Move Gradle build logic to a setup hook

README.org

@@ -2,7 +2,8 @@
 
 [[./assets/gradle2nix.png]]
 
-Generate [[https://nixos.org/nix/][Nix]] expressions which build [[https://gradle.org/][Gradle]]-based projects.
+Generate [[https://nixos.org/nix/][Nix]] expressions which build
+[[https://gradle.org/][Gradle]]-based projects.
 
 ** Table of contents
 
@@ -13,6 +14,10 @@ Generate [[https://nixos.org/nix/][Nix]] expressions which build [[https://gradl
 - [[#usage][Usage]]
   - [[#for-packagers][For packagers]]
   - [[#specifying-the-gradle-installation][Specifying the Gradle installation]]
+- [[#reference][Reference]]
+  - [[#buildGradlePackage][=buildGradlePackage=]]
+  - [[#buildMavenRepo][=buildMavenRepo=]]
+  - [[#gradleSetupHook][=gradleSetupHook=]]
 - [[#contributing][Contributing]]
 - [[#license][License]]
 #+END_QUOTE
@@ -25,7 +30,8 @@ is that it is purely functional; a "package" is a function which
 accepts inputs (source code, configuration, etc) and produces an
 output (binaries, a Java JAR, documentation, really anything).
 
-One benefit of a functional build system is [[https://reproducible-builds.org/][reproducibility]]. If you
+One benefit of a functional build system is
+[[https://reproducible-builds.org/][reproducibility]]. If you
 specify your inputs precisely, and take care not to introduce
 impurities—such as files retrieved over a network without tracking
 their content—you will receive, byte-for-byte, the exact output as
@@ -42,31 +48,33 @@ inputs, including:
 - Environment variables and command-line options
 - Artifacts cached on the system hosting the build
 
-=gradle2nix= helps to solve this problem by leveraging Nix to control
+=gradle2nix= helps to solve this problem by leveraging Nix to
-the most common inputs to a Gradle build. When run on a project, it
+control the most common inputs to a Gradle build. When run on a
-will record all dependencies for both the build environment (including
+project, it will record all dependencies for both the build
-=plugins= and =buildscript= blocks) and the project, and provide a Nix
+environment (including =plugins= and =buildscript= blocks) and the
-expression to run the build given these dependencies. The build itself
+project, and provide a Nix expression to run the build given these
-is then run in a sandbox, where only content-tracked network requests
+dependencies. The build itself is then run in a sandbox, where only
-are allowed to fetch dependencies, and a local Maven repository is
+content-tracked network requests are allowed to fetch dependencies,
-created on-the-fly to host the dependency artifacts somewhere Gradle
+and a local Maven repository is created on-the-fly to host the
-can resolve them without a network.
+dependency artifacts somewhere Gradle can resolve them without a
+network.
 
 This tool is useful for both development and packaging. You can use
 =gradle2nix= to:
 
-- Create isolated and reproducible development environments that work
+- Create isolated and reproducible development environments that
-  anywhere Nix itself can run;
+  work anywhere Nix itself can run.
 - Reduce or eliminate flakiness and maintenance headaches from CI/CD
-  pipelines
+  pipelines.
 - Distribute a recipe which can reliably build a Gradle project in
-  repositories such as the [[https://nixos.org/nixpkgs/][Nix Package Collection]].
+  repositories such as the [[https://nixos.org/nixpkgs/][Nix Package
+  Collection]].
 
 ** Installation
 
-A [[./gradle.nix][Nix expression]] (generated by =gradle2nix= itself) is provided for
+A [[./gradle.nix][Nix expression]] (generated by =gradle2nix=
-convenience. The following expression will fetch and build the latest
+itself) is provided for convenience. The following expression will
-version of this package:
+fetch and build the latest version of this package:
 
 #+begin_src nix
 import (fetchTarball "https://github.com/tadfisher/gradle2nix/archive/master.tar.gz")  {}
@@ -93,8 +101,9 @@ nix-env -if "https://github.com/tadfisher/gradle2nix/archive/master.tar.gz"
 =gradle2nix= is not yet packaged in =nixpkgs= itself, but work is
 [[https://github.com/NixOS/nixpkgs/pull/77422][in progress]].
 
-The [[./gradle.nix][buildGradlePackage]] function is provided via the
+The [[./nix/build-gradle-package.nix][buildGradlePackage]] function
-=gradle2nix.passthru.buildGradlePackage= attribute.
+is provided via the =gradle2nix.passthru.buildGradlePackage=
+attribute.
 
 #+begin_src nix
 { pkgs ? import <nixpkgs> {} }:
@@ -106,23 +115,24 @@ gradle2nix.buildGradlePackage {
   pname = "my-package";
   version = "1.0";
   lockFile = ./gradle.lock;
-  gradleFlags = [ "installDist" ];
+  gradleInstallFlags = [ "installDist" ];
   # ...
 }
 #+end_src
 
 *** Flake
 
-A [[./flake.nix][flake.nix]] is provided for those using [[https://nixos.wiki/wiki/Flakes][Nix flakes]]. For example, the
+A [[./flake.nix][flake.nix]] is provided for those using
-following will build and run =gradle2nix= with the arguments provided
+[[https://nixos.wiki/wiki/Flakes][Nix flakes]]. For example, the
-after =--=:
+following will build and run =gradle2nix= with the arguments
+provided after =--=:
 
 #+begin_example
 nix run github:tadfisher/gradle2nix -- --help
 #+end_example
 
-The [[./gradle.nix][buildGradlePackage]] function is provided via the
+The [[./nix/build-gradle-package.nix][buildGradlePackage]] function
-=builders= output.
+is provided via the =builders= output.
 
 #+begin_src nix
 {
@@ -134,7 +144,7 @@ The [[./gradle.nix][buildGradlePackage]] function is provided via the
       pname = "my-package";
       version = "1.0";
       lockFile = ./gradle.lock;
-      gradleFlags = [ "installDist" ];
+      gradleInstallFlags = [ "installDist" ];
       # ...
     };
   };
@@ -169,12 +179,12 @@ Arguments:
   <args>  Extra arguments to pass to Gradle
 #+end_example
 
-Simply running =gradle2nix= in the root directory of a project should
+Simply running =gradle2nix= in the root directory of a project
-be enough for most projects. This will produce two files, by default
+should be enough for most projects. This will produce a lock file,
-called =gradle.lock= and =gradle.nix=, which contain the
+by default called =gradle.lock=, which contains the pinned
-pinned dependencies for the project and a standard build expression
+dependencies for the project. An example of a build expression using
-which can be imported or called by other Nix expressions. An example
+this lock file can be found in this project's
-of such an expression can be found in this project's [[./gradle2nix.nix][gradle2nix.nix]].
+[[./default.nix][default.nix]].
 
