Refactor and improve tests (#466)

* Install and run a production server in tests

* Small improvements

* Add FabricAPI build test
Create new GradleProjectTestTrait replacing the old trait
Improve groovy code formatting.

* Refactor tests

* Fix MultiProjectTest + fix logging for fabric api test

* Cleanup and fixes

* Update fabric api + run in parallel for speed

* Set server memory + fix error

build.gradle

@@ -104,6 +104,7 @@ dependencies {
 		exclude module: 'groovy-all'
 	}
 	testImplementation 'io.javalin:javalin:3.13.9'
+	testImplementation 'net.fabricmc:fabric-installer:0.7.4'
 
 	compileOnly 'org.jetbrains:annotations:21.0.1'
 }

codenarc.groovy

@@ -24,7 +24,7 @@ ruleset {
     SpaceAfterSwitch
     SpaceAfterWhile
     SpaceAroundClosureArrow
-    SpaceAroundMapEntryColon
+    SpaceAroundMapEntryColon(characterAfterColonRegex: /\ /)
     SpaceAroundOperator
     SpaceBeforeClosingBrace
     SpaceBeforeOpeningBrace
@@ -61,6 +61,13 @@ ruleset {
     FieldTypeRequired
     MethodParameterTypeRequired
 
+    // Imports
+    UnusedImport
+    UnnecessaryGroovyImport
+    NoWildcardImports(ignoreStaticImports: true)
+    ImportFromSamePackage
+    DuplicateImport
+
     //Misc
     LongLiteralWithLowerCaseL
 }

src/main/java/net/fabricmc/loom/build/MixinRefmapHelper.java

@@ -29,6 +29,7 @@ import java.io.IOException;
 import java.io.InputStreamReader;
 import java.nio.file.Path;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Objects;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -36,6 +37,7 @@ import java.util.stream.StreamSupport;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
+import com.google.gson.JsonArray;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonPrimitive;
 import org.gradle.api.Project;
@@ -108,7 +110,13 @@ public final class MixinRefmapHelper {
 
 	@NotNull
 	private static Collection<String> getMixinConfigurationFiles(JsonObject fabricModJson) {
-		return StreamSupport.stream(fabricModJson.getAsJsonArray("mixins").spliterator(), false)
+		JsonArray mixins = fabricModJson.getAsJsonArray("mixins");
+
+		if (mixins == null) {
+			return Collections.emptyList();
+		}
+
+		return StreamSupport.stream(mixins.spliterator(), false)
 				.map(e -> {
 					if (e instanceof JsonPrimitive str) {
 						return str.getAsString();

src/main/java/net/fabricmc/loom/configuration/processors/MinecraftProcessedProvider.java

@@ -54,7 +54,7 @@ public class MinecraftProcessedProvider extends MinecraftMappedProvider {
 	protected void addDependencies(DependencyInfo dependency, Consumer<Runnable> postPopulationScheduler) {
 		if (jarProcessorManager.isInvalid(projectMappedJar) || isRefreshDeps()) {
 			getProject().getLogger().info(":processing mapped jar");
-			invalidateJars();
+			invalidateJar();
 
 			try {
 				FileUtils.copyFile(super.getMappedJar(), projectMappedJar);
@@ -69,16 +69,14 @@ public class MinecraftProcessedProvider extends MinecraftMappedProvider {
 				getProject().getDependencies().module("net.minecraft:minecraft-" + projectMappedClassifier + ":" + getMinecraftProvider().minecraftVersion() + "/" + getExtension().getMappingsProvider().mappingsIdentifier()));
 	}
 
-	private void invalidateJars() {
+	private void invalidateJar() {
-		File dir = projectMappedJar.getParentFile();
+		if (projectMappedJar.exists()) {
-
+			getProject().getLogger().warn("Invalidating project jar");
-		if (dir.exists()) {
-			getProject().getLogger().warn("Invalidating project jars");
 
 			try {
-				FileUtils.cleanDirectory(dir);
+				FileUtils.forceDelete(projectMappedJar);
 			} catch (IOException e) {
-				throw new RuntimeException("Failed to invalidate jars, try stopping gradle daemon or closing the game", e);
+				throw new RuntimeException("Failed to invalidate jar, try stopping gradle daemon or closing the game", e);
 			}
 		}
 	}

src/test/groovy/net/fabricmc/loom/test/LoomTestConstants.groovy

@@ -1,7 +1,7 @@
 /*
  * This file is part of fabric-loom, licensed under the MIT License (MIT).
  *
- * Copyright (c) 2016-2021 FabricMC
+ * Copyright (c) 2021 FabricMC
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -22,25 +22,11 @@
  * SOFTWARE.
  */
 
-package net.fabricmc.loom.test.util
+package net.fabricmc.loom.test
 
-import org.zeroturnaround.zip.ZipUtil
+class LoomTestConstants {
+    public final static String DEFAULT_GRADLE = "7.0.1"
+    public final static String PRE_RELEASE_GRADLE = "7.3-20210827230026+0000"
 
-trait ArchiveAssertionsTrait {
+    public final static String[] STANDARD_TEST_VERSIONS = [DEFAULT_GRADLE, PRE_RELEASE_GRADLE]
-	String getArchiveEntry(String name, String entry, String project = "") {
-		def file = getOutputFile(name, project)
-
-		def bytes = ZipUtil.unpackEntry(file, entry)
-
-		if (bytes == null) {
-			throw new FileNotFoundException("Could not find ${entry} in ${name}")
-		}
-
-		new String(bytes as byte[])
-	}
-
-	boolean hasArchiveEntry(String name, String entry, String project = "") {
-		def file = getOutputFile(name, project)
-		ZipUtil.unpackEntry(file, entry) != null
-	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/AccessWidenerTest.groovy

