.c b/engine/common/host.c
index 2465bbb0..12ffa724 100644
--- a/engine/common/host.c
+++ b/engine/common/host.c
@@ -40,12 +40,16 @@ GNU General Public License for more details.
 #include "input.h"
 #include "enginefeatures.h"
 #include "render_api.h"	// decallist_t
-
+#include "tests.h"
 
 pfnChangeGame	pChangeGame = NULL;
 host_parm_t		host;	// host parms
 sysinfo_t		SI;
 
+#ifdef XASH_ENGINE_TESTS
+struct tests_stats_s tests_stats;
+#endif
+
 CVAR_DEFINE( host_developer, "developer", "0", 0, "engine is in development-mode" );
 CVAR_DEFINE_AUTO( sys_ticrate, "100", 0, "framerate in dedicated mode" );
 
@@ -771,6 +775,19 @@ void Host_Userconfigd_f( void )
 	Mem_Free( t );
 }
 
+#if XASH_ENGINE_TESTS
+static void Host_RunTests( void )
+{
+	memset( &tests_stats, 0, sizeof( tests_stats ));
+
+	Test_RunLibCommon();
+
+	Msg( "Done! %d passed, %d failed\n", tests_stats.passed, tests_stats.failed );
+
+	Sys_Quit();
+}
+#endif
+
 /*
 =================
 Host_InitCommon
@@ -827,6 +844,14 @@ void Host_InitCommon( int argc, char **argv, const char *progname, qboolean bCha
 		}
 	}
 
+#if XASH_ENGINE_TESTS
+	if( Sys_CheckParm( "-runtests" ))
+	{
+		host.allow_console = true;
+		developer = DEV_EXTENDED;
+	}
+#endif
+
 	host.con_showalways = true;
 
 #if XASH_DEDICATED
@@ -896,6 +921,11 @@ void Host_InitCommon( int argc, char **argv, const char *progname, qboolean bCha
 
 	Con_Init(); // early console running to catch all the messages
 
+#if XASH_ENGINE_TESTS
+	if( Sys_CheckParm( "-runtests" ))
+		Host_RunTests();
+#endif
+
 	Platform_Init();
 
 	baseDir = getenv( "XASH3D_BASEDIR" );
diff --git a/engine/common/tests.h b/engine/common/tests.h
new file mode 100644
index 00000000..6eff238d
--- /dev/null
+++ b/engine/common/tests.h
@@ -0,0 +1,28 @@
+#ifndef TESTS_H
+#define TESTS_H
+
+#if XASH_ENGINE_TESTS
+
+struct tests_stats_s
+{
+	uint passed;
+	uint failed;
+};
+
+extern struct tests_stats_s tests_stats;
+
+#define TRUN( x ) Msg( "Running " #x "\n" ); x
+
+#define TASSERT( exp ) \
+	if(!( exp )) \
+	{ \
+		tests_stats.failed++; \
+		Msg( "assert failed at %s:%i\n", __FILE__, __LINE__ ) \
+	} \
+	else tests_stats.passed++;
+
+void Test_RunLibCommon( void );
+
+#endif
+
+#endif /* TESTS_H */
diff --git a/engine/wscript b/engine/wscript
index 38022b5a..1e080128 100644
--- a/engine/wscript
+++ b/engine/wscript
@@ -29,6 +29,9 @@ def options(opt):
 	grp.add_option('--enable-static-binary', action = 'store_true', dest = 'STATIC', default = False,
 		help = 'build static binary(not recommended, --single-binary required) [default: %default]')
 
+	grp.add_option('--enable-engine-tests', action = 'store_true', dest = 'ENGINE_TESTS', default = False,
+		help = 'embed tests into the engine, jump into them by -runtests command line switch [default: %default]')
+
 	opt.load('sdl2')
 
 def configure(conf):
@@ -79,6 +82,9 @@ def configure(conf):
 	if hasattr(conf.options, 'DLLEMU'):
 		conf.define_cond('XASH_DLL_LOADER', conf.options.DLLEMU)
 
+	conf.env.ENGINE_TESTS = conf.options.ENGINE_TESTS
+
+	conf.define_cond('XASH_ENGINE_TESTS', conf.env.ENGINE_TESTS)
 	conf.define_cond('XASH_STATIC_LIBS', conf.env.STATIC_LINKING)
 	conf.define_cond('XASH_CUSTOM_SWAP', conf.options.CUSTOM_SWAP)
 	conf.define_cond('SINGLE_BINARY', conf.env.SINGLE_BINARY)
@@ -92,6 +98,8 @@ def configure(conf):
 def build(bld):
 	is_cxx_link = False
 	libs = [ 'public', 'dllemu' ]
+
+	# basic build: dedicated only
 	source = bld.path.ant_glob([
 		'common/*.c',
 		'common/imagelib/*.c',
@@ -99,7 +107,9 @@ def build(bld):
 		'common/soundlib/libmpg/*.c',
 		'server/*.c'])
 
-	# basic build: dedicated only, no dependencies
+	if bld.env.ENGINE_TESTS:
+		source += bld.path.ant_glob(['tests/*.c'])
+
 	if bld.env.DEST_OS == 'win32':
 		libs += ['USER32', 'SHELL32', 'GDI32', 'ADVAPI32', 'DBGHELP', 'PSAPI', 'WS2_32' ]
 		source += bld.path.ant_glob(['platform/win32/*.c'])
@@ -146,7 +156,7 @@ def build(bld):
 			'client/vgui/*.c',
 			'client/avi/*.c'])
 
-	includes = ['common', 'server', 'client', 'client/vgui', '.', '../public', '../common', '../pm_shared' ]
+	includes = ['common', 'server', 'client', 'client/vgui', 'tests', '.', '../public', '../common', '../pm_shared' ]
 
 	if bld.env.SINGLE_BINARY:
 		install_path = bld.env.BINDIR