Improve commandline help for encodepassword command in the CLI

Closes gh-38203

spring-boot-project/spring-boot-cli/src/main/java/org/springframework/boot/cli/command/encodepassword/EncodePasswordCommand.java

@@ -44,6 +44,7 @@
  * {@link Command} to encode passwords for use with Spring Security.
  *
  * @author Phillip Webb
+ * @author Moritz Halbritter
  * @since 2.0.0
  */
 public class EncodePasswordCommand extends OptionParsingCommand {
@@ -70,8 +71,8 @@ public String getUsageHelp() {
 	@Override
 	public Collection<HelpExample> getExamples() {
 		List<HelpExample> examples = new ArrayList<>();
-		examples
-			.add(new HelpExample("To encode a password with the default encoder", "spring encodepassword mypassword"));
+		examples.add(new HelpExample("To encode a password with the default (bcrypt) encoder",
+				"spring encodepassword mypassword"));
 		examples.add(new HelpExample("To encode a password with pbkdf2", "spring encodepassword -a pbkdf2 mypassword"));
 		return examples;
 	}
@@ -82,12 +83,16 @@ private static final class EncodePasswordOptionHandler extends OptionHandler {
 
 		@Override
 		protected void options() {
-			this.algorithm = option(Arrays.asList("algorithm", "a"), "The algorithm to use").withRequiredArg()
+			this.algorithm = option(Arrays.asList("algorithm", "a"),
+					"The algorithm to use. Supported algorithms: "
+							+ StringUtils.collectionToDelimitedString(ENCODERS.keySet(), ", ")
+							+ ". The default algorithm uses bcrypt")
+				.withRequiredArg()
 				.defaultsTo("default");
 		}
 
 		@Override
-		protected ExitStatus run(OptionSet options) throws Exception {
+		protected ExitStatus run(OptionSet options) {
 			if (options.nonOptionArguments().size() != 1) {
 				Log.error("A single password option must be provided");
 				return ExitStatus.ERROR;

spring-boot-project/spring-boot-cli/src/test/java/org/springframework/boot/cli/command/encodepassword/EncodePasswordCommandTests.java

@@ -37,6 +37,7 @@
  * Tests for {@link EncodePasswordCommand}.
  *
  * @author Phillip Webb
+ * @author Moritz Halbritter
  */
 @ExtendWith(MockitoExtension.class)
 class EncodePasswordCommandTests {
@@ -67,6 +68,17 @@ void encodeWithNoAlgorithmShouldUseBcrypt() throws Exception {
 		assertThat(status).isEqualTo(ExitStatus.OK);
 	}
 
+	@Test
+	void encodeWithDefaultShouldUseBcrypt() throws Exception {
+		EncodePasswordCommand command = new EncodePasswordCommand();
+		ExitStatus status = command.run("-a", "default", "boot");
+		then(this.log).should().info(this.message.capture());
+		assertThat(this.message.getValue()).startsWith("{bcrypt}");
+		assertThat(PasswordEncoderFactories.createDelegatingPasswordEncoder().matches("boot", this.message.getValue()))
+			.isTrue();
+		assertThat(status).isEqualTo(ExitStatus.OK);
+	}
+
 	@Test
 	void encodeWithBCryptShouldUseBCrypt() throws Exception {
 		EncodePasswordCommand command = new EncodePasswordCommand();