[SR-15550] Loading a resource from a bundle fails due to incorrect bundle path #4372

swift-ci · 2021-12-03T15:37:28Z


Previous ID	SR-15550
Radar	None
Original Reporter	dlbuckley (JIRA User)
Type	Bug
Status	Closed
Resolution	Done

Attachment: Download

Environment

macOS 12.0.1

Xcode 13.1

Additional Detail from JIRA


Votes	0
Component/s	Foundation, Package Manager
Labels	Bug
Assignee	@Kyle-Ye
Priority	Medium

md5: e29ed1c01a487ed1bfed5abc764a545c

Issue Description:

I created a new executable SPM project today and tried to load a simple file resource using `Bundle` but ran into an issue where the Bundle seems to be initialised with the wrong path. Due to this calling methods like `url(forResource: ...` are unable to find the correct resource and return `nil`.

I have attached a demo project to demonstrate this, but here are the reproduction steps just in case:

1) Open terminal and create a new SPM project using `swift package init --type=executable`

2) Create a new file and add it somewhere in the `Sources` directory.

3) Add a reference to the new file to the `executableTarget` in the `Package.swift` resulting in something like:

.executableTarget(
            name: "AOC-D1C1",
            dependencies: [],
            resources: [.copy("Input.txt")])

4) Open `main.swift` and try to locate the file using `Bundle.main.url(forResource: "Input", withExtension: "txt")`

5) The returning `URL` is `nil` and the bundle `.bundlePath` property points to the executable directory, but not the `.bundle` within the directory.

Kyle-Ye · 2021-12-03T17:20:46Z

Kyle-Ye · 2021-12-03T17:23:47Z

You could use Bundle.module to get the bundle you want.

But there seems to be another problem here: Xcode will give an error if you try to use Bundle.module. (Maybe because it is a executable target or it is in the main.swift file? I do not know, and I think we can post another SR for it)

Saying that, using Bundle.module and building it in terminal with `swift build` or `swift run` is OK.

I think it's a bug of Xcode's private SwiftPM.

[Update] since it was not a bug on swift-package-manager rather the Xcode's private SwiftPM. I think we should file it to Feedback instead of opening a new SR bug in the forum.

Kyle-Ye · 2021-12-03T17:29:10Z

FYI: dlbuckley (JIRA User)

```

> cat ./Sources/AOC-D1C1/main.swift

import Foundation

let urlFromMain = Bundle.module.url(forResource: "Input", withExtension: "txt")

print("(urlFromMain?.absoluteString ?? "Not found in main")")

> swift run

[3/3] Build complete!

file:///Users/kyle/Downloads/AOC-D1C1/.build/arm64-apple-macosx/debug/AOC-D1C1_AOC-D1C1.bundle/Input.txt

```

My environment

```

Swift version: Apple Swift version 5.5.1 (swiftlang-1300.0.31.4 clang-1300.0.29.6)

Target: arm64-apple-macosx12.0

Unix version: Darwin 21.2.0 Darwin Kernel Version 21.2.0: Tue Nov 16 23:24:18 PST 2021; root:xnu-8019.61.4~4/RELEASE_ARM64_T8101 arm64 arm;

macOS version: 12.1

Xcode-select path: '/Applications/Xcode.app/Contents/Developer'

Xcode: Xcode 13.1 (Build version 13A1030d)

```

swift-ci · 2021-12-03T20:52:16Z

Comment by Dale Buckley (JIRA)

@Kyle-Ye I did notice after I filed this that I couldn't define my own `Bundle.module` as one was already defined which seemed odd. I can file a feedback instead if you think that would help it get visibility in the right place?

Thanks for investigating.