 *** For packagers
 
@@ -211,16 +221,203 @@ gradle2nix --gradle-home=`nix eval nixpkgs#gradle.outPath`/lib/gradle
 gradle2nix --gradle-wrapper=8.7
 #+end_example
 
+** Reference
+
+*** =buildGradlePackage=
+
+This function is a convenience wrapper around =stdenv.mkDerivation=
+that simplifies building Gradle projects with the lock files
+produced by =gradle2nix=. It performs the following:
+
+1. Applies [[#gradleSetupHook][=gradleSetupHook=]], overriding the
+  required =gradle= package if specified.
+2. Builds the offline Maven repository with
+  [[#buildMavenRepo][=buildMavenRepo=]].
+3. Sets the JDK used to run Gradle if specified.
+4. Applies the offline repo to the Gradle build using an
+  initialization script.
+
+- Source:
+  [[./nix/build-gradle-package.nix][build-gradle-package.nix]]
+- Location:
+  - Nix :: =gradle2nix.passthru.buildGradlePackage=
+  - Flake :: =builders.${system}.buildGradlePackage=
+
+**** Arguments to =buildGradlePackage=
+
+- =lockFile= :: Path to the lock file generated by =gradle2nix=
+  (e.g. =gradle.lock=).
+- =gradlePackage= :: The Gradle package to use. Default is
+  =pkgs.gradle=.
+- =buildJdk= :: Override the default JDK used to run Gradle itself.
+- =fetchers= :: Override functions which fetch dependency
+  artifacts.
+
+  See [[#fetchers][detailed documentation]] below.
+- =overrides= :: Override artifacts in the offline Maven repository.
+
+  See [[#override][detailed documentation]] below.
+
+In addition, this function accepts:
+- All arguments to =stdenv.mkDerivation=.
+- Arguments specific to =gradleSetupHook= (see
+  [[#gradleSetupHook][below]]).
+
+*** =buildMavenRepo=
+
+This function takes a lock file and produces a derivation which
+downloads all dependencies into a Maven local repository. The
+derivation provides a passthru =gradleInitScript= attribute, which
+is a Gradle initialization script that can be applied using =gradle
+--init-script== or placed in =$GRADLE_USER_HOME/init.d=. The init
+script replaces all repositories referenced in the project with the
+local repository.
+
+- Source: [[./nix/build-maven-repo.nix][build-maven-repo.nix]]
+- Location:
+  - Nix :: =gradle2nix.passthru.buildMavenRepo=
+  - Flake :: =builders.${system}.buildMavenRepo=
+
+**** Arguments to =buildMavenRepo=
+- =lockFile= :: Path to the lock file generated by gradle2nix (e.g.
+  =gradle.lock=).
+- =fetchers= :: Override functions which fetch dependency
+  artifacts.
+
+  See [[#fetchers][detailed documentation]] below.
+- =overrides= :: Override artifacts in the offline Maven repository.
+
+  See [[#override][detailed documentation]] below.
+
+*** =gradleSetupHook=
+
+A
+[[https://nixos.org/manual/nixpkgs/unstable/#ssec-setup-hooks][setup
+hook]] to simplify building Gradle packages. Overrides the default
+configure, build, check, and install phases.
+
+To use, add =gradleSetupHook= to a derivation's =nativeBuildInputs=.
+
+- Source: [[./nix/setup-hook.sh][setup-hook.sh]]
+- Location:
+  - Nix :: =gradle2nix.passthru.gradleSetupHook=
+  - Flake :: =packages.${system}.gradleSetupHook=
+
+**** Variables controlling =gradleSetupHook=
+- =gradleInitScript= :: Path to an
+  [[https://docs.gradle.org/current/userguide/init_scripts.html][initialization
+  script]] used by =gradle= during all phases.
+- =gradleFlags= :: Controls the arguments passed to =gradle= during
+  all phases.
+- =gradleBuildFlags= :: Controls the arguments passed to =gradle=
+  during the build phase. The build phase is skipped if this is
+  unset.
+- =gradleCheckFlags= :: Controls the arguments passed to =gradle=
+  during the check phase. The check phase is skipped if this is
+  unset.
+- =gradleInstallFlags= :: Controls the arguments passed to =gradle=
+  during the install phase. This install phase is skipped if this is
+  unset.
+- =dontUseGradleConfigure= :: When set to true, don't use the
+  predefined =gradleConfigurePhase=. This will also disable the use
+  of =gradleInitScript=.
+- =dontUseGradleCheck= :: When set to true, don't use the predefined
+  =gradleCheckPhase=.
+- =dontUseGradleInstall= :: When set to true, don't use the
+  predefined =gradleInstallPhase=.
+
+**** Honored variables
+
+The following variables commonly used by =stdenv.mkDerivation= are
+honored by =gradleSetupHook=.
+
+- =enableParallelBuilding=
+- =enableParallelChecking=
+- =enableParallelInstalling=
+
+*** Common arguments
+**** =fetchers=
+
+Names in this set are URL schemes such as "https" or "s3". Values
+are functions which take an artifact in the form ={ url, hash }=
+and fetches it into the Nix store. For example:
+
+#+begin_src nix
+{
+  s3 = { name, url, hash }: fetchs3 {
+    s3url = url;
+    # TODO This doesn't work without patching fetchs3 to accept SRI hashes
+    inherit name hash;
+    region = "us-west-2";
+    credentials = {
+      access_key_id = "foo";
+      secret_access_key = "bar";
+    };
+  };
+}
+#+end_src
+
+**** =overrides=
+
+This is an attrset of the form:
+
+#+begin_src nix
+{
+  "${group}:${module}:${version}" = {
+    "${filename}" = <override function>;
+  }
+}
+#+end_src
+
+The override function takes the original derivation from 'fetchers'
+(e.g. the result of 'fetchurl') and produces a new derivation to
+replace it.
+
+- Replace a dependency's JAR artifact:
+
+  #+begin_src nix
+  {
+    "com.squareup.okio:okio:3.9.0"."okio-3.9.0.jar" = _: fetchurl {
+      url = "https://repo.maven.apache.org/maven2/com/squareup/okio/okio/3.9.0/okio-3.9.0.jar";
+      hash = "...";
+      downloadToTemp = true;
+      postFetch = "install -Dt $out/com/squareup/okio/okio/3.9.0/ $downloadedFile"
+    };
+  }
+  #+end_src
+
+- Patch a JAR containing native binaries:
+
+  #+begin_src nix
+  {
+    "com.android.tools.build:aapt2:8.5.0-rc02-11315950" = {
+      "aapt2-8.5.0-rc02-11315950-linux.jar" = src: runCommandCC src.name {
+        nativeBuildInputs = [ jdk autoPatchelfHook ];
+        dontAutoPatchelf = true;
+      } ''
+        cp ${src} aapt2.jar
+        jar xf aapt2.jar aapt2
+        chmod +x aapt2
+        autoPatchelf aapt2
+        jar uf aapt2.jar aapt2
+        cp aapt2.jar $out
+      '';
+    }
+  }
+  #+end_src
+
 ** Contributing
 
 Bug reports and feature requests are encouraged.
 
-[[https://github.com/tadfisher/gradle2nix/issues/new][Create an issue]]
+[[https://github.com/tadfisher/gradle2nix/issues/new][Create an
+issue]]
 
 Code contributions are also encouraged. Please review the test cases
-in the [[./fixtures][fixtures]] directory and create a new one to reproduce any fixes
+in the [[./fixtures][fixtures]] directory and create a new one to
-or test new features. See the [[./app/src/test/kotlin/org/nixos/gradle2nix/GoldenTest.kt][existing tests]]
+reproduce any fixes or test new features. See the
-for examples of testing with these fixtures.
+[[./app/src/test/kotlin/org/nixos/gradle2nix/GoldenTest.kt][existing
+tests]] for examples of testing with these fixtures.
 
