make testing more robust

.snippets/c.snippets

@@ -0,0 +1,7 @@
+snippet testfile
+	#include <criterion/criterion.h>
+	#include "allocator.h"
+
+	Test($1, $2) {
+		$0
+	}

_allocator_impl.c

@@ -0,0 +1,5 @@
+// This is used to have a single file that implements the allocators when all
+// the test files are compiled together.
+
+#define ALLOCATOR_IMPLEMENTATION
+#include "allocator.h"

makefile

@@ -18,7 +18,7 @@ test:
 		echo "No test files found!"; \
 	else \
 		echo "Compiling all test files into $(TESTBIN)..."; \
-		$(CC) $(CFLAGS) $$files -o $(TESTBIN) $(LDFLAGS); \
+		$(CC) $(CFLAGS) _allocator_impl.c $$files -o $(TESTBIN) $(LDFLAGS); \
 		echo "Running tests..."; \
 		$(TESTBIN); \
 	fi

test_std_allocator.c

@@ -1,7 +1,7 @@
 #include <criterion/criterion.h>
-#define ALLOCATOR_IMPLEMENTATION
 #include "allocator.h"
 
+
 Test(std_allocator, test) {
     allocator_t this = allocator_stdlib;
     void *ptr = allocator_alloc(this, 10);