✅ add support for Windows

.github/workflows/gradle.yml

@@ -15,7 +15,10 @@ jobs:
       - uses: gradle/actions/wrapper-validation@v6
   build:
     name: "Javaagent Gradle Plugin Validation"
-    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.platform }}
     steps:
       - uses: actions/checkout@v7.0.0
       - uses: actions/setup-java@v5.4.0
@@ -29,4 +32,4 @@ jobs:
           cache-read-only: false
 
       - name: Execute Gradle build
-        run: ./gradlew build
+        run: ${{ matrix.platform == 'windows-latest' && '.\gradlew.bat' || './gradlew' }} build

example-projects/buildSrc/build.gradle.kts

@@ -12,6 +12,6 @@ dependencies {
     implementation("com.ryandens:plugin:0.11.0")
     */
     implementation("com.gradleup.shadow:com.gradleup.shadow.gradle.plugin:9.4.3")
-    implementation("io.opentelemetry.instrumentation.muzzle-generation:io.opentelemetry.instrumentation.muzzle-generation.gradle.plugin:2.27.0-alpha")
-    implementation("io.opentelemetry.instrumentation.muzzle-check:io.opentelemetry.instrumentation.muzzle-check.gradle.plugin:2.27.0-alpha")
+    implementation("io.opentelemetry.instrumentation.muzzle-generation:io.opentelemetry.instrumentation.muzzle-generation.gradle.plugin:2.29.0-alpha")
+    implementation("io.opentelemetry.instrumentation.muzzle-check:io.opentelemetry.instrumentation.muzzle-check.gradle.plugin:2.29.0-alpha")
 }

jib/src/functionalTest/kotlin/JavaagentJibExtensionFunctionalTest.kt

@@ -91,14 +91,16 @@ class JavaagentJibExtensionFunctionalTest {
         buildArgs: List<String>,
     ): BuildResult {
         val helloWorldDir = File(functionalTestDir, "hello-world")
-        File("src/functionalTest/resources/hello-world-project/").copyRecursively(helloWorldDir)
+        File(
+            "src${File.separator}functionalTest${File.separator}resources${File.separator}hello-world-project",
+        ).copyRecursively(helloWorldDir)
         val simpleAgentTestDir = File(functionalTestDir, "simple-agent")
         val simpleAgentBuildScript = simpleAgentTestDir.resolve("build.gradle.kts")
-        File("../simple-agent/").copyRecursively(simpleAgentTestDir)
+        File("..${File.separator}simple-agent").copyRecursively(simpleAgentTestDir)
         // remove a constant from the above file
         simpleAgentBuildScript.writeText(
             simpleAgentBuildScript.readText().replace(
-                "id(\"com.ryandens.java-conventions\")\n",
+                "id(\"com.ryandens.java-conventions\")",
                 "",
             ),
         )

plugin/src/functionalTest/kotlin/com/ryandens/javaagent/JavaagentPluginFunctionalTest.kt

@@ -1,10 +1,12 @@
 package com.ryandens.javaagent
 
 import org.gradle.internal.jvm.Jvm
+import org.gradle.internal.os.OperatingSystem
 import org.gradle.testkit.runner.BuildResult
 import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome
 import java.io.File
+import java.nio.file.Paths
 import kotlin.test.AfterTest
 import kotlin.test.BeforeTest
 import kotlin.test.Test
@@ -23,9 +25,13 @@ class JavaagentPluginFunctionalTest {
 
     private lateinit var helloWorldDir: File
 
+    private val isWindows = OperatingSystem.current().isWindows
+
+    private val scriptExtension = if (isWindows) ".bat" else ""
+
     @BeforeTest
     fun beforeEach() {
-        functionalTestDir = File("build/functionalTest")
+        functionalTestDir = File("build", "functionalTest")
         functionalTestDir.mkdirs()
         helloWorldDir = File(functionalTestDir, "hello-world")
     }
@@ -69,7 +75,8 @@ class JavaagentPluginFunctionalTest {
     }
 
