refactor: inline code

src/internal/base64.ts

@@ -1,16 +1,3 @@
-let toBase64_: (input: string) => string;
-if (typeof Buffer === 'undefined') {
-  toBase64_ = (input: string): string => {
-    const utf8Bytes = new TextEncoder().encode(input);
-    const binaryString = Array.from(utf8Bytes, (byte) =>
-      String.fromCodePoint(byte)
-    ).join('');
-    return btoa(binaryString);
-  };
-} else {
-  toBase64_ = (input: string): string => Buffer.from(input).toString('base64');
-}
-
 /**
  * This works the same as `Buffer.from(input).toString('base64')`
  * to work on both Node.js and browser environment.
@@ -25,4 +12,13 @@ if (typeof Buffer === 'undefined') {
  *
  * @example const encodedHeader = toBase64(JSON.stringify(header));
  */
-export const toBase64 = toBase64_;
+export const toBase64: (input: string) => string =
+  typeof Buffer === 'undefined'
+    ? (input) => {
+        const utf8Bytes = new TextEncoder().encode(input);
+        const binaryString = Array.from(utf8Bytes, (byte) =>
+          String.fromCodePoint(byte)
+        ).join('');
+        return btoa(binaryString);
+      }
+    : (input) => Buffer.from(input).toString('base64');