strtabs demo mutator

README.md

@@ -154,8 +154,8 @@ This is only necessary for destructor-based types. `mutate`, `default` and `==`
 - Don't `echo`  in a fuzz target as it slows down execution speed.
 - Prefer `-d:danger|release` for maximum performance.
 - Once you have a crash you can recompile with `-d:debug` and pass the crashing test case as parameter.
-- With this line `when defined(dumpFuzzInput): debugEcho(x)` in a target and `-d:dumpFuzzInput`, observe the crashing input.
-- You could compile without sanitizers, AddressSanitizer slows down by 2x, but it's not recommended.
+- Use `debugEcho(x)` in a target to print the crashing input.
+- You could compile without sanitizers, AddressSanitizer slows down programs by ~2x, but it's not recommended.
 
 ### What's not supported
 

examples/fuzz_html.nim

@@ -52,7 +52,7 @@ when isMainModule:
   proc default(_: typedesc[HtmlNode]): HtmlNode =
     HtmlNode(tag: text, s: "")
 
-  func fuzzTarget(x: HtmlNode) =
+  proc fuzzTarget(x: HtmlNode) =
     when defined(dumpFuzzInput): debugEcho(x)
     # Here you could feed `$x` to htmlparser.parseHtml and make sure it doesn't crash.
     #var errors: seq[string] = @[]

examples/fuzz_strtabs.nim

@@ -0,0 +1,21 @@
+import drchaos/mutator, std/[strtabs, random]
+
+proc mutate(data: var StringTableRef; sizeIncreaseHint: int; enforceChanges: bool; r: var Rand) =
+  var value: seq[tuple[key, value: string]]
+  for p in pairs(data):
+    value.add p
+  repeatMutateInplace(mutateSeq(value, tmp, 2, sizeIncreaseHint, r))
+  clear(data)
+  for key, val in value.items:
+    data[key] = val
+
+proc mutate(value: var string; sizeIncreaseHint: int; enforceChanges: bool; r: var Rand) =
+  repeatMutate(mutateUtf8String(move value, 4, sizeIncreaseHint, r))
+
+proc default(_: typedesc[StringTableRef]): StringTableRef =
+  newStringTable(modeCaseSensitive)
+
+func fuzzTarget(x: StringTableRef) =
+  doAssert x != {"key1": "val1", "key2": "val2"}.newStringTable
+
+defaultMutator(fuzzTarget)

experiments/xtables_mutator.nim

@@ -1,5 +1,6 @@
 # WARNING: This mutator crashes for OrderedTable and it's too slow with Table.
 # TODO: split into files and make it compile again.
+# Use https://nim-lang.org/docs/importutils.html
 import random
 include std/tables
 

tests/tvariants2.nim

@@ -21,6 +21,6 @@ func fuzzTarget(x: ContentNode) =
     ContentNode(kind: Text, textStr: "mychild"),
     ContentNode(kind: Br)
   ])
-  doAssert x != data
+  doAssert x != x
 
 defaultMutator(fuzzTarget)