3 files changed, 31 insertions, 9 deletions
diff --git a/src/gleam_stdlib.mjs b/src/gleam_stdlib.mjs
index 69644dc..112007f 100644
--- a/src/gleam_stdlib.mjs
+++ b/src/gleam_stdlib.mjs
@@ -350,21 +350,18 @@ export function codepoint(int) {
 }
 
 export function string_to_codepoint_integer_list(string) {
-  return List.fromArray(
-    Array.from(string)
-      .map(item => item.codePointAt(0))
-  );
+  return List.fromArray(Array.from(string).map((item) => item.codePointAt(0)));
 }
 
 export function utf_codepoint_list_to_string(utf_codepoint_integer_list) {
   return utf_codepoint_integer_list
     .toArray()
-    .map(x => String.fromCodePoint(x.value))
+    .map((x) => String.fromCodePoint(x.value))
     .join("");
 }
 
 export function utf_codepoint_to_int(utf_codepoint) {
-	return utf_codepoint.value;
+  return utf_codepoint.value;
 }
 
 export function regex_check(regex, string) {
@@ -646,9 +643,13 @@ export function decode_bool(data) {
 }
 
 export function decode_bit_string(data) {
-  return BitString.isBitString(data)
-    ? new Ok(data)
-    : decoder_error("BitString", data);
+  if (BitString.isBitString(data)) {
+    return new Ok(data);
+  }
+  if (data instanceof Uint8Array) {
+    return new Ok(new BitString(data));
+  }
+  return decoder_error("BitString", data);
 }
 
 export function decode_tuple(data) {
diff --git a/test/gleam/dynamic_test.gleam b/test/gleam/dynamic_test.gleam
index 104c1fa..9d1aeba 100644
--- a/test/gleam/dynamic_test.gleam
+++ b/test/gleam/dynamic_test.gleam
@@ -39,6 +39,18 @@ if erlang {
   }
 }
 
+if javascript {
+  external fn uint8array(List(Int)) -> dynamic.Dynamic =
+    "../gleam_stdlib_test_ffi.mjs" "uint8array"
+
+  pub fn bit_string_erlang_test() {
+    [1, 1, 2, 3, 5, 8]
+    |> uint8array
+    |> dynamic.bit_string
+    |> should.equal(Ok(<<1, 1, 2, 3, 5, 8>>))
+  }
+}
+
 pub fn string_test() {
   ""
   |> dynamic.from
diff --git a/test/gleam_stdlib_test_ffi.mjs b/test/gleam_stdlib_test_ffi.mjs
index 90eeaf0..cbf0382 100755
--- a/test/gleam_stdlib_test_ffi.mjs
+++ b/test/gleam_stdlib_test_ffi.mjs
@@ -33,3 +33,12 @@ ${passes} passes
 ${failures} failures`);
   process.exit(failures ? 1 : 0);
 }
+
+export function uint8array(list) {
+  let ints = list.toArray();
+  let array = new Uint8Array(ints.length);
+  for (let i = 0; i < ints.length; i++) {
+    array[i] = ints[i];
+  }
+  return array;
+}