Harmonize assertions on text file content

This commit harmonizes assertions on text file content by sharing the
code that reads and validate candidates. Make sure that streams are
properly closed which may fix build failures on Windows.

See gh-862

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/build/gradle/GradleProjectGenerationConfigurationTests.java

@@ -16,10 +16,7 @@
 
 package io.spring.initializr.generator.spring.build.gradle;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
@@ -46,8 +43,6 @@ import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -115,7 +110,7 @@ class GradleProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void buildDotGradleIsContributedWhenGeneratingGradleProject() throws IOException {
+	void buildDotGradleIsContributedWhenGeneratingGradleProject() {
 		ProjectDescription description = new ProjectDescription();
 		description.setPlatformVersion(Version.parse("2.1.0.RELEASE"));
 		description.setLanguage(new JavaLanguage("11"));
@@ -124,8 +119,7 @@ class GradleProjectGenerationConfigurationTests {
 		ProjectStructure projectStructure = this.projectTester.generate(description);
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths).contains("build.gradle");
-		Path path = projectStructure.resolve("build.gradle");
+		List<String> lines = projectStructure.readAllLines("build.gradle");
-		String[] lines = readAllLines(path);
 		assertThat(lines).containsExactly("plugins {",
 				"    id 'org.springframework.boot' version '2.1.0.RELEASE'",
 				"    id 'java'", "}", "",
@@ -173,12 +167,4 @@ class GradleProjectGenerationConfigurationTests {
 		assertThat(generate).hasSize((contributorExpected) ? 1 : 0);
 	}
 
-	private static String[] readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		String[] lines = content.split("\\r?\\n");
-		assertThat(content).endsWith(System.lineSeparator());
-		return lines;
-	}
-
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/build/gradle/SettingsGradleProjectContributorTests.java

@@ -24,6 +24,7 @@ import java.util.List;
 import io.spring.initializr.generator.buildsystem.gradle.GradleBuild;
 import io.spring.initializr.generator.io.IndentingWriterFactory;
 import io.spring.initializr.generator.io.SimpleIndentStrategy;
+import io.spring.initializr.generator.test.project.ProjectStructure;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -78,9 +79,7 @@ class SettingsGradleProjectContributorTests {
 		Path projectDir = Files.createTempDirectory(this.directory, "project-");
 		new SettingsGradleProjectContributor(build, indentingWriterFactory)
 				.contribute(projectDir);
-		Path settingsGradle = projectDir.resolve("settings.gradle");
+		return new ProjectStructure(projectDir).readAllLines("settings.gradle");
-		assertThat(settingsGradle).isRegularFile();
-		return Files.readAllLines(settingsGradle);
 	}
 
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/code/groovy/GroovyProjectGenerationConfigurationTests.java

@@ -16,12 +16,7 @@
 
 package io.spring.initializr.generator.spring.code.groovy;
 
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
-import java.util.Arrays;
 import java.util.List;
 
 import io.spring.initializr.generator.buildsystem.maven.MavenBuildSystem;
@@ -36,8 +31,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -70,14 +63,14 @@ class GroovyProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void testClassIsContributed() throws IOException {
+	void testClassIsContributed() {
 		ProjectStructure projectStructure = this.projectTester
 				.generate(new ProjectDescription());
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/test/groovy/com/example/demo/DemoApplicationTests.groovy");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure.readAllLines(
-				.resolve("src/test/groovy/com/example/demo/DemoApplicationTests.groovy"));
+				"src/test/groovy/com/example/demo/DemoApplicationTests.groovy");
 		assertThat(lines).containsExactly("package com.example.demo", "",
 				"import org.junit.Test", "import org.junit.runner.RunWith",
 				"import org.springframework.boot.test.context.SpringBootTest",
@@ -88,8 +81,7 @@ class GroovyProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging()
+	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging() {
-			throws IOException {
 		ProjectDescription description = new ProjectDescription();
 		description.setPackaging(new WarPackaging());
 		description.setApplicationName("Demo2Application");
@@ -97,8 +89,8 @@ class GroovyProjectGenerationConfigurationTests {
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/main/groovy/com/example/demo/ServletInitializer.groovy");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure.readAllLines(
-				.resolve("src/main/groovy/com/example/demo/ServletInitializer.groovy"));
+				"src/main/groovy/com/example/demo/ServletInitializer.groovy");
 		assertThat(lines).containsExactly("package com.example.demo", "",
 				"import org.springframework.boot.builder.SpringApplicationBuilder",
 				"import org.springframework.boot.web.servlet.support.SpringBootServletInitializer",
@@ -108,12 +100,4 @@ class GroovyProjectGenerationConfigurationTests {
 				"        application.sources(Demo2Application)", "    }", "", "}");
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		String[] lines = content.split("\\r?\\n");
-		assertThat(content).endsWith(System.lineSeparator());
-		return Arrays.asList(lines);
-	}
-
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/code/java/JavaProjectGenerationConfigurationTests.java

