Check if maven has published current version before deploying

build.gradle.kts

@@ -79,3 +79,41 @@ tasks.named<org.jetbrains.dokka.gradle.DokkaMultiModuleTask>("dokkaHtmlMultiModu
     outputDirectory.set(file("docs/${project.property("VERSION_NAME")}"))
     includes.from("README.md")
 }
+
+tasks.register("listPublications") {
+    description = "Lists all Maven publications with their coordinates (groupId:artifactId:version)"
+    group = "publishing"
+
+    // Ensure all subprojects are evaluated before running
+    dependsOn(subprojects.map { "${it.path}:tasks" })
+
+    doLast {
+        val groupId = project.findProperty("GROUP") as String? ?: "com.revenuecat.purchases"
+        val version = project.findProperty("VERSION_NAME") as String? ?: project.version.toString()
+        val pomArtifactId = project.findProperty("POM_ARTIFACT_ID") as String?
+
+        subprojects.forEach { subproject ->
+            // Check if maven publish plugin is applied
+            val hasMavenPublish = subproject.plugins.hasPlugin("com.vanniktech.maven.publish")
+
+            if (hasMavenPublish) {
+                // Get the publishing extension
+                val publishing = subproject.extensions.findByType<org.gradle.api.publish.PublishingExtension>()
+
+                if (publishing != null) {
+                    publishing.publications.forEach { publication ->
+                        if (publication is org.gradle.api.publish.maven.MavenPublication) {
+                            // Use POM_ARTIFACT_ID property if set, otherwise use publication's artifactId
+                            val artifactId = pomArtifactId ?: publication.artifactId
+                            val pubGroupId = publication.groupId ?: groupId
+                            val pubVersion = publication.version ?: version
+
+                            // Output in format: groupId:artifactId:version
+                            println("$pubGroupId:$artifactId:$pubVersion")
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

fastlane/Fastfile

@@ -105,6 +105,24 @@ platform :android do
     )
   end
 
+  desc "Check if version already exists in Maven Central"
+  lane :validate_version_not_in_maven_central do |options|
+    version = options[:version] || current_version_number
+    UI.message("Checking if version #{version} already exists in Maven Central...")
+
+    group_id = "com.revenuecat.purchases"
+
+    artifact_ids = discover_published_artifacts
+
+    if artifact_ids.empty?
+      UI.user_error!("No artifacts discovered. There should be artifacts deployed")
+    else
+      UI.message("Found #{artifact_ids.length} artifacts to check: #{artifact_ids.join(', ')}")
+      check_version_not_in_maven_central(version, group_id, artifact_ids)
+      UI.success("Version #{version} does not exist in Maven Central. Proceeding with deployment.")
+    end
+  end
+
   desc "Upload and close a release"
   lane :deploy do |options|
     version = current_version_number
@@ -116,6 +134,10 @@ platform :android do
       "mavenCentralPassword" => ENV['MAVEN_CENTRAL_PORTAL_PASSWORD'],
       "RELEASE_SIGNING_ENABLED" => true
     }
+
+    # Check if version already exists in Maven Central before deploying
+    validate_version_not_in_maven_central(version: version)
+
     UI.verbose("Deploying #{version}")
     gradle(
       tasks: [
@@ -143,6 +165,94 @@ platform :android do
     github_release(version: version) unless is_snapshot_version?(version)
   end
 
+  def discover_published_artifacts
+    artifacts = Set.new
+
+    UI.message("Discovering all publications...")
+
+    # Run gradle command from project root to discover all publications
+    Dir.chdir("..") do
+      cmd = ["./gradlew", "listPublications", "--no-daemon", "--quiet"]
+      output = sh(cmd.join(" "), log: false)
+
+      # Parse output to extract artifact IDs
+      output.split("\n").each do |line|
+        line.strip!
+        # Format is: groupId:artifactId:version
+        # Only accept lines that match the format and have artifact IDs starting with "purchases-"
+        if line.match?(/^[^:]+:[^:]+:[^:]+$/)
+          parts = line.split(":")
+          artifact_id = parts[1] if parts.length == 3
+          # Only add artifact IDs that start with "purchases-" to filter out project names and other noise
+          if artifact_id && artifact_id.start_with?("purchases-")
+            artifacts.add(artifact_id)
+          end
+        end
+      end
+    end
+
+    # Add the custom artifact IDs that are published via deploy_specific_package
+    # These use POM_ARTIFACT_ID to override the artifact ID, so they might not appear
+    # in the default publications list, but they will be published with these IDs
+    artifacts.add("purchases-custom-entitlement-computation")
+    artifacts.add("purchases-debug-view")
+
+    artifacts.to_a
+  end
+
+  def check_version_not_in_maven_central(version, group_id, artifact_ids)
+    base_url = "https://repo1.maven.org/maven2"
+    existing_artifacts = []
+
+    artifact_ids.each do |artifact_id|
+      # Convert group ID dots to slashes for URL path
+      group_path = group_id.gsub(".", "/")
+      url = "#{base_url}/#{group_path}/#{artifact_id}/#{version}/"
+
+      UI.verbose("Checking Maven Central: #{url}")
+
+      # Use curl to check if the version directory exists (HTTP HEAD request)
+      # Don't use -f flag so we can check the HTTP status code
+      # Use -L to follow redirects
+      begin
+        # Capture both stdout (HTTP code) and stderr separately
+        result = sh("curl -s -S -o /dev/null -w '%{http_code}' -L -I '#{url}' 2>&1", log: false).strip
+
+        # Extract the HTTP status code (last 3 digits at the end of the output)
+        match_result = result.match(/(\d{3})\s*$/)
+        if match_result.nil?
+          UI.important("Could not parse HTTP status code for #{url}. Response: #{result}")
+          next
+        end
+
+        http_code = match_result[1]
+
+        if http_code == "200"
+          existing_artifacts << artifact_id
+          UI.important("Artifact #{group_id}:#{artifact_id}:#{version} already exists in Maven Central")
+        elsif http_code != "404"
+          # If we get an unexpected status code, warn but don't fail
+          UI.important("Unexpected HTTP status #{http_code} when checking #{url}")
+        end
+      rescue => e
+        UI.important("Failed to check #{url}: #{e.message}")
+        # Continue checking other artifacts even if one fails
+        next
+      end
+    end
+
+    unless existing_artifacts.empty?
+      error_message = "Version #{version} already exists in Maven Central for the following artifacts:\n"
+      existing_artifacts.each do |artifact_id|
+        group_path = group_id.gsub(".", "/")
+        maven_url = "#{base_url}/#{group_path}/#{artifact_id}/#{version}/"
+        error_message += "  - #{group_id}:#{artifact_id}:#{version}\n    #{maven_url}\n"
+      end
+      error_message += "\nDeployment cancelled to prevent duplicate releases."
+      UI.user_error!(error_message)
+    end
+  end
+
   def deploy_specific_package(variant, artifact_id, module_to_deploy, gradle_properties)
     gradle_properties["ANDROID_VARIANT_TO_PUBLISH"] = variant
     gradle_properties["POM_ARTIFACT_ID"] = artifact_id

fastlane/README.md

@@ -63,6 +63,14 @@ Automatically bumps version, replaces version numbers, updates changelog and cre
 
 Creates github release
 
+### android validate_version_not_in_maven_central
+
+```sh
+[bundle exec] fastlane android validate_version_not_in_maven_central
+```
+
+Check if version already exists in Maven Central
+
 ### android deploy
 
 ```sh