1 files changed, 15 insertions, 0 deletions
diff --git a/tests/js/t21247.nim b/tests/js/t21247.nim
new file mode 100644
index 000000000..5b38787b3
--- /dev/null
+++ b/tests/js/t21247.nim
@@ -0,0 +1,15 @@
+import std/typetraits
+
+type
+  QueryParams* = distinct seq[(string, string)]
+
+converter toBase*(params: var QueryParams): var seq[(string, string)] =
+  params.distinctBase
+
+proc foo(): QueryParams =
+  # Issue was that the implicit converter call didn't say that it took the
+  # address of the parameter it was converting. This led to the parameter not being
+  # passed as a fat pointer which toBase expected
+  result.add(("hello", "world"))
+
+assert foo().distinctBase() == @[("hello", "world")]