Test dependencies

[ph1ps]

Hello,
I am someone, both as a package user and package author, who tries to keep the list of dependencies to a minimum. Also SwiftPackageIndex has the notion of keeping the number of dependencies down, since it is included in the package score and it is also actively displaying this number to any potential users on the package page.

In Swift 5.2 a change (SE-0226) was introduced that test dependencies of packages are not being resolved anymore. However, currently in SwiftPackageIndex they are counted towards the number dependencies of a package (although it is mentioned explicitly, that test dependencies are counted).

I have to be honest here, without wanting to sound ungrateful towards this project and the people maintaining this, this bothers me. In fact it bothered me so much, that I have copied parts of test dependencies I needed into my repositories, to get to 0 dependencies, which from a maintenance standpoint is not very optimal.

I wanted to start this discussion, to maybe get more insights into what the reason behind this is and also what can be done about it or even what has been attempted to do about this. I think the code that parses this number from any project is not public, at least I could not find the correct piece in this project, so I had to resort to asking here rather than checking myself.

Please do not get me wrong, I am not trying to step on anyone's toe, I am just trying to understand the reasoning/challenges. Thank you.

[daveverwer]

We use the show-dependencies command in SwiftPM to get this information. It includes all dependencies, including test target dependencies. For example, the output for your swift-concurrency-limiter package is:

MacBookPro:swift-concurrency-limiter (main) $ xcrun swift package show-dependencies
.
├── swift-collections<https://github.com/apple/swift-collections@1.1.4>
└── swift-clocks<https://github.com/pointfreeco/swift-clocks@1.0.6>
    ├── swift-concurrency-extras<https://github.com/pointfreeco/swift-concurrency-extras@1.3.1>
    └── xctest-dynamic-overlay<https://github.com/pointfreeco/xctest-dynamic-overlay@1.5.2>

Or in JSON:

{
  "identity": "swift-concurrency-limiter",
  "name": "swift-concurrency-limiter",
  "url": "/Users/dave/Desktop/swift-concurrency-limiter",
  "version": "unspecified",
  "path": "/Users/dave/Desktop/swift-concurrency-limiter",
  "dependencies": [
    {
      "identity": "swift-collections",
      "name": "swift-collections",
      "url": "https://github.com/apple/swift-collections",
      "version": "1.1.4",
      "path": "/Users/dave/Desktop/swift-concurrency-limiter/.build/checkouts/swift-collections",
      "dependencies": [

      ]
    },
    {
      "identity": "swift-clocks",
      "name": "swift-clocks",
      "url": "https://github.com/pointfreeco/swift-clocks",
      "version": "1.0.6",
      "path": "/Users/dave/Desktop/swift-concurrency-limiter/.build/checkouts/swift-clocks",
      "dependencies": [
        {
          "identity": "swift-concurrency-extras",
          "name": "swift-concurrency-extras",
          "url": "https://github.com/pointfreeco/swift-concurrency-extras",
          "version": "1.3.1",
          "path": "/Users/dave/Desktop/swift-concurrency-limiter/.build/checkouts/swift-concurrency-extras",
          "dependencies": [

          ]
        },
        {
          "identity": "xctest-dynamic-overlay",
          "name": "xctest-dynamic-overlay",
          "url": "https://github.com/pointfreeco/xctest-dynamic-overlay",
          "version": "1.5.2",
          "path": "/Users/dave/Desktop/swift-concurrency-limiter/.build/checkouts/xctest-dynamic-overlay",
          "dependencies": [

          ]
        }
      ]
    }
  ]
}

It would be great if this data included the dependency type, but it currently does not. I believe that SE-0226 was more around the internal dependency resolution rather than anything we can access.

I also wouldn’t worry too much about the package score. Score is only used when two packages that rank equally on the text search need ordering one above the other. There is a secondary use for the score, which is that we hope that it also encourages good development practices, like trying to minimise dependencies, but it’s not something we expect people to try to optimise for search ranking as it’s not used like that.

We do check back from time to time to see if there is more or better information we can display around dependencies, but this is the best we can do for now.

[daveverwer]

Yes, we have considered this approach before but it's not how we ended up implementing it.

[finestructure]

Just to expand a little on Dave's reply, that's the solution we came up with a while back, too. Better dependency tracking is something we'd like to do but it hasn't quite made it to the top of the priority list yet.

[ph1ps]

@finestructure

Better dependency tracking is something we'd like to do but it hasn't quite made it to the top of the priority list yet

Priority list of implementing or doing conceptual work / thinking about it? If this is about implementing, I am willing to help on that, if you are open to contributions in this regard.

[finestructure]

Thanks a lot for the offer, @ph1ps , but unfortunately most of the changes would be in the builder, which is not open source.

[ph1ps]

Got it 👍🏻