Add complete test coverage for 2.rkt

Final/2.rkt

@@ -288,4 +288,14 @@
             {lam {fX}
                  {body-proc {lam {x} {{fX fX} x}}}}}}})
 
-  (test (run fact-prog) (numV 120)))
+  (test (run fact-prog) (numV 120)))
+
+; stupid tests for coverage
+(module+ test
+  (test/exn (parse-error 'invalid-syntax) "invalid-syntax")
+  (test (parse `(error "test error")) (errorE "test error"))
+  (test/exn (parse `(error 123)) "parse error")
+  (test/exn (parse `(unknown 1 2 3)) "parse error")
+  (test/exn (arith-op + (numV 1) (errorV "not a number")) "expects a number")
+  (test/exn (parse `#f) "parse error"))
+