Fix version references in Gradle KTS build

Closes gh-901

initializr-generator-spring/src/test/resources/project/gradle/bom-property-build.gradle.kts.gen

@@ -21,6 +21,6 @@ dependencies {
 
 dependencyManagement {
 	imports {
-		mavenBom("org.acme:foo-bom:${fooVersion}")
+		mavenBom("org.acme:foo-bom:${property("fooVersion")}")
 	}
 }

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/gradle/GradleBuildWriter.java

@@ -40,7 +40,6 @@ import io.spring.initializr.generator.buildsystem.gradle.GradleBuild.Configurati
 import io.spring.initializr.generator.buildsystem.gradle.GradleBuild.TaskCustomization;
 import io.spring.initializr.generator.io.IndentingWriter;
 import io.spring.initializr.generator.version.VersionProperty;
-import io.spring.initializr.generator.version.VersionReference;
 
 /**
  * {@link GradleBuild} writer abstraction.
@@ -188,27 +187,7 @@ public abstract class GradleBuildWriter {
 		writer.println("}");
 	}
 
-	private String bomAsString(BillOfMaterials bom) {
+	protected abstract String bomAsString(BillOfMaterials bom);
-		String version = determineVersion(bom.getVersion());
-		return bomAsString(bom, version);
-	}
-
-	protected abstract String bomAsString(BillOfMaterials bom, String version);
-
-	protected final String determineVersion(VersionReference versionReference) {
-		if (versionReference != null) {
-			if (versionReference.isProperty()) {
-				VersionProperty property = versionReference.getProperty();
-				return "${" + (property.isInternal() ? property.toCamelCaseFormat()
-						: externalVersionPropertyAsString(property.toStandardFormat()))
-						+ "}";
-			}
-			return versionReference.getValue();
-		}
-		return null;
-	}
-
-	protected abstract String externalVersionPropertyAsString(String standardFormat);
 
 	protected abstract void writeTasksWithTypeCustomizations(IndentingWriter writer,
 			GradleBuild build);

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/gradle/GroovyDslGradleBuildWriter.java

@@ -24,6 +24,7 @@ import io.spring.initializr.generator.buildsystem.BillOfMaterials;
 import io.spring.initializr.generator.buildsystem.Dependency;
 import io.spring.initializr.generator.buildsystem.MavenRepository;
 import io.spring.initializr.generator.io.IndentingWriter;
+import io.spring.initializr.generator.version.VersionProperty;
 import io.spring.initializr.generator.version.VersionReference;
 
 /**
@@ -138,15 +139,24 @@ public class GroovyDslGradleBuildWriter extends GradleBuildWriter {
 	}
 
 	@Override
-	protected String bomAsString(BillOfMaterials bom, String version) {
+	protected String bomAsString(BillOfMaterials bom) {
 		String quoteStyle = determineQuoteStyle(bom.getVersion());
 		return "mavenBom " + quoteStyle + bom.getGroupId() + ":" + bom.getArtifactId()
-				+ ":" + version + quoteStyle;
+				+ ":" + determineVersion(bom.getVersion()) + quoteStyle;
 	}
 
-	@Override
+	private String determineVersion(VersionReference versionReference) {
-	protected String externalVersionPropertyAsString(String standardFormat) {
+		if (versionReference != null) {
-		return "property('" + standardFormat + "')";
+			if (versionReference.isProperty()) {
+				VersionProperty property = versionReference.getProperty();
+				return "${"
+						+ (property.isInternal() ? property.toCamelCaseFormat()
+								: ("property('" + property.toStandardFormat() + "')"))
+						+ "}";
+			}
+			return versionReference.getValue();
+		}
+		return null;
 	}
 
 	@Override

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/gradle/KotlinDslGradleBuildWriter.java

@@ -27,6 +27,8 @@ import io.spring.initializr.generator.buildsystem.MavenRepository;
 import io.spring.initializr.generator.buildsystem.gradle.GradleBuild.ConfigurationCustomization;
 import io.spring.initializr.generator.buildsystem.gradle.GradleBuild.TaskCustomization;
 import io.spring.initializr.generator.io.IndentingWriter;
+import io.spring.initializr.generator.version.VersionProperty;
+import io.spring.initializr.generator.version.VersionReference;
 
 /**
  * A {@link GradleBuild} writer for {@code build.gradle.kts}.
@@ -151,14 +153,22 @@ public class KotlinDslGradleBuildWriter extends GradleBuildWriter {
 	}
 
 	@Override
-	protected String bomAsString(BillOfMaterials bom, String version) {
+	protected String bomAsString(BillOfMaterials bom) {
 		return "mavenBom(\"" + bom.getGroupId() + ":" + bom.getArtifactId() + ":"
-				+ version + "\")";
+				+ determineVersion(bom.getVersion()) + "\")";
 	}
 
-	@Override
+	private String determineVersion(VersionReference versionReference) {
-	protected String externalVersionPropertyAsString(String standardFormat) {
+		if (versionReference != null) {
-		return "property(\"" + standardFormat + "\")";
+			if (versionReference.isProperty()) {
+				VersionProperty property = versionReference.getProperty();
+				return "${property(\"" + (property.isInternal()
+						? property.toCamelCaseFormat() : property.toStandardFormat())
+						+ "\")}";
+			}
+			return versionReference.getValue();
+		}
+		return null;
 	}
 
 	@Override

initializr-generator/src/test/java/io/spring/initializr/generator/buildsystem/gradle/KotlinDslGradleBuildWriterTests.java

@@ -251,7 +251,7 @@ class KotlinDslGradleBuildWriterTests {
 				DependencyScope.COMPILE);
 		List<String> lines = generateBuild(build);
 		assertThat(lines).containsSequence("dependencies {",
-				"    implementation(\"org.jetbrains.kotlin:kotlin-stdlib-jdk8:${kotlinVersion}\")",
+				"    implementation(\"org.jetbrains.kotlin:kotlin-stdlib-jdk8:${property(\"kotlinVersion\")}\")",
 				"}");
 	}
 
@@ -425,7 +425,7 @@ class KotlinDslGradleBuildWriterTests {
 		List<String> lines = generateBuild(build);
 		assertThat(lines).containsSequence("dependencyManagement {", "    imports {",
 				"        mavenBom(\"com.example:my-project-dependencies:1.0.0.RELEASE\")",
-				"        mavenBom(\"com.example:root-dependencies:${rootVersion}\")",
+				"        mavenBom(\"com.example:root-dependencies:${property(\"rootVersion\")}\")",
 				"    }", "}");
 	}