Fix semver check

buildSrc/src/main/java/com/google/firebase/gradle/plugins/FirebaseLibraryPlugin.kt

@@ -91,6 +91,7 @@ class FirebaseLibraryPlugin : BaseFirebaseLibraryPlugin() {
 
   private fun getSemverTaskAar(project: Project, firebaseLibrary: FirebaseLibraryExtension) {
     project.mkdir("semver")
+    project.mkdir("semver/previous-version")
     project.tasks.register<GmavenCopier>("copyPreviousArtifacts") {
       dependsOn("bundleReleaseAar")
       project.file("semver/previous.aar").delete()
@@ -111,7 +112,10 @@ class FirebaseLibraryPlugin : BaseFirebaseLibraryPlugin() {
 
     project.tasks.register<Copy>("extractPreviousClasses") {
       dependsOn("copyPreviousArtifacts")
-      if (project.file("semver/previous.aar").exists()) {
+      if (
+        GmavenHelper(firebaseLibrary.groupId.get(), firebaseLibrary.artifactId.get())
+          .isPresentInGmaven()
+      ) {
         from(project.zipTree("semver/previous.aar"))
         into(project.file("semver/previous-version"))
       }
@@ -121,15 +125,15 @@ class FirebaseLibraryPlugin : BaseFirebaseLibraryPlugin() {
 
     val previousJarFile = project.file("semver/previous-version/classes.jar").absolutePath
     project.tasks.register<ApiDiffer>("semverCheck") {
+      dependsOn("extractCurrentClasses")
+      dependsOn("extractPreviousClasses")
       currentJar.value(currentJarFile)
       previousJar.value(previousJarFile)
       version.value(firebaseLibrary.version)
       previousVersionString.value(
         GmavenHelper(firebaseLibrary.groupId.get(), firebaseLibrary.artifactId.get())
           .getLatestReleasedVersion()
       )
-      dependsOn("extractCurrentClasses")
-      dependsOn("extractPreviousClasses")
     }
   }
 

buildSrc/src/main/java/com/google/firebase/gradle/plugins/GmavenHelper.kt

@@ -15,6 +15,7 @@
 package com.google.firebase.gradle.plugins
 
 import java.io.FileNotFoundException
+import java.net.HttpURLConnection
 import java.net.URL
 import javax.xml.parsers.DocumentBuilder
 import javax.xml.parsers.DocumentBuilderFactory
@@ -30,6 +31,16 @@ class GmavenHelper(val groupId: String, val artifactId: String) {
     return "${GMAVEN_ROOT}/${groupIdAsPath}/${artifactId}/${version}/${pomFileName}"
   }
 
+  fun isPresentInGmaven(): Boolean {
+    val groupIdAsPath = groupId.replace(".", "/")
+    val u = URL("${GMAVEN_ROOT}/${groupIdAsPath}/${artifactId}/maven-metadata.xml")
+    val huc: HttpURLConnection = u.openConnection() as HttpURLConnection
+    huc.setRequestMethod("GET") // OR  huc.setRequestMethod ("HEAD");
+    huc.connect()
+    val code: Int = huc.getResponseCode()
+    return code == HttpURLConnection.HTTP_OK
+  }
+
   fun getArtifactForVersion(version: String, isJar: Boolean): String {
     val fileName =
       if (isJar == true) "${artifactId}-${version}.jar" else "${artifactId}-${version}.aar"

buildSrc/src/main/java/com/google/firebase/gradle/plugins/PublishingPlugin.kt

@@ -450,7 +450,6 @@ abstract class PublishingPlugin : Plugin<Project> {
     project.tasks.register(SEMVER_CHECK_TASK) {
       for (releasingProject in releasingProjects) {
         val semverCheckTask = releasingProject.tasks.named("semverCheck")
-
         dependsOn(semverCheckTask)
       }
     }

buildSrc/src/main/java/com/google/firebase/gradle/plugins/semver/GmavenCopier.kt

@@ -36,16 +36,14 @@ abstract class GmavenCopier : DefaultTask() {
   @TaskAction
   fun run() {
     val mavenHelper = GmavenHelper(groupId.get(), artifactId.get())
+    if (!mavenHelper.isPresentInGmaven()) {
+      return
+    }
     val gMavenPath =
       mavenHelper.getArtifactForVersion(
         mavenHelper.getLatestReleasedVersion(),
         !aarAndroidFile.get()
       )
-    try {
-      URL(gMavenPath).openStream().use { Files.copy(it, Paths.get(filePath.get())) }
-    } catch (_: java.io.FileNotFoundException) {
-      // Gmaven Artifact doesn't exist.
-      return
-    }
+    URL(gMavenPath).openStream().use { Files.copy(it, Paths.get(filePath.get())) }
   }
 }