Add SourceCodeStructure abstraction

Closes gh-987

initializr-generator/src/main/java/io/spring/initializr/generator/buildsystem/BuildSystem.java

@@ -20,6 +20,7 @@ import java.nio.file.Path;
 import java.util.Objects;
 
 import io.spring.initializr.generator.language.Language;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 
 import org.springframework.core.io.support.SpringFactoriesLoader;
 
@@ -45,12 +46,12 @@ public interface BuildSystem {
 		return null;
 	}
 
-	default Path getMainDirectory(Path projectRoot, Language language) {
-		return projectRoot.resolve("src/main/" + language.id());
+	default SourceCodeStructure getMainDirectory(Path projectRoot, Language language) {
+		return new SourceCodeStructure(projectRoot.resolve("src/main/" + language.id()));
 	}
 
-	default Path getTestDirectory(Path projectRoot, Language language) {
-		return projectRoot.resolve("src/test/" + language.id());
+	default SourceCodeStructure getTestDirectory(Path projectRoot, Language language) {
+		return new SourceCodeStructure(projectRoot.resolve("src/test/" + language.id()));
 	}
 
 	static BuildSystem forId(String id) {

initializr-generator/src/main/java/io/spring/initializr/generator/language/SourceCodeStructure.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr.generator.language;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * Provide dedicated method for directories that hold code.
+ *
+ * @author Stephane Nicoll
+ */
+public class SourceCodeStructure {
+
+	private final Path rootDirectory;
+
+	public SourceCodeStructure(Path rootDirectory) {
+		this.rootDirectory = rootDirectory;
+	}
+
+	public Path getRootDirectory() {
+		return this.rootDirectory;
+	}
+
+	/**
+	 * Resource a source file, creating its package structure if necessary.
+	 * @param packageName the name of the package
+	 * @param file the name of the file (including its extension)
+	 * @return the file to use to store a {@code CompilationUnit} with the specified
+	 * package name name
+	 * @throws IOException if an error occurred while trying to create the directory
+	 * structure
+	 */
+	public Path resolveSourceFile(String packageName, String file) throws IOException {
+		return createPackage(packageName).resolve(file);
+	}
+
+	/**
+	 * Create the specified package if necessary.
+	 * @param packageName the name of the package to create
+	 * @return the directory where source code to this package should reside
+	 * @throws IOException if an error occurred while trying to create the directory
+	 * structure
+	 */
+	public Path createPackage(String packageName) throws IOException {
+		if (!Files.exists(this.rootDirectory)) {
+			Files.createDirectories(this.rootDirectory);
+		}
+		Path directory = this.rootDirectory.resolve(packageName.replace('.', '/'));
+		Files.createDirectories(directory);
+		return directory;
+	}
+
+}

initializr-generator/src/main/java/io/spring/initializr/generator/language/SourceCodeWriter.java

@@ -17,7 +17,6 @@
 package io.spring.initializr.generator.language;
 
 import java.io.IOException;
-import java.nio.file.Path;
 
 /**
  * A writer for some {@link SourceCode}.
@@ -28,11 +27,12 @@ import java.nio.file.Path;
 public interface SourceCodeWriter<S extends SourceCode<?, ?>> {
 
 	/**
-	 * Writes, to the given {@code directory}, the given {@code sourceCode}.
-	 * @param directory the root directory beneath which the source code is written
+	 * Write, to the given {@code structure}, the given {@code sourceCode}.
+	 * @param structure the {@link SourceCodeStructure} beneath which the source code is
+	 * written
 	 * @param sourceCode the source code to write
 	 * @throws IOException if writing fails
 	 */
-	void writeTo(Path directory, S sourceCode) throws IOException;
+	void writeTo(SourceCodeStructure structure, S sourceCode) throws IOException;
 
 }

initializr-generator/src/main/java/io/spring/initializr/generator/language/groovy/GroovySourceCodeWriter.java

@@ -40,6 +40,7 @@ import io.spring.initializr.generator.language.Annotatable;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
 import io.spring.initializr.generator.language.SourceCode;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.language.SourceCodeWriter;
 
 /**
@@ -87,18 +88,15 @@ public class GroovySourceCodeWriter implements SourceCodeWriter<GroovySourceCode
 	}
 
