Add version range support for Kotlin version

Closes gh-556

initializr-generator/src/main/java/io/spring/initializr/generator/ProjectGenerator.java

@@ -340,6 +340,7 @@ public class ProjectGenerator {
 		ProjectRequest request = requestResolver.resolve(originalRequest, metadata);
 
 		// request resolved so we can log what has been requested
+		Version bootVersion = Version.safeParse(request.getBootVersion());
 		List<Dependency> dependencies = request.getResolvedDependencies();
 		List<String> dependencyIds = dependencies.stream().map(Dependency::getId)
 				.collect(Collectors.toList());
@@ -352,7 +353,7 @@ public class ProjectGenerator {
 
 		// Kotlin supported as of M6
 		final boolean kotlinSupport = VERSION_2_0_0_M6
-				.compareTo(Version.safeParse(request.getBootVersion())) <= 0;
+				.compareTo(bootVersion) <= 0;
 		model.put("kotlinSupport", kotlinSupport);
 
 		if (isMavenBuild(request)) {
@@ -419,8 +420,8 @@ public class ProjectGenerator {
 		// Add various versions
 		model.put("dependencyManagementPluginVersion", metadata.getConfiguration()
 				.getEnv().getGradle().getDependencyManagementPluginVersion());
-		model.put("kotlinVersion",
+		model.put("kotlinVersion", metadata.getConfiguration().getEnv().getKotlin()
-				metadata.getConfiguration().getEnv().getKotlin().getVersion());
+				.resolveKotlinVersion(bootVersion));
 		if ("kotlin".equals(request.getLanguage())) {
 			model.put("kotlin", true);
 		}
@@ -433,15 +434,15 @@ public class ProjectGenerator {
 
 		// Gradle plugin has changed as from 1.3.0
 		model.put("bootOneThreeAvailable", VERSION_1_3_0_M1
-				.compareTo(Version.safeParse(request.getBootVersion())) <= 0);
+				.compareTo(bootVersion) <= 0);
 
 		model.put("bootTwoZeroAvailable", VERSION_2_0_0_M1
-				.compareTo(Version.safeParse(request.getBootVersion())) <= 0);
+				.compareTo(bootVersion) <= 0);
 
 		// Gradle plugin has changed again as from 1.4.2
 		model.put("springBootPluginName",
 				(VERSION_1_4_2_M1
-						.compareTo(Version.safeParse(request.getBootVersion())) <= 0
+						.compareTo(bootVersion) <= 0
 						? "org.springframework.boot" : "spring-boot"));
 
 		// New testing stuff

initializr-generator/src/main/java/io/spring/initializr/generator/ProjectRequest.java

@@ -196,7 +196,7 @@ public class ProjectRequest extends BasicProjectRequest {
 
 		initializeRepositories(metadata, requestedVersion);
 
-		initializeProperties(metadata);
+		initializeProperties(metadata, requestedVersion);
 
 		afterResolution(metadata);
 	}
@@ -219,12 +219,14 @@ public class ProjectRequest extends BasicProjectRequest {
 		}));
 	}
 
-	protected void initializeProperties(InitializrMetadata metadata) {
+	protected void initializeProperties(InitializrMetadata metadata,
+			Version requestedVersion) {
+		String kotlinVersion = metadata.getConfiguration().getEnv().getKotlin()
+				.resolveKotlinVersion(requestedVersion);
 		if ("gradle".equals(build)) {
 			buildProperties.getGradle().put("springBootVersion", this::getBootVersion);
 			if ("kotlin".equals(getLanguage())) {
-				buildProperties.getGradle().put("kotlinVersion", () -> metadata
+				buildProperties.getGradle().put("kotlinVersion", () -> kotlinVersion);
-						.getConfiguration().getEnv().getKotlin().getVersion());
 			}
 		}
 		else {
@@ -235,7 +237,7 @@ public class ProjectRequest extends BasicProjectRequest {
 					this::getJavaVersion);
 			if ("kotlin".equals(getLanguage())) {
 				buildProperties.getVersions().put(new VersionProperty("kotlin.version"),
-						() -> metadata.getConfiguration().getEnv().getKotlin().getVersion());
+						() -> kotlinVersion);
 				buildProperties.getMaven().put("kotlin.compiler.incremental", () -> "true");
 			}
 		}

initializr-generator/src/main/java/io/spring/initializr/metadata/InitializrConfiguration.java

@@ -26,6 +26,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
 
+import com.fasterxml.jackson.annotation.JsonIgnore;
+import io.spring.initializr.util.InvalidVersionException;
+import io.spring.initializr.util.Version;
+import io.spring.initializr.util.VersionParser;
+import io.spring.initializr.util.VersionRange;
+
 import org.springframework.boot.context.properties.NestedConfigurationProperty;
 import org.springframework.util.StringUtils;
 