@@ -24,30 +24,25 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ArchiveAssertionsTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
-import net.fabricmc.loom.test.util.ProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class AccessWidenerTest extends Specification implements ProjectTestTrait, ArchiveAssertionsTrait {
+class AccessWidenerTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"accesswidener"
-	}
-
 	@Unroll
-	def "accesswidener (gradle #gradle)"() {
+	def "accesswidener (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "accesswidener", version: version)
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
 		then:
 			result.task(":build").outcome == SUCCESS
-			getArchiveEntry("fabric-example-mod-1.0.0.jar", "modid.accesswidener") == expected().replaceAll('\r', '')
+			gradle.getOutputZipEntry("fabric-example-mod-1.0.0.jar", "modid.accesswidener") == expected().replaceAll('\r', '')
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 
 	String expected() {

src/test/groovy/net/fabricmc/loom/test/integration/CustomManifestTest.groovy

@@ -24,21 +24,19 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class CustomManifestTest extends Specification implements ProjectTestTrait {
+class CustomManifestTest extends Specification implements GradleProjectTestTrait {
-    @Override
+    @Unroll
-    String name() {
+    def "customManifest (gradle #version)"() {
-        "minimalBase"
+        setup:
-    }
+            def gradle = gradleProject(project: "minimalBase", version: version)
-
+            gradle.buildGradle << '''
-    @Override
-    def filesReady() {
-        buildGradle() << '''
                 loom {
                     customMinecraftManifest = "https://maven.fabricmc.net/net/minecraft/1_18_experimental-snapshot-1.json"
                 }
@@ -49,17 +47,13 @@ class CustomManifestTest extends Specification implements ProjectTestTrait {
                     modImplementation "net.fabricmc:fabric-loader:0.11.6"
                 }
             '''
-    }
-
-    @Unroll
-    def "customManifest (gradle #gradle)"() {
         when:
-            def result = create("build", gradle)
+            def result = gradle.run(task: "build")
+
         then:
             result.task(":build").outcome == SUCCESS
+
         where:
-            gradle              | _
+            version << STANDARD_TEST_VERSIONS
-            DEFAULT_GRADLE      | _
-            PRE_RELEASE_GRADLE  | _
     }
 }

src/test/groovy/net/fabricmc/loom/test/integration/DecompileTest.groovy

@@ -24,28 +24,27 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class DecompileTest extends Specification implements ProjectTestTrait {
+class DecompileTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"decompile"
-	}
-
 	@Unroll
-	def "#decompiler gradle #gradle"() {
+	def "#decompiler gradle #version"() {
+		setup:
+			def gradle = gradleProject(project: "decompile", version: version)
+
 		when:
-			def result = create(task, gradle)
+			def result = gradle.run(task: task)
 
 		then:
 			result.task(":${task}").outcome == SUCCESS
 
 		where:
-			decompiler 		| task								| gradle
+			decompiler 		| task								| version
 			'fernflower'	| "genSources"						| DEFAULT_GRADLE
 			'fernflower'	| "genSources"						| PRE_RELEASE_GRADLE
 			'cfr' 			| "genSourcesWithExperimentalCfr"	| DEFAULT_GRADLE

src/test/groovy/net/fabricmc/loom/test/integration/DependencyResolutionManagementTest.groovy

@@ -24,29 +24,27 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class DependencyResolutionManagementTest extends Specification implements ProjectTestTrait {
+class DependencyResolutionManagementTest extends Specification implements GradleProjectTestTrait {
-    @Override
-    String name() {
-        "dependencyResolutionManagement"
-    }
-
     @Unroll
-    def "build (gradle #gradle)"() {
+    def "build (gradle #version)"() {
+        setup:
+            def gradle = gradleProject(project: "dependencyResolutionManagement", version: version)
+
         when:
-            def result = create("build", gradle)
+            def result = gradle.run(task: "build")
+
         then:
             result.task(":basic:build").outcome == SUCCESS
             result.task(":projmap:build").outcome == SUCCESS
 
         where:
-        gradle              | _
+            version << STANDARD_TEST_VERSIONS
-        DEFAULT_GRADLE      | _
-        PRE_RELEASE_GRADLE  | _
     }
 }

src/test/groovy/net/fabricmc/loom/test/integration/ExperimentalVersionsTest.groovy

@@ -24,38 +24,34 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class ExperimentalVersionsTest extends Specification implements ProjectTestTrait {
+class ExperimentalVersionsTest extends Specification implements GradleProjectTestTrait {
-    @Override
+    @Unroll
-    String name() {
+    def "experimental versions (gradle #version)"() {
-        "minimalBase"
+        setup:
-    }
+            def gradle = gradleProject(project: "minimalBase", version: version)
 
-    @Override
+            gradle.buildGradle << '''
-    def filesReady() {
-        buildGradle() << '''
                 dependencies {
                     minecraft "com.mojang:minecraft:1.18_experimental-snapshot-1"
                     mappings "net.fabricmc:yarn:1.18_experimental-snapshot-1+build.2:v2"
                     modImplementation "net.fabricmc:fabric-loader:0.11.6"
                 }
             '''
-    }
 
-    @Unroll
-    def "experimental versions (gradle #gradle)"() {
         when:
-            def result = create("build", gradle)
+            def result = gradle.run(task: "build")
+
         then:
             result.task(":build").outcome == SUCCESS
+
         where:
-            gradle              | _
+            version << STANDARD_TEST_VERSIONS
-            DEFAULT_GRADLE      | _
-            PRE_RELEASE_GRADLE  | _
     }
 }

src/test/groovy/net/fabricmc/loom/test/integration/FabricAPITest.groovy

@@ -0,0 +1,69 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2021 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.test.integration
+
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
+import net.fabricmc.loom.test.util.ServerRunner
+import spock.lang.Specification
+import spock.lang.Timeout
+import spock.lang.Unroll
+
+import java.util.concurrent.TimeUnit
+
+import static net.fabricmc.loom.test.LoomTestConstants.*
+import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+
+@Timeout(value = 30, unit = TimeUnit.MINUTES)
+class FabricAPITest extends Specification implements GradleProjectTestTrait {
+	private static final String API_VERSION = "0.0.0+loom"
+
+	@Unroll
+	def "build and run (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(
+					repo: "https://github.com/modmuss50/fabric.git",
+					commit: "cb31cccd34cb91f70cae6bac80208f5ec3650f33",
+					version: version
+			)
+
+			// Set the version to something constant
+			gradle.buildGradle.text = gradle.buildGradle.text.replace('Globals.baseVersion + "+" + (ENV.GITHUB_RUN_NUMBER ? "" : "local-") + getBranch()', "\"$API_VERSION\"")
+
+			def server = ServerRunner.create(gradle.projectDir, "1.17.1")
+										.withMod(gradle.getOutputFile("fabric-api-${API_VERSION}.jar"))
+		when:
+			def result = gradle.run(tasks: ["build", "publishToMavenLocal"], args: ["--parallel", "-x", "check"]) // Note: checkstyle does not appear to like being ran in a test runner
+			gradle.printOutputFiles()
+
+			def serverResult = server.run()
+		then:
+			result.task(":build").outcome == SUCCESS
+
+			serverResult.successful()
+			serverResult.output.contains("fabric@$API_VERSION")
+		where:
+			version << STANDARD_TEST_VERSIONS
+	}
+}

src/test/groovy/net/fabricmc/loom/test/integration/Java16ProjectTest.groovy

@@ -24,27 +24,26 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class Java16ProjectTest extends Specification implements ProjectTestTrait {
+class Java16ProjectTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"java16"
-	}
-
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "java16", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/KotlinTest.groovy