 	@Override
-	public void writeTo(Path directory, GroovySourceCode sourceCode) throws IOException {
-		if (!Files.exists(directory)) {
-			Files.createDirectories(directory);
-		}
+	public void writeTo(SourceCodeStructure structure, GroovySourceCode sourceCode) throws IOException {
 		for (GroovyCompilationUnit compilationUnit : sourceCode.getCompilationUnits()) {
-			writeTo(directory, compilationUnit);
+			writeTo(structure, compilationUnit);
 		}
 	}
 
-	private void writeTo(Path directory, GroovyCompilationUnit compilationUnit) throws IOException {
-		Path output = fileForCompilationUnit(directory, compilationUnit);
-		Files.createDirectories(output.getParent());
+	private void writeTo(SourceCodeStructure structure, GroovyCompilationUnit compilationUnit) throws IOException {
+		Path output = structure.resolveSourceFile(compilationUnit.getPackageName(),
+				compilationUnit.getName() + ".groovy");
 		try (IndentingWriter writer = this.indentingWriterFactory.createIndentingWriter("groovy",
 				Files.newBufferedWriter(output))) {
 			writer.println("package " + compilationUnit.getPackageName());
@@ -248,15 +246,6 @@ public class GroovySourceCodeWriter implements SourceCodeWriter<GroovySourceCode
 				+ String.join(", ", methodInvocation.getArguments()) + ")");
 	}
 
-	private Path fileForCompilationUnit(Path directory, GroovyCompilationUnit compilationUnit) {
-		return directoryForPackage(directory, compilationUnit.getPackageName())
-				.resolve(compilationUnit.getName() + ".groovy");
-	}
-
-	private Path directoryForPackage(Path directory, String packageName) {
-		return directory.resolve(packageName.replace('.', '/'));
-	}
-
 	private Set<String> determineImports(GroovyCompilationUnit compilationUnit) {
 		List<String> imports = new ArrayList<>();
 		for (GroovyTypeDeclaration typeDeclaration : compilationUnit.getTypeDeclarations()) {

initializr-generator/src/main/java/io/spring/initializr/generator/language/java/JavaSourceCodeWriter.java

@@ -40,6 +40,7 @@ import io.spring.initializr.generator.language.Annotatable;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
 import io.spring.initializr.generator.language.SourceCode;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.language.SourceCodeWriter;
 
 /**
@@ -88,17 +89,15 @@ public class JavaSourceCodeWriter implements SourceCodeWriter<JavaSourceCode> {
 	}
 
 	@Override
-	public void writeTo(Path directory, JavaSourceCode sourceCode) throws IOException {
-		if (!Files.exists(directory)) {
-			Files.createDirectories(directory);
-		}
+	public void writeTo(SourceCodeStructure structure, JavaSourceCode sourceCode) throws IOException {
 		for (JavaCompilationUnit compilationUnit : sourceCode.getCompilationUnits()) {
-			writeTo(directory, compilationUnit);
+			writeTo(structure, compilationUnit);
 		}
 	}
 
-	private void writeTo(Path directory, JavaCompilationUnit compilationUnit) throws IOException {
-		Path output = fileForCompilationUnit(directory, compilationUnit);
+	private void writeTo(SourceCodeStructure structure, JavaCompilationUnit compilationUnit) throws IOException {
+		Path output = structure.resolveSourceFile(compilationUnit.getPackageName(),
+				compilationUnit.getName() + ".java");
 		Files.createDirectories(output.getParent());
 		try (IndentingWriter writer = this.indentingWriterFactory.createIndentingWriter("java",
 				Files.newBufferedWriter(output))) {
@@ -250,15 +249,6 @@ public class JavaSourceCodeWriter implements SourceCodeWriter<JavaSourceCode> {
 				+ String.join(", ", methodInvocation.getArguments()) + ")");
 	}
 
-	private Path fileForCompilationUnit(Path directory, JavaCompilationUnit compilationUnit) {
-		return directoryForPackage(directory, compilationUnit.getPackageName())
-				.resolve(compilationUnit.getName() + ".java");
-	}
-
-	private Path directoryForPackage(Path directory, String packageName) {
-		return directory.resolve(packageName.replace('.', '/'));
-	}
-
 	private Set<String> determineImports(JavaCompilationUnit compilationUnit) {
 		List<String> imports = new ArrayList<>();
 		for (JavaTypeDeclaration typeDeclaration : compilationUnit.getTypeDeclarations()) {

initializr-generator/src/main/java/io/spring/initializr/generator/language/kotlin/KotlinSourceCodeWriter.java