 ** License
 

app/src/main/kotlin/org/nixos/gradle2nix/GradleRunner.kt

@@ -16,7 +16,8 @@ fun connect(
     config: Config,
     projectDir: File = config.projectDir,
 ): ProjectConnection =
-    GradleConnector.newConnector()
+    GradleConnector
+        .newConnector()
         .apply {
             when (val source = config.gradleSource) {
                 is GradleSource.Distribution -> useDistribution(source.uri)
@@ -24,8 +25,7 @@ fun connect(
                 GradleSource.Project -> useBuildDistribution()
                 is GradleSource.Wrapper -> useGradleVersion(source.version)
             }
-        }
+        }.forProjectDirectory(projectDir)
-        .forProjectDirectory(projectDir)
         .connect()
 
 suspend fun ProjectConnection.buildModel(): GradleBuild =
@@ -67,8 +67,7 @@ suspend fun ProjectConnection.build(
                 "--refresh-dependencies",
                 "--gradle-user-home=${config.gradleHome}",
                 "--init-script=${config.appHome}/init.gradle",
-            )
+            ).apply {
-            .apply {
                 if (config.logger.stacktrace) {
                     addArguments("--stacktrace")
                 }
@@ -80,12 +79,14 @@ suspend fun ProjectConnection.build(
                     withSystemProperties(
                         mapOf(
                             "org.gradle.internal.operations.trace" to
-                                config.outDir.toPath().resolve("debug").absolutePathString(),
+                                config.outDir
+                                    .toPath()
+                                    .resolve("debug")
+                                    .absolutePathString(),
                         ),
                     )
                 }
-            }
+            }.run(
-            .run(
                 object : ResultHandler<DependencySet> {
                     override fun onComplete(result: DependencySet) {
                         continuation.resume(result)

app/src/main/kotlin/org/nixos/gradle2nix/Main.kt

@@ -48,13 +48,19 @@ val JsonFormat =
     }
 
 sealed interface GradleSource {
-    data class Distribution(val uri: URI) : GradleSource
+    data class Distribution(
+        val uri: URI,
+    ) : GradleSource
 
-    data class Path(val path: File) : GradleSource
+    data class Path(
+        val path: File,
+    ) : GradleSource
 
     data object Project : GradleSource
 
-    data class Wrapper(val version: String) : GradleSource
+    data class Wrapper(
+        val version: String,
+    ) : GradleSource
 }
 
 enum class LogLevel {
@@ -64,9 +70,10 @@ enum class LogLevel {
     ERROR,
 }
 
-class Gradle2Nix : CliktCommand(
+class Gradle2Nix :
+    CliktCommand(
         name = "gradle2nix",
-) {
+    ) {
     private val tasks: List<String> by option(
         "--task",
         "-t",
@@ -93,8 +100,7 @@ class Gradle2Nix : CliktCommand(
         "-o",
         metavar = "DIR",
         help = "Path to write generated files",
-    )
+    ).file(canBeFile = false, canBeDir = true)
-        .file(canBeFile = false, canBeDir = true)
         .defaultLazy("<project>") { projectDir }
 
     internal val lockFile: String by option(
@@ -133,8 +139,7 @@ class Gradle2Nix : CliktCommand(
     private val logLevel: LogLevel by option(
         "--log",
         help = "Print messages with this priority or higher",
-    )
+    ).enum<LogLevel>(key = { it.name.lowercase() })
-        .enum<LogLevel>(key = { it.name.lowercase() })
         .default(LogLevel.INFO, "info")
 
     private val dumpEvents: Boolean by option(
@@ -192,7 +197,9 @@ class Gradle2Nix : CliktCommand(
                         addAll(root.editableBuilds)
                     }
                 builds.mapNotNull { build ->
-                    build.rootProject.projectDirectory.resolve("buildSrc").takeIf { it.exists() }
+                    build.rootProject.projectDirectory
+                        .resolve("buildSrc")
+                        .takeIf { it.exists() }
                 }
             }
 

app/src/main/kotlin/org/nixos/gradle2nix/Process.kt

@@ -8,8 +8,8 @@ import kotlin.io.encoding.ExperimentalEncodingApi
 fun processDependencies(
     config: Config,
     dependencySets: Iterable<DependencySet>,
-): Env {
+): Env =
-    return buildMap<DependencyCoordinates, Map<String, Artifact>> {
+    buildMap<DependencyCoordinates, Map<String, Artifact>> {
         for (dependencySet in dependencySets) {
             val env = dependencySet.toEnv()
 
@@ -40,16 +40,14 @@ fun processDependencies(
         artifacts.toSortedMap()
     }.toSortedMap(coordinatesComparator)
         .mapKeys { (coordinates, _) -> coordinates.id }
-}
 
-private fun DependencySet.toEnv(): Map<DependencyCoordinates, Map<String, Artifact>> {
+private fun DependencySet.toEnv(): Map<DependencyCoordinates, Map<String, Artifact>> =
-    return dependencies.associate { dep ->
+    dependencies.associate { dep ->
         dep.coordinates to
             dep.artifacts.associate {
                 it.name to Artifact(it.url, it.hash.toSri())
             }
     }
-}
 
 @OptIn(ExperimentalEncodingApi::class, ExperimentalStdlibApi::class)
 internal fun String.toSri(): String =

app/src/main/kotlin/org/nixos/gradle2nix/Version.kt

@@ -2,7 +2,11 @@ package org.nixos.gradle2nix
 
 import java.util.concurrent.ConcurrentHashMap
 
-class Version(val source: String, val parts: List<String>, base: Version?) : Comparable<Version> {
+class Version(
+    val source: String,
+    val parts: List<String>,
+    base: Version?,
+) : Comparable<Version> {
     private val base: Version
     val numericParts: List<Long?>
 

app/src/test/kotlin/org/nixos/gradle2nix/GoldenTest.kt

@@ -3,7 +3,8 @@ package org.nixos.gradle2nix
 import io.kotest.core.extensions.install
 import io.kotest.core.spec.style.FunSpec
 
-class GoldenTest : FunSpec({
+class GoldenTest :
+    FunSpec({
         install(MavenRepo)
 
         context("basic") {
@@ -44,4 +45,4 @@ class GoldenTest : FunSpec({
         context("subprojects") {
             golden("subprojects/multi-module")
         }
-})
+    })

app/src/test/kotlin/org/nixos/gradle2nix/TestUtil.kt

@@ -47,9 +47,7 @@ private val json =
 
 val testLogger = Logger(logLevel = LogLevel.DEBUG, stacktrace = true)
 
-fun fixture(path: String): File {
+fun fixture(path: String): File = Paths.get("../fixtures", path).toFile()
-    return Paths.get("../fixtures", path).toFile()
-}
 
 @OptIn(ExperimentalKotest::class, ExperimentalSerializationApi::class, KotestInternal::class)
 suspend fun TestScope.fixture(
@@ -60,7 +58,8 @@ suspend fun TestScope.fixture(
     val tmp = Paths.get("build/tmp/gradle2nix").apply { toFile().mkdirs() }
     val baseDir = Paths.get("../fixtures/projects", project).toFile()
     val children =
-        baseDir.listFiles(FileFilter { it.isDirectory && (it.name == "groovy" || it.name == "kotlin") })
+        baseDir
+            .listFiles(FileFilter { it.isDirectory && (it.name == "groovy" || it.name == "kotlin") })
             ?.toList()
     val cases =
         if (children.isNullOrEmpty()) {
@@ -175,8 +174,8 @@ object MavenRepo : MountableExtension<MavenRepo.Config, NettyApplicationEngine>,
         return tryStart(3).also { this.server = it }
     }
 