Kyle-Ye · 2021-12-04T06:14:46Z

Yes, the swift-package-manager will create a Bundle.module for automatically. So you can not create one on your own. (Using Xcode will do the same thing, but it use a private SwiftPM framework not the open source one, so there will be some different when you call `swift build` and in Xcode hit run)

The BuildPlan file is how Bundle.module work:

swift-package-manager/Sources/Build/BuildPlan.swift

Lines 661 to 707 in 77f7ac7

    
               private func generateResourceAccessor() throws { 
        
                   // Do nothing if we're not generating a bundle. 
        
                   guard let bundlePath = self.bundlePath else { return } 
        
                   let mainPathSubstitution: String 
        
                   if buildParameters.triple.isWASI() { 
        
                       // We prefer compile-time evaluation of the bundle path here for WASI. There's no benefit in evaluating this at runtime,  
        
                       // especially as Bundle support in WASI Foundation is partial. We expect all resource paths to evaluate to  
        
                       // `/\(resourceBundleName)/\(resourcePath)`, which allows us to pass this path to JS APIs like `fetch` directly, or to 
        
                       // `<img src=` HTML attributes. The resources are loaded from the server, and we can't hardcode the host part in the URL. 
        
                       // Making URLs relative by starting them with `/\(resourceBundleName)` makes it work in the browser. 
        
                       let mainPath = AbsolutePath(Bundle.main.bundlePath).appending(component: bundlePath.basename).pathString 
        
                       mainPathSubstitution = #""\#(mainPath.asSwiftStringLiteralConstant)""# 
        
                   } else { 
        
                       mainPathSubstitution = #"Bundle.main.bundleURL.appendingPathComponent("\#(bundlePath.basename.asSwiftStringLiteralConstant)").path"# 
        
                   } 
        
                   let stream = BufferedOutputByteStream() 
        
                   stream <<< """ 
        
                   import class Foundation.Bundle 
        
                   extension Foundation.Bundle { 
        
                       static var module: Bundle = { 
        
                           let mainPath = \(mainPathSubstitution) 
        
                           let buildPath = "\(bundlePath.pathString.asSwiftStringLiteralConstant)" 
        
                           let preferredBundle = Bundle(path: mainPath) 
        
                           guard let bundle = preferredBundle != nil ? preferredBundle : Bundle(path: buildPath) else { 
        
                               fatalError("could not load resource bundle: from \\(mainPath) or \\(buildPath)") 
        
                           } 
        
                           return bundle 
        
                       }() 
        
                   } 
        
                   """ 
        
                   let subpath = RelativePath("resource_bundle_accessor.swift") 
        
                   // Add the file to the dervied sources. 
        
                   derivedSources.relativePaths.append(subpath) 
        
                   // Write this file out. 
        
                   // FIXME: We should generate this file during the actual build. 
        
                   let path = derivedSources.root.appending(subpath) 
        
                   try self.fileSystem.writeIfChanged(path: path, bytes: stream.bytes) 
        
               }

There is some discussion on Xcode's SwiftPM and open source swift-package-manager
#3824

dlbuckley (JIRA User)

swift-ci · 2021-12-04T09:03:28Z

Comment by Dale Buckley (JIRA)

Filed feedback with FB number: FB9794565

It does seem a bit silly that there are differences based on how it's built depending on if it's build using Xcode or SPM directly.

The private Xcode SPM stuff has tripped us over (as a team) previously when we were trying to build out a custom framework caching system, fingers crossed this can be unified in future so we only have one version of SPM used by `swift build` and Xcode build systems.

Kyle-Ye · 2021-12-04T09:43:59Z

Yes, that's what I am hoping too. Certainly Xcode or Apple has some private thing to do, but I think it can be done upon the open source swift-package-manager with some customisation rather than maintaining a completely new one.

swift-ci transferred this issue from apple/swift-issues Apr 25, 2022

shahmishal transferred this issue from apple/swift May 4, 2022

This issue was closed.

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[SR-15550] Loading a resource from a bundle fails due to incorrect bundle path #4372

[SR-15550] Loading a resource from a bundle fails due to incorrect bundle path #4372

swift-ci commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

swift-ci commented Dec 3, 2021

Kyle-Ye commented Dec 4, 2021

swift-ci commented Dec 4, 2021

Kyle-Ye commented Dec 4, 2021

[SR-15550] Loading a resource from a bundle fails due to incorrect bundle path #4372

[SR-15550] Loading a resource from a bundle fails due to incorrect bundle path #4372

Comments

swift-ci commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

Kyle-Ye commented Dec 3, 2021

swift-ci commented Dec 3, 2021

Kyle-Ye commented Dec 4, 2021

swift-ci commented Dec 4, 2021

Kyle-Ye commented Dec 4, 2021