Polish "Use NBT plugin version from gradle.properties in image tests"

See gh-32643

spring-boot-project/spring-boot-tools/spring-boot-gradle-test-support/src/main/java/org/springframework/boot/testsupport/gradle/testkit/GradleBuild.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.testsupport.gradle.testkit;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
@@ -28,6 +29,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Properties;
 import java.util.jar.JarFile;
 
 import com.fasterxml.jackson.annotation.JsonView;
@@ -57,6 +59,7 @@ import org.springframework.util.FileCopyUtils;
 import org.springframework.util.FileSystemUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.fail;
 
 /**
  * A {@code GradleBuild} is used to run a Gradle build using {@link GradleRunner}.
@@ -176,6 +179,11 @@ public class GradleBuild {
 		return this;
 	}
 
+	public GradleBuild scriptPropertyFrom(File propertiesFile, String key) {
+		this.scriptProperties.put(key, getProperty(propertiesFile, key));
+		return this;
+	}
+
 	public BuildResult build(String... arguments) {
 		try {
 			BuildResult result = prepareRunner(arguments).build();
@@ -291,4 +299,23 @@ public class GradleBuild {
 		}
 	}
 
+	private String getProperty(File propertiesFile, String key) {
+		try {
+			assertThat(propertiesFile).withFailMessage("Expecting properties file to exist at path '%s'",
+					propertiesFile.getCanonicalFile()).exists();
+			Properties properties = new Properties();
+			try (FileInputStream input = new FileInputStream(propertiesFile)) {
+				properties.load(input);
+				String value = properties.getProperty(key);
+				assertThat(value).withFailMessage("Expecting properties file '%s' to contain the key '%s'",
+						propertiesFile.getCanonicalFile(), key).isNotEmpty();
+				return value;
+			}
+		}
+		catch (IOException ex) {
+			fail("Error reading properties file '" + propertiesFile + "'");
+			return null;
+		}
+	}
+
 }

spring-boot-system-tests/spring-boot-image-tests/src/systemTest/java/org/springframework/boot/image/paketo/PaketoBuilderTests.java

@@ -17,7 +17,6 @@
 package org.springframework.boot.image.paketo;
 
 import java.io.File;
-import java.io.FileInputStream;
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
@@ -25,7 +24,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Properties;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import java.util.jar.Attributes;
@@ -73,19 +71,11 @@ class PaketoBuilderTests {
 	void configureGradleBuild() throws IOException {
 		this.gradleBuild.scriptProperty("systemTestMavenRepository",
 				new File("build/system-test-maven-repository").getAbsoluteFile().toURI().toASCIIString());
-		this.gradleBuild.scriptProperty("nativeBuildToolsVersion", getNativeBuildToolsVersion());
+		this.gradleBuild.scriptPropertyFrom(new File("../../gradle.properties"), "nativeBuildToolsVersion");
 		this.gradleBuild.expectDeprecationMessages("BPL_SPRING_CLOUD_BINDINGS_ENABLED.*true.*Deprecated");
 		this.gradleBuild.expectDeprecationMessages("BOM table is deprecated");
 	}
 
-	private String getNativeBuildToolsVersion() throws IOException {
-		Properties gradleProperties = new Properties();
-		try (FileInputStream input = new FileInputStream("../../gradle.properties")) {
-			gradleProperties.load(input);
-			return gradleProperties.getProperty("nativeBuildToolsVersion");
-		}
-	}
-
 	@Test
 	void executableJarApp() throws Exception {
 		writeMainClass();