--- a/src/preprocess_test.c	Tue Sep 03 09:41:17 2019 +0200
+++ b/src/preprocess_test.c	Tue Sep 03 09:41:40 2019 +0200
@@ -22,11 +22,11 @@
 
     ypreprocess_resolve_builtins(&program);
     yexpr_debug(&program);
-    ypreprocess_defn(&program);
+    ypreprocess_refs(&program);
     yexpr_debug(&program);
 
-    yvalue_t* func = yvalue_get(yref_new_c("my-func"));
-    assert(func != NULL);
+    /// We can't do these anymore, as functions are now anonymous:
+    /*
     fprintf(stderr, "arg ref 0: %lu\n",
             YVEC_AT(&func->value.func.args, 0, yarg_desc_t)->argref.ref.id);
     fprintf(stderr, "arg ref 1: %lu\n",
@@ -37,6 +37,7 @@
     fprintf(
         stderr, "arg name 1: %s\n",
         ystr_str(&YVEC_AT(&func->value.func.args, 1, yarg_desc_t)->argname));
+    */
 
     yeval_state_t state;
     state.call_stack = YVEC_NEW(NULL, 0, yexpr_t);
@@ -51,8 +52,45 @@
     yexpr_destroy(&result);
 }
 
+void test_preprocess_refs(void) {
+    fprintf(stderr, "test_preprocess_refs ===========\n");
+
+    // my-func adds the two arguments plus 42.
+    ystr_t input = ystr_new(
+            "(defn my-func (arg) (+ arg 1))"
+            "(let a 33)"
+            "(let b 44)"
+            "(+ a b)"
+            "(let a b)"
+            "(my-func a)");
+    yexpr_t program = yexpr_new();
+    ystr_t error = ystr_new(NULL);
+    assert(yparse_str(&input, &program, &error));
+
+    yexpr_debug(&program);
+    ypreprocess_resolve_builtins(&program);
+    ypreprocess_defn(&program);
+    yexpr_debug(&program);
+    ypreprocess_refs(&program);
+    yexpr_debug(&program);
+
+    yeval_state_t state;
+    state.call_stack = YVEC_NEW(NULL, 0, yexpr_t);
+    yexpr_t result = yeval_list_return_last(&state, &program.value.list, 0);
+    assert(result.typ == YEXPR_NUMBER);
+    assert(45 == result.value.n);
+    yexpr_debug(&result);
+
+    yexpr_destroy(&program);
+    ystr_destroy(&input);
+    ystr_destroy(&error);
+    yvec_destroy(&state.call_stack);
+}
+
 int main(void) {
     test_preprocess_defn();
+    test_preprocess_refs();
+    fprintf(stderr, "global destroy ===========\n");
     yvalue_free_all();
     return 0;
 }