add hs_throw_error() implementation and fix bug in tests

2 files changed, 29 insertions, 4 deletions

diff --git a/src/hs_throw_error.c b/src/hs_throw_error.c
new file mode 100644
index 0000000..b2377dd
--- /dev/null
+++ b/src/hs_throw_error.c
@@ -0,0 +1,23 @@
+#include <stdlib.h>
+
+#include "honeysuckle.h"
+
+void hs_throw_error(lua_State *L, const char *format_string, ...)
+{
+    va_list args, args_;
+    va_start(args, format_string);
+    va_copy(args_, args);
+
+    int string_size = vsnprintf(NULL, 0, format_string, args_);
+    va_end(args_);
+
+    char *string = malloc((string_size+1) * sizeof(char));
+    if (string == NULL)
+	lua_pushstring(L, "there was an error allocating memory for an error message");
+    else {
+	vsnprintf(string, string_size+1, format_string, args);
+	lua_pushstring(L, string);
+	free(string);
+    }
+    lua_error(L);
+}
diff --git a/src/tests/hs_throw_error_tests.c b/src/tests/hs_throw_error_tests.c
index 1c5af6a..ebb05b4 100644
--- a/src/tests/hs_throw_error_tests.c
+++ b/src/tests/hs_throw_error_tests.c
@@ -1,11 +1,11 @@
 #include "hs_tests.h"
 
-const char *err_string = "";
+char err_string[32] = "";
 
 int set_err_string(lua_State *L)
 {
     if (lua_isstring(L, -1))
-	err_string = lua_tostring(L, -1);
+	strcpy(err_string, lua_tostring(L, -1));
     return 0;
 }
 
@@ -18,8 +18,9 @@ int throw_const_error(lua_State *L)
 
 TEST(hs_throw_error_constant)
 {
-    lua_pushcfunction(L, throw_const_error);
+    lua_pushcfunction(L, set_err_string);
     int pos = lua_gettop(L);
+    lua_pushcfunction(L, throw_const_error);
     int result = lua_pcall(L, 0, 0, pos);
     mu_assert_equal(result, LUA_ERRRUN);
     mu_assert_str_not_equal(err_string, "");
@@ -36,8 +37,9 @@ int throw_number_error(lua_State *L)
 
 TEST(hs_throw_error_format)
 {
-    lua_pushcfunction(L, throw_number_error);
+    lua_pushcfunction(L, set_err_string);
     int pos = lua_gettop(L);
+    lua_pushcfunction(L, throw_number_error);
     int result = lua_pcall(L, 0, 0, pos);
     mu_assert_equal(result, LUA_ERRRUN);
     mu_assert_str_not_equal(err_string, "");