fix(core): use enumeratorAtPath for iOS shallow entity enumeration (NativeScript#11182)

Author: NathanWalker

apps/automated/src/file-system/file-system-tests.ts

@@ -370,9 +370,11 @@ export var testEnumEntities = function () {
 	var file = documents.getFile('Test.txt');
 	var file1 = documents.getFile('Test1.txt');
 	var testFolder = documents.getFolder('testFolder');
+	var nestedFile = testFolder.getFile('Nested.txt');
 	var fileFound = false;
 	var file1Found = false;
 	var testFolderFound = false;
+	var nestedFileFound = false;
 	var console = {
 		log: function (file) {
 			if (file === 'Test.txt') {
@@ -381,6 +383,8 @@ export var testEnumEntities = function () {
 				file1Found = true;
 			} else if (file === 'testFolder') {
 				testFolderFound = true;
+			} else if (file === 'Nested.txt') {
+				nestedFileFound = true;
 			}
 		},
 	};
@@ -395,9 +399,11 @@ export var testEnumEntities = function () {
 	TKUnit.assert(fileFound, 'Failed to enumerate Test.txt');
 	TKUnit.assert(file1Found, 'Failed to enumerate Test1.txt');
 	TKUnit.assert(testFolderFound, 'Failed to enumerate testFolder');
+	TKUnit.assert(!nestedFileFound, 'eachEntity should not enumerate nested files');
 
 	file.remove();
 	file1.remove();
+	nestedFile.remove();
 	testFolder.remove();
 	// << (hide)
 	// << file-system-enum-content

packages/core/file-system/file-system-access.ios.ts

@@ -629,27 +629,34 @@ export class FileSystemAccess {
 	private enumEntities(path: string, callback: (entity: { path: string; name: string; extension: string }) => boolean, onError?: (error) => any) {
 		try {
 			const fileManager = NSFileManager.defaultManager;
-			let files: NSArray<string>;
-			try {
-				files = fileManager.contentsOfDirectoryAtPathError(path);
-			} catch (ex) {
-				if (onError) {
-					onError(new Error("Failed to enum files for folder '" + path + "': " + ex));
-				}
+			if (!this.folderExists(path)) {
+				console.error(`Failed to enum files for folder '${path}': no folder exists at path`);
+				return;
+			}
 
+			const enumerator = fileManager.enumeratorAtPath(path);
+			if (!enumerator) {
+				console.error(`Failed to enum files for folder '${path}': unable to create directory enumerator`);
 				return;
 			}
 
-			for (let i = 0; i < files.count; i++) {
-				const file = files.objectAtIndex(i);
+			let file = enumerator.nextObject() as string;
+			while (file) {
+				// Only surface direct children to match the previous shallow enumeration contract.
+				if (enumerator.level > 1) {
+					file = enumerator.nextObject() as string;
+					continue;
+				}
 
 				const info = {
 					path: this.concatPath(path, file),
 					name: file,
 					extension: '',
 				};
 
-				if (!this.folderExists(this.joinPath(path, file))) {
+				if (this.folderExists(this.joinPath(path, file))) {
+					enumerator.skipDescendants();
+				} else {
 					info.extension = this.getFileExtension(info.path);
 				}
 
@@ -658,6 +665,8 @@ export class FileSystemAccess {
 					// the callback returned false meaning we should stop the iteration
 					break;
 				}
+
+				file = enumerator.nextObject() as string;
 			}
 		} catch (ex) {
 			if (onError) {