fix: feat: strategy engine game theory tournaments (#5) (closes #217)

node_modules/@exodus/bytes/fallback/base58check.js

@@ -0,0 +1,52 @@
+import { toBase58, fromBase58 } from '@exodus/bytes/base58.js'
+import { assertU8, fromUint8 } from './_utils.js'
+
+const E_CHECKSUM = 'Invalid checksum'
+
+// checksum length is 4, i.e. only the first 4 bytes of the hash are used
+
+function encodeWithChecksum(arr, checksum) {
+  // arr type in already validated in input
+  const res = new Uint8Array(arr.length + 4)
+  res.set(arr, 0)
+  res.set(checksum.slice(0, 4), arr.length)
+  return toBase58(res)
+}
+
+function decodeWithChecksum(str) {
+  const arr = fromBase58(str) // checks input
+  const payloadSize = arr.length - 4
+  if (payloadSize < 0) throw new Error(E_CHECKSUM)
+  return [arr.slice(0, payloadSize), arr.slice(payloadSize)]
+}
+
+function assertChecksum(c, r) {
+  if ((c[0] ^ r[0]) | (c[1] ^ r[1]) | (c[2] ^ r[2]) | (c[3] ^ r[3])) throw new Error(E_CHECKSUM)
+}
+
+export const makeBase58check = (hashAlgo, hashAlgoSync) => {
+  const apis = {
+    async encode(arr) {
+      assertU8(arr)
+      return encodeWithChecksum(arr, await hashAlgo(arr))
+    },
+    async decode(str, format = 'uint8') {
+      const [payload, checksum] = decodeWithChecksum(str)
+      assertChecksum(checksum, await hashAlgo(payload))
+      return fromUint8(payload, format)
+    },
+  }
+  if (!hashAlgoSync) return apis
+  return {
+    ...apis,
+    encodeSync(arr) {
+      assertU8(arr)
+      return encodeWithChecksum(arr, hashAlgoSync(arr))
+    },
+    decodeSync(str, format = 'uint8') {
+      const [payload, checksum] = decodeWithChecksum(str)
+      assertChecksum(checksum, hashAlgoSync(payload))
+      return fromUint8(payload, format)
+    },
+  }
+}