@@ -16,12 +16,7 @@
 
 package io.spring.initializr.generator.spring.code.java;
 
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
-import java.util.Arrays;
 import java.util.List;
 
 import io.spring.initializr.generator.buildsystem.maven.MavenBuildSystem;
@@ -36,8 +31,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -71,14 +64,14 @@ class JavaProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void testClassIsContributed() throws IOException {
+	void testClassIsContributed() {
 		ProjectDescription description = new ProjectDescription();
 		ProjectStructure projectStructure = this.projectTester.generate(description);
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/test/java/com/example/demo/DemoApplicationTests.java");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure
-				.resolve("src/test/java/com/example/demo/DemoApplicationTests.java"));
+				.readAllLines("src/test/java/com/example/demo/DemoApplicationTests.java");
 		assertThat(lines).containsExactly("package com.example.demo;", "",
 				"import org.junit.Test;", "import org.junit.runner.RunWith;",
 				"import org.springframework.boot.test.context.SpringBootTest;",
@@ -89,8 +82,7 @@ class JavaProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging()
+	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging() {
-			throws IOException {
 		ProjectDescription description = new ProjectDescription();
 		description.setPackaging(new WarPackaging());
 		description.setApplicationName("MyDemoApplication");
@@ -98,8 +90,8 @@ class JavaProjectGenerationConfigurationTests {
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/main/java/com/example/demo/ServletInitializer.java");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure
-				.resolve("src/main/java/com/example/demo/ServletInitializer.java"));
+				.readAllLines("src/main/java/com/example/demo/ServletInitializer.java");
 		assertThat(lines).containsExactly("package com.example.demo;", "",
 				"import org.springframework.boot.builder.SpringApplicationBuilder;",
 				"import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;",
@@ -133,12 +125,4 @@ class JavaProjectGenerationConfigurationTests {
 				"src/test/java/com/example/demo/MyApplicationTests.java");
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		String[] lines = content.split("\\r?\\n");
-		assertThat(content).endsWith(System.lineSeparator());
-		return Arrays.asList(lines);
-	}
-
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/code/kotlin/KotlinProjectGenerationConfigurationTests.java

@@ -16,12 +16,7 @@
 
 package io.spring.initializr.generator.spring.code.kotlin;
 
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Path;
-import java.util.Arrays;
 import java.util.List;
 
 import io.spring.initializr.generator.buildsystem.maven.MavenBuildSystem;
@@ -36,8 +31,6 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -73,14 +66,14 @@ class KotlinProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void testClassIsContributed() throws IOException {
+	void testClassIsContributed() {
 		ProjectStructure projectStructure = this.projectTester
 				.generate(new ProjectDescription());
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/test/kotlin/com/example/demo/DemoApplicationTests.kt");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure
-				.resolve("src/test/kotlin/com/example/demo/DemoApplicationTests.kt"));
+				.readAllLines("src/test/kotlin/com/example/demo/DemoApplicationTests.kt");
 		assertThat(lines).containsExactly("package com.example.demo", "",
 				"import org.junit.Test", "import org.junit.runner.RunWith",
 				"import org.springframework.boot.test.context.SpringBootTest",
@@ -91,8 +84,7 @@ class KotlinProjectGenerationConfigurationTests {
 	}
 
 	@Test
-	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging()
+	void servletInitializerIsContributedWhenGeneratingProjectThatUsesWarPackaging() {
-			throws IOException {
 		ProjectDescription description = new ProjectDescription();
 		description.setPackaging(new WarPackaging());
 		description.setApplicationName("KotlinDemoApplication");
@@ -100,8 +92,8 @@ class KotlinProjectGenerationConfigurationTests {
 		List<String> relativePaths = projectStructure.getRelativePathsOfProjectFiles();
 		assertThat(relativePaths)
 				.contains("src/main/kotlin/com/example/demo/ServletInitializer.kt");
-		List<String> lines = readAllLines(projectStructure
+		List<String> lines = projectStructure
-				.resolve("src/main/kotlin/com/example/demo/ServletInitializer.kt"));
+				.readAllLines("src/main/kotlin/com/example/demo/ServletInitializer.kt");
 		assertThat(lines).containsExactly("package com.example.demo", "",
 				"import org.springframework.boot.builder.SpringApplicationBuilder",
 				"import org.springframework.boot.web.servlet.support.SpringBootServletInitializer",
@@ -111,12 +103,4 @@ class KotlinProjectGenerationConfigurationTests {
 				"    }", "", "}");
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		String[] lines = content.split("\\r?\\n");
-		assertThat(content).endsWith(System.lineSeparator());
-		return Arrays.asList(lines);
-	}
-
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/configuration/ApplicationPropertiesContributorTests.java

