toHex polyfill

src/pdf/uint8ArrayToHexPolyfill.ts

@@ -0,0 +1,22 @@
+type Uint8ArrayWithToHex = Uint8Array & {
+  toHex?: () => string;
+};
+
+const uint8ArrayPrototype = Uint8Array.prototype as Uint8ArrayWithToHex;
+
+if (typeof uint8ArrayPrototype.toHex !== 'function') {
+  Object.defineProperty(Uint8Array.prototype, 'toHex', {
+    value: function toHex(this: Uint8Array): string {
+      const hex = new Array<string>(this.length);
+
+      for (let index = 0; index < this.length; index += 1) {
+        const value = this[index].toString(16);
+        hex[index] = value.length === 1 ? `0${value}` : value;
+      }
+
+      return hex.join('');
+    },
+    writable: true,
+    configurable: true,
+  });
+}