     @Test fun `can attach to test task`() {
-        val otelVersion = "1.11.1"
+        // A real third-party javaagent used to verify the plugin attaches it and it logs its version banner.
+        val otelVersion = "2.29.0"
         val dependencies = """
             javaagent project(':simple-agent')
             testJavaagent 'io.opentelemetry.javaagent:opentelemetry-javaagent:$otelVersion'
@@ -92,7 +99,8 @@ class JavaagentPluginFunctionalTest {
     }
 
     @Test fun `can attach two agents to application run task`() {
-        val otelVersion = "1.11.1"
+        // A real third-party javaagent used to verify the plugin attaches it and it logs its version banner.
+        val otelVersion = "2.29.0"
         val dependencies = """
             javaagent project(':simple-agent')
             javaagent 'io.opentelemetry.javaagent:opentelemetry-javaagent:$otelVersion'
@@ -120,27 +128,30 @@ class JavaagentPluginFunctionalTest {
         val result = runBuild(listOf("--configuration-cache", "build", "installDist", "execStartScript"))
 
         // verify the distribution was created properly
-        val applicationDistribution = File(functionalTestDir, "hello-world/build/distributions/hello-world.tar")
+        val applicationDistribution =
+            File(functionalTestDir, "hello-world${File.separator}build${File.separator}distributions${File.separator}hello-world.tar")
         assertTrue(applicationDistribution.exists())
 
         // verify the expected text was injected into the start script
-        val expectedDefaultJavaOpts = """
+        val applicationDistributionScript =
+            File(functionalTestDir, "hello-world${File.separator}build${File.separator}scripts${File.separator}hello-world$scriptExtension")
+        if (isWindows) {
+            val expectedWindowsDefaultJvmOpts = """set DEFAULT_JVM_OPTS="-javaagent:%APP_HOME%\agent-libs\simple-agent.jar" "-Xmx256m""""
+            assertTrue(applicationDistributionScript.readText().contains(expectedWindowsDefaultJvmOpts))
+        } else {
+            val expectedDefaultJavaOpts = """
 DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/agent-libs/simple-agent.jar -Xmx256m"
 """
-        val applicationDistributionScript = File(functionalTestDir, "hello-world/build/scripts/hello-world")
-        assertTrue(applicationDistributionScript.readText().contains(expectedDefaultJavaOpts))
-
-        /*
-         * TODO add support for windows
-         * val expectedWindowsDefaultJvmOpts = """
-DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
-"""
-        val applicationDistributionScript = File(functionalTestDir, "hello-world/build/scripts/hello-world.bat")
-        assertTrue(applicationDistributionScript.readText().contains(expectedWindowsDefaultJvmOpts))
-         */
+            assertTrue(applicationDistributionScript.readText().contains(expectedDefaultJavaOpts))
+        }
 
         // verify the agent was added to the /lib/ dir of the distribution
-        assertTrue(File(functionalTestDir, "hello-world/build/install/hello-world/agent-libs/simple-agent.jar").exists())
+        assertTrue(
+            File(
+                functionalTestDir,
+                "hello-world/build/install/hello-world/agent-libs/simple-agent.jar".replace("/", File.separator),
+            ).exists(),
+        )
 
         // Verify the result
         assertTrue(result.output.contains("Hello World!"))
@@ -154,23 +165,23 @@ DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
     @Test fun `can handle upgrade of agent with build cache`() {
         createJavaagentProject(
             """
-            javaagent 'io.opentelemetry.javaagent:opentelemetry-javaagent:1.30.0'
+            javaagent 'io.opentelemetry.javaagent:opentelemetry-javaagent:2.28.0'
             """.trimIndent(),
         )
 
         val firstBuild = runBuild(listOf("--build-cache", "build", "installDist", "execStartScript"))
 
         assertTrue(
-            firstBuild.output.contains("io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 1.30.0"),
+            firstBuild.output.contains("io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 2.28.0"),
         )
 
         val buildScript = helloWorldDir.resolve("build.gradle")
 
