1 files changed, 38 insertions, 0 deletions
diff --git a/vanilla/node_modules/@exodus/bytes/fallback/encoding.api.js b/vanilla/node_modules/@exodus/bytes/fallback/encoding.api.js
new file mode 100644
index 0000000..8dc5243
--- /dev/null
+++ b/vanilla/node_modules/@exodus/bytes/fallback/encoding.api.js
@@ -0,0 +1,38 @@
+// TODO: make this more strict against Symbol.toStringTag
+// Is not very significant though, anything faking Symbol.toStringTag could as well override
+// prototypes, which is not something we protect against
+
+function isAnyArrayBuffer(x) {
+  if (x instanceof ArrayBuffer) return true
+  if (globalThis.SharedArrayBuffer && x instanceof SharedArrayBuffer) return true
+  if (!x || typeof x.byteLength !== 'number') return false
+  const s = Object.prototype.toString.call(x)
+  return s === '[object ArrayBuffer]' || s === '[object SharedArrayBuffer]'
+}
+
+export function fromSource(x) {
+  if (x instanceof Uint8Array) return x
+  if (ArrayBuffer.isView(x)) return new Uint8Array(x.buffer, x.byteOffset, x.byteLength)
+  if (isAnyArrayBuffer(x)) {
+    if ('detached' in x) return x.detached === true ? new Uint8Array() : new Uint8Array(x)
+    // Old engines without .detached, try-catch
+    try {
+      return new Uint8Array(x)
+    } catch {
+      return new Uint8Array()
+    }
+  }
+
+  throw new TypeError('Argument must be a SharedArrayBuffer, ArrayBuffer or ArrayBufferView')
+}
+
+// Warning: unlike whatwg-encoding, returns lowercased labels
+// Those are case-insensitive and that's how TextDecoder encoding getter normalizes them
+export function getBOMEncoding(input) {
+  const u8 = fromSource(input) // asserts
+  if (u8.length >= 3 && u8[0] === 0xef && u8[1] === 0xbb && u8[2] === 0xbf) return 'utf-8'
+  if (u8.length < 2) return null
+  if (u8[0] === 0xff && u8[1] === 0xfe) return 'utf-16le'
+  if (u8[0] === 0xfe && u8[1] === 0xff) return 'utf-16be'
+  return null
+}