@@ -21,6 +21,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.List;
 
+import io.spring.initializr.generator.test.project.ProjectStructure;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -40,11 +41,9 @@ class ApplicationPropertiesContributorTests {
 	void applicationConfigurationWithDefaultSettings() throws IOException {
 		Path projectDir = Files.createTempDirectory(this.directory, "project-");
 		new ApplicationPropertiesContributor().contribute(projectDir);
-		Path configuration = projectDir
+		List<String> lines = new ProjectStructure(projectDir)
-				.resolve("src/main/resources/application.properties");
+				.readAllLines("src/main/resources/application.properties");
-		assertThat(configuration).isRegularFile();
+		assertThat(lines).isEmpty();
-		List<String> lines = Files.readAllLines(configuration);
-		assertThat(lines).containsOnly("");
 	}
 
 }

initializr-generator-spring/src/test/java/io/spring/initializr/generator/spring/documentation/HelpDocumentProjectContributorTests.java

@@ -22,6 +22,7 @@ import java.nio.file.Path;
 import java.util.List;
 
 import io.spring.initializr.generator.io.template.MustacheTemplateRenderer;
+import io.spring.initializr.generator.test.project.ProjectStructure;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -64,7 +65,7 @@ class HelpDocumentProjectContributorTests {
 		assertThat(lines).containsExactly("# Getting Started", "", "### Guides",
 				"The following guides illustrate how to use some features concretely:",
 				"", "* [test](https://test.example.com)",
-				"* [test2](https://test2.example.com)", "");
+				"* [test2](https://test2.example.com)");
 	}
 
 	@Test
@@ -77,7 +78,7 @@ class HelpDocumentProjectContributorTests {
 				"### Reference Documentation",
 				"For further reference, please consider the following sections:", "",
 				"* [doc](https://test.example.com)",
-				"* [doc2](https://test2.example.com)", "");
+				"* [doc2](https://test2.example.com)");
 	}
 
 	@Test
@@ -88,7 +89,7 @@ class HelpDocumentProjectContributorTests {
 		List<String> lines = generateDocument(document);
 		assertThat(lines).containsExactly("# Getting Started", "", "### Additional Links",
 				"These additional references should also help you:", "",
-				"* [Something](https://test.example.com)", "");
+				"* [Something](https://test.example.com)");
 	}
 
 	@Test
@@ -116,9 +117,7 @@ class HelpDocumentProjectContributorTests {
 	private List<String> generateDocument(HelpDocument document) throws IOException {
 		Path projectDir = Files.createTempDirectory(this.directory, "project-");
 		new HelpDocumentProjectContributor(document).contribute(projectDir);
-		Path helpDocument = projectDir.resolve("HELP.md");
+		return new ProjectStructure(projectDir).readAllLines("HELP.md");
-		assertThat(helpDocument).isRegularFile();
-		return Files.readAllLines(helpDocument);
 	}
 
 }

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

@@ -16,25 +16,20 @@
 
 package io.spring.initializr.generator.language.groovy;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.lang.reflect.Modifier;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.time.temporal.ChronoUnit;
-import java.util.Arrays;
 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.test.io.PathTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -218,8 +213,7 @@ class GroovySourceCodeWriterTests {
 	private List<String> writeSingleType(GroovySourceCode sourceCode, String location)
 			throws IOException {
 		Path source = writeSourceCode(sourceCode).resolve(location);
-		assertThat(source).isRegularFile();
+		return PathTestUtils.readAllLines(source);
-		return readAllLines(source);
 	}
 
 	private Path writeSourceCode(GroovySourceCode sourceCode) throws IOException {
@@ -228,12 +222,4 @@ class GroovySourceCodeWriterTests {
 		return projectDirectory;
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		String[] lines = content.split("\\r?\\n");
-		assertThat(content).endsWith(System.lineSeparator());
-		return Arrays.asList(lines);
-	}
-
 }

