Improve validation of layertools input

This commit improves the validation performed on the user
input provided to the layertools jarmode to provide more
clear error messages when the input is not correct and
reduce the chance of ambiguity.

Fixes gh-22042

spring-boot-project/spring-boot-tools/spring-boot-jarmode-layertools/src/test/java/org/springframework/boot/jarmode/layertools/CommandTests.java

@@ -30,11 +30,13 @@ import org.springframework.boot.jarmode.layertools.Command.Parameters;
 
 import static org.assertj.core.api.Assertions.as;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 /**
  * Tests for {@link Command}.
  *
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 class CommandTests {
 
@@ -77,6 +79,20 @@ class CommandTests {
 		assertThat(command.getRunParameters()).containsExactly("test2", "test3");
 	}
 
+	@Test
+	void runWithUnknownOptionThrowsException() {
+		TestCommand command = new TestCommand("test", VERBOSE_FLAG, LOG_LEVEL_OPTION);
+		assertThatExceptionOfType(UnknownOptionException.class).isThrownBy(() -> run(command, "--invalid"))
+				.withMessage("--invalid");
+	}
+
+	@Test
+	void runWithOptionMissingRequiredValueThrowsException() {
+		TestCommand command = new TestCommand("test", VERBOSE_FLAG, LOG_LEVEL_OPTION);
+		assertThatExceptionOfType(MissingValueException.class)
+				.isThrownBy(() -> run(command, "--verbose", "--log-level")).withMessage("--log-level");
+	}
+
 	@Test
 	void findWhenNameMatchesReturnsCommand() {
 		TestCommand test1 = new TestCommand("test1");

spring-boot-project/spring-boot-tools/spring-boot-jarmode-layertools/src/test/java/org/springframework/boot/jarmode/layertools/LayerToolsJarModeTests.java

@@ -39,6 +39,7 @@ import static org.mockito.Mockito.mock;
  * Tests for {@link LayerToolsJarMode}.
  *
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 class LayerToolsJarModeTests {
 
@@ -79,6 +80,24 @@ class LayerToolsJarModeTests {
 		assertThat(this.out).hasSameContentAsResource("list-output.txt");
 	}
 
+	@Test
+	void mainWithUnknownCommandShowsErrorAndHelp() {
+		new LayerToolsJarMode().run("layertools", new String[] { "invalid" });
+		assertThat(this.out).hasSameContentAsResource("error-command-unknown-output.txt");
+	}
+
+	@Test
+	void mainWithUnknownOptionShowsErrorAndCommandHelp() {
+		new LayerToolsJarMode().run("layertools", new String[] { "extract", "--invalid" });
+		assertThat(this.out).hasSameContentAsResource("error-option-unknown-output.txt");
+	}
+
+	@Test
+	void mainWithOptionMissingRequiredValueShowsErrorAndCommandHelp() {
+		new LayerToolsJarMode().run("layertools", new String[] { "extract", "--destination" });
+		assertThat(this.out).hasSameContentAsResource("error-option-missing-value-output.txt");
+	}
+
 	private File createJarFile(String name) throws IOException {
 		File file = new File(this.temp, name);
 		try (ZipOutputStream jarOutputStream = new ZipOutputStream(new FileOutputStream(file))) {

spring-boot-project/spring-boot-tools/spring-boot-jarmode-layertools/src/test/resources/org/springframework/boot/jarmode/layertools/error-command-unknown-output.txt

@@ -0,0 +1,9 @@
+Error: Unknown command "invalid"
+
+Usage:
+  java -Djarmode=layertools -jar test.jar
+
+Available commands:
+  list     List layers from the jar that can be extracted
+  extract  Extracts layers from the jar for image creation
+  help     Help about any command

spring-boot-project/spring-boot-tools/spring-boot-jarmode-layertools/src/test/resources/org/springframework/boot/jarmode/layertools/error-option-missing-value-output.txt

@@ -0,0 +1,9 @@
+Error: Option "--destination" for the extract command requires a value
+
+Extracts layers from the jar for image creation
+
+Usage:
+  java -Djarmode=layertools -jar test.jar extract [options] [<layer>...]
+
+Options:
+  --destination string  The destination to extract files to

spring-boot-project/spring-boot-tools/spring-boot-jarmode-layertools/src/test/resources/org/springframework/boot/jarmode/layertools/error-option-unknown-output.txt

@@ -0,0 +1,9 @@
+Error: Unknown option "--invalid" for the extract command
+
+Extracts layers from the jar for image creation
+
+Usage:
+  java -Djarmode=layertools -jar test.jar extract [options] [<layer>...]
+
+Options:
+  --destination string  The destination to extract files to