         // replace the agent version with a newer version
-        buildScript.writeText(buildScript.readText().replace("1.30.0", "1.31.0"))
+        buildScript.writeText(buildScript.readText().replace("2.28.0", "2.29.0"))
         val secondBuild = runBuild(listOf("--build-cache", "build", "installDist", "execStartScript"))
         assertTrue(
-            secondBuild.output.contains("io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 1.31.0"),
+            secondBuild.output.contains("io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 2.29.0"),
         )
     }
 
@@ -180,24 +191,36 @@ DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
         val result = runBuild(listOf("build", "installDist", "execStartScript"))
 
         // verify the distribution was created properly
-        val applicationDistribution = File(functionalTestDir, "hello-world/build/distributions/hello-world.tar")
+        val applicationDistribution =
+            File(functionalTestDir, "hello-world${File.separator}build${File.separator}distributions${File.separator}hello-world.tar")
         assertTrue(applicationDistribution.exists())
 
-        val applicationDistributionScript = File(functionalTestDir, "hello-world/build/scripts/hello-world")
-        assertTrue(applicationDistributionScript.readText().contains("""DEFAULT_JVM_OPTS="-Xmx256m"""))
-
-        assertFalse(File(functionalTestDir, "hello-world/build/install/hello-world/agent-libs/").exists())
+        val applicationDistributionScript =
+            File(functionalTestDir, "hello-world${File.separator}build${File.separator}scripts${File.separator}hello-world$scriptExtension")
+        if (isWindows) {
+            assertTrue(applicationDistributionScript.readText().contains("""set DEFAULT_JVM_OPTS="-Xmx256m""""))
+        } else {
+            assertTrue(applicationDistributionScript.readText().contains("""DEFAULT_JVM_OPTS="-Xmx256m"""))
+        }
+
+        assertFalse(
+            File(
+                functionalTestDir,
+                "hello-world${File.separator}build${File.separator}install${File.separator}hello-world${File.separator}agent-libs/",
+            ).exists(),
+        )
         assertTrue(result.output.contains("Hello World!"))
     }
 
     private fun createJavaagentProject(dependencies: String) {
-        File("src/functionalTest/resources/hello-world-project/").copyRecursively(helloWorldDir)
+        val helloWorldDir = File(functionalTestDir, "hello-world")
+        Paths.get("src", "functionalTest", "resources", "hello-world-project").toFile().copyRecursively(helloWorldDir)
         val simpleAgentTestDir = File(functionalTestDir, "simple-agent")
         val simpleAgentBuildScript = simpleAgentTestDir.resolve("build.gradle.kts")
-        File("../simple-agent/").copyRecursively(simpleAgentTestDir)
+        Paths.get("..", "simple-agent").toFile().copyRecursively(simpleAgentTestDir)
         simpleAgentBuildScript.writeText(
             simpleAgentBuildScript.readText().replace(
-                "id(\"com.ryandens.java-conventions\")\n",
+                "id(\"com.ryandens.java-conventions\")",
                 "",
             ),
         )
@@ -210,6 +233,23 @@ DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
             """,
         )
 