@@ -24,28 +24,26 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
-import spock.lang.IgnoreIf
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class KotlinTest extends Specification implements ProjectTestTrait {
+class KotlinTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"kotlin"
-	}
-
 	@Unroll
-	def "kotlin build (gradle #gradle)"() {
+	def "kotlin build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "kotlin", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/LegacyProjectTest.groovy

@@ -24,24 +24,27 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
 // This test uses gradle 4.9 and 1.14.4 v1 mappings
-class LegacyProjectTest extends Specification implements ProjectTestTrait {
+class LegacyProjectTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"legacy"
-	}
-
 	@Unroll
-	def "build"() {
+	def "legacy build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "legacy", version: version)
+
 		when:
-			def result = create("build", DEFAULT_GRADLE)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
+		where:
+			version << STANDARD_TEST_VERSIONS
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/LocalFileDependencyTest.groovy

@@ -24,27 +24,26 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class LocalFileDependencyTest extends Specification implements ProjectTestTrait {
+class LocalFileDependencyTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"localFileDependency"
-	}
-
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "localFileDependency", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/MavenProjectTest.groovy

@@ -24,13 +24,14 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ArchiveAssertionsTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import net.fabricmc.loom.test.util.MockMavenServerTrait
 import spock.lang.Specification
 import spock.lang.Stepwise
 import spock.lang.Unroll
 import spock.util.environment.RestoreSystemProperties
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static java.lang.System.setProperty
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
@@ -38,20 +39,23 @@ import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
  * This tests publishing a range of versions and then tries to resolve and build against them
  */
 @Stepwise
-class MavenProjectTest extends Specification implements MockMavenServerTrait, ArchiveAssertionsTrait {
+class MavenProjectTest extends Specification implements MockMavenServerTrait, GradleProjectTestTrait {
 	@RestoreSystemProperties
 	@Unroll
-	def "publish lib #version #gradle"() {
+	def "publish lib #version #gradleVersion"() {
-		given:
+		setup:
 			setProperty('loom.test.version', version)
-			library = true
+			def gradle = gradleProject(project: "mavenLibrary", version: gradleVersion, sharedFiles: true)
+
 		when:
-			def result = create("publish", gradle)
+			def result = gradle.run(tasks: ["clean", "publish"])
+
 		then:
 			result.task(":publish").outcome == SUCCESS
-			hasArchiveEntry("fabric-example-lib-${version}.jar", "net/fabricmc/example/ExampleLib.class")
+			gradle.hasOutputZipEntry("fabric-example-lib-${version}.jar", "net/fabricmc/example/ExampleLib.class")
+
 		where:
-			version           | gradle
+			version           | gradleVersion
 			'1.0.0'           | DEFAULT_GRADLE
 			'1.0.0'           | PRE_RELEASE_GRADLE
 			'1.1.0'           | DEFAULT_GRADLE
@@ -64,17 +68,20 @@ class MavenProjectTest extends Specification implements MockMavenServerTrait, Ar
 
 	@RestoreSystemProperties
 	@Unroll
-	def "resolve #version #gradle"() {
+	def "resolve #version #gradleVersion"() {
 		given:
 			setProperty('loom.test.resolve', "com.example:fabric-example-lib:${version}")
-			library = false
+			def gradle = gradleProject(project: "maven", version: gradleVersion, sharedFiles: true)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(tasks: ["clean", "build"])
+
 		then:
 			result.task(":build").outcome == SUCCESS
-			hasArchiveEntry("fabric-example-mod-1.0.0.jar", "net/fabricmc/examplemod/ExampleMod.class")
+			gradle.hasOutputZipEntry("fabric-example-mod-1.0.0.jar", "net/fabricmc/examplemod/ExampleMod.class")
+
 		where:
-			version                      | gradle
+			version                      | gradleVersion
 			'1.0.0'                      | DEFAULT_GRADLE
 			'1.0.0'                      | PRE_RELEASE_GRADLE
 			'1.1.+'                      | DEFAULT_GRADLE
@@ -87,12 +94,4 @@ class MavenProjectTest extends Specification implements MockMavenServerTrait, Ar
 			'2.0.0-SNAPSHOT:classifier'  | DEFAULT_GRADLE
 			'master-SNAPSHOT:classifier' | DEFAULT_GRADLE
 	}
-
-	// Set to true when to build and publish the mavenLibrary
-	private boolean library = false
-
-	@Override
-	String name() {
-		library ? "mavenLibrary" : "maven"
-	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/MixinApAutoRefmapTest.groovy

@@ -24,30 +24,29 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 import com.google.gson.JsonParser;
 import java.util.jar.JarFile
 
