Implement test target and add the first test

make test will now compile the tests to test/test.
The first test, testing string_replace_char from utils.c, was added.

Makefile

@@ -54,7 +54,7 @@ clean-dunstify:
 clean-doc:
 	rm -f dunst.1
 
-clean: clean-dunst clean-dunstify clean-doc
+clean: clean-dunst clean-dunstify clean-doc test-clean
 
 doc: dunst.1
 dunst.1: README.pod
@@ -89,4 +89,15 @@ uninstall:
 	@echo Removing documentation directory ${DESTDIR}${PREFIX}/share/dunst
 	rm -rf ${DESTDIR}${PREFIX}/share/dunst
 
+test: test/test
+
+TEST_SRC = $(shell ls test/*.c)
+TEST_OBJ = $(TEST_SRC:.c=.o)
+
+test/test: ${OBJ} ${TEST_OBJ}
+	${CC} ${CFLAGS} -o $@ ${TEST_OBJ} ${OBJ} ${LDFLAGS}
+
+test-clean:
+	rm -f test/test test/*.o
+
 .PHONY: all options clean dist install uninstall

test/test.c

@@ -0,0 +1,12 @@
+#include "greatest.h"
+
+SUITE_EXTERN(utils);
+
+GREATEST_MAIN_DEFS();
+
+int main(int argc, char *argv[]) {
+        GREATEST_MAIN_BEGIN();
+        RUN_SUITE(utils);
+        GREATEST_MAIN_END();
+}
+/* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */

test/utils.c

@@ -0,0 +1,19 @@
+#include "greatest.h"
+#include "src/utils.h"
+
+TEST test_string_replace_char(void)
+{
+        char *text = calloc(128, sizeof(char));
+        strcpy(text, "a aa aaa");
+        ASSERT_STR_EQ(string_replace_char('a', 'b', text), "b bb bbb");
+        strcpy(text, "");
+        ASSERT_STR_EQ(string_replace_char('a', 'b', text), "");
+        free(text);
+        PASS();
+}
+
+SUITE(utils)
+{
+        RUN_TEST(test_string_replace_char);
+}
+/* vim: set tabstop=8 shiftwidth=8 expandtab textwidth=0: */