Add matrix testing infrastructure

build.gradle

@@ -16,6 +16,7 @@ allprojects {
 	group = 'org.springframework.restdocs'
 	repositories {
 		mavenCentral()
+		maven { url 'https://repo.spring.io/libs-snapshot' }
 	}
 }
 
@@ -51,6 +52,7 @@ subprojects {
 	apply plugin: 'propdeps-eclipse'
 	apply plugin: 'propdeps-maven'
 	apply plugin: 'maven'
+	apply plugin: 'matrixtest'
 
 	sourceCompatibility = 1.8
 	targetCompatibility = 1.8

buildSrc/src/main/groovy/org/springframework/restdocs/build/matrix/MatrixTestExtension.groovy

@@ -0,0 +1,106 @@
+/*
+ * Copyright 2014-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.restdocs.build.matrix
+
+import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.api.plugins.JavaBasePlugin
+import org.gradle.api.tasks.testing.Test
+
+public class MatrixTestExtension {
+
+	private List<Entry> entries = []
+
+	MatrixTestExtension(Project project) {
+		project.afterEvaluate {
+			configureTestTasks(project)
+		}
+	}
+
+	void methodMissing(String name, args) {
+		Entry entry = new Entry();
+		Closure closure = args[0]
+		closure.delegate = entry
+		closure.resolveStrategy = Closure.DELEGATE_FIRST
+		closure.call()
+		entries << entry
+	}
+
+	void configureTestTasks(Project project) {
+		if (!entries.empty) {
+			cartesianProduct(entries.collect { entry ->
+				entry.versions.collect { ['group': entry.group, 'version': it] }
+			}).forEach { configureTestTask(project, it) }
+		}
+	}
+
+	void configureTestTask(Project project, List<Map<String, String>> versionSelectors) {
+		String identifier = "";
+		versionSelectors.forEach {
+			identifier += "_${it.group}_${it.version}"
+		}
+		String description = "Runs the unit tests using "
+		description += versionSelectors.collect { "${it.group} ${it.version}" }.join(", ")
+		Test matrixTest = project.tasks.create("matrixTest" + identifier, Test) { test ->
+			test.setDescription(description);
+			test.setGroup(JavaBasePlugin.VERIFICATION_GROUP);
+			def testSourceSet = project.sourceSets.test
+			def configuration = project.configurations.create(testSourceSet.runtimeClasspathConfigurationName + identifier) {
+				extendsFrom(project.configurations.getByName(testSourceSet.runtimeClasspathConfigurationName))
+				resolutionStrategy.eachDependency { dependency ->
+					versionSelectors
+							.findAll{ it.group == dependency.requested.group }
+							.each { dependency.useVersion it.version }
+					}
+				}
+			}
+			classpath = project.files(testSourceSet.output, project.sourceSets.main.output, configuration)
+		}
+		project.tasks.getByName('check').dependsOn(matrixTest)
+	}
+
+	List<List<Map<String, String>>> cartesianProduct(List<List<Map<String, String>>> lists) {
+		if (lists.size() == 1) {
+			return lists
+		}
+		return cartesianProduct(lists, 0)
+	}
+
+	List<List<Map<String, String>>> cartesianProduct(List<List<Map<String, String>>> lists, int index) {
+		List<List<Map<String, String>>> result = [];
+		if (index == lists.size()) {
+			result.add([]);
+		} else {
+			lists.get(index).each { list ->
+				cartesianProduct(lists, index + 1).each { product ->
+					product.add(list)
+					result.add(product)
+				}
+			}
+		}
+		return result;
+	}
+
+	class Entry {
+
+		String group
+
+		List<String> versions
+
+	}
+
+}

buildSrc/src/main/groovy/org/springframework/restdocs/build/matrix/MatrixTestPlugin.groovy

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2014-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.restdocs.build.matrix
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+
+public class MatrixTestPlugin implements Plugin<Project> {
+
+	public void apply(Project project) {
+		project.extensions.create('matrixTest', MatrixTestExtension, project)
+	}
+
+}

buildSrc/src/main/groovy/org/springframework/restdocs/build/samples/SampleBuildConfigurer.groovy

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2017 the original author or authors.
+ * Copyright 2014-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.restdocs.build
+package org.springframework.restdocs.build.samples
 
 import org.gradle.api.GradleException
 import org.gradle.api.Project

buildSrc/src/main/groovy/org/springframework/restdocs/build/samples/SamplesExtension.groovy

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2015 the original author or authors.
+ * Copyright 2014-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.restdocs.build
+package org.springframework.restdocs.build.samples
 
 import org.gradle.api.Project
 import org.gradle.api.Task

buildSrc/src/main/groovy/org/springframework/restdocs/build/samples/SamplesPlugin.groovy

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2015 the original author or authors.
+ * Copyright 2014-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.restdocs.build
+package org.springframework.restdocs.build.samples
 
 import org.gradle.api.Plugin
 import org.gradle.api.Project

buildSrc/src/main/resources/META-INF/gradle-plugins/matrixtest.properties

@@ -0,0 +1 @@
+implementation-class: org.springframework.restdocs.build.matrix.MatrixTestPlugin

buildSrc/src/main/resources/META-INF/gradle-plugins/samples.properties

@@ -1 +1 @@
-implementation-class: org.springframework.restdocs.build.SamplesPlugin
+implementation-class: org.springframework.restdocs.build.samples.SamplesPlugin