+import static net.fabricmc.loom.test.LoomTestConstants.STANDARD_TEST_VERSIONS
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class MixinApAutoRefmapTest extends Specification implements ProjectTestTrait {
+class MixinApAutoRefmapTest extends Specification implements GradleProjectTestTrait {
-    @Override
-    String name() {
-        "mixinApAutoRefmap"
-    }
-
     @Unroll
-    def "build (gradle #gradle)"() {
+    def "build (gradle #version)"() {
+        setup:
+            def gradle = gradleProject(project: "mixinApAutoRefmap", version: version)
+
         when:
-        def result = create("build", gradle)
+            def result = gradle.run(task: "build")
 
         then:
             result.task(":build").outcome == SUCCESS
 
             // verify the ref-map name is correctly generated
-        def jar = new JarFile(getOutputFile("fabric-example-mod-1.0.0-universal.jar").absoluteFile)
+            def jar = new JarFile(gradle.getOutputFile("fabric-example-mod-1.0.0-universal.jar").absoluteFile)
             jar.getEntry("refmap0000.json") == null
             jar.getEntry("refmap0001.json") != null
             jar.getEntry("refmap0002.json") != null
@@ -69,8 +68,6 @@ class MixinApAutoRefmapTest extends Specification implements ProjectTestTrait {
             !j5.asJsonObject.has("refmap")
 
         where:
-        gradle              | _
+            version << STANDARD_TEST_VERSIONS
-        DEFAULT_GRADLE      | _
-        PRE_RELEASE_GRADLE  | _
     }
 }

src/test/groovy/net/fabricmc/loom/test/integration/MixinApSimpleTest.groovy

@@ -24,40 +24,38 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
+
 import spock.lang.Specification
 import spock.lang.Unroll
 
 import java.util.jar.JarFile
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class MixinApSimpleTest extends Specification implements ProjectTestTrait {
+class MixinApSimpleTest extends Specification implements GradleProjectTestTrait {
-    @Override
-    String name() {
-        "mixinApSimple"
-    }
-
     @Unroll
-    def "build (gradle #gradle)"() {
+    def "build (gradle #version)"() {
+        setup:
+            def gradle = gradleProject(project: "mixinApSimple", version: version)
+
         when:
-        def result = create("build", gradle)
+            def result = gradle.run(task: "build")
 
         then:
             result.task(":build").outcome == SUCCESS
 
             // verify the ref-map name is correctly generated
-        def main = new JarFile(getOutputFile("fabric-example-mod-1.0.0-dev.jar").absoluteFile)
+            def main = new JarFile(gradle.getOutputFile("fabric-example-mod-1.0.0-dev.jar").absoluteFile)
             main.getEntry("main-refmap0000.json") != null
-        def mixin = new JarFile(getOutputFile("fabric-example-mod-1.0.0-mixin.jar").absoluteFile)
+            def mixin = new JarFile(gradle.getOutputFile("fabric-example-mod-1.0.0-mixin.jar").absoluteFile)
             mixin.getEntry("default-refmap0000.json") != null
-        def mixin1 = new JarFile(getOutputFile("fabric-example-mod-1.0.0-mixin1.jar").absoluteFile)
+            def mixin1 = new JarFile(gradle.getOutputFile("fabric-example-mod-1.0.0-mixin1.jar").absoluteFile)
             mixin1.getEntry("main-refmap0000.json") == null
             mixin1.getEntry("default-refmap0000.json") == null
 
         where:
-        gradle              | _
+            version << STANDARD_TEST_VERSIONS
-        DEFAULT_GRADLE      | _
-        PRE_RELEASE_GRADLE  | _
     }
 }

src/test/groovy/net/fabricmc/loom/test/integration/MojangMappingsProjectTest.groovy

@@ -24,27 +24,26 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class MojangMappingsProjectTest extends Specification implements ProjectTestTrait {
+class MojangMappingsProjectTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"mojangMappings"
-	}
-
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "mojangMappings", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/MultiProjectTest.groovy

@@ -24,23 +24,22 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ArchiveAssertionsTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
-import net.fabricmc.loom.test.util.ProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.STANDARD_TEST_VERSIONS
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class MultiProjectTest extends Specification implements ProjectTestTrait, ArchiveAssertionsTrait {
+class MultiProjectTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"multiproject"
-	}
-
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "multiproject", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
 			result.task(":core:build").outcome == SUCCESS
@@ -49,13 +48,11 @@ class MultiProjectTest extends Specification implements ProjectTestTrait, Archiv
 			result.task(":remapAllJars").outcome == SUCCESS
 			result.task(":remapAllSources").outcome == SUCCESS
 
-			hasArchiveEntry("multiproject-1.0.0.jar", "META-INF/jars/example-1.0.0.jar")
+			gradle.hasOutputZipEntry("multiproject-1.0.0.jar", "META-INF/jars/example-1.0.0.jar")
-			hasArchiveEntry("multiproject-1.0.0.jar", "META-INF/jars/core-1.0.0.jar")
+			gradle.hasOutputZipEntry("multiproject-1.0.0.jar", "META-INF/jars/core-1.0.0.jar")
-			hasArchiveEntry("multiproject-1.0.0.jar", "META-INF/jars/fabric-api-base-0.2.1+9354966b7d.jar")
+			gradle.hasOutputZipEntry("multiproject-1.0.0.jar", "META-INF/jars/fabric-api-base-0.2.1+9354966b7d.jar")
 
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/ParchmentTest.groovy

@@ -24,29 +24,26 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
+import static net.fabricmc.loom.test.LoomTestConstants.STANDARD_TEST_VERSIONS
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class ParchmentTest extends Specification implements ProjectTestTrait {
+class ParchmentTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"parchment"
-	}
-
 	@Unroll
-	def "parchment #gradle"() {
+	def "parchment #version"() {
+		setup:
+			def gradle = gradleProject(project: "parchment", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
 
 		then:
 			result.task(":build").outcome == SUCCESS
 
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 }

src/test/groovy/net/fabricmc/loom/test/integration/ReproducibleBuildTest.groovy

@@ -27,40 +27,37 @@ package net.fabricmc.loom.test.integration
 import com.google.common.hash.HashCode
 import com.google.common.hash.Hashing
 import com.google.common.io.Files
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 import spock.util.environment.RestoreSystemProperties
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static java.lang.System.setProperty
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class ReproducibleBuildTest extends Specification implements ProjectTestTrait {
+class ReproducibleBuildTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"reproducible"
-	}
-
 	@RestoreSystemProperties
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "reproducible", version: version)
+
 		when:
 			setProperty('loom.test.reproducible', 'true')
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
-			getOutputHash("fabric-example-mod-1.0.0.jar") == modHash
+			generateMD5(gradle.getOutputFile("fabric-example-mod-1.0.0.jar")) == modHash
-			getOutputHash("fabric-example-mod-1.0.0-sources.jar") in sourceHash // Done for different line endings.
+			generateMD5(gradle.getOutputFile("fabric-example-mod-1.0.0-sources.jar")) in sourceHash // Done for different line endings.
+
 		where:
-			gradle              | modHash                               | sourceHash
+			version              | modHash                               | sourceHash
 			DEFAULT_GRADLE      | "ed3306ef60f434c55048cba8de5dab95"    | ["be31766e6cafbe4ae3bca9e35ba63169", "7348b0bd87d36d7ec6f3bca9c2b66062"]
 			PRE_RELEASE_GRADLE  | "ed3306ef60f434c55048cba8de5dab95"    | ["be31766e6cafbe4ae3bca9e35ba63169", "7348b0bd87d36d7ec6f3bca9c2b66062"]
 	}
 