-    private fun tryStart(attempts: Int): NettyApplicationEngine {
+    private fun tryStart(attempts: Int): NettyApplicationEngine =
-        return try {
+        try {
             val p = config.port ?: Random.nextInt(10000, 65000)
             val s =
                 embeddedServer(Netty, port = p, host = config.host) {
@@ -202,7 +201,6 @@ object MavenRepo : MountableExtension<MavenRepo.Config, NettyApplicationEngine>,
         } catch (e: Throwable) {
             if (config.port == null && attempts > 0) tryStart(attempts - 1) else throw e
         }
-    }
 
     override suspend fun afterSpec(spec: Spec) {
         server?.stop()

default.nix

@@ -5,9 +5,16 @@
 with pkgs;
 
 let
-  buildMavenRepo = callPackage ./maven-repo.nix { };
+  buildMavenRepo = callPackage ./nix/build-maven-repo.nix { };
 
-  buildGradlePackage = callPackage ./gradle.nix { inherit buildMavenRepo; };
+  gradleSetupHook = makeSetupHook {
+    name = "gradle-setup-hook";
+    propagatedBuildInputs = [ gradle ];
+  } ./nix/setup-hook.sh;
+
+  buildGradlePackage = callPackage ./nix/build-gradle-package.nix {
+    inherit buildMavenRepo gradleSetupHook;
+  };
 
   gradle2nix = buildGradlePackage {
     pname = "gradle2nix";
@@ -30,9 +37,9 @@ let
       };
     };
 
-    gradleFlags = [ "installDist" ];
+    gradleInstallFlags = [ ":app:installDist" ];
 
-    installPhase = ''
+    postInstall = ''
       mkdir -p $out/{bin,/lib/gradle2nix}
       cp -r app/build/install/gradle2nix/* $out/lib/gradle2nix/
       rm $out/lib/gradle2nix/bin/gradle2nix.bat
@@ -40,7 +47,7 @@ let
     '';
 
     passthru = {
-      inherit buildGradlePackage buildMavenRepo;
+      inherit buildGradlePackage buildMavenRepo gradleSetupHook;
     };
 
     meta = with lib; {

flake.lock

@@ -20,11 +20,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1716769173,
+        "lastModified": 1718160348,
-        "narHash": "sha256-7EXDb5WBw+d004Agt+JHC/Oyh/KTUglOaQ4MNjBbo5w=",
+        "narHash": "sha256-9YrUjdztqi4Gz8n3mBuqvCkMo4ojrA6nASwyIKWMpus=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9ca3f649614213b2aaf5f1e16ec06952fe4c2632",
+        "rev": "57d6973abba7ea108bac64ae7629e7431e0199b6",
         "type": "github"
       },
       "original": {

flake.nix

@@ -20,15 +20,15 @@
         inherit (nixpkgs) lib;
       in
       {
-        builders = rec {
+        builders = {
-          buildMavenRepo = pkgs.callPackage ./maven-repo.nix { };
+          inherit (self.packages.${system}.gradle2nix) buildGradlePackage buildMavenRepo;
-          buildGradlePackage = pkgs.callPackage ./gradle.nix { inherit buildMavenRepo; };
+          default = self.packages.${system}.buildGradlePackage;
-          default = buildGradlePackage;
         };
 
-        packages = rec {
+        packages = {
+          inherit (self.packages.${system}.gradle2nix) gradleSetupHook;
           gradle2nix = pkgs.callPackage ./default.nix { };
-          default = gradle2nix;
+          default = self.packages.${system}.gradle2nix;
         };
 
         apps = rec {

gradle.nix

@@ -1,238 +0,0 @@
-# This file is generated by gradle2nix.
-#
-# Example usage (e.g. in default.nix):
-#
-#     with (import <nixpkgs> {});
-#     let
-#       buildGradle = callPackage ./gradle.nix {};
-#     in
-#       buildGradle {
-#         lockFile = ./gradle.lock;
-#
-#         src = ./.;
-#
-#         gradleFlags = [ "installDist" ];
-#
-#         installPhase = ''
-#           mkdir -p $out
-#           cp -r app/build/install/myproject $out
-#         '';
-#       }
-
-{
-  lib,
-  stdenv,
-  gradle,
-  buildMavenRepo,
-  writeText,
-}:
-
-let
-  defaultGradle = gradle;
-in
-
-{
-  # Path to the lockfile generated by gradle2nix (e.g. gradle.lock).
-  lockFile ? null,
-  pname ? "project",
-  version ? null,
-  enableParallelBuilding ? true,
-  # The Gradle package to use. Default is 'pkgs.gradle'.
-  gradle ? defaultGradle,
-  # Arguments to Gradle used to build the project in buildPhase.
-  gradleFlags ? [ "build" ],
-  # Enable debugging for the Gradle build; this will cause Gradle to run
-  # a debug server and wait for a JVM debugging client to attach.
-  enableDebug ? false,
-  # Additional code to run in the Gradle init script (init.gradle).
-  extraInit ? "",
-  # Override the default JDK used to run Gradle itself.
-  buildJdk ? null,
-  # Override functions which fetch dependency artifacts.
-  # Keys in this set are URL schemes such as "https" or "s3".
-  # Values are functions which take a dependency in the form
-  # `{ urls, hash }` and fetch into the Nix store. For example:
-  #
-  #   {
-  #     s3 = { name, urls, hash }: fetchs3 {
-  #       s3url = builtins.head urls;
-  #       # TODO This doesn't work without patching fetchs3 to accept SRI hashes
-  #       inherit name hash;
-  #       region = "us-west-2";
-  #       credentials = {
-  #         access_key_id = "foo";
-  #         secret_access_key = "bar";
-  #       };
-  #     };
-  #   }
-  fetchers ? { },
-  # Overlays for dependencies in the offline Maven repository.
-  #
-  # Acceps an attrset of dependencies (usually parsed from 'lockFile'), and produces an attrset
-  # containing dependencies to merge into the final set.
-  #
-  # The attrset is of the form:
-  #
-  #   {
-  #      "${group}:${module}:${version}" = <derivation>;
-  #      # ...
-  #   }
-  #
-  # A dependency derivation unpacks multiple source files into a single Maven-style directory named
-  # "${out}/${groupPath}/${module}/${version}/", where 'groupPath' is the dependency group ID with dot
-  # characters ('.') replaced by the path separator ('/').
-  #
-  # Examples:
-  #
-  # 1. Add or replace a dependency with a single JAR file:
-  #
-  #    (_: {
-  #      "com.squareup.okio:okio:3.9.0" = fetchurl {
-  #        url = "https://repo.maven.apache.org/maven2/com/squareup/okio/okio/3.9.0/okio-3.9.0.jar";
-  #        hash = "...";
-  #        downloadToTemmp = true;
-  #        postFetch = "install -Dt $out/com/squareup/okio/okio/3.9.0/ $downloadedFile"
-  #      };
-  #    })
-  #
-  # 2. Remove a dependency entirely:
-  #
-  #    # This works because the result is filtered for values that are derivations.
-  #    (_: {
-  #      "org.apache.log4j:core:2.23.1" = null;
-  #    })
-  overlays ? [ ],
-  ...
-}@args:
-
-let
-  inherit (builtins) removeAttrs;
-
-  inherit (lib) versionAtLeast versionOlder;
-
-  offlineRepo = buildMavenRepo {
-    inherit
-      lockFile
-      pname
-      version
-      fetchers
-      overlays
-      ;
-  };
-
-  initScript = writeText "init.gradle" ''
-    import org.gradle.util.GradleVersion
-
-    static boolean versionAtLeast(String version) {
-        return GradleVersion.current() >= GradleVersion.version(version)
-    }
-
-    static void configureRepos(RepositoryHandler repositories) {
-        repositories.configureEach { ArtifactRepository repo ->
-            if (repo instanceof MavenArtifactRepository) {
-                repo.setArtifactUrls(new HashSet<URI>())
-                repo.url 'file:${offlineRepo}'
-                repo.metadataSources {
-                    gradleMetadata()
-                    mavenPom()
-                    artifact()
-                }
-            } else if (repo instanceof IvyArtifactRepository) {
-                repo.url 'file:${offlineRepo}'
-                repo.layout('maven')
-                repo.metadataSources {
-                    gradleMetadata()
-                    ivyDescriptor()
-                    artifact()
-                }
-            } else if (repo instanceof UrlArtifactRepository) {
-                repo.url 'file:/homeless-shelter'
-            }
-        }
-    }
-
-    beforeSettings { settings ->
-        configureRepos(settings.pluginManagement.repositories)
-        configureRepos(settings.buildscript.repositories)
-        if (versionAtLeast("6.8")) {
-            configureRepos(settings.dependencyResolutionManagement.repositories)
-        }
-    }
-
-    beforeProject { project ->
-        configureRepos(project.buildscript.repositories)
-        configureRepos(project.repositories)
-    }
-
-    ${extraInit}
-  '';
-
-  buildGradlePackage = stdenv.mkDerivation (
-    finalAttrs:
-    {
-
-      inherit
-        buildJdk
-        enableParallelBuilding
-        enableDebug
-        gradle
-        gradleFlags
-        pname
-        version
-        ;
-
-      dontStrip = true;
-
-      nativeBuildInputs = [ finalAttrs.gradle ];
-
-      buildPhase =
-        let
-          finalGradleFlags =
-            [
-              "--console=plain"
-              "--no-build-cache"
-              "--no-configuration-cache"
-              "--no-daemon"
-              "--no-watch-fs"
-              "--offline"
-            ]
-            ++ lib.optional (finalAttrs.buildJdk != null) "-Dorg.gradle.java.home=${finalAttrs.buildJdk.home}"
-            ++ lib.optional finalAttrs.enableDebug "-Dorg.gradle.debug=true"
-            ++ lib.optional finalAttrs.enableParallelBuilding "--parallel"
-            ++ lib.optional (versionAtLeast finalAttrs.gradle.version "8.0") "--init-script=${initScript}"
-            ++ finalAttrs.gradleFlags;
-        in
-        ''
-          runHook preBuild
-
-          (
-          set -eux
-
-          export NIX_OFFLINE_REPO='${offlineRepo}'
-          export GRADLE_USER_HOME="$(mktemp -d)"
-
-          ${lib.optionalString (versionOlder finalAttrs.gradle.version "8.0") ''
-            # Work around https://github.com/gradle/gradle/issues/1055
-            mkdir -p "$GRADLE_USER_HOME/init.d"
-            ln -s ${initScript} "$GRADLE_USER_HOME/init.d/nix-init.gradle"
-          ''}
-
-          gradle ${builtins.toString finalGradleFlags}
-          )
-
-          runHook postBuild
-        '';
-
-      passthru = {
-        inherit offlineRepo;
-      };
-    }
-    // removeAttrs args [
-      "lockFile"
-      "extraInit"
-      "fetchers"
-      "overlays"
-    ]
-  );
-in
-buildGradlePackage