+        // On Windows a `.bat` file is not a directly executable image, so it cannot be launched via
+        // ProcessBuilder/CreateProcess (which is what Gradle's Exec task uses). It must be run through the
+        // command interpreter instead, e.g. `cmd /c hello-world.bat`.
+        val execCommandLine =
+            if (isWindows) {
+                "'cmd', '/c', 'hello-world.bat'"
+            } else {
+                "'./hello-world'"
+            }
+        // Escape backslashes and quotes so a Windows JAVA_HOME embeds cleanly in the generated Groovy string literal.
+        val javaHome =
+            Jvm
+                .current()
+                .getJavaHome()
+                .toString()
+                .replace("\\", "\\\\")
+                .replace("\"", "\\\"")
         helloWorldDir.resolve("build.gradle").writeText(
             """
                 plugins {
@@ -232,12 +272,11 @@ DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
                 }
 
                 task execStartScript(type: Exec) {
-                    inputs.files(fileTree('${helloWorldDir.canonicalPath}/build/install/') {
-                        builtBy tasks.named('installDist')
-                    })
-                    workingDir '${helloWorldDir.canonicalPath}/build/install/hello-world/bin/'
-                    commandLine './hello-world'
-                    environment JAVA_HOME: "${Jvm.current().getJavaHome()}"
+                    dependsOn('installDist')
+                    inputs.files(layout.buildDirectory.dir('install'))
+                    workingDir(layout.buildDirectory.dir('install').map { it.dir('hello-world').dir('bin') })
+                    commandLine $execCommandLine
+                    environment JAVA_HOME: "$javaHome"
                 }
 
                 test {
@@ -262,6 +301,20 @@ DEFAULT_JVM_OPTS="-javaagent:${"$"}APP_HOME/lib/simple-agent.jar -Xmx256m"
         runner.withPluginClasspath()
         runner.withArguments(buildArgs)
         runner.withProjectDir(functionalTestDir)
+        if (isWindows) {
+            // Keep the TestKit Gradle home short. Its default lives under the deeply nested
+            // build/tmp/functionalTest/work/.gradle-test-kit, which pushes cached agent jars -- e.g. the
+            // OpenTelemetry javaagent at caches/modules-2/files-2.1/.../<sha1>/opentelemetry-javaagent-<ver>.jar
+            // -- past Windows' 260-character MAX_PATH. The JVM's native appendToBootstrapClassLoaderSearch
+            // then rejects the path with IllegalArgumentException and the agent fails to install. Rooting the
+            // TestKit home at the drive root keeps the full agent jar path comfortably within the limit.
+            val driveRoot =
+                functionalTestDir.absoluteFile
+                    .toPath()
+                    .root
+                    .toFile()
+            runner.withTestKitDir(File(driveRoot, "gtk"))
+        }
         return runner.build()
     }
 }

plugin/src/main/kotlin/com/ryandens/javaagent/JavaagentApplicationDistributionPlugin.kt

@@ -6,9 +6,10 @@ import org.gradle.api.Project
 import org.gradle.api.artifacts.Configuration
 import org.gradle.api.distribution.DistributionContainer
 import org.gradle.api.distribution.plugins.DistributionPlugin
-import org.gradle.api.internal.plugins.WindowsStartScriptGenerator
 import org.gradle.api.plugins.ApplicationPlugin
+import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.application.CreateStartScripts
+import java.io.File
 
 /**
  * Gradle plugin for configuration of the [DistributionPlugin.MAIN_DISTRIBUTION_NAME] after it has been configured by
@@ -52,14 +53,9 @@ class JavaagentApplicationDistributionPlugin :
                     .plus(it.defaultJvmOpts ?: listOf())
             it.inputs.files(javaagentConfiguration)
             // custom start script generator that replaces the placeholder
-            it.unixStartScriptGenerator =
-                JavaagentAwareStartScriptGenerator(
-                    javaagentConfiguration.map { configuration ->
-                        configuration.files
-                    },
-                )
-            // TODO build support for windows
-            it.windowsStartScriptGenerator = WindowsStartScriptGenerator()
+            val agentFiles: Provider<Set<File>> = javaagentConfiguration.map { configuration -> configuration.files }
+            it.unixStartScriptGenerator = JavaagentAwareStartScriptGenerator(agentFiles, Platform.UNIX)
+            it.windowsStartScriptGenerator = JavaagentAwareStartScriptGenerator(agentFiles, Platform.WINDOWS)
         }
     }
 }