-	String getOutputHash(String name) {
-		generateMD5(getOutputFile(name))
-	}
-
 	String generateMD5(File file) {
 		HashCode hash = Files.asByteSource(file).hash(Hashing.md5())
 		return hash.asBytes().encodeHex() as String

src/test/groovy/net/fabricmc/loom/test/integration/RunConfigTest.groovy

@@ -24,25 +24,25 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
 import spock.lang.Specification
 import spock.lang.Unroll
 
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
 // This test runs a mod that exits on mod init
-class RunConfigTest extends Specification implements ProjectTestTrait {
+class RunConfigTest extends Specification implements GradleProjectTestTrait {
-	@Override
-	String name() {
-		"runconfigs"
-	}
-
 	@Unroll
-	def "#task"() {
+	def "Run config #task"() {
+		setup:
+			def gradle = gradleProject(project: "runconfigs", sharedFiles: true)
+
 		when:
-			def result = create(task)
+			def result = gradle.run(task: task)
+
 		then:
 			result.task(":${task}").outcome == SUCCESS
+
 		where:
 			task                | _
 			'runClient'         | _

src/test/groovy/net/fabricmc/loom/test/integration/SignedProjectTest.groovy

@@ -24,14 +24,14 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ArchiveAssertionsTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
-
 import net.fabricmc.loom.test.util.MockMavenServerTrait
 import spock.lang.Specification
 import spock.lang.Stepwise
 import spock.lang.Unroll
 import spock.util.environment.RestoreSystemProperties
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static java.lang.System.setProperty
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
@@ -39,25 +39,22 @@ import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
  * This tests publishing signed artifacts to a maven server
  */
 @Stepwise
-class SignedProjectTest extends Specification implements MockMavenServerTrait, ArchiveAssertionsTrait {
+class SignedProjectTest extends Specification implements MockMavenServerTrait, GradleProjectTestTrait {
 	@Unroll
 	@RestoreSystemProperties
-	def "sign and publish lib #gradle"() {
+	def "sign and publish lib #version"() {
-		given:
+		setup:
 			setProperty('loom.test.secretKey', PRIVATE_KEY)
+			def gradle = gradleProject(project: "signed", version: version)
+
 		when:
-			def result = create("publish", gradle)
+		def result = gradle.run(task: "publish")
+
 		then:
 			result.task(":publish").outcome == SUCCESS
-		where:
-			gradle             | _
-			DEFAULT_GRADLE     | _
-			PRE_RELEASE_GRADLE | _
-	}
 
-	@Override
+		where:
-	String name() {
+			version << STANDARD_TEST_VERSIONS
-		"signed"
 	}
 
 	static final String PRIVATE_KEY = """

src/test/groovy/net/fabricmc/loom/test/integration/SimpleProjectTest.groovy

@@ -24,36 +24,48 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ArchiveAssertionsTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.ServerRunner
 import spock.lang.Specification
+import spock.lang.Timeout
 import spock.lang.Unroll
 
+import java.util.concurrent.TimeUnit
+
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
+import static net.fabricmc.loom.test.LoomTestConstants.*
 
-class SimpleProjectTest extends Specification implements ProjectTestTrait, ArchiveAssertionsTrait {
+@Timeout(value = 20, unit = TimeUnit.MINUTES)
-	@Override
+class SimpleProjectTest extends Specification implements GradleProjectTestTrait {
-	String name() {
-		"simple"
-	}
-
 	@Unroll
-	def "build (gradle #gradle)"() {
+	def "build and run (gradle #version)"() {
+		setup:
+			def gradle = gradleProject(project: "simple", version: version)
+
+			def server = ServerRunner.create(gradle.projectDir, "1.16.5")
+										.withMod(gradle.getOutputFile("fabric-example-mod-1.0.0.jar"))
+										.withFabricApi()
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+			def serverResult = server.run()
 		then:
 			result.task(":build").outcome == SUCCESS
-			getArchiveEntry("fabric-example-mod-1.0.0.jar", "META-INF/MANIFEST.MF").contains("Fabric-Loom-Version: 0.0.0+unknown")
+			gradle.getOutputZipEntry("fabric-example-mod-1.0.0.jar", "META-INF/MANIFEST.MF").contains("Fabric-Loom-Version: 0.0.0+unknown")
+
+			serverResult.successful()
+			serverResult.output.contains("Hello simple Fabric mod") // A check to ensure our mod init was actually called
 		where:
-			gradle              | _
+			version              | _
 			DEFAULT_GRADLE       | _
 			PRE_RELEASE_GRADLE   | _
 	}
 
 	@Unroll
 	def "#ide config generation"() {
+		setup:
+			def gradle = gradleProject(project: "simple", sharedFiles: true)
 		when:
-			def result = create(ide)
+			def result = gradle.run(task: ide)
 		then:
 			result.task(":${ide}").outcome == SUCCESS
 		where:

src/test/groovy/net/fabricmc/loom/test/integration/UnpickTest.groovy

@@ -24,47 +24,48 @@
 
 package net.fabricmc.loom.test.integration
 
-import net.fabricmc.loom.test.util.ProjectTestTrait
+import net.fabricmc.loom.test.util.GradleProjectTestTrait
+
 import org.zeroturnaround.zip.ZipUtil
 import spock.lang.Specification
 
 import java.nio.charset.StandardCharsets
 
+import static net.fabricmc.loom.test.LoomTestConstants.*
 import static org.gradle.testkit.runner.TaskOutcome.SUCCESS
 
-class UnpickTest extends Specification implements ProjectTestTrait {
+class UnpickTest extends Specification implements GradleProjectTestTrait {
 	static final String MAPPINGS = "21w13a/net.fabricmc.yarn.21w13a.21w13a+build.30-v2"
 