@@ -319,6 +325,7 @@ public class InitializrConfiguration {
 		public void validate() {
 			maven.parent.validate();
 			boms.forEach((k, v) -> v.validate());
+			kotlin.validate();
 		}
 
 		public void merge(Env other) {
@@ -329,7 +336,7 @@ public class InitializrConfiguration {
 			invalidApplicationNames = other.invalidApplicationNames;
 			forceSsl = other.forceSsl;
 			gradle.merge(other.gradle);
-			kotlin.version = other.kotlin.version;
+			kotlin.merge(other.kotlin);
 			maven.merge(other.maven);
 			other.boms.forEach(boms::putIfAbsent);
 			other.repositories.forEach(repositories::putIfAbsent);
@@ -360,17 +367,114 @@ public class InitializrConfiguration {
 		public static class Kotlin {
 
 			/**
-			 * Kotlin version to use.
+			 * Default kotlin version.
+			 */
+			private String defaultVersion;
+
+			/**
+			 * Kotlin version mappings.
+			 */
+			private final List<Mapping> mappings = new ArrayList<>();
+
+			/**
+			 * Resolve the kotlin version to use based on the Spring Boot version.
+			 * @param bootVersion the Spring Boot version
+			 * @return the kotlin version to use
+			 */
+			public String resolveKotlinVersion(Version bootVersion) {
+				for (Mapping mapping : this.mappings) {
+					if (mapping.range.match(bootVersion)) {
+						return mapping.version;
+					}
+				}
+				if (defaultVersion == null) {
+					throw new InvalidInitializrMetadataException(
+							"No Kotlin version mapping available for " + bootVersion);
+				}
+				return this.defaultVersion;
+			}
+
+			public String getDefaultVersion() {
+				return this.defaultVersion;
+			}
+
+			public void setDefaultVersion(String defaultVersion) {
+				this.defaultVersion = defaultVersion;
+			}
+
+			public List<Mapping> getMappings() {
+				return this.mappings;
+			}
+
+			public void validate() {
+				VersionParser simpleParser = new VersionParser(Collections.emptyList());
+				mappings.forEach(m -> {
+					if (m.versionRange == null) {
+						throw new InvalidInitializrMetadataException(
+								"VersionRange is mandatory, invalid version mapping for " + this);
+					}
+					m.range = simpleParser.parseRange(m.versionRange);
+					if (m.version == null) {
+						throw new InvalidInitializrMetadataException(
+								"Version is mandatory, invalid version mapping for " + this);
+					}
+				});
+			}
+
+			public void updateVersionRange(VersionParser versionParser) {
+				mappings.forEach(it -> {
+					try {
+						it.range = versionParser.parseRange(it.versionRange);
+					}
+					catch (InvalidVersionException ex) {
+						throw new InvalidInitializrMetadataException(
+								"Invalid version range " + it.versionRange + " for " + this, ex);
+					}
+				});
+			}
+
+			private void merge(Kotlin other) {
+				this.defaultVersion = other.defaultVersion;
+				this.mappings.clear();
+				this.mappings.addAll(other.mappings);
+			}
+
+			/**
+			 * Map several attribute of the dependency for a given version range.
+			 */
+			public static class Mapping {
+
+				/**
+				 * The version range of this mapping.
+				 */
+				private String versionRange;
+
+				/**
+				 * The kotlin version for this mapping.
 				 */
 				private String version;
 
+				@JsonIgnore
+				private VersionRange range;
+
+				public String getVersionRange() {
+					return this.versionRange;
+				}
+
+				public void setVersionRange(String versionRange) {
+					this.versionRange = versionRange;
+				}
+
 				public String getVersion() {
-				return version;
+					return this.version;
 				}
 
 				public void setVersion(String version) {
 					this.version = version;
 				}
+
+			}
+
 		}
 
 		public static class Maven {

initializr-generator/src/main/java/io/spring/initializr/metadata/InitializrMetadata.java

@@ -218,6 +218,7 @@ public class InitializrMetadata {
 		dependencies.updateVersionRange(parser);
 		configuration.getEnv().getBoms().values()
 				.forEach(it -> it.updateVersionRange(parser));
+		configuration.getEnv().getKotlin().updateVersionRange(parser);
 	}
 
 	/**

initializr-generator/src/test/java/io/spring/initializr/metadata/InitializrConfigurationTests.java

@@ -16,11 +16,16 @@
 
 package io.spring.initializr.metadata;
 
+import io.spring.initializr.metadata.InitializrConfiguration.Env.Kotlin;
+import io.spring.initializr.util.Version;
 import org.junit.Test;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
 
 /**
+ * Tests for {@link InitializrConfiguration}.
+ *
  * @author Stephane Nicoll
  */
 public class InitializrConfigurationTests {
@@ -159,4 +164,35 @@ public class InitializrConfigurationTests {
 		assertEquals("http://foo/bar/", this.properties.getEnv().getArtifactRepository());
 	}
 
