added test case module

test-find-toplevel-variables.rkt

@@ -0,0 +1,46 @@
+#lang racket
+(require "find-toplevel-variables.rkt"
+         "parse.rkt")
+
+;; test-find-toplevel-variables
+(define-syntax (test stx)
+  (syntax-case stx ()
+    [(_ s exp)
+     (with-syntax ([stx stx])
+       (syntax/loc #'stx
+         (let ([results (find-toplevel-variables (parse s))])
+           (unless (equal? results exp)
+             (raise-syntax-error #f (format "Expected ~s, got ~s" exp results)
+                                 #'stx)))))]))
+
+
+(test '(define (factorial n)
+           (if (= n 0)
+               1
+               (* (factorial (- n 1))
+                  n)))
+      
+      '(* - = factorial))
+
+(test '(begin
+         (define (factorial n)
+           (fact-iter n 1))
+         (define (fact-iter n acc)
+           (if (= n 0)
+               acc
+               (fact-iter (- n 1) (* acc n)))))
+      '(* - = fact-iter factorial))
+
+(test '(define (gauss n)
+         (if (= n 0)
+             0
+             (+ (gauss (- n 1))
+                n)))
+      '(+ - = gauss))
+
+(test '(define (fib n)
+           (if (< n 2)
+               1
+               (+ (fib (- n 1))
+                  (fib (- n 2)))))
+      '(+ - < fib))