add toplvl checking form

turnstile/examples/tests/rackunit-typechecking.rkt

@@ -1,7 +1,7 @@
 #lang racket/base
 (require (for-syntax rackunit syntax/srcloc) rackunit macrotypes/typecheck)
 (provide check-type typecheck-fail check-not-type check-props check-runtime-exn
-         check-equal/rand
+         check-equal/rand typecheck-fail/toplvl
          (rename-out [typecheck-fail check-stx-err]))
 
 (begin-for-syntax
@@ -88,6 +88,27 @@
                   (expand/df #'e)))))
      #'(void)]))
 
+(define-syntax (typecheck-fail/toplvl stx)
+  (syntax-parse stx #:datum-literals (:)
+    [(_ e (~optional (~seq #:with-msg msg-pat) #:defaults ([msg-pat #'""])))
+     #:with msg:str 
+            (eval-syntax (datum->syntax #'here (syntax->datum #'msg-pat)))
+     #:when (with-check-info*
+             (list (make-check-expected (syntax-e #'msg))
+                   (make-check-expression (syntax->datum stx))
+                   (make-check-location (build-source-location-list stx))
+                   (make-check-name 'typecheck-fail)
+                   (make-check-params (list (syntax->datum #'e) (syntax-e #'msg))))
+             (λ ()
+               (check-exn
+                (λ (ex)
+                  (and (or (exn:fail? ex) (exn:test:check? ex))
+                       ; check err msg matches
+                       (regexp-match? (syntax-e #'msg) (exn-message ex))))
+                (λ ()
+                  (local-expand #'e 'top-level null)))))
+     #'(void)]))
+
 (define-syntax (check-runtime-exn stx)
   (syntax-parse stx
     [(_ e)