1 files changed, 21 insertions, 0 deletions
diff --git a/tests/js/tneginthash.nim b/tests/js/tneginthash.nim
new file mode 100644
index 000000000..c082405c9
--- /dev/null
+++ b/tests/js/tneginthash.nim
@@ -0,0 +1,21 @@
+# issue #19929
+
+import std/[tables, hashes]
+
+type Foo = object
+  a: int
+
+proc hash(f: Foo): Hash =
+  var h: Hash = 0
+  h = h !& hash(f.a)
+  result = !$h
+
+proc transpose[T, S](data: array[T, S]): Table[S, T] =
+  for i, x in data:
+    result[x] = i
+
+const xs = [Foo(a: 5), Foo(a: -5)]
+const x = transpose(xs)
+
+doAssert x[Foo(a: -5)] == 1
+doAssert x[Foo(a: 5)] == 0