Consider using publishing.repository for repository url and credentials

[vlsi]

Description

The plugin assumes id("publishing") plugin for the publications, so have you considered using publishing.repositories declaration for the repository and the credentials?

If nmcp could fetch the repo url from there, it might be easier for the end users to declare the repositories in one place only rather than in two (nmcp for releases and publishing.repositories for snapshots).

[martinbonnin]

If anything, I'd probably want to abstract publishing.repositories more than reusing it... I find maven-publish to be one of the most obscure APIs in Gradle and it has limitations such as non-lazy APIs so I'd rather not couple it more than required.

There might be a parallel universe where nmcp doesn't even depend on maven-publish and "just" publishes SoftwareComponents instead of Publications. This is a very long way but this being a hobby project, I'd like to keep that option open as much as possible.

[vlsi]

There's ivy-publish plugin.

On the other hand, nmcp goes for Central Portal and currently it is a maven repository, so it is fair to say nmcp requires users to configure maven-publish and MavenPublication.

---

Frankly, Gradle's publishing.repositories.credentials fails better than nmpm when credentials are not provided.
Gradle's repository credentials provide user with exact property names which they need to set while the current ncmp's error message is not actionable for the end user.

Compare:

# gradle's maven-publish
$ ./gradlew publishAllPublicationsToCentralSnapshotsRepository

* What went wrong:
Credentials required for this build could not be resolved.
> The following Gradle properties are missing for 'centralSnapshots' credentials:
    - centralSnapshotsUsername
    - centralSnapshotsPassword

with

# nmcp
$ ./gradlew publishMavenJavaPublicationToCentralPortal

* What went wrong:
Some problems were found with the configuration of task ':agent:publishMavenJavaPublicationToCentralPortal' (type 'NmcpPublishTask').
  - In plugin 'com.gradleup.nmcp' type 'nmcp.NmcpPublishTask' property 'password' doesn't have a configured value.

    Reason: This property isn't marked as optional and no value has been configured.

    Possible solutions:
      1. Assign a value to 'password'.
      2. Mark property 'password' as optional.

    For more information, please refer to https://docs.gradle.org/8.13/userguide/validation_problems.html#value_not_set in the Gradle documentation.
  - In plugin 'com.gradleup.nmcp' type 'nmcp.NmcpPublishTask' property 'username' doesn't have a configured value.

    Reason: This property isn't marked as optional and no value has been configured.

    Possible solutions:
      1. Assign a value to 'username'.
      2. Mark property 'username' as optional.

    For more information, please refer to https://docs.gradle.org/8.13/userguide/validation_problems.html#value_not_set in the Gradle documentation.

---

Lastly, the repository url being non-lazy might be acceptable here.
We discuss Central Portal here, so it might be reasonable if ncmp plugin creates a MavenRepository which points to the releases or snapshots URL based on the project version.

---

Yet another idea is to move ncmp (or whatever) extension to publishing where it logically belongs.

I am leaning towards that the current

ncmp {
    waitTimeout = 10.minute
    publicationType = "USER_MANAGED"
}

is less user-friendly than

publishing {
    centralPortal {
        waitTimeout = 10.minute
        publicationType = "USER_MANAGED"
    }
}

In other words, if centralPortal becomes an extension of publishing, then it would be easier to read and understand for the unprepared users.

[martinbonnin]

Closing this one, I want to leave the possibility to use Nmcp without maven-publish and/or publishing