feat(Storage): Adding subpath strategy to the List operation

Amplify/Categories/Storage/Operation/Request/StorageListRequest.swift

@@ -60,6 +60,11 @@ public extension StorageListRequest {
         @available(*, deprecated, message: "Use `path` in Storage API instead of `Options`")
         public let path: String?
 
+        /// The strategy to use when listing contents from subpaths. Defaults to [`.include`](x-source-tag://SubpathStrategy.include)
+        ///
+        /// - Tag: StorageListRequestOptions.subpathStrategy
+        public let subpathStrategy: SubpathStrategy
+
         /// Number between 1 and 1,000 that indicates the limit of how many entries to fetch when
         /// retreiving file lists from the server.
         ///
@@ -94,15 +99,47 @@ public extension StorageListRequest {
         public init(accessLevel: StorageAccessLevel = .guest,
                     targetIdentityId: String? = nil,
                     path: String? = nil,
+                    subpathStrategy: SubpathStrategy = .include,
                     pageSize: UInt = 1000,
                     nextToken: String? = nil,
                     pluginOptions: Any? = nil) {
             self.accessLevel = accessLevel
             self.targetIdentityId = targetIdentityId
             self.path = path
+            self.subpathStrategy = subpathStrategy
             self.pageSize = pageSize
             self.nextToken = nextToken
             self.pluginOptions = pluginOptions
         }
     }
 }
+
+public extension StorageListRequest.Options {
+    /// Represents the strategy used when listing contents from subpaths relative to the given path.
+    ///
+    /// - Tag: StorageListRequestOptions.SubpathStrategy
+    enum SubpathStrategy {
+        /// Items from nested subpaths are included in the results
+        ///
+        /// - Tag: SubpathStrategy.include
+        case include
+
+        /// Items from nested subpaths are not included in the results. Their subpaths are instead grouped under [`StorageListResult.excludedSubpaths`](StorageListResult.excludedSubpaths).
+        ///
+        /// - Parameter delimitedBy: The delimiter used to determine subpaths. Defaults to `"/"`
+        ///
+        /// - SeeAlso: [`StorageListResult.excludedSubpaths`](x-source-tag://StorageListResult.excludedSubpaths)
+        ///
+        /// - Tag: SubpathStrategy.excludeWithDelimiter
+        case exclude(delimitedBy: String = "/")
+
+        /// Items from nested subpaths are not included in the results. Their subpaths are instead grouped under [`StorageListResult.excludedSubpaths`](StorageListResult.excludedSubpaths).
+        ///
+        /// - SeeAlso: [`StorageListResult.excludedSubpaths`](x-source-tag://StorageListResult.excludedSubpaths)
+        ///
+        /// - Tag: SubpathStrategy.exclude
+        public static var exclude: SubpathStrategy {
+            return .exclude()
+        }
+    }
+}

Amplify/Categories/Storage/Result/StorageListResult.swift

@@ -17,8 +17,13 @@ public struct StorageListResult {
     /// [StorageCategoryBehavior.list](x-source-tag://StorageCategoryBehavior.list).
     ///
     /// - Tag: StorageListResult.init
-    public init(items: [Item], nextToken: String? = nil) {
+    public init(
+        items: [Item],
+        excludedSubpaths: [String] = [],
+        nextToken: String? = nil
+    ) {
         self.items = items
+        self.excludedSubpaths = excludedSubpaths
         self.nextToken = nextToken
     }
 
@@ -27,6 +32,13 @@ public struct StorageListResult {
     /// - Tag: StorageListResult.items
     public var items: [Item]
 
+
+    /// Array of excluded subpaths in the Result. 
+    /// This field is only populated when [`StorageListRequest.Options.subpathStrategy`](x-source-tag://StorageListRequestOptions.subpathStragegy) is set to [`.exclude()`](x-source-tag://SubpathStrategy.exclude).
+    ///
+    /// - Tag: StorageListResult.excludedSubpaths
+    public var excludedSubpaths: [String]
+
     /// Opaque string indicating the page offset at which to resume a listing. This value is usually copied to
     /// [StorageListRequestOptions.nextToken](x-source-tag://StorageListRequestOptions.nextToken).
     ///