nix/build-gradle-package.nix

@@ -0,0 +1,145 @@
+# This file is generated by gradle2nix.
+#
+# Example usage (e.g. in default.nix):
+#
+#     with (import <nixpkgs> {});
+#     let
+#       buildGradle = callPackage ./gradle.nix {};
+#     in
+#       buildGradle {
+#         lockFile = ./gradle.lock;
+#
+#         src = ./.;
+#
+#         gradleFlags = [ "installDist" ];
+#
+#         installPhase = ''
+#           mkdir -p $out
+#           cp -r app/build/install/myproject $out
+#         '';
+#       }
+
+{
+  lib,
+  stdenv,
+  gradle,
+  buildMavenRepo,
+  gradleSetupHook,
+  writeText,
+}:
+
+{
+  # Path to the lockfile generated by gradle2nix (e.g. gradle.lock).
+  lockFile ? null,
+  pname ? "project",
+  version ? null,
+  # The Gradle package to use. Default is 'pkgs.gradle'.
+  gradlePackage ? gradle,
+  # Override the default JDK used to run Gradle itself.
+  buildJdk ? null,
+  # Override functions which fetch dependency artifacts.
+  # Names in this set are URL schemes such as "https" or "s3".
+  # Values are functions which take a dependency in the form
+  # `{ urls, hash }` and fetch into the Nix store. For example:
+  #
+  #   {
+  #     s3 = { name, urls, hash }: fetchs3 {
+  #       s3url = builtins.head urls;
+  #       # TODO This doesn't work without patching fetchs3 to accept SRI hashes
+  #       inherit name hash;
+  #       region = "us-west-2";
+  #       credentials = {
+  #         access_key_id = "foo";
+  #         secret_access_key = "bar";
+  #       };
+  #     };
+  #   }
+  fetchers ? { },
+  # Override artifacts in the offline Maven repository.
+  #
+  # This is an attrset is of the form:
+  #
+  #   {
+  #     "${group}:${module}:${version}" = {
+  #       "${filename}" = <override function>;
+  #     }
+  #   }
+  #
+  # The override function takes the original derivation from 'fetchers' (e.g. the result of
+  # 'fetchurl') and produces a new derivation to replace it.
+  #
+  # Examples:
+  #
+  # 1. Replace a dependency's JAR artifact:
+  #
+  #    {
+  #      "com.squareup.okio:okio:3.9.0"."okio-3.9.0.jar" = _: fetchurl {
+  #        url = "https://repo.maven.apache.org/maven2/com/squareup/okio/okio/3.9.0/okio-3.9.0.jar";
+  #        hash = "...";
+  #        downloadToTemp = true;
+  #        postFetch = "install -Dt $out/com/squareup/okio/okio/3.9.0/ $downloadedFile"
+  #      };
+  #    }
+  #
+  # 2. Patch a JAR containing native binaries:
+  #
+  #    {
+  #      "com.android.tools.build:aapt2:8.5.0-rc02-11315950" = {
+  #        "aapt2-8.5.0-rc02-11315950-linux.jar" = src: runCommandCC src.name {
+  #          nativeBuildInputs = [ jdk autoPatchelfHook ];
+  #          dontAutoPatchelf = true;
+  #        } ''
+  #          cp ${src} aapt2.jar
+  #          jar xf aapt2.jar aapt2
+  #          chmod +x aapt2
+  #          autoPatchelf aapt2
+  #          jar uf aapt2.jar aapt2
+  #          cp aapt2.jar $out
+  #        '';
+  #      }
+  #    }
+  overrides ? { },
+  ...
+}@args:
+
+let
+  inherit (builtins) removeAttrs;
+
+  gradleSetupHook' = gradleSetupHook.overrideAttrs (_: {
+    propagatedBuildInputs = [ gradlePackage ];
+  });
+
+  offlineRepo =
+    if lockFile != null then buildMavenRepo { inherit lockFile fetchers overrides; } else null;
+
+  buildGradlePackage = stdenv.mkDerivation (
+    finalAttrs:
+    {
+
+      inherit buildJdk pname version;
+
+      inherit (offlineRepo) gradleInitScript;
+
+      dontStrip = true;
+
+      nativeBuildInputs = (args.nativeBuildInputs or [ ]) ++ [ gradleSetupHook' ];
+
+      gradleFlags =
+        [ "--console=plain" ]
+        ++ lib.optional (finalAttrs.buildJdk != null) "-Dorg.gradle.java.home=${finalAttrs.buildJdk.home}";
+
+      passthru =
+        lib.optionalAttrs (offlineRepo != null) { inherit offlineRepo; } // (args.passthru or { });
+    }
+    // removeAttrs args [
+      "gradle"
+      "gradleInitScript"
+      "lockFile"
+      "fetchers"
+      "nativeBuildInputs"
+      "overlays"
+      "passthru"
+    ]
+  );
+in
+buildGradlePackage

