Comment check on top-most signed bit

polkadot-js · Aug 22, 2023 · ff9d02a · ff9d02a
1 parent 26dbfb4
commit ff9d02a
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/packages/util/src/u8a/toNumber.ts b/packages/util/src/u8a/toNumber.ts
@@ -15,6 +15,10 @@ interface ToNumberOptions {
 export function u8aToNumber (value: Uint8Array, { isNegative = false }: ToNumberOptions = {}): number {
   const count = value.length;
 
+  // When the value is a i{8, 16, 24, 32, 40, 40} values and the top-most bit
+  // indicates a signed value, we use a two's complement conversion. If one of these
+  // flags are not set, we just do a normal unsigned conversion (the same shortcut
+  // applies in both the u8aTo{BigInt, Bn} conversions as well)
   if (isNegative && (value[count - 1] & 0x80)) {
     switch (count) {
       case 0: