Fixed caching of downloaded contracts in Gradle

without this change when using a daemon, for snapshot versions of downloaded contracts allways the same folder is returned
with this change we cache only non snapshot artifacts; also there's a switch you can set to disable caching at all

fixes #343

docs/src/main/asciidoc/verifier/rest.adoc

@@ -124,6 +124,7 @@ contracts {
     }
     contractsPath = ''
     contractsWorkOffline = false
+    cacheDownloadedContracts = true
 }
 
 tasks.create(type: Jar, name: 'verifierStubsJar', dependsOn: 'generateClientStubs') {
@@ -443,8 +444,9 @@ If you want to download your contract definitions from a Maven repository you ca
  - **contractDependency** - the contract dependency that contains all the packaged contracts
  - **contractsPath** - path to concrete contracts in the JAR with packaged contracts. Defaults to `groupid/artifactid` where `gropuid` is slash separated.
  - **contractsWorkOffline** - if the dependencies should be downloaded or local Maven only should be reused
-
+ - **cacheDownloadedContracts** - if you want to reuse download JARs that contain contract definitions.
-For complete information take a look at https://cloud.spring.io/spring-cloud-contract/spring-cloud-contract-maven-plugin/plugin-info.html[Plugin Documentation]
+ We cache only non-snapshot, explicitly provided versions (e.g. `+` or `1.0.0.BUILD-SNAPSHOT` won't get cached).
+ By default this feature is turned on.
 
 ====== Single base class for all tests
 

spring-cloud-contract-stub-runner/src/main/java/org/springframework/cloud/contract/stubrunner/StubConfiguration.java

@@ -86,6 +86,10 @@ public class StubConfiguration {
 		return StringUtils.hasText(this.groupId) && StringUtils.hasText(this.artifactId);
 	}
 
+	/**
+	 * Returns a colon separated representation of the stub configuration
+	 * (e.g. groupid:artifactid:version:classifier)
+	 */
 	public String toColonSeparatedDependencyNotation() {
 		if (!isDefined()) {
 			return "";
@@ -102,6 +106,13 @@ public class StubConfiguration {
 		return StringUtils.hasText(value) ? value : "";
 	}
 
+	/**
+	 * Checks if ivy notation matches group and artifact ids
+	 *
+	 * @param ivyNotationAsString - e.g. group:artifact:version:classifier
+	 * @return {@code true} if artifact id matches and there's no group id. Or if
+	 * both group id and artifact id are present and matching
+	 */
 	public boolean groupIdAndArtifactMatches(String ivyNotationAsString) {
 		String[] parts = ivyNotationFrom(ivyNotationAsString);
 		String groupId = parts[0];
@@ -112,6 +123,14 @@ public class StubConfiguration {
 		return this.groupId.equals(groupId) && this.artifactId.equals(artifactId);
 	}
 
+	/**
+	 * Returns {@code true} for a snapshot or a LATEST (+) version
+	 */
+	public boolean isVersionChanging() {
+		return DEFAULT_VERSION.equals(this.version) ||
+				this.version.toLowerCase().contains("snapshot");
+	}
+
 	public String getGroupId() {
 		return this.groupId;
 	}

spring-cloud-contract-stub-runner/src/test/groovy/org/springframework/cloud/contract/stubrunner/AetherStubDownloaderSpec.groovy

@@ -1,18 +1,20 @@
 package org.springframework.cloud.contract.stubrunner
 
 import io.specto.hoverfly.junit.HoverflyRule
-import org.eclipse.aether.RepositorySystemSession;
+import org.eclipse.aether.RepositorySystemSession
 import org.junit.Rule
 import org.springframework.util.ResourceUtils
+import spock.lang.IgnoreIf
 import spock.lang.Specification
 import spock.util.environment.RestoreSystemProperties
 
-
 class AetherStubDownloaderSpec extends Specification {
 
     @Rule
     HoverflyRule hoverflyRule = HoverflyRule.buildFromClassPathResource("simulation.json").build()
 
+    // CI tools sometimes can't reach the `test.jfrog.io` address
+    @IgnoreIf({ Boolean.valueOf(env['CI']) })
     def 'Should be able to download from a repository using username and password authentication'() {
         given:
         StubRunnerOptions stubRunnerOptions = new StubRunnerOptionsBuilder()

spring-cloud-contract-stub-runner/src/test/groovy/org/springframework/cloud/contract/stubrunner/StubConfigurationSpec.groovy

