New graph-support lib.

build-logic/convention/src/main/kotlin/com/autonomousapps/convention/ConventionPlugin.kt

@@ -35,7 +35,9 @@ class ConventionPlugin : Plugin<Project> {
     val signing = extensions.getByType(SigningExtension::class.java)
     val publishing = extensions.getByType(PublishingExtension::class.java)
 
-    val publishToMavenCentral = tasks.register("publishToMavenCentral")
+    val publishToMavenCentral = tasks.register("publishToMavenCentral") {
+      it.notCompatibleWithConfigurationCache("Publishing is not compatible")
+    }
 
     extensions.configure(JavaPluginExtension::class.java) { j ->
       j.withJavadocJar()
@@ -97,7 +99,7 @@ class ConventionPlugin : Plugin<Project> {
         finalizedBy(promoteTask)
         doLast {
           if (isSnapshot.get()) {
-            logger.quiet("Browse files at https://oss.sonatype.org/content/repositories/snapshots/com/autonomousapps")
+            logger.quiet("Browse files at https://oss.sonatype.org/content/repositories/snapshots/com/autonomousapps/")
           } else {
             logger.quiet("After publishing to Sonatype, visit https://oss.sonatype.org to close and release from staging")
           }

build.gradle.kts

@@ -117,6 +117,8 @@ dependencies {
   api(libs.javax.inject)
   api(libs.moshi.core)
   api(libs.moshix.sealed.runtime)
+
+  implementation(project(":graph-support"))
   implementation(libs.kotlin.stdlib.jdk8)
   implementation(libs.moshi.kotlin)
   implementation(libs.moshix.sealed.reflect)

graph-support/build.gradle.kts

@@ -0,0 +1,47 @@
+plugins {
+  id("org.jetbrains.kotlin.jvm")
+  id("convention")
+  id("com.autonomousapps.dependency-analysis")
+}
+
+group = "com.autonomousapps"
+version = "0.1"
+
+kotlin {
+  explicitApi()
+}
+
+dagp {
+  version(version)
+  pom {
+    name.set("Graph Support Library")
+    description.set("A graph support library for the JVM")
+    url.set("https://github.com/autonomousapps/dependency-analysis-android-gradle-plugin")
+    inceptionYear.set("2022")
+  }
+  publishTaskDescription("Publishes to Maven Central and promotes.")
+}
+
+// We only use the Jupiter platform (JUnit 5)
+configurations.all {
+  exclude(mapOf("group" to "junit", "module" to "junit"))
+  exclude(mapOf("group" to "org.junit.vintage", "module" to "junit-vintage-engine"))
+}
+
+dependencies {
+  api(libs.guava) {
+    because("Graphs")
+  }
+
+  testImplementation(platform(libs.junit.bom))
+  testImplementation(libs.junit.api)
+  testImplementation(libs.junit.params)
+  testImplementation(libs.truth)
+  testRuntimeOnly(libs.junit.engine)
+
+  testImplementation(libs.truth)
+}
+
+tasks.withType<Test>().configureEach {
+  useJUnitPlatform()
+}

src/main/kotlin/com/autonomousapps/internal/graph/DominanceTree.kt → graph-support/src/main/kotlin/com/autonomousapps/graph/DominanceTree.kt

@@ -1,6 +1,5 @@
-package com.autonomousapps.internal.graph
+package com.autonomousapps.graph
 
-import com.autonomousapps.internal.unsafeLazy
 import com.google.common.graph.ElementOrder
 import com.google.common.graph.Graph
 import com.google.common.graph.GraphBuilder
@@ -13,7 +12,7 @@ import com.google.common.graph.GraphBuilder
  * @see <a href="http://www.hipersoft.rice.edu/grads/publications/dom14.pdf">A Simple, Fast Dominance Algorithm.</a>
  */
 @Suppress("UnstableApiUsage") // Guava graphs
-internal class DominanceTree<N : Any>(
+public class DominanceTree<N : Any>(
   private val backingGraph: Graph<N>,
   private val root: N
 ) {
@@ -78,7 +77,7 @@ internal class DominanceTree<N : Any>(
     return left
   }
 
-  val dominanceGraph: Graph<N> by unsafeLazy {
+  public val dominanceGraph: Graph<N> by lazy(LazyThreadSafetyMode.NONE) {
     val builder = GraphBuilder.directed()
       .allowsSelfLoops(false)
       .incidentEdgeOrder(ElementOrder.stable<N>())

src/main/kotlin/com/autonomousapps/internal/graph/DominanceTreeWriter.kt → graph-support/src/main/kotlin/com/autonomousapps/graph/DominanceTreeWriter.kt

@@ -1,16 +1,14 @@
-package com.autonomousapps.internal.graph
-
-import org.gradle.kotlin.dsl.support.appendReproducibleNewLine
+package com.autonomousapps.graph
 
