Add simple test using ad-hoc defined "mytest" module

Makefile.am

@@ -92,6 +92,8 @@ test_re_split_SOURCES = tests/test-re-split.c tests/util.c
 test_re_split_LDADD = libyara/.libs/libyara.a
 test_async_SOURCES = tests/test-async.c tests/util.c
 test_async_LDADD = libyara/.libs/libyara.a
+test_module_SOURCES = tests/test-module.c tests/util.c
+test_module_LDADD = libyara/.libs/libyara.a
 
 TESTS = $(check_PROGRAMS)
 TESTS_ENVIRONMENT = TOP_SRCDIR=$(top_srcdir) TOP_BUILDDIR=$(top_builddir)
@@ -109,7 +111,8 @@ check_PROGRAMS = \
   test-math \
   test-stack \
   test-re-split \
-  test-async
+  test-async \
+  test-module
 
 EXTRA_PROGRAMS = tests/mapper
 CLEANFILES = tests/mapper$(EXEEXT)

tests/test-module.c

@@ -0,0 +1,92 @@
+/*
+Copyright (c) 2022. The YARA Authors. All Rights Reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+may be used to endorse or promote products derived from this software without
+specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <yara.h>
+
+#include "util.h"
+
+#define MODULE_NAME mytest
+
+begin_declarations
+declare_integer("fortytwo");
+end_declarations
+
+int module_initialize(YR_MODULE* module)
+{
+  return ERROR_SUCCESS;
+}
+
+int module_finalize(YR_MODULE* module)
+{
+  return ERROR_SUCCESS;
+}
+
+int module_load(
+    YR_SCAN_CONTEXT* context,
+    YR_OBJECT* module_object,
+    void* module_data,
+    size_t module_data_size)
+{
+  yr_set_integer(42, module_object, "fortytwo");
+
+  return ERROR_SUCCESS;
+}
+
+int module_unload(YR_OBJECT* module_object)
+{
+  return ERROR_SUCCESS;
+}
+
+yr_module_define();
+
+#undef MODULE_NAME
+
+int main(int argc, char** argv)
+{
+  int result = 0;
+
+  YR_DEBUG_INITIALIZE();
+  YR_DEBUG_FPRINTF(1, stderr, "+ %s() { // in %s\n", __FUNCTION__, __FILE__);
+
+  init_top_srcdir();
+  yr_initialize();
+
+  yr_modules_add(&mytest__module);
+
+  assert_true_rule(
+      "import \"mytest\" rule test { condition: mytest.fortytwo == 42 }",
+      NULL);
+
+  yr_finalize();
+
+  YR_DEBUG_FPRINTF(
+      1, stderr, "} = %d // %s() in %s\n", result, __FUNCTION__, __FILE__);
+
+  return result;
+}