Tidy up classes

.buildkite/pipeline.extra-steps.gradle

@@ -52,8 +52,6 @@ blockStep(':rocket: Release!') {
     }
 }
 
-triggerStep 'other-pipeline'
-
 triggerStep 'other-pipeline', {
     branches 'master'
     async true

buildSrc/src/main/groovy/com/widen/plugins/buildkite/BuildkiteExtension.groovy

@@ -0,0 +1,63 @@
+package com.widen.plugins.buildkite
+
+import groovy.transform.PackageScope
+import org.gradle.api.Project
+
+class BuildkiteExtension {
+    @PackageScope
+    Project project
+
+    @PackageScope
+    final Map<String, Closure<BuildkitePipeline>> pipelines = [:]
+
+    @PackageScope
+    final Map<String, String> pluginVersions = [
+        docker: 'v3.2.0',
+        'docker-compose': 'v3.0.3',
+    ]
+
+    /**
+     * The default agent queue name to use for steps that do not specify one.
+     */
+    String defaultAgentQueue = 'builder'
+
+    /**
+     * Whether detected pipeline script files should be included automatically.
+     */
+    boolean includeScripts = true
+
+    /**
+     * Set the default agent queue name.
+     */
+    void defaultAgentQueue(String queueName) {
+        defaultAgentQueue = queueName
+    }
+
+    /**
+     * Specify the version of a Buildkite plugin that should be used inside pipelines if no version is specified.
+     */
+    void pluginVersion(String name, String version) {
+        pluginVersions[name] = version
+    }
+
+    /**
+     * Defines the default pipeline.
+     */
+    void pipeline(@DelegatesTo(strategy = Closure.DELEGATE_FIRST, value = BuildkitePipeline) Closure closure) {
+        pipeline('default', closure)
+    }
+
+    /**
+     * Defines a named pipeline.
+     */
+    void pipeline(
+        String name,
+        @DelegatesTo(strategy = Closure.DELEGATE_FIRST, value = BuildkitePipeline) Closure closure
+    ) {
+        pipelines[name] = {
+            def pipeline = new BuildkitePipeline(project, this)
+            pipeline.with(closure)
+            return pipeline
+        }
+    }
+}

buildSrc/src/main/groovy/com/widen/plugins/buildkite/BuildkitePipeline.groovy

@@ -2,17 +2,20 @@ package com.widen.plugins.buildkite
 
 import groovy.json.JsonBuilder
 import groovy.json.JsonOutput
+import org.gradle.api.Project
 
 import java.nio.file.Files
 import java.time.Duration
 
 class BuildkitePipeline implements ConfigurableEnvironment {
-    private final BuildkitePlugin.Config pluginConfig
+    private final Project project
+    private final BuildkiteExtension buildkite
     private final Map<String, String> env = [:]
-    private final List steps = []
+    private final List<Object> steps = []
 
-    BuildkitePipeline(BuildkitePlugin.Config pluginConfig) {
-        this.pluginConfig = pluginConfig
+    BuildkitePipeline(Project project, BuildkiteExtension buildkite) {
+        this.project = project
+        this.buildkite = buildkite
     }
 
     /**
@@ -68,7 +71,7 @@ class BuildkitePipeline implements ConfigurableEnvironment {
     class CommandStep extends Step implements ConfigurableEnvironment {
         // Set defaults.
         {
-            agentQueue pluginConfig.defaultAgentQueue
+            agentQueue buildkite.defaultAgentQueue
         }
 
         /**
@@ -216,8 +219,8 @@ class BuildkitePipeline implements ConfigurableEnvironment {
             }
 
             // If no version is given and a default version is defined, set it.
-            if (!name.contains("#") && pluginConfig.pluginVersions.containsKey(name)) {
-                name += "#${pluginConfig.pluginVersions[name]}"
+            if (!name.contains("#") && buildkite.pluginVersions.containsKey(name)) {
+                name += "#${buildkite.pluginVersions[name]}"
             }
 
             model.get('plugins', []) << [
@@ -321,7 +324,7 @@ class BuildkitePipeline implements ConfigurableEnvironment {
 
