Fix semver check (#5241)

During the m134 release we were releasing firebase-sessions for the
first time and due to which the semver test was broken. Hence the if
conditions were added. These if conditions were not being evaluated
correctly since it dependend on a malleable state of things. So now it's
moved to checking in Gmaven itself if the project exists instead of
depending on a malleable state which keeps being updated by the gradle
tasks.

Author: VinayGuthal

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())) }
   }
 }