Figure out a better pattern for exposing iso funcs

1 files changed, 90 insertions, 0 deletions

diff --git a/packages/server/src/helpers/iso/isoUint8Array.ts b/packages/server/src/helpers/iso/isoUint8Array.ts
new file mode 100644
index 0000000..5237937
--- /dev/null
+++ b/packages/server/src/helpers/iso/isoUint8Array.ts
@@ -0,0 +1,90 @@
+/**
+ * Make sure two Uint8Arrays are deeply equivalent
+ */
+export function areEqual(array1: Uint8Array, array2: Uint8Array): boolean {
+  if (array1.length != array2.length) {
+    return false;
+  }
+
+  return array1.every((val, i) => val === array2[i]);
+}
+
+/**
+ * Convert a Uint8Array to Hexadecimal.
+ *
+ * A replacement for `Buffer.toString('hex')`
+ */
+export function toHex(array: Uint8Array): string {
+  const hexParts = Array.from(array, i => i.toString(16).padStart(2, "0"));
+
+  // adce000235bcc60a648b0b25f1f05503
+  return hexParts.join('');
+}
+
+/**
+ * Convert a hexadecimal string to isoUint8Array.
+ *
+ * A replacement for `Buffer.from('...', 'hex')`
+ */
+export function fromHex(hex: string): Uint8Array {
+  if (!hex) {
+    return Uint8Array.from([]);
+  }
+
+  const isValid = hex.length !== 0 && hex.length % 2 === 0 && !/[^a-fA-F0-9]/u.test(hex);
+
+  if (!isValid) {
+    throw new Error('Invalid hex string');
+  }
+
+  const byteStrings = hex.match(/.{1,2}/g) ?? [];
+
+  return Uint8Array.from(byteStrings.map((byte) => parseInt(byte, 16)));
+}
+
+/**
+ * Combine multiple Uint8Arrays into a single Uint8Array
+ */
+export function concat(arrays: Uint8Array[]): Uint8Array {
+  let pointer = 0;
+  const totalLength = arrays.reduce((prev, curr) => prev + curr.length, 0);
+
+  const toReturn = new Uint8Array(totalLength);
+
+  arrays.forEach((arr) => {
+    toReturn.set(arr, pointer);
+    pointer += arr.length;
+  });
+
+  return toReturn;
+}
+
+/**
+ * Convert bytes into a UTF-8 string
+ */
+export function toUTF8String(array: Uint8Array): string {
+  const decoder = new globalThis.TextDecoder("utf-8");
+  return decoder.decode(array);
+}
+
+/**
+ * Convert a UTF-8 string back into bytes
+ */
+export function fromUTF8String(utf8String: string): Uint8Array {
+  const encoder = new globalThis.TextEncoder();
+  return encoder.encode(utf8String);
+}
+
+/**
+ * Convert an ASCII string to Uint8Array
+ */
+export function fromASCIIString(value: string): Uint8Array {
+  return Uint8Array.from(value.split("").map(x => x.charCodeAt(0)));
+}
+
+/**
+ * Prepare a DataView we can slice our way around in as we parse the bytes in a Uint8Array
+ */
+export function toDataView(array: Uint8Array): DataView {
+  return new DataView(array.buffer, array.byteOffset, array.length);
+}