ci: Publish snapshot builds to Maven Central (#1107)

* ci: Publish snapshot builds to Maven Central on push to main

Add a `mavenCentralSnapshots` repository to both plugin-build and
sentry-kotlin-compiler-plugin build files, and a new GitHub Actions
workflow that publishes `-SNAPSHOT` versions on every push to main.

This gives consumers early access to unreleased changes without
waiting for a formal release. The snapshot flow is completely
independent from the existing craft-based release process.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* ci: Disable cancel-in-progress for snapshot publishing

Cancelling a running publish can leave the Maven snapshot repository
in an inconsistent state (e.g. partial artifacts or mismatched plugin
versions between the Gradle Plugin and Kotlin Compiler Plugin).
Queuing instead ensures each publish completes atomically.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Update .github/workflows/publish-snapshot.yml

Co-authored-by: Burak Yigit Kaya <byk@sentry.io>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Co-authored-by: Burak Yigit Kaya <byk@sentry.io>

Author: 3 people

.github/workflows/publish-snapshot.yml

@@ -0,0 +1,52 @@
+name: Publish Snapshot
+
+on:
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: false
+
+jobs:
+  publish-snapshot:
+    name: Publish snapshot to Maven Central
+    runs-on: ubuntu-latest
+    environment: production
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@0723195856401067f7a2779048b490ace7a47d7c # pin@v4
+
+      - name: Set up Java
+        uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+
+      - name: Determine snapshot version
+        id: version
+        run: |
+          VERSION=$(grep "^version = " plugin-build/gradle.properties | cut -d' ' -f3)
+          echo "snapshot_version=${VERSION}-SNAPSHOT" >> "$GITHUB_OUTPUT"
+
+      - name: Publish Gradle Plugin snapshot
+        working-directory: plugin-build
+        run: >
+          ../gradlew publishAllPublicationsToMavenCentralSnapshotsRepository
+          -Pversion=${{ steps.version.outputs.snapshot_version }}
+        env:
+          ORG_GRADLE_PROJECT_mavenCentralUsername: ${{ secrets.OSSRH_USERNAME }}
+          ORG_GRADLE_PROJECT_mavenCentralPassword: ${{ secrets.OSSRH_PASSWORD }}
+
+      - name: Publish Kotlin Compiler Plugin snapshot
+        working-directory: sentry-kotlin-compiler-plugin
+        run: >
+          ../gradlew publishAllPublicationsToMavenCentralSnapshotsRepository
+          -PVERSION_NAME=${{ steps.version.outputs.snapshot_version }}
+        env:
+          ORG_GRADLE_PROJECT_mavenCentralUsername: ${{ secrets.OSSRH_USERNAME }}
+          ORG_GRADLE_PROJECT_mavenCentralPassword: ${{ secrets.OSSRH_PASSWORD }}

plugin-build/build.gradle.kts

@@ -323,3 +323,18 @@ tasks.withType<ValidatePlugins>().configureEach {
   failOnWarning.set(true)
   enableStricterValidation.set(true)
 }
+
+plugins.withId("com.vanniktech.maven.publish.base") {
+  configure<PublishingExtension> {
+    repositories {
+      maven {
+        name = "mavenCentralSnapshots"
+        url = uri("https://central.sonatype.com/repository/maven-snapshots/")
+        credentials {
+          username = findProperty("mavenCentralUsername")?.toString()
+          password = findProperty("mavenCentralPassword")?.toString()
+        }
+      }
+    }
+  }
+}

sentry-kotlin-compiler-plugin/build.gradle.kts

@@ -73,6 +73,14 @@ plugins.withId("com.vanniktech.maven.publish.base") {
         name = "mavenTestRepo"
         url = file("${rootProject.projectDir}/../build/mavenTestRepo").toURI()
       }
+      maven {
+        name = "mavenCentralSnapshots"
+        url = uri("https://central.sonatype.com/repository/maven-snapshots/")
+        credentials {
+          username = findProperty("mavenCentralUsername")?.toString()
+          password = findProperty("mavenCentralPassword")?.toString()
+        }
+      }
     }
   }
 }