nix/build-maven-repo.nix

@@ -2,16 +2,15 @@
   lib,
   stdenv,
   fetchurl,
+  substitute,
   symlinkJoin,
 }:
 
 {
   # Path to the lockfile generated by gradle2nix (e.g. gradle.lock).
   lockFile,
-  pname ? "project",
-  version ? null,
   # Override functions which fetch dependency artifacts.
-  # Keys in this set are URL schemes such as "https" or "s3".
+  # Names in this set are URL schemes such as "https" or "s3".
   # Values are functions which take a dependency in the form
   # `{ urls, hash }` and fetch into the Nix store. For example:
   #
@@ -28,42 +27,50 @@
   #     };
   #   }
   fetchers ? { },
-  # Overlays for dependencies in the offline Maven repository.
+  # Override artifacts in the offline Maven repository.
   #
-  # Acceps an attrset of dependencies (usually parsed from 'lockFile'), and produces an attrset
+  # This is an attrset is of the form:
-  # containing dependencies to merge into the final set.
-  #
-  # The attrset is of the form:
   #
   #   {
-  #      "${group}:${module}:${version}" = <derivation>;
+  #     "${group}:${module}:${version}" = {
-  #      # ...
+  #       "${filename}" = <override function>;
+  #     }
   #   }
   #
-  # A dependency derivation unpacks multiple source files into a single Maven-style directory named
+  # The override function takes the original derivation from 'fetchers' (e.g. the result of
-  # "${out}/${groupPath}/${module}/${version}/", where 'groupPath' is the dependency group ID with dot
+  # 'fetchurl') and produces a new derivation to replace it.
-  # characters ('.') replaced by the path separator ('/').
   #
   # Examples:
   #
-  # 1. Add or replace a dependency with a single JAR file:
+  # 1. Replace a dependency's JAR artifact:
   #
-  #    (_: {
+  #    {
-  #      "com.squareup.okio:okio:3.9.0" = fetchurl {
+  #      "com.squareup.okio:okio:3.9.0"."okio-3.9.0.jar" = _: fetchurl {
   #        url = "https://repo.maven.apache.org/maven2/com/squareup/okio/okio/3.9.0/okio-3.9.0.jar";
   #        hash = "...";
-  #        downloadToTemmp = true;
+  #        downloadToTemp = true;
   #        postFetch = "install -Dt $out/com/squareup/okio/okio/3.9.0/ $downloadedFile"
   #      };
-  #    })
+  #    }
   #
-  # 2. Remove a dependency entirely:
+  # 2. Patch a JAR containing native binaries:
   #
-  #    # This works because the result is filtered for values that are derivations.
+  #    {
-  #    (_: {
+  #      "com.android.tools.build:aapt2:8.5.0-rc02-11315950" = {
-  #      "org.apache.log4j:core:2.23.1" = null;
+  #        "aapt2-8.5.0-rc02-11315950-linux.jar" = src: runCommandCC src.name {
-  #    })
+  #          nativeBuildInputs = [ jdk autoPatchelfHook ];
-  overlays ? [ ],
+  #          dontAutoPatchelf = true;
+  #        } ''
+  #          cp ${src} aapt2.jar
+  #          jar xf aapt2.jar aapt2
+  #          chmod +x aapt2
+  #          autoPatchelf aapt2
+  #          jar uf aapt2.jar aapt2
+  #          cp aapt2.jar $out
+  #        '';
+  #      }
+  #    }
+  overrides ? { },
 }:
 
 let
@@ -116,25 +123,28 @@ let
   } // fetchers;
 
   fetch =
-    name:
+    coords: overrides: name:
     { url, hash }:
     let
       scheme = head (builtins.match "([a-z0-9+.-]+)://.*" url);
       fetch' = getAttr scheme fetchers';
+      artifact = fetch' { inherit url hash; };
+      override = overrides.name or lib.id;
     in
-    fetch' { inherit url hash; };
+    override artifact;
 
   mkModule =
     id: artifacts:
     let
       coords = toCoordinates id;
       modulePath = "${replaceStrings [ "." ] [ "/" ] coords.group}/${coords.module}/${coords.version}";
+      moduleOverrides = overrides.${id} or { };
     in
     stdenv.mkDerivation {
       pname = sanitizeDerivationName "${coords.group}-${coords.module}";
       version = coords.uniqueVersion;
 
-      srcs = mapAttrsToList fetch artifacts;
+      srcs = mapAttrsToList (fetch coords moduleOverrides) artifacts;
 
       dontPatch = true;
       dontConfigure = true;
@@ -156,34 +166,24 @@ let
       allowSubstitutes = false;
     };
 
-  # Intermediate dependency spec.
+  modulePaths =
-  #
-  # We want to allow overriding dependencies via the 'dependencies' function,
-  # so we pass an intermediate set that maps each Maven coordinate to the
-  # derivation created with 'mkModule'. This allows users extra flexibility
-  # to do things like patching native libraries with patchelf or replacing
-  # artifacts entirely.
-  lockedDependencies =
-    final:
-    if lockFile == null then
-      { }
-    else
     let
-        lockedDependencySpecs = fromJSON (readFile lockFile);
+      dependencies = fromJSON (readFile lockFile);
+      modules = mapAttrs mkModule dependencies;
     in
-      mapAttrs mkModule lockedDependencySpecs;
+    filter lib.isDerivation (attrValues modules);
 