 @Suppress("UnstableApiUsage") // Guava
-internal class DominanceTreeWriter<N : Any>(
+public class DominanceTreeWriter<N : Any>(
   private val root: N,
   private val tree: DominanceTree<N>,
   private val nodeWriter: NodeWriter<N>,
 ) {
 
   private val builder = StringBuilder()
-  val string: String get() = builder.toString()
+  public val string: String get() = builder.toString()
 
   init {
     compute()
@@ -20,7 +18,7 @@ internal class DominanceTreeWriter<N : Any>(
     val visiting = linkedMapOf<N, MutableSet<N>>()
 
     // start by printing root node
-    builder.appendReproducibleNewLine(nodeWriter.toString(root))
+    builder.appendLine(nodeWriter.toString(root))
 
     fun dfs(node: N) {
       val subs = tree.dominanceGraph.successors(node).run { nodeWriter.comparator()?.let { sortedWith(it) } ?: this }
@@ -45,7 +43,7 @@ internal class DominanceTreeWriter<N : Any>(
           }
         }
 
-        builder.appendReproducibleNewLine(nodeWriter.toString(sub))
+        builder.appendLine(nodeWriter.toString(sub))
 
         dfs(sub)
 
@@ -57,12 +55,12 @@ internal class DominanceTreeWriter<N : Any>(
     dfs(root)
   }
 
-  internal interface NodeWriter<N : Any> {
+  public interface NodeWriter<N : Any> {
     /** A [Comparator] for sorting nodes of type [N]. May be null if you don't care about print order. */
-    fun comparator(): Comparator<N>?
+    public fun comparator(): Comparator<N>?
 
     /** String representation of [node] that will be printed to console. */
-    fun toString(node: N): String
+    public fun toString(node: N): String
   }
 
   private companion object {

graph-support/src/main/kotlin/com/autonomousapps/graph/Graphs.kt

@@ -0,0 +1,32 @@
+package com.autonomousapps.graph
+
+import com.google.common.graph.Graph
+import com.google.common.graph.Graphs as GuavaGraphs
+
+@Suppress("UnstableApiUsage") // Guava graphs
+public object Graphs {
+
+  public fun <N : Any> Graph<N>.reachableNodes(node: N, excludeSelf: Boolean = true): Set<N> {
+    val reachable = GuavaGraphs.reachableNodes(this, node)
+    return if (excludeSelf) {
+      reachable.filterNotTo(HashSet()) { it == node }
+    } else {
+      reachable
+    }
+  }
+
+  public fun <N : Any> Graph<N>.parents(node: N): Set<N> = predecessors(node)
+
+  public fun <N : Any> Graph<N>.children(node: N): Set<N> = successors(node)
+
+  /**
+   * Returns an ordered list of nodes if there is a path from [source] to [target]. If there is no path, returns an
+   * empty list.
+   */
+  public fun <N : Any> Graph<N>.shortestPath(source: N, target: N): Iterable<N> {
+    val path = ShortestPath(this, source)
+    return path.pathTo(target)
+  }
+
+  public fun <N : Any> Graph<N>.topological(source: N): Iterable<N> = Topological(this, source).order
+}

src/main/kotlin/com/autonomousapps/internal/graph/ShortestPath.kt → graph-support/src/main/kotlin/com/autonomousapps/graph/ShortestPath.kt

@@ -1,12 +1,12 @@
-package com.autonomousapps.internal.graph
+package com.autonomousapps.graph
 
 import com.google.common.graph.EndpointPair
 import com.google.common.graph.Graph
 import java.util.*
 
 /** With thanks to Algorithms, 4th Ed. */
 @Suppress("UnstableApiUsage") // Guava graphs
-internal class ShortestPath<N>(
+public class ShortestPath<N>(
   graph: Graph<N>,
   private val source: N
 ) where N : Any {
@@ -29,12 +29,12 @@ internal class ShortestPath<N>(
     }
   }
 
-  fun hasPathTo(other: N): Boolean {
+  public fun hasPathTo(other: N): Boolean {
     val dist = distTo[other] ?: return false
     return dist < Float.MAX_VALUE
   }
 
-  fun pathTo(other: N): Iterable<N> {
+  public fun pathTo(other: N): Iterable<N> {
     if (!hasPathTo(other)) return emptyList()
 
     // Flatten the list of edges into a list of nodes

src/main/kotlin/com/autonomousapps/internal/graph/Topological.kt → graph-support/src/main/kotlin/com/autonomousapps/graph/Topological.kt

@@ -1,17 +1,17 @@
-package com.autonomousapps.internal.graph
+package com.autonomousapps.graph
 
 import com.google.common.graph.Graph
 import com.google.common.graph.Traverser
 import java.util.*
 
 /** With thanks to Algorithms, 4th Ed. See p582 for the explanation for why we want the reverse postorder. */
 @Suppress("UnstableApiUsage") // Guava graphs
-internal class Topological<N>(
+public class Topological<N>(
   graph: Graph<N>,
   source: N
 ) where N : Any {
 