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

@@ -16,25 +16,20 @@
 
 package io.spring.initializr.generator.language.java;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.lang.reflect.Modifier;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.time.temporal.ChronoUnit;
-import java.util.Arrays;
 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.test.io.PathTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -220,8 +215,7 @@ class JavaSourceCodeWriterTests {
 	private List<String> writeSingleType(JavaSourceCode sourceCode, String location)
 			throws IOException {
 		Path source = writeSourceCode(sourceCode).resolve(location);
-		assertThat(source).isRegularFile();
+		return PathTestUtils.readAllLines(source);
-		return readAllLines(source);
 	}
 
 	private Path writeSourceCode(JavaSourceCode sourceCode) throws IOException {
@@ -230,12 +224,4 @@ class JavaSourceCodeWriterTests {
 		return projectDirectory;
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		assertThat(content).endsWith(System.lineSeparator());
-		String[] lines = content.split("\\r?\\n");
-		return Arrays.asList(lines);
-	}
-
 }

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

@@ -16,24 +16,19 @@
 
 package io.spring.initializr.generator.language.kotlin;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
-import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.time.temporal.ChronoUnit;
-import java.util.Arrays;
 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.test.io.PathTestUtils;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
-import org.springframework.util.StreamUtils;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
@@ -230,8 +225,7 @@ class KotlinSourceCodeWriterTests {
 	private List<String> writeSingleType(KotlinSourceCode sourceCode, String location)
 			throws IOException {
 		Path source = writeSourceCode(sourceCode).resolve(location);
-		assertThat(source).isRegularFile();
+		return PathTestUtils.readAllLines(source);
-		return readAllLines(source);
 	}
 
 	private Path writeSourceCode(KotlinSourceCode sourceCode) throws IOException {
@@ -240,12 +234,4 @@ class KotlinSourceCodeWriterTests {
 		return projectDirectory;
 	}
 
-	private static List<String> readAllLines(Path file) throws IOException {
-		String content = StreamUtils.copyToString(
-				new FileInputStream(new File(file.toString())), StandardCharsets.UTF_8);
-		assertThat(content).endsWith(System.lineSeparator());
-		String[] lines = content.split("\\r?\\n");
-		return Arrays.asList(lines);
-	}
-
 }

initializr-generator/src/test/java/io/spring/initializr/generator/test/io/PathTestUtils.java

@@ -0,0 +1,65 @@
+/*
+ * 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
+ *
+ *      http://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.test.io;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Arrays;
+import java.util.List;
+
+import org.springframework.util.FileCopyUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * {@link Path}-related test utilities.
+ *
+ * @author Stephane Nicoll
+ */
+public final class PathTestUtils {
+
+	private PathTestUtils() {
+	}
+
+	/**
+	 * Read all lines from the specified {@link Path source}. Check the given
+	 * {@code source} is a regular file that ends with a new line.
+	 * @param source a text file
+	 * @return all lines from the file
+	 */
+	public static List<String> readAllLines(Path source) {
+		assertThat(source).isRegularFile();
+		try {
+			BufferedReader reader = Files.newBufferedReader(source,
+					StandardCharsets.UTF_8);
+			StringWriter writer = new StringWriter();
+			FileCopyUtils.copy(reader, writer);
+			String content = writer.toString();
+			String[] lines = content.split("\\r?\\n");
+			assertThat(content).endsWith(System.lineSeparator());
+			return Arrays.asList(lines);
+		}
+		catch (IOException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
+}

initializr-generator/src/test/java/io/spring/initializr/generator/test/project/ProjectStructure.java

@@ -25,6 +25,8 @@ import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
 import java.util.List;
 
+import io.spring.initializr.generator.test.io.PathTestUtils;
+
 /**
  * Test helper to assert content of a generated project structure.
  *
@@ -51,7 +53,7 @@ public class ProjectStructure {
 	}
 
 	/**
-	 * Resolve a {@link Path} relative to the project directory
+	 * Resolve a {@link Path} relative to the project directory.
 	 * @param other the path string to resolve against the root of the project structure
 	 * @return the resulting path
 	 * @see Path#resolve(String)
@@ -60,6 +62,18 @@ public class ProjectStructure {
 		return this.projectDirectory.resolve(other);
 	}
 
+	/**
+	 * Resolve a {@link Path} relative to the project directory and return all lines.
+	 * Check that the resolved {@link Path} is a regular text file that ends with a
+	 * newline.
+	 * @param other the path string to resolve against the root of the project structure
+	 * @return all lines from the resolve file
+	 * @see PathTestUtils#readAllLines(Path)
+	 */
+	public List<String> readAllLines(String other) {
+		return PathTestUtils.readAllLines(resolve(other));
+	}
+
 	/**
 	 * Return the relative paths of all files.
 	 * @return the relative path of all files