+	@Test
+	public void resolveKotlinVersionMatchingMapping() {
+		Kotlin kotlin = this.properties.getEnv().getKotlin();
+		kotlin.setDefaultVersion("1.2.3");
+		kotlin.getMappings().add(createKotlinVersionMapping(
+				"[1.4.0.RELEASE,1.5.0.RELEASE)", "1.5"));
+		kotlin.getMappings().add(createKotlinVersionMapping("1.5.0.RELEASE", "1.6"));
+		kotlin.validate();
+		assertThat(kotlin.resolveKotlinVersion(Version.parse("1.5.3.RELEASE")))
+				.isEqualTo("1.6");
+	}
+
+	@Test
+	public void resolveKotlinVersionUsingDefault() {
+		Kotlin kotlin = this.properties.getEnv().getKotlin();
+		kotlin.setDefaultVersion("1.2.3");
+		kotlin.getMappings().add(createKotlinVersionMapping(
+				"[1.4.0.RELEASE,1.5.0.RELEASE)", "1.5"));
+		kotlin.validate();
+		assertThat(kotlin.resolveKotlinVersion(Version.parse("1.3.2.RELEASE")))
+				.isEqualTo("1.2.3");
+	}
+
+	private Kotlin.Mapping createKotlinVersionMapping(String versionRange,
+			String kotlinVersion){
+		Kotlin.Mapping mapping = new Kotlin.Mapping();
+		mapping.setVersionRange(versionRange);
+		mapping.setVersion(kotlinVersion);
+		return mapping;
+	}
+
 }

initializr-generator/src/test/java/io/spring/initializr/metadata/InitializrMetadataBuilderTests.java

@@ -33,6 +33,8 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
 /**
+ * Tests for {@link InitializrMetadataBuilder}.
+ * 
  * @author Stephane Nicoll
  */
 public class InitializrMetadataBuilderTests {
@@ -163,8 +165,6 @@ public class InitializrMetadataBuilderTests {
 		assertEquals(defaultEnv.getFallbackApplicationName(),
 				actualEnv.getFallbackApplicationName());
 		assertEquals(defaultEnv.isForceSsl(), actualEnv.isForceSsl());
-		assertEquals(defaultEnv.getKotlin().getVersion(),
-				actualEnv.getKotlin().getVersion());
 	}
 
 	@Test
@@ -184,7 +184,7 @@ public class InitializrMetadataBuilderTests {
 				actualEnv.getSpringBootMetadataUrl());
 		assertEquals("FooBarApplication", actualEnv.getFallbackApplicationName());
 		assertEquals(false, actualEnv.isForceSsl());
-		assertEquals("1.0.0-beta-2423", actualEnv.getKotlin().getVersion());
+		assertEquals("1.0.0-beta-2423", actualEnv.getKotlin().getDefaultVersion());
 	}
 
 	@Test

initializr-generator/src/test/java/io/spring/initializr/metadata/InitializrMetadataTests.java

@@ -20,6 +20,7 @@ import java.util.Arrays;
 import java.util.List;
 
 import io.spring.initializr.metadata.BillOfMaterials.Mapping;
+import io.spring.initializr.metadata.InitializrConfiguration.Env.Kotlin;
 import io.spring.initializr.test.metadata.InitializrMetadataTestBuilder;
 import io.spring.initializr.util.Version;
 import org.junit.Rule;
@@ -173,7 +174,11 @@ public class InitializrMetadataTests {
 				"1.3.x.BUILD-SNAPSHOT", null, null, "0.2.0.RELEASE"));
 		InitializrMetadata metadata = InitializrMetadataTestBuilder
 				.withDefaults().addDependencyGroup("test", dependency)
-				.addBom("foo-bom", bom).build();
+				.addBom("foo-bom", bom)
+				.setKotlinEnv("1.3",
+						createKotlinVersionMapping("[1.2.0.RELEASE,1.3.x.RELEASE]", "1.1"),
+						createKotlinVersionMapping("1.3.x.BUILD-SNAPSHOT", "1.2"))
+				.build();
 
 		List<DefaultMetadataElement> bootVersions = Arrays.asList(
 				DefaultMetadataElement.create("1.3.6.RELEASE", "1.3.6", false),
@@ -187,6 +192,8 @@ public class InitializrMetadataTests {
 				.resolve(Version.parse("1.3.6.RELEASE")).getVersion()).isEqualTo("0.1.0.RELEASE");
 		assertThat(metadata.getDependencies().get("bar")
 				.resolve(Version.parse("1.3.7.BUILD-SNAPSHOT")).getVersion()).isEqualTo("0.2.0.RELEASE");
+		assertThat(metadata.getConfiguration().getEnv().getKotlin()
+				.resolveKotlinVersion(Version.parse("1.3.7.BUILD-SNAPSHOT"))).isEqualTo("1.2");
 	}
 
