Add deep transitive projects to release

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

@@ -219,18 +219,34 @@ abstract class PublishingPlugin : Plugin<Project> {
 
     if (projectsToPublish == null) return null
 
-    val projectNames = projectsToPublish.split(",")
+    val publishingProjects =
+      allFirebaseLibraries.filter { it.artifactId.get() in projectsToPublish.split(",") }
 
+    val librariesToRelease = getDeepTransitiveReleases(publishingProjects, libraryGroups)
+
+    return ReleaseMetadata(librariesToRelease, releaseName)
+  }
+
+  /**
+   * Finds all transitive libraries that need to be released so that the input list of project names
+   * can be released. This includes all project level dependencies, and anything in the same library
+   * group.
+   */
+  private tailrec fun getDeepTransitiveReleases(
+    inputProjects: List<FirebaseLibraryExtension>,
+    libraryGroups: Map<String, List<FirebaseLibraryExtension>>
+  ): List<FirebaseLibraryExtension> {
     val libraryGroupsToRelease =
-      allFirebaseLibraries
-        .filter { it.artifactId.get() in projectNames }
+      inputProjects
+        .flatMap { it.resolveProjectLevelDependencies() + it }
         .map { it.libraryGroupName }
-    val librariesToRelease =
+    val projectsToRelease =
       libraryGroups
         .filterKeys { it in libraryGroupsToRelease }
         .flatMap { it.value }
         .distinctBy { it.artifactId.get() }
-    return ReleaseMetadata(librariesToRelease, releaseName)
+    return if (inputProjects == projectsToRelease) inputProjects
+    else getDeepTransitiveReleases(projectsToRelease, libraryGroups)
   }
 
   private fun releaseMetadataFromReleaseConfig(

buildSrc/src/test/kotlin/com/google/firebase/gradle/plugins/PublishingPluginTests.kt

@@ -113,7 +113,27 @@ class PublishingPluginTests {
         Project(name = "childProject2", version = "0.9", projectDependencies = setOf(project1))
 
       withProjects(project1, project2)
-      publishAndFail(project2)
+      publish(project2)
+
+      project1.pomOrNull().shouldNotBeNull()
+      project2.pom.dependencies shouldHaveSingleElement project1.toArtifact()
+    }
+  }
+
+  @Test
+  fun `Publish with very transitive dependency`() {
+    with(controller) {
+      val project1 = Project(name = "childProject1", version = "1.0", libraryGroup = "libraryGroup")
+      val project2 =
+        Project(name = "childProject2", version = "0.9", projectDependencies = setOf(project1))
+      val project3 = Project(name = "childProject3", version = "1.0", libraryGroup = "libraryGroup")
+
+      withProjects(project1, project2, project3)
+      publish(project2)
+
+      project1.pomOrNull().shouldNotBeNull()
+      project3.pomOrNull().shouldNotBeNull()
+      project2.pom.dependencies shouldHaveSingleElement project1.toArtifact()
     }
   }