-  finalDependencies =
+  mavenRepo = symlinkJoin {
-    let
+    name = "gradle-maven-repo";
-      composedExtension = lib.composeManyExtensions overlays;
+    paths = modulePaths;
-      extended = lib.extends composedExtension lockedDependencies;
+    passthru.gradleInitScript = substitute {
-      fixed = lib.fix extended;
+      src = ./init.gradle;
-    in
+      substitutions = [
-    filter lib.isDerivation (attrValues fixed);
+        "--replace"
-
+        "@mavenRepo@"
-  offlineRepo = symlinkJoin {
+        "${mavenRepo}"
-    name = if version != null then "${pname}-${version}-gradle-repo" else "${pname}-gradle-repo";
+      ];
-    paths = finalDependencies;
+    };
   };
 in
-offlineRepo
+mavenRepo

nix/init.gradle

@@ -0,0 +1,42 @@
+import org.gradle.util.GradleVersion
+
+static boolean versionAtLeast(String version) {
+    return GradleVersion.current() >= GradleVersion.version(version)
+}
+
+static void configureRepos(RepositoryHandler repositories) {
+    repositories.configureEach { ArtifactRepository repo ->
+        if (repo instanceof MavenArtifactRepository) {
+            repo.setArtifactUrls(new HashSet<URI>())
+            repo.url 'file:@mavenRepo@'
+            repo.metadataSources {
+                gradleMetadata()
+                mavenPom()
+                artifact()
+            }
+        } else if (repo instanceof IvyArtifactRepository) {
+            repo.url 'file:@mavenRepo@'
+            repo.layout('maven')
+            repo.metadataSources {
+                gradleMetadata()
+                ivyDescriptor()
+                artifact()
+            }
+        } else if (repo instanceof UrlArtifactRepository) {
+            repo.url 'file:/homeless-shelter'
+        }
+    }
+}
+
+beforeSettings { settings ->
+    configureRepos(settings.pluginManagement.repositories)
+    configureRepos(settings.buildscript.repositories)
+    if (versionAtLeast("6.8")) {
+        configureRepos(settings.dependencyResolutionManagement.repositories)
+    }
+}
+
+beforeProject { project ->
+    configureRepos(project.buildscript.repositories)
+    configureRepos(project.repositories)
+}

nix/setup-hook.sh

@@ -0,0 +1,125 @@
+# shellcheck shell=bash disable=SC2206,SC2155
+
+gradleConfigurePhase() {
+    runHook preConfigure
+
+    if ! [[ -v enableParallelBuilding ]]; then
+        enableParallelBuilding=1
+        echo "gradle: enabled parallel building"
+    fi
+
+    if ! [[ -v enableParallelChecking ]]; then
+        enableParallelChecking=1
+        echo "gradle: enabled parallel checking"
+    fi
+
+    if ! [[ -v enableParallelInstalling ]]; then
+        enableParallelInstalling=1
+        echo "gradle: enabled parallel installing"
+    fi
+
+    export GRADLE_USER_HOME="$(mktemp -d)"
+
+    if [ -n "$gradleInitScript" ]; then
+        if [ ! -f "$gradleInitScript" ]; then
+            echo "gradleInitScript is not a file path: $gradleInitScript"
+            exit 1
+        fi
+        mkdir -p "$GRADLE_USER_HOME/init.d"
+        ln -s "$gradleInitScript" "$GRADLE_USER_HOME/init.d"
+    fi
+
+    runHook postConfigure
+}
+
+gradleBuildPhase() {
+    runHook preBuild
+
+    if [ -z "${gradleBuildFlags:-}" ] && [ -z "${gradleBuildFlagsArray[*]}" ]; then
+        echo "gradleBuildFlags is not set, doing nothing"
+    else
+        local flagsArray=(
+            $gradleFlags "${gradleFlagsArray[@]}"
+            $gradleBuildFlags "${gradleBuildFlagsArray[@]}"
+        )
+
+        if [ -n "$enableParallelBuilding" ]; then
+            flagsArray+=(--parallel --max-workers ${NIX_BUILD_CORES})
+        else
+            flagsArray+=(--no-parallel)
+        fi
+
+        echoCmd 'gradleBuildPhase flags' "${flagsArray[@]}"
+
+        gradle "${flagsArray[@]}"
+    fi
+
+    runHook postBuild
+}
+
+gradleCheckPhase() {
+    runHook preCheck
+
+    if [ -z "${gradleCheckFlags:-}" ] && [ -z "${gradleCheckFlagsArray[*]}" ]; then
+        echo "gradleCheckFlags is not set, doing nothing"
+    else
+        local flagsArray=(
+            $gradleFlags "${gradleFlagsArray[@]}"
+            $gradleCheckFlags "${gradleCheckFlagsArray[@]}"
+            ${gradleCheckTasks:-check}
+        )
+
+        if [ -n "$enableParallelChecking" ]; then
+            flagsArray+=(--parallel --max-workers ${NIX_BUILD_CORES})
+        else
+            flagsArray+=(--no-parallel)
+        fi
+
+        echoCmd 'gradleCheckPhase flags' "${flagsArray[@]}"
+
+        gradle "${flagsArray[@]}"
+    fi
+
+    runHook postCheck
+}
+
+gradleInstallPhase() {
+    runHook preInstall
+
+    if [ -z "${gradleInstallFlags:-}" ] && [ -z "${gradleInstallFlagsArray[*]}" ]; then
+        echo "gradleInstallFlags is not set, doing nothing"
+    else
+        local flagsArray=(
+            $gradleFlags "${gradleFlagsArray[@]}"
+            $gradleInstallFlags "${gradleInstallFlagsArray[@]}"
+        )
+
+        if [ -n "$enableParallelInstalling" ]; then
+            flagsArray+=(--parallel --max-workers ${NIX_BUILD_CORES})
+        else
+            flagsArray+=(--no-parallel)
+        fi
+
+        echoCmd 'gradleInstallPhase flags' "${flagsArray[@]}"
+
+        gradle "${flagsArray[@]}"
+    fi
+
+    runHook postInstall
+}
+
+if [ -z "${dontUseGradleConfigure-}" ] && [ -z "${configurePhase-}" ]; then
+    configurePhase=gradleConfigurePhase
+fi
+
+if [ -z "${dontUseGradleBuild-}" ] && [ -z "${buildPhase-}" ]; then
+    buildPhase=gradleBuildPhase
+fi
+
+if [ -z "${dontUseGradleCheck-}" ] && [ -z "${checkPhase-}" ]; then
+    checkPhase=gradleCheckPhase
+fi
+
+if [ -z "${dontUseGradleInstall-}" ] && [ -z "${installPhase-}" ]; then
+    installPhase=gradleInstallPhase
+fi

plugin/base/src/main/kotlin/Gradle2NixPlugin.gradle69.kt

@@ -1,7 +1,8 @@
 package org.nixos.gradle2nix
 
-abstract class Gradle2NixPlugin : AbstractGradle2NixPlugin(
+abstract class Gradle2NixPlugin :
+    AbstractGradle2NixPlugin(
         GradleCacheAccessFactoryBase,
         DependencyExtractorApplierBase,
         ResolveAllArtifactsApplierBase,
-)
+    )

plugin/base/src/main/kotlin/GradleCacheAccess.gradle69.kt

@@ -4,12 +4,12 @@ import org.gradle.api.internal.artifacts.ivyservice.ArtifactCachesProvider
 import org.gradle.api.invocation.Gradle
 
 object GradleCacheAccessFactoryBase : GradleCacheAccessFactory {
-    override fun create(gradle: Gradle): GradleCacheAccess {
+    override fun create(gradle: Gradle): GradleCacheAccess = GradleCacheAccessBase(gradle)
-        return GradleCacheAccessBase(gradle)
-    }
 }
 
-class GradleCacheAccessBase(gradle: Gradle) : GradleCacheAccess {
+class GradleCacheAccessBase(
+    gradle: Gradle,
+) : GradleCacheAccess {
     private val artifactCachesProvider = gradle.service<ArtifactCachesProvider>()
 
     override fun useCache(block: () -> Unit) {

plugin/common/src/main/kotlin/DependencyExtractor.kt

@@ -116,22 +116,27 @@ private fun cachedComponentId(file: File): DependencyCoordinates? {
     val parts = file.invariantSeparatorsPath.split('/')
     if (parts.size < 6) return null
     if (parts[parts.size - 6] != "files-2.1") return null
-    return parts.dropLast(2).takeLast(3).joinToString(":").let(DefaultDependencyCoordinates::parse)
+    return parts
+        .dropLast(2)
+        .takeLast(3)
+        .joinToString(":")
+        .let(DefaultDependencyCoordinates::parse)
 }
 