-	@Override
-	String name() {
-		"unpick"
-	}
-
 	def "unpick decompile"() {
+		setup:
+			def gradle = gradleProject(project: "unpick", version: version)
+
 		when:
-			def result = create("genSources", gradle)
+			def result = gradle.run(task: "genSources")
 		then:
 			result.task(":genSources").outcome == SUCCESS
-			getClassSource("net/minecraft/block/CakeBlock.java").contains("Block.DEFAULT_SET_BLOCK_STATE_FLAG")
+			getClassSource(gradle, "net/minecraft/block/CakeBlock.java").contains("Block.DEFAULT_SET_BLOCK_STATE_FLAG")
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 
 	def "unpick build"() {
+		setup:
+			def gradle = gradleProject(project: "unpick", version: version)
+
 		when:
-			def result = create("build", gradle)
+			def result = gradle.run(task: "build")
+
 		then:
 			result.task(":build").outcome == SUCCESS
+
 		where:
-			gradle              | _
+			version << STANDARD_TEST_VERSIONS
-			DEFAULT_GRADLE      | _
-			PRE_RELEASE_GRADLE  | _
 	}
 
-	String getClassSource(String classname, String mappings = MAPPINGS) {
+	private static String getClassSource(GradleProject gradle, String classname, String mappings = MAPPINGS) {
-		File sourcesJar = getGeneratedSources(mappings)
+		File sourcesJar = gradle.getGeneratedSources(mappings)
 		return new String(ZipUtil.unpackEntry(sourcesJar, classname), StandardCharsets.UTF_8)
 	}
 }

src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/LayeredMappingsSpecification.groovy

@@ -33,7 +33,6 @@ import net.fabricmc.loom.configuration.providers.mappings.MappingLayer
 import net.fabricmc.loom.configuration.providers.mappings.MappingsProvider
 import net.fabricmc.loom.configuration.providers.mappings.MappingsSpec
 import net.fabricmc.mappingio.format.Tiny2Writer
-import net.fabricmc.mappingio.tree.MappingTree
 import net.fabricmc.mappingio.tree.MemoryMappingTree
 import org.gradle.api.logging.Logger
 import spock.lang.Specification

src/test/groovy/net/fabricmc/loom/test/unit/layeredmappings/ParchmentMappingLayerTest.groovy

@@ -27,7 +27,6 @@ package net.fabricmc.loom.test.unit.layeredmappings
 import net.fabricmc.loom.configuration.providers.mappings.intermediary.IntermediaryMappingsSpec
 import net.fabricmc.loom.configuration.providers.mappings.mojmap.MojangMappingsSpec
 import net.fabricmc.loom.configuration.providers.mappings.parchment.ParchmentMappingsSpec
-import net.fabricmc.loom.configuration.providers.minecraft.MinecraftVersionMeta
 
 class ParchmentMappingLayerTest extends LayeredMappingsSpecification {
     def "Read parchment mappings" () {

src/test/groovy/net/fabricmc/loom/test/util/GradleProjectTestTrait.groovy

@@ -0,0 +1,203 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2021 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.test.util
+
+import groovy.transform.Immutable
+import net.fabricmc.loom.test.LoomTestConstants
+import org.gradle.testkit.runner.BuildResult
+import org.gradle.testkit.runner.GradleRunner
+import org.zeroturnaround.zip.ZipUtil
+import spock.lang.Shared
+
+trait GradleProjectTestTrait {
+    @Lazy
+    @Shared
+    private static File sharedProjectDir = File.createTempDir()
+    @Lazy
+    @Shared
+    private static File sharedGradleHomeDir = File.createTempDir()
+
+    GradleProject gradleProject(Map options) {
+        String gradleVersion = options.version as String ?: LoomTestConstants.DEFAULT_GRADLE
+        String warningMode = options.warningMode as String ?: "fail"
+        File projectDir = options.projectDir as File ?: options.sharedFiles ? sharedProjectDir : File.createTempDir()
+        File gradleHomeDir = options.gradleHomeDir as File ?: options.sharedFiles ? sharedGradleHomeDir : File.createTempDir()
+
+        setupProject(options, projectDir)
+
+        return new GradleProject(
+                gradleVersion: gradleVersion,
+                projectDir: projectDir.absolutePath,
+                gradleHomeDir: gradleHomeDir.absolutePath,
+                warningMode: warningMode
+        )
+    }
+
+    private void setupProject(Map options, File projectDir) {
+        if (options.project) {
+            copyProjectFromResources(options.project as String, projectDir)
+            return
+        }
+
+        if (options["repo"]) {
+            String repo  = options.repo
+            String commit = options.commit
+
+            exec(projectDir, "git", "clone", repo, ".")
+            exec(projectDir, "git", "checkout", commit)
+
+            return
+        }
+
+        throw new UnsupportedOperationException("No project setup method was supplied")
+    }
+
+    private void exec(File projectDir, String... args) {
+        def process = args.execute([], projectDir)
+        process.consumeProcessOutput(System.out, System.err)
+
+        def exitCode = process.waitFor()
+
+        if (exitCode != 0) {
+             throw new RuntimeException("Command failed with exit code: $exitCode")
+        }
+    }
+
+    private void copyProjectFromResources(String project, File projectDir) {
+        def projectSourceDir = new File("src/test/resources/projects/$project")
+
+        if (!projectSourceDir.exists()) {
+            throw new FileNotFoundException("Failed to find project directory at: $projectSourceDir.absolutePath")
+        }
+
+        // Cleanup some basic things if they already exists
+        new File(projectDir, "src").deleteDir()
+        new File(projectDir, "build.gradle").delete()
+        new File(projectDir, "settings.gradle").delete()
+
+        projectSourceDir.eachFileRecurse { file ->
+            if (file.isDirectory()) {
+                return
+            }
+
+            def path = file.path.replace(projectSourceDir.path, "")
+
+            File tempFile = new File(projectDir, path)
+
+            if (tempFile.exists()) {
+                tempFile.delete()
+            }
+
+            tempFile.parentFile.mkdirs()
+            tempFile.bytes = file.bytes
+        }
+    }
+
+    @Immutable
+    static class GradleProject {
+        private String gradleVersion
+        private String projectDir
+        private String gradleHomeDir
+
+        private String warningMode
+
+        BuildResult run(Map options) {
+            // Setup the system props to tell loom that its running in a test env
+            // And override the CI check to ensure that everything is ran
+            System.setProperty("fabric.loom.test", "true")
+            System.setProperty("fabric.loom.ci", "false")
+            System.setProperty("maven.repo.local", new File(getGradleHomeDir(), "m2").absolutePath)
+
+            def runner = this.runner
+            def args = []
+
+            if (options.task) {
+                args << options.task
+            }
+
+            args.addAll(options.tasks ?: [])
+
+            args << "--stacktrace"
+            args << "--warning-mode" << warningMode
+            args << "--gradle-user-home" << gradleHomeDir
+            args.addAll(options.args ?: [])
+
+            runner.withArguments(args as String[])
+
+            return runner.build()
+        }
+
+        private GradleRunner getRunner() {
+            return GradleRunner.create()
+                    .withProjectDir(getProjectDir())
+                    .withPluginClasspath()
+                    .withGradleVersion(gradleVersion)
+                    .forwardOutput()
+                    .withDebug(true)
+        }
+
+        File getProjectDir() {
+            return new File(projectDir)
+        }
+
+        File getGradleHomeDir() {
+            return new File(gradleHomeDir)
+        }
+
+        File getOutputFile(String filename) {
+            return new File(getProjectDir(), "build/libs/$filename")
+        }
+
+        void printOutputFiles() {
+            new File(getProjectDir(), "build/libs/").listFiles().each {
+                println(it.name)
+            }
+        }
+
+        File getBuildGradle() {
+            return new File(getProjectDir(), "build.gradle")
+        }
+
+        String getOutputZipEntry(String filename, String entryName) {
+            def file = getOutputFile(filename)
+            def bytes = ZipUtil.unpackEntry(file, entryName)
+
+            if (bytes == null) {
+                throw new FileNotFoundException("Could not find ${entryName} in ${entryName}")
+            }
+
+            new String(bytes as byte[])
+        }
+
+        boolean hasOutputZipEntry(String filename, String entryName) {
+            def file = getOutputFile(filename)
+            return ZipUtil.unpackEntry(file, entryName) != null
+        }
+
+        File getGeneratedSources(String mappings) {
+            return new File(getGradleHomeDir(), "caches/fabric-loom/${mappings}/minecraft-mapped-sources.jar")
+        }
+    }
+}