@@ -45,4 +45,19 @@ class StubConfigurationSpec extends Specification {
 
 	}
 
+	@Unroll
+	def 'should resolve [#ivy] as a changing version [#result]'() {
+		given:
+			StubConfiguration stubConfiguration = new StubConfiguration(ivy)
+		expect:
+			result == stubConfiguration.isVersionChanging()
+		where:
+			ivy                                       || result
+			'group:artifact:1.0.0.RELEASE:classifier' || false
+			'group:artifact:1.0.0.BUILD-SNAPSHOT:'    || true
+			'group:artifact:1.0.0.SNAPSHOT'           || true
+			'group:artifact:+:'                       || true
+
+	}
+
 }

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ContractVerifierExtension.groovy

@@ -141,6 +141,12 @@ class ContractVerifierExtension {
 	 */
 	boolean excludeBuildFolders
 
+	/**
+	 * If set to true then will cache the folder where non snapshot contract artifacts
+	 * got downloaded.
+	 */
+	boolean cacheDownloadedContracts = true
+
 	void contractDependency(@DelegatesTo(Dependency) Closure closure) {
 		closure.delegate = contractDependency
 		closure.call()

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ExtensionToProperties.groovy

@@ -1,5 +1,6 @@
 package org.springframework.cloud.contract.verifier.plugin
 
+import groovy.transform.CompileStatic
 import groovy.transform.PackageScope
 import org.springframework.cloud.contract.verifier.config.ContractVerifierConfigProperties
 
@@ -7,6 +8,7 @@ import org.springframework.cloud.contract.verifier.config.ContractVerifierConfig
  * @author Marcin Grzejszczak
  */
 @PackageScope
+@CompileStatic
 class ExtensionToProperties {
 
 	protected static ContractVerifierConfigProperties fromExtension(ContractVerifierExtension extension) {

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/GradleContractsDownloader.groovy

@@ -1,5 +1,6 @@
 package org.springframework.cloud.contract.verifier.plugin
 
+import groovy.transform.CompileStatic
 import groovy.transform.PackageScope
 import org.gradle.api.Project
 import org.gradle.api.logging.Logger
@@ -15,13 +16,14 @@ import java.util.concurrent.ConcurrentHashMap
  * @author Marcin Grzejszczak
  */
 @PackageScope
+@CompileStatic
 class GradleContractsDownloader {
 
 	private static final String LATEST_VERSION = '+'
 
 	private final Project project
 	private final Logger log
-	private static final Map<StubConfiguration, File> downloadedContract = new ConcurrentHashMap<>()
+	protected static final Map<StubConfiguration, File> downloadedContract = new ConcurrentHashMap<>()
 	
 	GradleContractsDownloader(Project project, Logger log) {
 		this.project = project
@@ -31,24 +33,29 @@ class GradleContractsDownloader {
 	File downloadAndUnpackContractsIfRequired(ContractVerifierExtension extension,
 											  ContractVerifierConfigProperties config) {
 		File defaultContractsDir = extension.contractsDslDir
-		this.log.info("Project has group id [${this.project.group}], artifact id [${this.project.name}]")
+		this.log.info("Project has group id [{}], artifact id [{}]", this.project.group, this.project.name)
 		// download contracts, unzip them and pass as output directory
 		if (shouldDownloadContracts(extension)) {
 			this.log.info("For project [${this.project.name}] Download dependency is provided - will download contract jars")
 			this.log.info("Contract dependency [{}]", extension.contractDependency)
 			StubConfiguration configuration = stubConfiguration(extension.contractDependency)
 			this.log.info("Got the following contract dependency to download [{}]", configuration)
-			File cachedFolder = downloadedContract.get(configuration)
+			this.log.info("The contract dependency is a changing one [{}] and cache download switch is set to [{}]",
-			if (cachedFolder) {
+					configuration.isVersionChanging(), extension.cacheDownloadedContracts)
-				this.log.info("For project [${this.project.name}] Returning the cached location of the contracts")
+			if (!configuration.isVersionChanging() && extension.cacheDownloadedContracts) {
-				contractDownloader(extension, configuration).updatePropertiesWithInclusion(cachedFolder, config)
+				this.log.info("Resolved a non changing version - will try to return the folder from a cache")
-				return cachedFolder
+				File cachedFolder = downloadedContract.get(configuration)
+				if (cachedFolder) {
+					this.log.info("For project [{}] returning the cached location of the contracts", this.project.name)
+					contractDownloader(extension, configuration).updatePropertiesWithInclusion(cachedFolder, config)
+					return cachedFolder
+				}
 			}
 			File downloadedContracts = contractDownloader(extension, configuration).unpackedDownloadedContracts(config)
 			downloadedContract.put(configuration, downloadedContracts)
 			return downloadedContracts
 		}
-		this.log.info("For project [${this.project.name}] will use contracts provided in the folder [" + defaultContractsDir + "]")
+		this.log.info("For project [{}] will use contracts provided in the folder [{}]", this.project.name, defaultContractsDir)
 		return defaultContractsDir
 	}
 
@@ -58,12 +65,12 @@ class GradleContractsDownloader {
 						StringUtils.hasText(extension.contractDependency.stringNotation))
 	}
 
-	private ContractDownloader contractDownloader(ContractVerifierExtension extension, StubConfiguration configuration) {
+	protected ContractDownloader contractDownloader(ContractVerifierExtension extension, StubConfiguration configuration) {
 		return new ContractDownloader(stubDownloader(extension), configuration,
 				extension.contractsPath, this.project.group as String, this.project.name)
 	}
 
-	private AetherStubDownloader stubDownloader(ContractVerifierExtension extension) {
+	protected AetherStubDownloader stubDownloader(ContractVerifierExtension extension) {
 		return new AetherStubDownloader(
 				new StubRunnerOptionsBuilder()
 						.withStubRepositoryRoot(extension.contractsRepositoryUrl)

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/test/groovy/org/springframework/cloud/contract/verifier/plugin/GradleContractsDownloaderSpec.groovy

@@ -1,6 +1,11 @@
 package org.springframework.cloud.contract.verifier.plugin
 
+import org.gradle.api.Project
+import org.gradle.api.logging.Logger
+import org.springframework.cloud.contract.stubrunner.AetherStubDownloader
+import org.springframework.cloud.contract.stubrunner.ContractDownloader
 import org.springframework.cloud.contract.stubrunner.StubConfiguration
+import org.springframework.cloud.contract.verifier.config.ContractVerifierConfigProperties
 import spock.lang.Specification
 
 /**
@@ -8,6 +13,9 @@ import spock.lang.Specification
  */
 class GradleContractsDownloaderSpec extends Specification {
 
