fix(fs-extra): copy can take an async filter function (#24888)

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

@@ -48,7 +48,7 @@ fs.copy(src, dest,
 	{
 		overwrite: true,
 		preserveTimestamps: true,
-		filter: (src: string, dest: string) => false
+		filter: (src: string, dest: string) => Promise.resolve(false)
 	},
 	errorCallback
 );

types/fs-extra/index.d.ts

@@ -3,7 +3,8 @@
 // Definitions by: Alan Agius <https://github.com/alan-agius4>,
 //                 midknight41 <https://github.com/midknight41>,
 //                 Brendan Forster <https://github.com/shiftkey>,
-//                 Mees van Dijk <https://github.com/mees->
+//                 Mees van Dijk <https://github.com/mees->,
+//                 Justin Rockwood <https://github.com/jrockwood>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -16,7 +17,7 @@ export * from "fs";
 export function copy(src: string, dest: string, options?: CopyOptions): Promise<void>;
 export function copy(src: string, dest: string, callback: (err: Error) => void): void;
 export function copy(src: string, dest: string, options: CopyOptions, callback: (err: Error) => void): void;
-export function copySync(src: string, dest: string, options?: CopyOptions): void;
+export function copySync(src: string, dest: string, options?: CopyOptionsSync): void;
 
 export function move(src: string, dest: string, options?: MoveOptions): Promise<void>;
 export function move(src: string, dest: string, callback: (err: Error) => void): void;
@@ -254,7 +255,8 @@ export interface PathEntryStream {
     read(): PathEntry | null;
 }
 
-export type CopyFilter = (src: string, dest: string) => boolean;
+export type CopyFilterSync = (src: string, dest: string) => boolean;
+export type CopyFilterAsync = (src: string, dest: string) => Promise<boolean>;
 
 export type SymlinkType = "dir" | "file";
 
@@ -263,10 +265,14 @@ export interface CopyOptions {
     overwrite?: boolean;
     preserveTimestamps?: boolean;
     errorOnExist?: boolean;
-    filter?: CopyFilter;
+    filter?: CopyFilterSync | CopyFilterAsync;
     recursive?: boolean;
 }
 
+export interface CopyOptionsSync extends CopyOptions {
+    filter?: CopyFilterSync;
+}
+
 export interface MoveOptions {
     overwrite?: boolean;
     limit?: number;