Handle leaf template directory for Xcode, SPM, and Deployments

[grennis]

Please summarize your feature request

Can it be straightforward to handle these scenarios?

Describe the functionality you're seeking in more detail

I found it somewhat complex to configure the Leaf root directory when run in the 3 scenarios I need:

• Xcode for local development
• "swift test" for CI testing
• With the Vapor Heroku build package with a monorepo

Specifically, these 3 scenarios seem to all require different leaf configurations. While the docs indicate that I can set the working directory of the scheme to solve the Xcode configuration, this doesn't really work for multiple developers who will have different directory structures. (As far as I can tell, using $(SRCROOT), $(PACKAGE_ROOT), etc don't work in the "working directory" option for a scheme).

The best solution I have so far is to put the .leaf files in the Resources directory so they will get copied to DerivedData for running in Xcode, but this doesn't work with SPM or Heroku (Leaf refuses to load from the .bin or .swift-bin directory).

So right now my code to configure Leaf looks like this:

private func getLeafRootDirectory(app: Application) -> String {
    let pathFromPackage = "Sources/Resources/Templates"
    let pathFromRoot = "Packages/SwiftBackend/Sources/Resources/Templates"

    return if FileManager.default.fileExists(atPath: pathFromPackage) {
        // When running from SPM use the path from the package root
        pathFromPackage
    } else if FileManager.default.fileExists(atPath: pathFromRoot) {
        // When deployed on Linux use the path from the repo root
        pathFromRoot
    } else {
        // When run from Xcode, the working directory is in DerivedData
        Bundle.module.url(forResource: "OneOfMyTemplates", withExtension: "leaf")!.deletingLastPathComponent().directory
    }
}

Have you considered any alternatives?

No response

[grennis]

My suggestion would be:

• Leaf templates should be considered resources like localizations, assets, etc.
• Templates should be in Sources/Resources and processed by the .resources: [.process("Resources")]
• Leaf should then allow to load templates from the resources directory (bypassing the security check blocking the .swift-bin directory)
• While the docs indicate templates should be in "Resources" directory, I think the guidance is instructing to place them in root Resources directory instead of Sources/Resources where the "real" resources are. This was a point of confusion for me ramping up.

I'd be happy to work on these changes, but would like to hear back if this is a good direction or this is off track!

[0xTim]

Yes this is probably something the next version of Leaf will support. When the current version was released, SwiftPM resources didn't exist. You might be able to make it work with a custom source