@@ -36,6 +36,7 @@ import io.spring.initializr.generator.language.Annotatable;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
 import io.spring.initializr.generator.language.SourceCode;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.language.SourceCodeWriter;
 
 /**
@@ -53,17 +54,14 @@ public class KotlinSourceCodeWriter implements SourceCodeWriter<KotlinSourceCode
 	}
 
 	@Override
-	public void writeTo(Path directory, KotlinSourceCode sourceCode) throws IOException {
-		if (!Files.exists(directory)) {
-			Files.createDirectories(directory);
-		}
+	public void writeTo(SourceCodeStructure structure, KotlinSourceCode sourceCode) throws IOException {
 		for (KotlinCompilationUnit compilationUnit : sourceCode.getCompilationUnits()) {
-			writeTo(directory, compilationUnit);
+			writeTo(structure, compilationUnit);
 		}
 	}
 
-	private void writeTo(Path directory, KotlinCompilationUnit compilationUnit) throws IOException {
-		Path output = fileForCompilationUnit(directory, compilationUnit);
+	private void writeTo(SourceCodeStructure structure, KotlinCompilationUnit compilationUnit) throws IOException {
+		Path output = structure.resolveSourceFile(compilationUnit.getPackageName(), compilationUnit.getName() + ".kt");
 		Files.createDirectories(output.getParent());
 		try (IndentingWriter writer = this.indentingWriterFactory.createIndentingWriter("kotlin",
 				Files.newBufferedWriter(output))) {
@@ -281,15 +279,6 @@ public class KotlinSourceCodeWriter implements SourceCodeWriter<KotlinSourceCode
 				+ String.join(", ", functionInvocation.getArguments()) + ")");
 	}
 
-	private Path fileForCompilationUnit(Path directory, KotlinCompilationUnit compilationUnit) {
-		return directoryForPackage(directory, compilationUnit.getPackageName())
-				.resolve(compilationUnit.getName() + ".kt");
-	}
-
-	private Path directoryForPackage(Path directory, String packageName) {
-		return directory.resolve(packageName.replace('.', '/'));
-	}
-
 	private Set<String> determineImports(KotlinCompilationUnit compilationUnit) {
 		List<String> imports = new ArrayList<>();
 		for (KotlinTypeDeclaration typeDeclaration : compilationUnit.getTypeDeclarations()) {

initializr-generator/src/test/java/io/spring/initializr/generator/buildsystem/BuildSystemTests.java

@@ -20,6 +20,7 @@ import java.nio.file.Path;
 
 import io.spring.initializr.generator.buildsystem.gradle.GradleBuildSystem;
 import io.spring.initializr.generator.buildsystem.maven.MavenBuildSystem;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.language.java.JavaLanguage;
 import io.spring.initializr.generator.language.kotlin.KotlinLanguage;
 import org.junit.jupiter.api.Test;
@@ -53,14 +54,16 @@ class BuildSystemTests {
 
 	@Test
 	void defaultMainDirectory(@TempDir Path directory) {
-		Path mainDirectory = BuildSystem.forId("gradle").getMainDirectory(directory, new JavaLanguage());
-		assertThat(mainDirectory).isEqualTo(directory.resolve("src/main/java"));
+		SourceCodeStructure mainCodeStructure = BuildSystem.forId("gradle").getMainDirectory(directory,
+				new JavaLanguage());
+		assertThat(mainCodeStructure.getRootDirectory()).isEqualTo(directory.resolve("src/main/java"));
 	}
 
 	@Test
 	void defaultTestDirectory(@TempDir Path directory) {
-		Path mainDirectory = BuildSystem.forId("gradle").getTestDirectory(directory, new KotlinLanguage());
-		assertThat(mainDirectory).isEqualTo(directory.resolve("src/test/kotlin"));
+		SourceCodeStructure testCodeStructure = BuildSystem.forId("gradle").getTestDirectory(directory,
+				new KotlinLanguage());
+		assertThat(testCodeStructure.getRootDirectory()).isEqualTo(directory.resolve("src/test/kotlin"));
 	}
 
