Output artifact list during local publishing.

This effort replaces #494.

Author: allisonbm92

buildSrc/build.gradle

@@ -37,14 +37,14 @@ dependencies {
     implementation 'org.jsoup:jsoup:1.11.2'
     implementation 'digital.wup:android-maven-publish:3.6.2'
     implementation 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.20'
+    implementation 'org.json:json:20180813'
 
     implementation 'io.opencensus:opencensus-api:0.18.0'
     implementation 'io.opencensus:opencensus-exporter-stats-stackdriver:0.18.0'
     runtime 'io.opencensus:opencensus-impl:0.18.0'
 
     implementation 'com.android.tools.build:gradle:3.2.1'
     testImplementation 'junit:junit:4.12'
-    testImplementation 'org.json:json:20180813'
     testImplementation('org.spockframework:spock-core:1.1-groovy-2.4') {
         exclude group: 'org.codehaus.groovy'
     }

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/AffectedProjectFinder.groovy

@@ -25,6 +25,10 @@ class AffectedProjectFinder {
     Set<String> changedPaths;
 
     @Builder
+    AffectedProjectFinder(Project project, List<Pattern> ignorePaths) {
+        this(project, changedPaths(project.rootDir), ignorePaths)
+    }
+
     AffectedProjectFinder(Project project,
                           Set<String> changedPaths,
                           List<Pattern> ignorePaths) {
@@ -49,6 +53,13 @@ class AffectedProjectFinder {
         return project.subprojects
     }
 
+    private static Set<String> changedPaths(File workDir) {
+        return 'git diff --name-only --submodule=diff HEAD@{0} HEAD@{1}'
+                .execute([], workDir)
+                .text
+                .readLines()
+    }
+
     /**
      * Performs a post-order project tree traversal and returns a set of projects that own the
      * 'changedPaths'.

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/ci/ContinuousIntegrationPlugin.groovy

@@ -97,7 +97,6 @@ class ContinuousIntegrationPlugin implements Plugin<Project> {
 
         def affectedProjects = AffectedProjectFinder.builder()
                 .project(project)
-                .changedPaths(changedPaths(project.rootDir))
                 .ignorePaths(extension.ignorePaths)
                 .build()
                 .find()
@@ -143,13 +142,6 @@ class ContinuousIntegrationPlugin implements Plugin<Project> {
         }
     }
 
-    private static Set<String> changedPaths(File workDir) {
-        return 'git diff --name-only --submodule=diff HEAD@{0} HEAD@{1}'
-                .execute([], workDir)
-                .text
-                .readLines()
-    }
-
     private static final ANDROID_PLUGINS = ["com.android.application", "com.android.library",
                                            "com.android.test"]
 

buildSrc/src/main/groovy/com/google/firebase/gradle/plugins/publish/PublishingPlugin.groovy

@@ -14,13 +14,17 @@
 
 package com.google.firebase.gradle.plugins.publish
 
+import com.google.firebase.gradle.plugins.ci.AffectedProjectFinder
 import com.google.firebase.gradle.plugins.FirebaseLibraryExtension
 import digital.wup.android_maven_publish.AndroidMavenPublishPlugin
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.artifacts.ProjectDependency
 import org.gradle.api.publish.maven.MavenPublication
 import org.gradle.api.tasks.bundling.Jar
 import org.gradle.api.tasks.bundling.Zip
+import org.json.JSONArray
+import org.json.JSONObject
 