 	@Test
@@ -212,4 +219,12 @@ public class InitializrMetadataTests {
 		assertThat(metadata.getPackageName().getContent()).isEqualTo("org.acme.foobar");
 	}
 
+	private Kotlin.Mapping createKotlinVersionMapping(String versionRange,
+			String kotlinVersion){
+		Kotlin.Mapping mapping = new Kotlin.Mapping();
+		mapping.setVersionRange(versionRange);
+		mapping.setVersion(kotlinVersion);
+		return mapping;
+	}
+
 }

initializr-generator/src/test/java/io/spring/initializr/test/metadata/InitializrMetadataTestBuilder.java

@@ -24,6 +24,7 @@ import io.spring.initializr.metadata.BillOfMaterials;
 import io.spring.initializr.metadata.DefaultMetadataElement;
 import io.spring.initializr.metadata.Dependency;
 import io.spring.initializr.metadata.DependencyGroup;
+import io.spring.initializr.metadata.InitializrConfiguration.Env.Kotlin;
 import io.spring.initializr.metadata.InitializrConfiguration.Env.Maven.ParentPom;
 import io.spring.initializr.metadata.InitializrMetadata;
 import io.spring.initializr.metadata.InitializrMetadataBuilder;
@@ -190,9 +191,15 @@ public class InitializrMetadataTestBuilder {
 		return this;
 	}
 
-	public InitializrMetadataTestBuilder setKotlinEnv(String kotlinVersion) {
+	public InitializrMetadataTestBuilder setKotlinEnv(String defaultKotlinVersion,
-		builder.withCustomizer(it -> it.getConfiguration().getEnv()
+			Kotlin.Mapping... mappings) {
-				.getKotlin().setVersion(kotlinVersion));
+		builder.withCustomizer(it -> {
+			it.getConfiguration().getEnv().getKotlin()
+					.setDefaultVersion(defaultKotlinVersion);
+			for (Kotlin.Mapping mapping : mappings) {
+				it.getConfiguration().getEnv().getKotlin().getMappings().add(mapping);
+			}
+		});
 		return this;
 	}
 

initializr-generator/src/test/resources/application-test-custom-env.yml

@@ -7,4 +7,4 @@ initializr:
     invalidApplicationNames:
       - InvalidApplication
     kotlin:
-      version: 1.0.0-beta-2423
+      default-version: 1.0.0-beta-2423

initializr-generator/src/test/resources/application-test-default.yml

@@ -22,6 +22,13 @@ initializr:
         artifactId: my-api-dependencies-bom
         version: 1.0.0.RELEASE
         repositories: my-api-repo-3
+    kotlin:
+      defaultVersion: 1.2
+      mappings:
+        - versionRange: "[1.0.0.RELEASE,1.2.0.RELEASE)"
+          version: 1.0
+        - versionRange: "[1.2.0.RELEASE,1.5.0.RELEASE)"
+          version: 1.1
     repositories:
       my-api-repo-1:
         name: repo1

initializr-service/src/main/resources/application.yml

@@ -131,7 +131,7 @@ initializr:
     gradle:
       dependency-management-plugin-version: 0.6.0.RELEASE
     kotlin:
-      version: 1.1.61
+      default-version: 1.1.61
   dependencies:
     - name: Core
       content:

initializr-web/src/test/java/io/spring/initializr/web/project/MainControllerIntegrationTests.java

@@ -117,6 +117,14 @@ public class MainControllerIntegrationTests
 				.hasSpringBootStarterTest();
 	}
 
+	@Test
+	public void kotlinRange() {
+		downloadZip("/starter.zip?style=web&language=kotlin&bootVersion=1.2.1.RELEASE")
+				.isKotlinProject().isMavenProject()
+				.pomAssert().hasDependenciesCount(4)
+				.hasProperty("kotlin.version", "1.1");
+	}
+
 	@Test
 	public void gradleWarProject() {
 		downloadZip("/starter.zip?style=web&style=security&packaging=war&type=gradle.zip")

initializr-web/src/test/resources/metadata/config/test-default.json

@@ -37,7 +37,17 @@
       "dependencyManagementPluginVersion": "1.0.0.RELEASE"
     },
     "kotlin": {
-      "version": null
+      "defaultVersion": "1.2",
+      "mappings": [
+        {
+          "versionRange": "[1.0.0.RELEASE,1.2.0.RELEASE)",
+          "version": "1.0"
+        },
+        {
+          "versionRange": "[1.2.0.RELEASE,1.5.0.RELEASE)",
+          "version": "1.1"
+        }
+      ]
     },
     "maven": {
       "parent": {