 	@Test

initializr-generator/src/test/java/io/spring/initializr/generator/language/SourceCodeStructureTests.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2012-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.spring.initializr.generator.language;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link SourceCodeStructure}.
+ *
+ * @author Stephane Nicoll
+ */
+class SourceCodeStructureTests {
+
+	@Test
+	void createPackage(@TempDir Path dir) throws IOException {
+		Path target = new SourceCodeStructure(dir).createPackage("com.example.test");
+		assertThat(target).exists().isDirectory().isEqualByComparingTo(dir.resolve("com/example/test"));
+	}
+
+	@Test
+	void createExistingPackageReturnsExistingDirectory(@TempDir Path dir) throws IOException {
+		Path target = dir.resolve("com/example");
+		Files.createDirectories(target);
+		assertThat(target).exists().isDirectory();
+		Path path = new SourceCodeStructure(dir).createPackage("com.example");
+		assertThat(path).isEqualByComparingTo(target);
+	}
+
+	@Test
+	void resolveSourceFile(@TempDir Path dir) throws IOException {
+		Path rootDir = dir.resolve("com/example");
+		assertThat(rootDir).doesNotExist();
+		Path target = rootDir.resolve("Test.java");
+		Path path = new SourceCodeStructure(dir).resolveSourceFile("com.example", "Test.java");
+		assertThat(path).doesNotExist().isEqualByComparingTo(target);
+		assertThat(rootDir).exists().isDirectory();
+	}
+
+	@Test
+	void resolveSourceFileWithExistingPackage(@TempDir Path dir) throws IOException {
+		Path rootDir = dir.resolve("com/example");
+		Files.createDirectories(rootDir);
+		assertThat(rootDir).exists().isDirectory();
+		Path target = rootDir.resolve("Test.java");
+		assertThat(target).doesNotExist();
+		Path path = new SourceCodeStructure(dir).resolveSourceFile("com.example", "Test.java");
+		assertThat(path).doesNotExist().isEqualByComparingTo(target);
+	}
+
+}

initializr-generator/src/test/java/io/spring/initializr/generator/language/groovy/GroovySourceCodeWriterTests.java

@@ -26,6 +26,7 @@ import java.util.List;
 import io.spring.initializr.generator.io.IndentingWriterFactory;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.test.io.TextTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -277,7 +278,7 @@ class GroovySourceCodeWriterTests {
 
 	private Path writeSourceCode(GroovySourceCode sourceCode) throws IOException {
 		Path projectDirectory = Files.createTempDirectory(this.directory, "project-");
-		this.writer.writeTo(projectDirectory, sourceCode);
+		this.writer.writeTo(new SourceCodeStructure(projectDirectory), sourceCode);
 		return projectDirectory;
 	}
 

initializr-generator/src/test/java/io/spring/initializr/generator/language/java/JavaSourceCodeWriterTests.java

@@ -26,6 +26,7 @@ import java.util.List;
 import io.spring.initializr.generator.io.IndentingWriterFactory;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.test.io.TextTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -278,7 +279,7 @@ class JavaSourceCodeWriterTests {
 
 	private Path writeSourceCode(JavaSourceCode sourceCode) throws IOException {
 		Path projectDirectory = Files.createTempDirectory(this.directory, "project-");
-		this.writer.writeTo(projectDirectory, sourceCode);
+		this.writer.writeTo(new SourceCodeStructure(projectDirectory), sourceCode);
 		return projectDirectory;
 	}
 

initializr-generator/src/test/java/io/spring/initializr/generator/language/kotlin/KotlinSourceCodeWriterTests.java

@@ -25,6 +25,7 @@ import java.util.List;
 import io.spring.initializr.generator.io.IndentingWriterFactory;
 import io.spring.initializr.generator.language.Annotation;
 import io.spring.initializr.generator.language.Parameter;
+import io.spring.initializr.generator.language.SourceCodeStructure;
 import io.spring.initializr.generator.test.io.TextTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -335,7 +336,7 @@ class KotlinSourceCodeWriterTests {
 
 	private Path writeSourceCode(KotlinSourceCode sourceCode) throws IOException {
 		Path projectDirectory = Files.createTempDirectory(this.directory, "project-");
-		this.writer.writeTo(projectDirectory, sourceCode);
+		this.writer.writeTo(new SourceCodeStructure(projectDirectory), sourceCode);
 		return projectDirectory;
 	}