 @OptIn(ExperimentalSerializationApi::class)
 private fun parseFileMappings(file: File): Map<String, String>? =
     try {
-        Json.decodeFromStream<JsonObject>(file.inputStream())
+        Json
-            .jsonObject["variants"]?.jsonArray
+            .decodeFromStream<JsonObject>(file.inputStream())
+            .jsonObject["variants"]
+            ?.jsonArray
             ?.flatMap { it.jsonObject["files"]?.jsonArray ?: emptyList() }
             ?.map { it.jsonObject }
             ?.mapNotNull {
                 val name = it["name"]?.jsonPrimitive?.content ?: return@mapNotNull null
                 val url = it["url"]?.jsonPrimitive?.content ?: return@mapNotNull null
                 if (name != url) name to url else null
-            }
+            }?.toMap()
-            ?.toMap()
             ?.takeUnless { it.isEmpty() }
     } catch (e: Throwable) {
         null

plugin/common/src/main/kotlin/DependencySetModelBuilder.kt

@@ -17,11 +17,10 @@ class DependencySetModelBuilder(
     override fun buildAll(
         modelName: String,
         project: Project,
-    ): DependencySet {
+    ): DependencySet =
-        return dependencyExtractor.buildDependencySet(
+        dependencyExtractor.buildDependencySet(
             cacheAccess,
             checksumService,
             fileStoreAndIndexProvider,
         )
-    }
 }

plugin/common/src/main/kotlin/ResolveAllArtifacts.kt

@@ -38,14 +38,15 @@ abstract class AbstractResolveAllArtifactsApplier : ResolveAllArtifactsApplier {
 
 abstract class ResolveProjectDependenciesTask : DefaultTask() {
     @Internal
-    protected fun getReportableConfigurations(): List<Configuration> {
+    protected fun getReportableConfigurations(): List<Configuration> =
-        return project.configurations.filter { (it as? DeprecatableConfiguration)?.canSafelyBeResolved() ?: true }
+        project.configurations.filter {
+            (it as? DeprecatableConfiguration)?.canSafelyBeResolved() ?: true
         }
 
-    protected fun Configuration.artifactFiles(): FileCollection {
+    protected fun Configuration.artifactFiles(): FileCollection =
-        return incoming.artifactView { viewConfiguration ->
+        incoming
+            .artifactView { viewConfiguration ->
                 viewConfiguration.isLenient = true
                 viewConfiguration.componentFilter { it is ModuleComponentIdentifier }
             }.files
-    }
 }

plugin/gradle8/src/main/kotlin/DependencyExtractor.gradle8.kt

@@ -18,10 +18,12 @@ object DependencyExtractorApplierG8 : DependencyExtractorApplier {
         extractor: DependencyExtractor,
     ) {
         val serviceProvider =
-            gradle.sharedServices.registerIfAbsent(
+            gradle.sharedServices
+                .registerIfAbsent(
                     "nixDependencyExtractor",
                     DependencyExtractorService::class.java,
-            ) {}.map { service ->
+                ) {}
+                .map { service ->
                     service.apply { this.extractor = extractor }
                 }
 
@@ -31,7 +33,9 @@ object DependencyExtractorApplierG8 : DependencyExtractorApplier {
 
 @Suppress("UnstableApiUsage")
 internal abstract class DependencyExtractorService :
-    BuildService<BuildServiceParameters.None>, BuildOperationListener, AutoCloseable {
+    BuildService<BuildServiceParameters.None>,
+    BuildOperationListener,
+    AutoCloseable {
     var extractor: DependencyExtractor? = null
 
     override fun started(

plugin/gradle8/src/main/kotlin/ResolveAllArtifacts.gradle8.kt

@@ -23,13 +23,12 @@ abstract class ResolveProjectDependenciesTaskG8
     ) : ResolveProjectDependenciesTask() {
         private val artifactFiles = Cached.of { artifactFiles() }
 
-        private fun artifactFiles(): FileCollection {
+        private fun artifactFiles(): FileCollection =
-            return objects.fileCollection().from(
+            objects.fileCollection().from(
                 getReportableConfigurations().map { configuration ->
                     configuration.artifactFiles()
                 },
             )
-        }
 
         @TaskAction
         fun action() {

plugin/gradle80/src/main/kotlin/Gradle2NixPlugin.gradle80.kt

@@ -1,7 +1,8 @@
 package org.nixos.gradle2nix
 
-abstract class Gradle2NixPlugin : AbstractGradle2NixPlugin(
+abstract class Gradle2NixPlugin :
+    AbstractGradle2NixPlugin(
         GradleCacheAccessFactoryG80,
         DependencyExtractorApplierG8,
         ResolveAllArtifactsApplierG8,
-)
+    )

plugin/gradle80/src/main/kotlin/GradleCacheAccess.gradle80.kt

@@ -4,12 +4,12 @@ import org.gradle.api.internal.artifacts.ivyservice.ArtifactCachesProvider
 import org.gradle.api.invocation.Gradle
 
 object GradleCacheAccessFactoryG80 : GradleCacheAccessFactory {
-    override fun create(gradle: Gradle): GradleCacheAccess {
+    override fun create(gradle: Gradle): GradleCacheAccess = GradleCacheAccessG80(gradle)
-        return GradleCacheAccessG80(gradle)
-    }
 }
 
-class GradleCacheAccessG80(gradle: Gradle) : GradleCacheAccess {
+class GradleCacheAccessG80(
+    gradle: Gradle,
+) : GradleCacheAccess {
     private val artifactCachesProvider = gradle.service<ArtifactCachesProvider>()
 
     override fun useCache(block: () -> Unit) {

plugin/gradle81/src/main/kotlin/Gradle2NixPlugin.gradle81.kt

@@ -1,7 +1,8 @@
 package org.nixos.gradle2nix
 
-abstract class Gradle2NixPlugin : AbstractGradle2NixPlugin(
+abstract class Gradle2NixPlugin :
+    AbstractGradle2NixPlugin(
         GradleCacheAccessFactoryG81,
         DependencyExtractorApplierG8,
         ResolveAllArtifactsApplierG8,
-)
+    )

plugin/gradle81/src/main/kotlin/GradleCacheAccess.gradle81.kt

@@ -4,12 +4,12 @@ import org.gradle.api.internal.artifacts.ivyservice.ArtifactCachesProvider
 import org.gradle.api.invocation.Gradle
 
 object GradleCacheAccessFactoryG81 : GradleCacheAccessFactory {
-    override fun create(gradle: Gradle): GradleCacheAccess {
+    override fun create(gradle: Gradle): GradleCacheAccess = GradleCacheAccessG81(gradle)
-        return GradleCacheAccessG81(gradle)
-    }
 }
 
-class GradleCacheAccessG81(gradle: Gradle) : GradleCacheAccess {
+class GradleCacheAccessG81(
+    gradle: Gradle,
+) : GradleCacheAccess {
     private val artifactCachesProvider = gradle.service<ArtifactCachesProvider>()
 
     override fun useCache(block: () -> Unit) {