Add zo-read/parse/run fuzz tester.

collects/meta/props

@@ -1892,6 +1892,7 @@ path/s is either such a string or a list of them.
 "collects/tests/stepper/undefined.rktl" drdr:command-line #f
 "collects/tests/stepper/world-test.rktl" drdr:command-line #f
 "collects/tests/stepper/write-display.rktl" drdr:command-line #f
+"collects/tests/stress/fuzz.rkt" responsible (samth mflatt) drdr:command-line (racket "-t" * "-c")
 "collects/tests/stress.rkt" responsible (jay)
 "collects/tests/stxparse" responsible (ryanc)
 "collects/tests/stxparse/stxclass.rkt" drdr:command-line (gracket-text "-t" *)

collects/tests/stress/fuzz.rkt

@@ -0,0 +1,50 @@
+#lang racket
+
+(define (flip n bit)
+  (define new-bit (expt 2 bit))
+  (bitwise-xor new-bit n))
+
+(define (flip-file bs idx)
+  (define-values (byte bit) (quotient/remainder idx 8))  
+  (define val (bytes-ref bs byte))
+  (bytes-set! bs byte (flip val bit)))
+
+(define (run-file bs)
+  (eval (parameterize ([read-accept-compiled #t])
+          (with-input-from-bytes bs read))))
+
+
+(define sd #f)
+(define fl #f)
+(define dir #f)
+
+(define (run fname [seed (or sd (+ 1 (random (expt 2 30))))])
+  (printf "DrDr Ignore! random-seed ~s\n" seed)
+  (random-seed seed)
+  (define bs (file->bytes fname))
+  (define len (* 8 (bytes-length bs)))
+  (printf "name: ~a\n" fname)
+  (for ([i (in-range (quotient len 10000))])
+    (flip-file bs (random len)))
+  (with-handlers ([void void])
+    (run-file bs)))
+
+
+(command-line 
+ #:once-each
+ ["-s" seed "random seed" (set! sd (string->number seed))]
+ #:once-any
+ ["-f" file "filename to run"
+  (set! fl file)]
+ ["-d" dir* "dir to run" (set! dir dir*)]
+ ["-c" "run over all collections"
+ (set! dir (find-executable-path (find-system-path 'exec-file)
+				 (find-system-path 'collects-dir)))]
+  #:args () (void))
+
+(displayln dir)
+
+(cond [fl (run fl)]
+      [dir (for ([p (in-directory dir)]
+		 #:when (regexp-match "\\.zo" p))
+	      (run p))])