AmplifyPlugins/Storage/Sources/AWSS3StoragePlugin/Service/Storage/AWSS3StorageService+ListBehavior.swift

@@ -31,7 +31,7 @@ extension AWSS3StorageService {
         }
         let input = ListObjectsV2Input(bucket: bucket,
                                        continuationToken: options.nextToken,
-                                       delimiter: nil,
+                                       delimiter: options.subpathStrategy.delimiter,
                                        maxKeys: Int(options.pageSize),
                                        prefix: finalPrefix,
                                        startAfter: nil)
@@ -41,7 +41,20 @@ extension AWSS3StorageService {
             let items = try contents.map {
                 try StorageListResult.Item(s3Object: $0, prefix: prefix)
             }
-            return StorageListResult(items: items, nextToken: response.nextContinuationToken)
+
+            let commonPrefixes = response.commonPrefixes ?? []
+            let excludedSubpaths: [String] = commonPrefixes.compactMap {
+                guard let commonPrefix = $0.prefix else {
+                    return nil
+                }
+                return String(commonPrefix.dropFirst(prefix.count))
+            }
+
+            return StorageListResult(
+                items: items,
+                excludedSubpaths: excludedSubpaths,
+                nextToken: response.nextContinuationToken
+            )
         } catch let error as StorageErrorConvertible {
             throw error.storageError
         } catch {

AmplifyPlugins/Storage/Sources/AWSS3StoragePlugin/Support/Internal/SubpathStategy+Delimiter.swift

@@ -0,0 +1,20 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Amplify
+
+extension StorageListRequest.Options.SubpathStrategy {
+    /// The delimiter for this strategy 
+    var delimiter: String? {
+        switch self {
+        case .exclude(let delimiter):
+            return delimiter
+        case .include:
+            return nil
+        }
+    }
+}

AmplifyPlugins/Storage/Sources/AWSS3StoragePlugin/Tasks/AWSS3StorageListObjectsTask.swift

@@ -43,7 +43,7 @@ class AWSS3StorageListObjectsTask: StorageListObjectsTask, DefaultLogger {
         }
         let input = ListObjectsV2Input(bucket: storageBehaviour.bucket,
                                        continuationToken: request.options.nextToken,
-                                       delimiter: nil,
+                                       delimiter: request.options.subpathStrategy.delimiter,
                                        maxKeys: Int(request.options.pageSize),
                                        prefix: path,
                                        startAfter: nil)
@@ -57,9 +57,15 @@ class AWSS3StorageListObjectsTask: StorageListObjectsTask, DefaultLogger {
                 return StorageListResult.Item(
                     path: path,
                     eTag: s3Object.eTag,
-                    lastModified: s3Object.lastModified)
+                    lastModified: s3Object.lastModified
+                )
             }
-            return StorageListResult(items: items, nextToken: response.nextContinuationToken)
+            let commonPrefixes = response.commonPrefixes ?? []
+            return StorageListResult(
+                items: items,
+                excludedSubpaths: commonPrefixes.compactMap { $0.prefix },
+                nextToken: response.nextContinuationToken
+            )
         } catch let error as StorageErrorConvertible {
             throw error.storageError
         } catch {

AmplifyPlugins/Storage/Tests/AWSS3StoragePluginTests/AWSS3StoragePluginAsyncBehaviorTests.swift

@@ -114,4 +114,22 @@ class AWSS3StoragePluginAsyncBehaviorTests: XCTestCase {
         XCTAssertEqual(1, storageService.interactions.count)
     }
 