             // Pre-populate some config files.
             ['docker-compose.yml', 'docker-compose.buildkite.yml'].each {
-                if (Files.exists(pluginConfig.rootDir.toPath().resolve(it))) {
+                if (Files.exists(project.rootDir.toPath().resolve(it))) {
                     config.composeFile(it)
                 }
             }
@@ -619,7 +622,7 @@ class BuildkitePipeline implements ConfigurableEnvironment {
                 closure = (Closure) closure.clone()
                 closure.delegate = map
                 closure.resolveStrategy = Closure.OWNER_FIRST
-                closure()
+                closure.call()
 
                 model.get('build', [:])
                     .get('meta_data', [:])

buildSrc/src/main/groovy/com/widen/plugins/buildkite/BuildkitePlugin.groovy

@@ -3,19 +3,21 @@ package com.widen.plugins.buildkite
 import org.codehaus.groovy.control.CompilerConfiguration
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.Task
 
 class BuildkitePlugin implements Plugin<Project> {
+    private static final String GROUP = 'Buildkite'
+
     @Override
     void apply(Project project) {
-        def extension = project.extensions.create('buildkite', Extension)
+        def extension = project.extensions.create('buildkite', BuildkiteExtension)
+        extension.project = project
 
-        extension.config = new Config().with {
-            rootDir = project.rootDir
-            it
-        }
+        project.task('pipelines') { Task task ->
+            task.group = GROUP
+            task.description = "List all Buildkite pipelines."
 
-        project.task('pipelines') {
-            doLast {
+            task.doLast {
                 extension.pipelines.each {
                     println it.key
                 }
@@ -25,95 +27,45 @@ class BuildkitePlugin implements Plugin<Project> {
         // Run anything that needs to be done after plugin configuration has been evaluated.
         project.afterEvaluate {
             if (extension.includeScripts) {
-                def shell = new GroovyShell(project.buildscript.classLoader, new Binding(project: project), new
-                    CompilerConfiguration(
-                    scriptBaseClass: PipelineScript.class.name
-                ))
-
-                project.fileTree(project.rootDir) {
+                loadPipelineScripts(project, extension, project.fileTree(project.rootDir) {
                     include '.buildkite/pipeline*.gradle'
-                }.each { file ->
-                    def pipelineName = file.name.find(/pipeline\.([^.]+)\.gradle/) { x, name ->
-                        name.replaceAll(/[^a-zA-Z0-9]+([a-zA-Z0-9]+)/) { y, word ->
-                            word.capitalize()
-                        }
-                    } ?: 'default'
-
-                    def script = (PipelineScript) shell.parse(file)
-
-                    extension.pipeline(pipelineName) { BuildkitePipeline pipeline ->
-                        println(pipeline)
-                        script.setPipeline(pipeline)
-                        script.setBuildkite(extension)
-                        script.setProject(project)
-                        script.run()
-                    }
-                }
+                })
             }
 
             extension.pipelines.each { name, config ->
                 def taskName = name == 'default' ? 'uploadPipeline' : "upload${name.capitalize()}Pipeline"
 
-                project.tasks.create(taskName, UploadPipelineTask) {
-                    pipelineConfigure = config
+                project.tasks.create(taskName, UploadPipelineTask) { task ->
+                    task.group = GROUP
+                    task.description = "Upload the $name pipeline to the current job."
+                    task.pipelineConfig = config
                 }
             }
         }
     }
 
-    static class Config {
-        String defaultAgentQueue = 'builder'
-
-        final Map<String, String> pluginVersions = [
-            docker: 'v3.2.0',
-            'docker-compose': 'v3.0.3',
-        ]
-
-        File rootDir
-    }
-
-    static class Extension {
-        protected final Map<String, Closure<BuildkitePipeline>> pipelines = [:]
-        protected Config config
-
-        /**
-         * Whether detected pipeline script files should be included automatically.
-         */
-        boolean includeScripts = true
-
-        /**
-         * Set the default agent queue name to use for steps that do not specify one.
-         */
-        void defaultAgentQueue(String queueName) {
-            config.defaultAgentQueue = queueName
-        }
-
-        /**
-         * Specify the version of a Buildkite plugin that should be used inside pipelines if no version is specified.
-         */
-        void pluginVersion(String name, String version) {
-            config.pluginVersions[name] = version
-        }
-
-        /**
-         * Defines the default pipeline.
-         */
-        void pipeline(@DelegatesTo(strategy = Closure.DELEGATE_FIRST, value = BuildkitePipeline) Closure closure) {
-            pipeline('default', closure)
+    private static loadPipelineScripts(Project project, BuildkiteExtension extension, Iterable<File> files) {
+        def shell = new GroovyShell(project.buildscript.classLoader, new CompilerConfiguration(
+            scriptBaseClass: PipelineScript.class.name
+        ))
+
+        files.each { file ->
+            extension.pipeline(pipelineNameFromFile(file)) { BuildkitePipeline pipeline ->
+                // Avoid loading the file until the pipeline spec is actually requested.
+                def script = (PipelineScript) shell.parse(file)
+                script.setProject(project)
+                script.setBuildkite(extension)
+                script.setPipeline(pipeline)
+                script.run()
+            }
         }
+    }
 