-  val order: Iterable<N>
+  public val order: Iterable<N>
 
   init {
     val postorder: Iterable<N> = Traverser.forGraph(graph).depthFirstPostOrder(source)

src/test/kotlin/com/autonomousapps/internal/graph/GraphsTest.kt → graph-support/src/test/kotlin/com/autonomousapps/graph/GraphsTest.kt

@@ -1,11 +1,14 @@
-package com.autonomousapps.internal.graph
+@file:Suppress("UnstableApiUsage") // Guava
 
-import com.autonomousapps.test.graphOf
+package com.autonomousapps.graph
+
+import com.google.common.graph.ElementOrder
+import com.google.common.graph.GraphBuilder
+import com.google.common.graph.ImmutableGraph
 import com.google.common.truth.Truth.assertThat
 import org.junit.jupiter.api.Nested
 import org.junit.jupiter.api.Test
 
-@Suppress("UnstableApiUsage") // Guava
 internal class GraphsTest {
 
   @Nested inner class Topological {
@@ -125,3 +128,15 @@ internal class GraphsTest {
     }
   }
 }
+
+private fun <N : Any> graphOf(vararg pairs: Pair<N, N>): ImmutableGraph<N> {
+  val builder: ImmutableGraph.Builder<N> = GraphBuilder.directed()
+    .allowsSelfLoops(false)
+    .incidentEdgeOrder(ElementOrder.stable<N>())
+    .immutable()
+
+  pairs.forEach { (from, to) ->
+    builder.putEdge(from, to)
+  }
+  return builder.build()
+}

settings.gradle.kts

@@ -13,6 +13,8 @@ pluginManagement {
     }
     gradlePluginPortal()
     mavenCentral()
+
+    // snapshots are permitted, but only for dependencies I own
     maven {
       url = uri("https://oss.sonatype.org/content/repositories/snapshots/")
       content {
@@ -41,6 +43,7 @@ dependencyResolutionManagement {
     if (providers.systemProperty("local").isPresent) {
       mavenLocal()
     }
+    // snapshots are permitted, but only for dependencies I own
     maven {
       url = uri("https://oss.sonatype.org/content/repositories/snapshots/")
       content {
@@ -68,6 +71,7 @@ gradleEnterprise {
 
 rootProject.name = "dependency-analysis-gradle-plugin"
 
+include(":graph-support")
 include(":testkit")
 include(":testkit-truth")
 

src/main/kotlin/com/autonomousapps/internal/Bundles.kt

@@ -1,8 +1,8 @@
 package com.autonomousapps.internal
 
 import com.autonomousapps.extension.DependenciesHandler.SerializableBundles
-import com.autonomousapps.internal.graph.Graphs.children
-import com.autonomousapps.internal.graph.Graphs.reachableNodes
+import com.autonomousapps.graph.Graphs.children
+import com.autonomousapps.graph.Graphs.reachableNodes
 import com.autonomousapps.model.Advice
 import com.autonomousapps.model.Coordinates
 import com.autonomousapps.model.Coordinates.Companion.copy

src/main/kotlin/com/autonomousapps/internal/reason/DependencyAdviceExplainer.kt

@@ -1,6 +1,6 @@
 package com.autonomousapps.internal.reason
 
-import com.autonomousapps.internal.graph.Graphs.shortestPath
+import com.autonomousapps.graph.Graphs.shortestPath
 import com.autonomousapps.internal.utils.Colors
 import com.autonomousapps.internal.utils.Colors.colorize
 import com.autonomousapps.internal.utils.lowercase
@@ -56,10 +56,12 @@ internal class DependencyAdviceExplainer(
             "There is no advice regarding this dependency. It was removed because it matched a $bundle rule for " +
               "${printableIdentifier(trace.parent).colorize(Colors.BOLD)}, which is already declared."
           }
+
           is BundleTrace.UsedChild -> {
             "There is no advice regarding this dependency. It was removed because it matched a $bundle rule for " +
               "${printableIdentifier(trace.child).colorize(Colors.BOLD)}, which is declared and used."
           }
+
           else -> error("Trace was $trace, which makes no sense in this context")
         }
       } else if (wasFiltered) {
@@ -69,6 +71,7 @@ internal class DependencyAdviceExplainer(
         "There is no advice regarding this dependency."
       }
     }
+
     advice.isAdd() -> {
       val trace = findTrace()
       if (trace != null) {
@@ -80,13 +83,16 @@ internal class DependencyAdviceExplainer(
         "You have been advised to add this dependency to '${advice.toConfiguration!!.colorize(Colors.GREEN)}'."
       }
     }
+
     advice.isRemove() || advice.isProcessor() -> {
       "You have been advised to remove this dependency from '${advice.fromConfiguration!!.colorize(Colors.RED)}'."
     }
+
     advice.isChange() || advice.isRuntimeOnly() || advice.isCompileOnly() -> {
       "You have been advised to change this dependency to '${advice.toConfiguration!!.colorize(Colors.GREEN)}' " +
         "from '${advice.fromConfiguration!!.colorize(Colors.YELLOW)}'."
     }
+
     else -> error("Unknown advice type: $advice")
   }