+    /// - Given: A plugin configured with a mocked service
+    /// - When: The list API is invoked with subpathStrategy set to .exclude
+    /// - Then: The list of excluded subpaths and the list of items should be populated
+    func testPluginListWithCommonPrefixesAsync() async throws  {
+        storageService.listHandler = { (_, _) in
+            return .init(
+                items: [.init(path: "path")],
+                excludedSubpaths: ["subpath1", "subpath2"]
+            )
+        }
+        let output = try await storagePlugin.list(options: .init(subpathStrategy: .exclude))
+        XCTAssertEqual(1, output.items.count, String(describing: output))
+        XCTAssertEqual("path", output.items.first?.path)
+        XCTAssertEqual(2, output.excludedSubpaths.count)
+        XCTAssertEqual("subpath1", output.excludedSubpaths[0])
+        XCTAssertEqual("subpath2", output.excludedSubpaths[1])
+        XCTAssertEqual(1, storageService.interactions.count)
+    }
 }

AmplifyPlugins/Storage/Tests/AWSS3StoragePluginTests/Tasks/AWSS3StorageListObjectsTaskTests.swift

@@ -38,6 +38,7 @@ class AWSS3StorageListObjectsTaskTests: XCTestCase {
             storageBehaviour: serviceMock)
         let value = try await task.value
         XCTAssertEqual(value.items.count, 2)
+        XCTAssertTrue(value.excludedSubpaths.isEmpty)
         XCTAssertEqual(value.nextToken, "continuationToken")
         XCTAssertEqual(value.items[0].eTag, "tag")
         XCTAssertEqual(value.items[0].key, "key")
@@ -130,4 +131,81 @@ class AWSS3StorageListObjectsTaskTests: XCTestCase {
             XCTAssertEqual(field, "path", "Field in error should be `path`")
         }
     }
+
+    /// - Given: A configured Storage List Objects Task with mocked service
+    /// - When: AWSS3StorageListObjectsTask value is invoked with subpathStrategy set to .exclude
+    /// - Then: The delimiter should be set, the list of excluded subpaths and the list of items should be populated
+    func testListObjectsTask_withSubpathStrategyExclude_shouldSucceed() async throws {
+        let serviceMock = MockAWSS3StorageService()
+        let client = serviceMock.client as! MockS3Client
+        client.listObjectsV2Handler = { input in
+            XCTAssertNotNil(input.delimiter, "Expected delimiter to be set")
+            return .init(
+                commonPrefixes: [
+                    .init(prefix: "path/subpath1/"),
+                    .init(prefix: "path/subpath2/")
+                ],
+                contents: [
+                    .init(eTag: "tag", key: "path/result", lastModified: Date())
+                ],
+                nextContinuationToken: "continuationToken"
+            )
+        }
+
+        let request = StorageListRequest(
+            path: StringStoragePath.fromString("path/"),
+            options: .init(
+                subpathStrategy: .exclude
+            )
+        )
+        let task = AWSS3StorageListObjectsTask(
+            request,
+            storageConfiguration: AWSS3StoragePluginConfiguration(),
+            storageBehaviour: serviceMock
+        )
+        let value = try await task.value
+        XCTAssertEqual(value.items.count, 1)
+        XCTAssertEqual(value.items[0].eTag, "tag")
+        XCTAssertEqual(value.items[0].path, "path/result")
+        XCTAssertNotNil(value.items[0].lastModified)
+        XCTAssertEqual(value.excludedSubpaths.count, 2)
+        XCTAssertEqual(value.excludedSubpaths[0], "path/subpath1/")
+        XCTAssertEqual(value.excludedSubpaths[1], "path/subpath2/")
+        XCTAssertEqual(value.nextToken, "continuationToken")
+    }
+
+    /// - Given: A configured Storage List Objects Task with mocked service
+    /// - When: AWSS3StorageListObjectsTask value is invoked with subpathStrategy set to .include
+    /// - Then: The delimiter should not be set, the list of excluded subpaths should be empty and the list of items should be populated
+    func testListObjectsTask_withSubpathStrategyInclude_shouldSucceed() async throws {
+        let serviceMock = MockAWSS3StorageService()
+        let client = serviceMock.client as! MockS3Client
+        client.listObjectsV2Handler = { input in
+            XCTAssertNil(input.delimiter, "Expected delimiter to be nil")
+            return .init(
+                contents: [
+                    .init(eTag: "tag", key: "path", lastModified: Date()),
+                ],
+                nextContinuationToken: "continuationToken"
+            )
+        }
+
+        let request = StorageListRequest(
+            path: StringStoragePath.fromString("path"), 
+            options: .init(
+                subpathStrategy: .include
+            )
+        )
+        let task = AWSS3StorageListObjectsTask(
+            request,
+            storageConfiguration: AWSS3StoragePluginConfiguration(),
+            storageBehaviour: serviceMock)
+        let value = try await task.value
+        XCTAssertEqual(value.items.count, 1)
+        XCTAssertEqual(value.items[0].eTag, "tag")
+        XCTAssertEqual(value.items[0].path, "path")
+        XCTAssertNotNil(value.items[0].lastModified)
+        XCTAssertTrue(value.excludedSubpaths.isEmpty)
+        XCTAssertEqual(value.nextToken, "continuationToken")
+    }
 }

