[fs-extra] Make compatible with @types/[email protected] (DefinitelyTyped#51677)

Author: forivall

types/fs-extra/fs-extra-tests.ts

@@ -299,3 +299,9 @@ fs.realpath('src', (err, resolved) => {
 fs.realpath.native('src');
 // $ExpectType Promise<Buffer>
 fs.realpath.native('src', 'buffer');
+// $ExpectType Promise<string>
+fs.realpath.native('src', { encoding: 'utf-8' });
+// $ExpectType Promise<Buffer>
+fs.realpath.native('src', { encoding: 'buffer' });
+// $ExpectType Promise<string>
+fs.realpath.native('src', { encoding: null });

types/fs-extra/index.d.ts

@@ -229,9 +229,9 @@ export function realpath(path: PathLike, cache?: { [path: string]: string }): Pr
 /* tslint:disable:unified-signatures */
 export namespace realpath {
     const native: {
-        (path: PathLike, options: fs.BaseEncodingOptions | BufferEncoding | undefined | null): Promise<string>;
-        (path: PathLike, options: fs.BufferEncodingOption): Promise<Buffer>;
-        (path: PathLike, options: fs.BaseEncodingOptions | string | undefined | null): Promise<string | Buffer>;
+        (path: PathLike, options: { encoding: BufferEncoding | null } | BufferEncoding | undefined | null): Promise<string>;
+        (path: PathLike, options: { encoding: "buffer" } | "buffer"): Promise<Buffer>;
+        (path: PathLike, options: { encoding: BufferEncoding | null } | string | undefined | null): Promise<string | Buffer>;
         (path: PathLike): Promise<string>;
     } & typeof fs.realpath.native;
 }