Ensure BTreeSet has the correct decoded length (#4588)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
2022-02-21 18:07:11 +00:00
parent 13751b6fdf
commit cd9662ab4c
3 changed files with 25 additions and 1 deletions
@@ -133,6 +133,23 @@ describe('BTreeSet', (): void => {
    ).toEqual(17);
  });

+  it('correctly encodes/decodes the length', (): void => {
+    const none = new (BTreeSet.with(U32))(registry, []).toHex();
+    const some = new (BTreeSet.with(U32))(registry, [1, 2]).toHex();
+
+    // only the length byte
+    expect(none).toEqual('0x00');
+    expect(
+      (new (BTreeSet.with(U32))(registry, none)).initialU8aLength
+    ).toEqual(1);
+
+    // length byte + 2 values, 2 << 2 with u32 values
+    expect(some).toEqual('0x080100000002000000');
+    expect(
+      (new (BTreeSet.with(U32))(registry, some)).initialU8aLength
+    ).toEqual(1 + (2 * 4));
+  });
+
  it('correctly sorts numeric values', (): void => {
    expect(
      Array.from(new (BTreeSet.with(I32))(registry, mockI32SetObj)).map((k) => k.toNumber())
@@ -20,7 +20,7 @@ function decodeSetFromU8a<V extends Codec> (registry: Registry, ValClass: CodecC
    output.add(values[i]);
  }

-  return [output, decodedLength + offset];
+  return [output, decodedLength];
 }

 /** @internal */