AmplifyPlugins/Storage/Tests/StorageHostApp/AWSS3StoragePluginIntegrationTests/AWSS3StoragePluginListObjectsIntegrationTests.swift

@@ -189,4 +189,67 @@ class AWSS3StoragePluginListObjectsIntegrationTests: AWSS3StoragePluginTestBase
         }
     }
 
+    /// Given: Multiple objects uploaded to a public path
+    /// When: `Amplify.Storage.list` is invoked with `subpathStrategy: .exclude`
+    /// Then: The API should execute successfully and list objects for the given path, without including contens from its subpaths
+    func testList_withSubpathStrategyExclude_shouldExcludeSubpaths() async throws {
+        let path = UUID().uuidString
+        let data = Data(path.utf8)
+        let uniqueStringPath = "public/\(path)"
+
+        // Upload data
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "/test1"), data: data, options: nil).value
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "/test2"), data: data, options: nil).value
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "/subpath1/test"), data: data, options: nil).value
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "/subpath2/test"), data: data, options: nil).value
+
+        let result = try await Amplify.Storage.list(
+            path: .fromString("\(uniqueStringPath)/"),
+            options: .init(
+                subpathStrategy: .exclude
+            )
+        )
+
+        // Validate result
+        XCTAssertEqual(result.items.count, 2)
+        XCTAssertTrue(result.items.contains(where: { $0.path.hasPrefix("\(uniqueStringPath)/test") }), "Unexpected item")
+        XCTAssertEqual(result.excludedSubpaths.count, 2)
+        XCTAssertTrue(result.excludedSubpaths.contains(where: { $0.hasPrefix("\(uniqueStringPath)/subpath") }), "Unexpected excluded subpath")
+
+        // Clean up
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "/test1"))
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "/test2"))
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "/subpath1/test"))
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "/subpath2/test"))
+    }
+
+    /// Given: Multiple objects uploaded to a public path
+    /// When: `Amplify.Storage.list` is invoked with `subpathStrategy: .exclude(delimitedBy:)`
+    /// Then: The API should execute successfully and list objects for the given path, without including contents from any subpath that is determined by the given delimiter
+    func testList_withSubpathStrategyExclude_andCustomDelimiter_shouldExcludeSubpaths() async throws {
+        let path = UUID().uuidString
+        let data = Data(path.utf8)
+        let uniqueStringPath = "public/\(path)"
+
+        // Upload data
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "-test"), data: data, options: nil).value
+        _ = try await Amplify.Storage.uploadData(path: .fromString(uniqueStringPath + "-subpath-test"), data: data, options: nil).value
+
+        let result = try await Amplify.Storage.list(
+            path: .fromString("\(uniqueStringPath)-"),
+            options: .init(
+                subpathStrategy: .exclude(delimitedBy: "-")
+            )
+        )
+
+        // Validate result
+        XCTAssertEqual(result.items.count, 1)
+        XCTAssertEqual(result.items.first?.path, "\(uniqueStringPath)-test")
+        XCTAssertEqual(result.excludedSubpaths.count, 1)
+        XCTAssertEqual(result.excludedSubpaths.first, "\(uniqueStringPath)-subpath-")
+
+        // Clean up
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "-test"))
+        _ = try await Amplify.Storage.remove(path: .fromString(uniqueStringPath + "-subpath-test"))
+    }
 }