 /**
  * Enables releasing of the SDKs.
@@ -64,6 +68,16 @@ import org.gradle.api.tasks.bundling.Zip
  *           -PpublishMode=(RELEASE|SNAPSHOT) \
  *           publishProjectsToMavenLocal
  * </pre>
+ *
+ * <p><strong>Build recently changed snapshots</strong>
+ *
+ * <pre>
+ * ./gradlew publishChangedToBuildDir   # publishes changed projects to build/m2repository
+ * </pre>
+ *
+ * This option builds projects that have been changed by the latest git commit and all of their
+ * dependencies. They are published to the build directory. This workflow is intended for
+ * compatibility testing, where the changed projects need to be layered over a previous release.
  */
 class PublishingPlugin implements Plugin<Project> {
     @Override
@@ -83,9 +97,16 @@ class PublishingPlugin implements Plugin<Project> {
 
         def publishAllToLocal = project.task('publishAllToLocal')
         def publishAllToBuildDir = project.task('publishAllToBuildDir')
+        def publishChangedToBuildDir = project.task('publishChangedToBuildDir')
         def firebasePublish = project.task('firebasePublish')
 
         project.getGradle().projectsEvaluated {
+            // These three variables are used for generating the JSON file that lists the artifacts
+            // affected by the latest commit. This is generally useful only on CI builds.
+            def changedProjects = getChangedProjects(project)
+            def changedArtifacts = new HashSet<String>()
+            def allArtifacts = new HashSet<String>()
+
             project.subprojects { Project sub ->
                 if (!sub.plugins.hasPlugin('firebase-library')) {
                     return
@@ -121,11 +142,40 @@ class PublishingPlugin implements Plugin<Project> {
                             publisher.decorate(sub, it)
                         }
                     }
+
                     publishAllToLocal.dependsOn "$sub.path:publishMavenAarPublicationToMavenLocal"
                     publishAllToBuildDir.dependsOn "$sub.path:publishMavenAarPublicationToBuildDirRepository"
 
+                    // Update the changed and all sets each time an artifact is published. This is
+                    // used to build the JSON file of affected targets.
+                    sub.tasks.getByName("publishMavenAarPublicationToBuildDirRepository").doLast {
+                        def artifact = "$sub.group:$sub.name:$sub.version-SNAPSHOT"
+                        allArtifacts.add(artifact)
+
+                        if (changedProjects.contains(sub)) {
+                            changedArtifacts.add(artifact)
+                        }
+                    }
                 }
+
             }
+
+            // Build the JSON file of affected targets after all artifacts have been published.
+            publishAllToBuildDir.doLast {
+                def changed = new JSONArray()
+                changedArtifacts.each { changed.put(it) }
+
+                def all = new JSONArray()
+                allArtifacts.each { all.put(it) }
+
+                def json = new JSONObject()
+                json.put("all", all)
+                json.put("changed", changed)
+
+                def path = project.buildDir.toPath()
+                path.resolve("m2repository/changed-artifacts.json").write(json.toString())
+            }
+
             project.task('publishProjectsToMavenLocal') {
                 projectsToPublish.each { projectToPublish ->
                     dependsOn getPublishTask(projectToPublish, 'MavenLocal')
@@ -155,6 +205,31 @@ class PublishingPlugin implements Plugin<Project> {
         }
     }
 
+    private static Set<Project> getChangedProjects(Project p) {
+        Set<Project> roots = new AffectedProjectFinder(p, []).find()
+        HashSet<Project> changed = new HashSet<>()
+
+        getChangedProjectsLoop(roots, changed)
+        return changed
+    }
+
+    private static void getChangedProjectsLoop(Collection<Project> projects, Set<Project> changed) {
+      for (Project p : projects) {
+        // Skip processing and recursion if this project has already been added to the set.
+        if (!changed.add(p)) {
+          continue;
+        }
+
+        // Find all (head) dependencies to other projects in this respository.
+        def all = p.configurations.releaseRuntimeClasspath.allDependencies
+        def affected =
+            all.findAll { it instanceof ProjectDependency }.collect { it.getDependencyProject() }
+
+        // Recurse with the new dependencies.
+        getChangedProjectsLoop(affected, changed)
+      }
+    }
+
     private static String getPublishTask(Project p, String repoName) {
         return "${p.path}:publishMavenAarPublicationTo$repoName"
     }