Fix for incorrect resume behavior

Author: donnywals

Sources/TUSKit/TUSAPI.swift

@@ -19,7 +19,7 @@ public enum TUSAPIError: Error {
     public var localizedDescription: String {
         switch self {
         case .underlyingError(let error):
-            return error.localizedDescription
+            return "Underlying error: " + error.localizedDescription
         case .couldNotFetchStatus:
             return "Could not fetch status from server."
         case .couldNotFetchServerInfo:

Sources/TUSKit/TUSClient.swift

@@ -366,12 +366,21 @@ public final class TUSClient {
   @discardableResult
   public func resume(id: UUID) throws -> Bool {
       do {
-          var uploadMetadata: UploadMetadata?
+          var metaData: UploadMetadata?
           queue.sync {
-              uploadMetadata = uploads[id]
+              metaData = uploads[id]
           }
-          guard uploadMetadata != nil else { return false }
-          guard let metaData = try files.findMetadata(id: id) else {
+          
+          if metaData == nil {
+              guard let storedMetadata = try files.findMetadata(id: id) else {
+                  return false
+              }
+              
+              metaData = storedMetadata
+          }
+          
+          guard let metaData else {
+              // should never happen...
               return false
           }
 

TUSKitExample/TUSKitExample/Helpers/TUSWrapper.swift

@@ -40,12 +40,20 @@ class TUSWrapper: ObservableObject {
 
     @MainActor
     func resumeUpload(id: UUID) {
-        _ = try? client.resume(id: id)
-        
-        if case let .paused(bytesUploaded, totalBytes) = uploads[id] {
-            withAnimation {
-                uploads[id] = .uploading(bytesUploaded: bytesUploaded, totalBytes: totalBytes)
+        do {
+            guard try client.resume(id: id) == true else {
+                print("Upload not resumed; metadata not found")
+                return
             }
+            
+            if case let .paused(bytesUploaded, totalBytes) = uploads[id] {
+                withAnimation {
+                    uploads[id] = .uploading(bytesUploaded: bytesUploaded, totalBytes: totalBytes)
+                }
+            }
+        } catch {
+            print("Could not resume upload with id \(id)")
+            print(error)
         }
     }
 
@@ -99,6 +107,10 @@ extension TUSWrapper: TUSClientDelegate {
 
     func uploadFailed(id: UUID, error: Error, context: [String : String]?, client: TUSClient) {
         Task { @MainActor in
+            // Pausing an upload means we cancel it, so we don't want to show it as failed.
+            if let tusError = error as? TUSClientError, case .taskCancelled = tusError {
+                return
+            }
 
             withAnimation {
                 uploads[id] = .failed(error: error)

TUSKitExample/TUSKitExample/Screens/Upload/UploadsListView.swift

@@ -133,6 +133,10 @@ extension UploadsListView {
                                 UploadedRowView(key: idx.key, url: url)
                             case .failed(let error):
                                 FailedRowView(key: idx.key, error: error)
+                                    .onAppear {
+                                        print(error)
+                                        print(error.localizedDescription)
+                                    }
                         }
                     }
                     Divider()