src/test/groovy/net/fabricmc/loom/test/util/MockMavenServerTrait.groovy

@@ -27,7 +27,7 @@ package net.fabricmc.loom.test.util
 import io.javalin.Javalin
 import org.apache.commons.io.IOUtils
 
-trait MockMavenServerTrait extends ProjectTestTrait {
+trait MockMavenServerTrait {
     public final int mavenServerPort = 9876
     public final File testMavenDir = File.createTempDir()
     private Javalin server
@@ -74,7 +74,6 @@ trait MockMavenServerTrait extends ProjectTestTrait {
     @SuppressWarnings('unused')
     def cleanupSpec() {
         server.stop()
-        super.cleanupSpec()
     }
 
     File getMavenDirectory() {

src/test/groovy/net/fabricmc/loom/test/util/ProjectTestTrait.groovy

@@ -1,126 +0,0 @@
-/*
- * This file is part of fabric-loom, licensed under the MIT License (MIT).
- *
- * Copyright (c) 2016-2021 FabricMC
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-
-package net.fabricmc.loom.test.util
-
-import org.gradle.testkit.runner.BuildResult
-import org.gradle.testkit.runner.GradleRunner
-
-trait ProjectTestTrait {
-	final static String DEFAULT_GRADLE = "7.0.1"
-	final static String PRE_RELEASE_GRADLE = "7.3-20210724022245+0000"
-
-	static File gradleHome = File.createTempDir()
-	File testProjectDir = File.createTempDir()
-
-	abstract String name()
-
-	def copyInputFiles() {
-		println "Project directory: ${testProjectDir}"
-
-		def baseProjectDir = new File("src/test/resources/projects/" + name())
-
-		if (!baseProjectDir.exists()) {
-			throw new FileNotFoundException("Failed to find project directory at:" + baseProjectDir.absolutePath)
-		}
-
-		baseProjectDir.eachFileRecurse { file ->
-			if (file.isDirectory()) {
-				return
-			}
-
-			def path = file.path.replace(baseProjectDir.path, "")
-
-			File tempFile = new File(testProjectDir, path)
-
-			if (tempFile.exists()) {
-				tempFile.delete()
-			}
-
-			tempFile.parentFile.mkdirs()
-			tempFile.bytes = file.bytes
-		}
-
-		// Disable the CI checks to ensure nothing is skipped
-		System.setProperty("fabric.loom.ci", "false")
-	}
-
-	@SuppressWarnings('unused')
-	def cleanup() {
-		// Clean after each test
-		new File(testProjectDir, "build").deleteDir()
-		new File(testProjectDir, ".gradle").deleteDir()
-	}
-
-	@SuppressWarnings('unused')
-	def cleanupSpec() {
-		testProjectDir.deleteDir()
-		gradleHome.deleteDir()
-	}
-
-	File buildGradle() {
-		return new File(testProjectDir, "build.gradle")
-	}
-
-	def filesReady() {
-	}
-
-	BuildResult create(String task, String gradleVersion = DEFAULT_GRADLE) {
-		System.setProperty("fabric.loom.test", "true")
-		copyInputFiles()
-		filesReady()
-
-		GradleRunner.create()
-			.withProjectDir(testProjectDir)
-			.withArguments(task, "--stacktrace", "--warning-mode", warningMode(gradleVersion), "--gradle-user-home", gradleHomeDirectory(gradleVersion))
-			.withPluginClasspath()
-			.withGradleVersion(gradleVersion)
-			.forwardOutput()
-			.withDebug(true)
-			.build()
-	}
-
-	String warningMode(String gradleVersion) {
-		'fail'
-	}
-
-	String gradleHomeDirectory(String gradleVersion) {
-		// Each gradle version gets its own dir to run on, to ensure that a full run is done.
-		new File(gradleHome, gradleVersion).absolutePath
-	}
-
-	File getOutputFile(String name, String project = "") {
-		def file = new File(testProjectDir, "${project}build/libs/${name}")
-
-		if (!file.exists()) {
-			throw new FileNotFoundException("Could not find ${name} at ${file.absolutePath}")
-		}
-
-		return file
-	}
-
-	File getGeneratedSources(String mappings, String gradleVersion = DEFAULT_GRADLE) {
-		return new File(gradleHomeDirectory(gradleVersion), "caches/fabric-loom/${mappings}/minecraft-mapped-sources.jar")
-	}
-}

