Make sure superclass mandatory inits are provided

original commit: b1627984e258df8f23d1295ec554fe0d5b128ea5

pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/check-class-unit.rkt

@@ -377,7 +377,13 @@
                           list
                           (#%plain-app cons (quote init-id) arg:expr)
                           ...))
-            (for ([init-id (syntax->datum #'(init-id ...))]
+            (define provided-inits (syntax->datum #'(init-id ...)))
+            (for ([(name val) (in-dict super-inits)]
+                  #:when (not (cadr val)))
+              (unless (member name provided-inits)
+                (tc-error/expr "mandatory superclass init ~a not provided"
+                               name)))
+            (for ([init-id provided-inits]
                   [init-arg (syntax->list #'(arg ...))])
               (define maybe-expected (dict-ref super-inits init-id #f))
               (if maybe-expected

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt

@@ -338,6 +338,13 @@
                  (init x)))
     (new d%))
 
+   ;; fails, mandatory super-class init not provided
+   (check-err
+    (class: (class: object% (super-new)
+              (: x Integer)
+              (init x))
+      (super-new)))
+
    ;; test different internal/external names
    (check-ok
     (define c% (class: object% (super-new)