-        /**
-         * Defines a named pipeline.
-         */
-        void pipeline(
-            String name,
-            @DelegatesTo(strategy = Closure.DELEGATE_FIRST, value = BuildkitePipeline) Closure closure
-        ) {
-            pipelines[name] = {
-                def pipeline = new BuildkitePipeline(config)
-                pipeline.with(closure)
-                return pipeline
+    private static String pipelineNameFromFile(File file) {
+        return file.name.find(/pipeline\.([^.]+)\.gradle/) { x, name ->
+            name.replaceAll(/[^a-zA-Z0-9]+([a-zA-Z0-9]+)/) { y, word ->
+                word.capitalize()
             }
-        }
+        } ?: 'default'
     }
 }

buildSrc/src/main/groovy/com/widen/plugins/buildkite/PipelineScript.groovy

@@ -3,28 +3,30 @@ package com.widen.plugins.buildkite
 import org.gradle.api.Project
 
 /**
- * Base class for scripts
+ * Base class for scripts that define a Buildkite pipeline.
  */
 abstract class PipelineScript extends Script {
-    BuildkitePipeline pipeline
-    BuildkitePlugin.Extension buildkite
     Project project
+    BuildkiteExtension buildkite
+    BuildkitePipeline pipeline
 
     Object getProperty(String property) {
-        if ('buildkite' == property) {
-            return buildkite
+        try {
+            return getMetaClass().getProperty(this, property)
+        } catch (MissingPropertyException e) {
+            return pipeline.getProperty(property)
         }
-        if ('project' == property) {
-            return project
-        }
-        return pipeline.getProperty(property)
     }
 
     void setProperty(String property, Object newValue) {
         pipeline.setProperty(property, newValue)
     }
 
     Object invokeMethod(String name, Object args) {
-        return pipeline.invokeMethod(name, args)
+        try {
+            return getMetaClass().invokeMethod(this, name, args)
+        } catch (MissingMethodException e) {
+            return pipeline.invokeMethod(name, args)
+        }
     }
 }

buildSrc/src/main/groovy/com/widen/plugins/buildkite/UploadPipelineTask.groovy

@@ -1,23 +1,25 @@
 package com.widen.plugins.buildkite
 
 import groovy.json.JsonOutput
+import groovy.transform.PackageScope
 import org.gradle.api.DefaultTask
 import org.gradle.api.tasks.TaskAction
 
 /**
  * A Gradle task that uploads a pipeline during a build.
  */
 class UploadPipelineTask extends DefaultTask {
-    Closure<BuildkitePipeline> pipelineConfigure
+    @PackageScope
+    Closure<BuildkitePipeline> pipelineConfig
 
     /**
      * Upload the pipeline to Buildkite to be executed.
      */
     @TaskAction
     void upload() {
-        def pipeline = pipelineConfigure.call()
+        def pipeline = pipelineConfig.call()
 
-        if (System.env.BUILDKITE || System.env.CI) {
+        if (System.getenv('BUILDKITE') || System.getenv('CI')) {
             def cmd = ['buildkite-agent', 'pipeline', 'upload']
 
             if (!pipeline.interpolate) {
@@ -34,7 +36,7 @@ class UploadPipelineTask extends DefaultTask {
                 it << pipeline.toJson()
             }
             if (process.waitFor() != 0) {
-                throw new RuntimeException()
+                throw new RuntimeException("buildkite-agent returned exit code ${process.exitValue()}")
             }
         } else {
             print(JsonOutput.prettyPrint(pipeline.toJson()))