src/test/groovy/net/fabricmc/loom/test/util/ServerRunner.groovy

@@ -0,0 +1,208 @@
+/*
+ * This file is part of fabric-loom, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) 2016-2021 FabricMC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package net.fabricmc.loom.test.util
+
+import groovy.transform.Immutable
+
+import java.util.concurrent.TimeUnit
+
+class ServerRunner {
+    static final String LOADER_VERSION = "0.11.6"
+    static final Map<String, String> FABRIC_API_URLS = [
+            "1.16.5": "https://github.com/FabricMC/fabric/releases/download/0.37.1%2B1.16/fabric-api-0.37.1+1.16.jar",
+            "1.17.1": "https://github.com/FabricMC/fabric/releases/download/0.37.1%2B1.17/fabric-api-0.37.1+1.17.jar"
+    ]
+
+    final File serverDir
+    final String minecraftVersion
+
+    final List<File> mods = []
+
+    private ServerRunner(File serverDir, String minecraftVersion) {
+        this.serverDir = serverDir
+        this.minecraftVersion = minecraftVersion
+
+        this.serverDir.mkdirs()
+    }
+
+    static ServerRunner create(File testProjectDir, String minecraftVersion) {
+        return new ServerRunner(new File(testProjectDir, "server"), minecraftVersion)
+    }
+
+    def install() {
+        def args = [
+                "server",
+                "-dir",
+                serverDir.absolutePath,
+                "-mcversion",
+                minecraftVersion,
+                "-loader",
+                LOADER_VERSION,
+                "-downloadMinecraft"
+        ]
+
+        //noinspection UnnecessaryQualifiedReference
+        net.fabricmc.installer.Main.main(args as String[])
+
+        def eulaFile = new File(serverDir, "eula.txt")
+        eulaFile << "eula=true"
+
+        def serverPropsFile = new File(serverDir, "server.properties")
+        serverPropsFile << "level-type=FLAT" // Generates the world faster
+    }
+
+    ServerRunner withMod(File file) {
+        mods << file
+        return this
+    }
+
+    ServerRunner downloadMod(String url, String filename) {
+        File modFile = new File(serverDir, "downloadedMods/" + filename)
+        modFile.parentFile.mkdirs()
+
+        println("Downloading " + url)
+        modFile.bytes = new URL(url).bytes
+
+        return withMod(modFile)
+    }
+
+    ServerRunner withFabricApi() {
+        if (!FABRIC_API_URLS[minecraftVersion]) {
+            throw new UnsupportedOperationException("No Fabric api url for " + minecraftVersion)
+        }
+
+        return downloadMod(FABRIC_API_URLS[minecraftVersion], "fabricapi.jar")
+    }
+
+    ServerRunResult run() {
+        install()
+
+        // Copy the mods here so we can
+        mods.each {
+            if (!it.exists()) {
+                throw new FileNotFoundException(it.absolutePath)
+            }
+
+            File modFile = new File(serverDir, "mods/" + it.name)
+            modFile.parentFile.mkdirs()
+            modFile.bytes = it.bytes
+        }
+
+        String javaExecutablePath = ProcessHandle.current()
+                .info()
+                .command()
+                .orElseThrow()
+
+        var builder = new ProcessBuilder()
+        builder.directory(serverDir)
+        builder.command(javaExecutablePath, "-Xmx1G", "-jar", "fabric-server-launch.jar", "nogui")
+
+        Process process = builder.start()
+        def out = new StringBuffer()
+        def isStopping = false
+
+        process.consumeProcessOutput(
+                new ForwardingAppendable([System.out, out], {
+                    if (!isStopping && out.contains("Done ") && out.contains("For help, type \"help\"")) {
+                        isStopping = true
+
+                        Thread.start {
+                            println("Stopping server in 5 seconds")
+                            sleep(5000)
+
+                            println("Sending stop command")
+                            process.outputStream.withCloseable {
+                                it.write("stop\n".bytes)
+                            }
+                        }
+                    }
+                }),
+                new ForwardingAppendable([System.err, out])
+        )
+
+        addShutdownHook {
+            if (process.alive) {
+                process.destroy()
+            }
+        }
+
+        assert process.waitFor(10, TimeUnit.MINUTES)
+        int exitCode = process.exitValue()
+
+        println("Sever closed with exit code: " + exitCode)
+
+        return new ServerRunResult(exitCode, out.toString())
+    }
+
+    @Immutable
+    class ServerRunResult {
+        int exitCode
+        String output
+
+        boolean successful() {
+            return exitCode == 0 && output.contains("Done ")
+        }
+    }
+
+    private class ForwardingAppendable implements Appendable {
+        final List<Appendable> appendables
+        final Closure onAppended
+
+        ForwardingAppendable(List<Appendable> appendables, Closure onAppended = {}) {
+            this.appendables = appendables
+            this.onAppended = onAppended
+        }
+
+        @Override
+        Appendable append(CharSequence csq) throws IOException {
+            appendables.each {
+                it.append(csq)
+            }
+
+            onAppended.run()
+            return this
+        }
+
+        @Override
+        Appendable append(CharSequence csq, int start, int end) throws IOException {
+            appendables.each {
+                it.append(csq, start, end)
+            }
+
+            onAppended.run()
+            return this
+        }
+
+        @Override
+        Appendable append(char c) throws IOException {
+            appendables.each {
+                it.append(c)
+            }
+
+            onAppended.run()
+            return this
+        }
+    }
+}

src/test/resources/projects/simple/src/main/java/net/fabricmc/example/ExampleMod.java

@@ -9,6 +9,6 @@ public class ExampleMod implements ModInitializer {
 		// However, some things (like resources) may still be uninitialized.
 		// Proceed with mild caution.
 
-		System.out.println("Hello Fabric world!");
+		System.out.println("Hello simple Fabric mod");
 	}
 }