Integrated example project for Mill into CI task

The example project uses Mills meta-build to resolve the snapshot version from a properties file.
The properties-file is now integrated into `release_version_update.sh`.

Author: lostiniceland

.github/workflows/mill-plugin-tests.yaml

@@ -0,0 +1,44 @@
+name: Mill plugin tests
+
+on:
+  push:
+    paths:
+      - modules/openapi-generator-mill-plugin/**
+  pull_request:
+    paths:
+      - modules/openapi-generator-mill-plugin/**
+
+jobs:
+  test:
+    name: Mill plugin tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Set up JDK 11
+        uses: actions/setup-java@v5
+        with:
+          java-version: 11
+          distribution: 'temurin'
+      - name: Cache maven dependencies
+        uses: actions/cache@v5
+        env:
+          cache-name: cache-maven-repository
+        with:
+          path: |
+            ~/.m2/repository
+            ~/.gradle
+            !~/.gradle/caches/*/plugin-resolution/
+            !~/.m2/repository/org/openapitools/
+          key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/pom.xml') }}
+          restore-keys: |
+            ${{ runner.os }}-test-mill-plugin-${{ env.cache-name }}-
+            ${{ runner.os }}-test-mill-plugin-
+      - name: Run tests
+        env:
+          GRADLE_ENTERPRISE_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_ACCESS_KEY }}
+        run: |
+          ./mvnw clean install -DskipTests -Dmaven.javadoc.skip=true
+          (cd modules/openapi-generator-mill-plugin/example/ && ./mill __.compile)
+          (cd modules/openapi-generator-mill-plugin/example/ && ./mill openapi.validate)
+          (cd modules/openapi-generator-mill-plugin/example/ && ./mill validateOpenapiSpec $(pwd)/api/petstore-invalid.yaml)
+          

bin/utils/release/release_version_update.sh

@@ -93,6 +93,7 @@ declare -a xml_files=(
 declare -a properties_files=(
     "${root}/modules/openapi-generator-gradle-plugin/gradle.properties"
     "${root}/modules/openapi-generator-gradle-plugin/samples/local-spec/gradle.properties"
+    "${root}/modules/openapi-generator-mill-plugin/example/mill-build/version.properties"
 )
 
 ${cwd}/bump.sh -f ${version} -i ${inc} ${xml_files[@]}

…mill-test/api/petstore-v3.0-invalid.yaml …plugin/example/api/petstore-invalid.yamlmodules/openapi-generator-mill-plugin/mill-test/api/petstore-v3.0-invalid.yaml renamed to modules/openapi-generator-mill-plugin/example/api/petstore-invalid.yaml modules/openapi-generator-mill-plugin/mill-test/api/petstore-v3.0-invalid.yaml renamed to modules/openapi-generator-mill-plugin/example/api/petstore-invalid.yaml

@@ -1,7 +1,8 @@
 //| mill-version: 1.0.6
-//| mvnDeps:
-//|   - com.lihaoyi::mill-contrib-versionfile:$MILL_VERSION
-//|   - org.openapitools:openapi-generator-mill-plugin:$MILL_OPENAPITOOLS_PLUGIN_VERSION
+//| # usually you would add the plugin dependency like the following,
+//| # but for testing with SNAPSHOT versions, the plugin dependency is added in the meta-build
+//| # mvnDeps:
+//| #  - org.openapitools:openapi-generator-mill-plugin:$MILL_OPENAPITOOLS_PLUGIN_VERSION
 //|
 package build
 
@@ -12,13 +13,10 @@ import mill.scalalib.publish.PomSettings
 import mill.util.BuildInfo.{millBinPlatform, millVersion}
 import javalib.*
 
-import mill.contrib.versionfile.VersionFileModule
 import org.openapitools.generator.mill.OpenApiModule
 
 object `package` extends JavaModule with MavenModule with OpenApiModule {
 
-  // dependency on openapi-generator is set in Mills meta-build
-  // this is needed to point to a local maven repo
   override def mvnDeps = Seq(
     mvn"jakarta.platform:jakarta.jakartaee-api:11.0.0",
     mvn"com.fasterxml.jackson.core:jackson-databind:2.20.0",

…-mill-plugin/mill-test/api/petstore.yaml …or-mill-plugin/example/api/petstore.yamlmodules/openapi-generator-mill-plugin/mill-test/api/petstore.yaml renamed to modules/openapi-generator-mill-plugin/example/api/petstore.yaml modules/openapi-generator-mill-plugin/mill-test/api/petstore.yaml renamed to modules/openapi-generator-mill-plugin/example/api/petstore.yaml

@@ -0,0 +1,33 @@
+
+import coursier.LocalRepositories.Dangerous
+import coursier.Repositories
+import mill.scalalib.DepSyntax
+import mill.*
+import mill.api.Task
+import mill.meta.MillBuildRootModule
+import java.util.Properties
+import java.io.FileInputStream
+
+object `package` extends MillBuildRootModule {
+
+  override def repositories = Task {
+    Seq(
+      // central needed for default deps
+      Repositories.central.root,
+      // the previously installed snapshot is in local maven
+      // see docs on Coursier, why m2 is considered dangerous
+      Dangerous.maven2Local.root)
+  }
+
+  def propsFile = Task.Source("version.properties")
+
+  def readOpenapiSnapshotVersion: Task[String] = Task {
+    val props = new Properties()
+    props.load(new FileInputStream(propsFile().path.toIO))
+    props.getProperty("openApiGeneratorVersion")
+  }
+
+  override def mvnDeps = Seq(
+    mvn"org.openapitools:openapi-generator-mill-plugin:${readOpenapiSnapshotVersion()}"
+  )
+}