Scala GitHub Actions

Scala Release workflow

Setup

To use Scala Release workflow have to set up project:

add latest sbt-release plugin
add Evolution's artifactory plugin sbt-artifactory-plugin

defined command alias check which runs code quality checks, for example: scalafmt and scalafix, and binary compatibility check by sbt-version-policy:

addCommandAlias("fmt", "all scalafmtAll scalafmtSbt; scalafixEnable; scalafixAll") // optional: for development
addCommandAlias("check", "all versionPolicyCheck Compile/doc scalafmtCheckAll scalafmtSbtCheck; scalafixEnable; scalafixAll --check")
addCommandAlias("build", "all compile test") // optional: for development

as very minimum "no-op" placeholder:

addCommandAlias("check", "show version")

direct publishTo to Evolution's artifactory (for sbt-release using sbt-artifactory-plugin):
```
publishTo := Some(Resolver.evolutionReleases)
```

create release.yml file with content:

  name: Publish Release
  
  on:
    release:
      types: [published]
      branches: [main]
  
  jobs:
    release:
      uses: evolution-gaming/scala-github-actions/.github/workflows/release.yml@v1
      secrets: inherit

Usage

On GitHub:

go to Releases page
press Draft a new release button
make sure that version.sbt file in root of project have correct version string, like 1.2.3
in Choose a tag create a new tag (v1.2.3)
set Release title to the same string (v1.2.3)
press Generate release notes and review them
press Publish release button
navigate to Actions - there it is possible to follow

The above sequence will start Release workflow, which will:

validate consistency of git tag and version
run SBT commands clean; +all check test package to make sure that code quality is good
run SBT command +publish to publish packaged artifacts
if any of above steps will fail, the workflow will remove git tag and GitHub will mark release notes as draft and it will be possible to adjust code on main branch and attempt publishing again by navigating to drafted release and pressing Publish release button again

When release is published, make sure to amend version.sbt file with next version string.

Recommended Scala project setup

scalafmt

Minimal configuration requires usage of plugin like:

addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "<latest version>")

scalafix

Minimal configuration requires usage of plugin like:

addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "<latest version>")

binary compatibility

Requires usage of sbt-version-policy plugin like:

addSbtPlugin("ch.epfl.scala" % "sbt-version-policy" % "<latest version>")

scalac options

Evolution's plugin with very strict settings for Scala 2.12 and 2.13 projects

addSbtPlugin("com.evolution" % "sbt-scalac-opts-plugin" % "<latest version>")