+	Project project = Stub(Project)
+	Logger logger = Stub(Logger)
+
 	def "should parse dependency via string notation"() {
 		given:
 			String stringNotation = "com.example:foo:1.0.0:stubs"
@@ -37,6 +45,7 @@ class GradleContractsDownloaderSpec extends Specification {
 			stubConfig.version == "1.0.0"
 			stubConfig.classifier == "stubs"
 	}
+
 	def "should parse dependency via string notation with methods"() {
 		given:
 			String stringNotation = "com.example:foo:1.0.0:stubs"
@@ -66,4 +75,122 @@ class GradleContractsDownloaderSpec extends Specification {
 			stubConfig.version == "1.0.0"
 			stubConfig.classifier == "stubs"
 	}
+
+	def "should pick dependency from cache for a non snapshot contract dependency"() {
+		given:
+			ContractVerifierExtension ext = new ContractVerifierExtension()
+			ext.with {
+				contractDependency {
+					groupId("com.example")
+					artifactId("foo")
+					version("1.0.0")
+					classifier("stubs")
+				}
+				contractsRepositoryUrl = "foo"
+			}
+		and:
+			final AetherStubDownloader downloader = Mock(AetherStubDownloader)
+			final ContractDownloader contractDownloader = Mock(ContractDownloader)
+		and:
+			def gradleDownloader = stubbedContractDownloader(downloader, contractDownloader)
+		and:
+			StubConfiguration expectedStubConfig = new StubConfiguration("com.example:foo:1.0.0:stubs")
+			File expectedFileFromCache = new File("foo/bar")
+			GradleContractsDownloader.downloadedContract.put(expectedStubConfig, expectedFileFromCache)
+		when:
+			File file = gradleDownloader.downloadAndUnpackContractsIfRequired(ext, new ContractVerifierConfigProperties())
+		then:
+			file == expectedFileFromCache
+	}
+
+	def "should not pick dependency from cache for a non snapshot contract dependency with cache switch off"() {
+		given:
+			ContractVerifierExtension ext = new ContractVerifierExtension()
+			ext.with {
+				contractDependency {
+					groupId("com.example")
+					artifactId("foo")
+					version("1.0.0")
+					classifier("stubs")
+				}
+				contractsRepositoryUrl = "foo"
+				cacheDownloadedContracts = false
+			}
+		and:
+			final AetherStubDownloader downloader = Mock(AetherStubDownloader)
+			final ContractDownloader contractDownloader = Mock(ContractDownloader)
+		and:
+			def gradleDownloader = stubbedContractDownloader(downloader, contractDownloader)
+		and:
+			StubConfiguration expectedStubConfig = new StubConfiguration("com.example:foo:1.0.0:stubs")
+			File expectedFileFromCache = new File("foo/bar")
+			GradleContractsDownloader.downloadedContract.put(expectedStubConfig, expectedFileFromCache)
+		and:
+			File expectedFileNotFromCache = new File("foo/bar/baz")
+			contractDownloader.unpackedDownloadedContracts(_) >> expectedFileNotFromCache
+		when:
+			File file = gradleDownloader.downloadAndUnpackContractsIfRequired(ext, new ContractVerifierConfigProperties())
+		then:
+			file == expectedFileNotFromCache
+	}
+
+	def "should not pick dependency from cache for snapshot contract dependency"() {
+		given:
+			ContractVerifierExtension ext = new ContractVerifierExtension()
+			ext.with {
+				contractDependency {
+					groupId("com.example")
+					artifactId("foo")
+					version("1.0.0.BUILD-SNAPSHOT")
+					classifier("stubs")
+				}
+				contractsRepositoryUrl = "foo"
+			}
+		and:
+			final AetherStubDownloader downloader = Mock(AetherStubDownloader)
+			final ContractDownloader contractDownloader = Mock(ContractDownloader)
+			File expectedFileNotFromCache = new File("foo/bar/baz")
+			contractDownloader.unpackedDownloadedContracts(_) >> expectedFileNotFromCache
+		and:
+			def gradleDownloader = stubbedContractDownloader(downloader, contractDownloader)
+		when:
+			File file = gradleDownloader.downloadAndUnpackContractsIfRequired(ext, new ContractVerifierConfigProperties())
+		then:
+			file == expectedFileNotFromCache
+	}
+
+	private GradleContractsDownloader stubbedContractDownloader(downloader, contractDownloader) {
+		new GradleContractsDownloader(project, logger) {
+			@Override
+			protected AetherStubDownloader stubDownloader(ContractVerifierExtension extension) {
+				return downloader
+			}
+
+			@Override
+			protected ContractDownloader contractDownloader(ContractVerifierExtension extension, StubConfiguration configuration) {
+				return contractDownloader
+			}
+		}
+	}
+
+	def "should pick contract directory location from extension"() {
+		given:
+			ContractVerifierExtension ext = new ContractVerifierExtension()
+			ext.with {
+				contractsDslDir = new File("/foo/bar/baz")
+			}
+		and:
+			final AetherStubDownloader downloader = Mock(AetherStubDownloader)
+			final ContractDownloader contractDownloader = Mock(ContractDownloader)
+		and:
+			def gradleDownloader = stubbedContractDownloader(downloader, contractDownloader)
+		and:
+			StubConfiguration expectedStubConfig = new StubConfiguration("com.example:foo:1.0.0:stubs")
+			GradleContractsDownloader.downloadedContract.put(expectedStubConfig, new File("foo/bar"))
+		when:
+			File file = gradleDownloader.downloadAndUnpackContractsIfRequired(ext, new ContractVerifierConfigProperties())
+		then:
+			file == new File("/foo/bar/baz")
+	}
+
 }