Polish error messages

- Polish mandatory option message by using
  same format as in 3.0.x. (old parser)
- Remove prefixed code/position parts from
  all messages coming from a parser. (new parser)
- Backport #815
- Fixes #816

Author: jvalkeal

spring-shell-core/src/main/java/org/springframework/shell/command/parser/MessageResult.java

@@ -40,6 +40,6 @@ public static MessageResult of(ParserMessage parserMessage, int position, Object
 	 * @return a formatted message
 	 */
 	public String getMessage() {
-		return parserMessage.formatMessage(position, inserts);
+		return parserMessage.formatMessage(inserts);
 	}
 }

spring-shell-core/src/main/java/org/springframework/shell/command/parser/Parser.java

@@ -23,7 +23,6 @@
 import java.util.List;
 import java.util.Set;
 import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.springframework.core.ResolvableType;
 import org.springframework.core.convert.ConversionService;
@@ -37,6 +36,7 @@
 import org.springframework.shell.command.parser.Parser.ParseResult.ArgumentResult;
 import org.springframework.shell.command.parser.Parser.ParseResult.OptionResult;
 import org.springframework.shell.command.parser.ParserConfig.Feature;
+import org.springframework.util.StringUtils;
 
 /**
  * Interface to parse command line arguments.
@@ -439,12 +439,19 @@ private List<MessageResult> validateOptionNotMissing(CommandRegistration registr
 
 			return requiredOptions2.stream()
 				.map(o -> {
-					String ln = o.getLongNames() != null
-							? Stream.of(o.getLongNames()).collect(Collectors.joining(","))
-							: "";
-					String sn = o.getShortNames() != null ? Stream.of(o.getShortNames()).map(n -> Character.toString(n))
-							.collect(Collectors.joining(",")) : "";
-					return MessageResult.of(ParserMessage.MANDATORY_OPTION_MISSING, 0, ln, sn);
+					String ins0 = "";
+					if (o.getLongNames().length > 0) {
+						ins0 = "--" + o.getLongNames()[0];
+					}
+					else if (o.getShortNames().length > 0) {
+						ins0 = "-" + o.getShortNames()[0];
+					}
+
+					String ins1 = "";
+					if (StringUtils.hasText(o.getDescription())) {
+						ins1 = ", " + o.getDescription();
+					}
+					return MessageResult.of(ParserMessage.MANDATORY_OPTION_MISSING, 0, ins0, ins1);
 				})
 				.collect(Collectors.toList());
 		}

spring-shell-core/src/main/java/org/springframework/shell/command/parser/ParserMessage.java

@@ -39,7 +39,7 @@
 public enum ParserMessage {
 
 	ILLEGAL_CONTENT_BEFORE_COMMANDS(Type.ERROR, 1000, "Illegal content before commands ''{0}''"),
-	MANDATORY_OPTION_MISSING(Type.ERROR, 2000, "Missing mandatory option, longnames=''{0}'', shortnames=''{1}''"),
+	MANDATORY_OPTION_MISSING(Type.ERROR, 2000, "Missing mandatory option ''{0}''{1}"),
 	UNRECOGNISED_OPTION(Type.ERROR, 2001, "Unrecognised option ''{0}''"),
 	ILLEGAL_OPTION_VALUE(Type.ERROR, 2002, "Illegal option value ''{0}'', reason ''{1}''"),
 	NOT_ENOUGH_OPTION_ARGUMENTS(Type.ERROR, 2003, "Not enough arguments for option ''{0}'', requires at least ''{1}''"),
@@ -64,18 +64,40 @@ public Type getType() {
 		return type;
 	}
 
-	public String formatMessage(int position, Object... inserts) {
+	/**
+	 * Format message without code and position parts.
+	 *
+	 * @param inserts the inserts
+	 * @return formatted message
+	 */
+	public String formatMessage(Object... inserts) {
+		return formatMessage(false, -1, inserts);
+	}
+
+	/**
+	 * Format message.
+	 *
+	 * <p>For example code and position 2000E:(pos 0):
+	 *
+	 * @param useCode Add code part
+	 * @param position position info, not printed if negative
+	 * @param inserts the inserts
+	 * @return formatted message
+	 */
+	public String formatMessage(boolean useCode, int position, Object... inserts) {
 		StringBuilder msg = new StringBuilder();
-		msg.append(code);
-		switch (type) {
-			case WARNING:
-				msg.append("W");
-				break;
-			case ERROR:
-				msg.append("E");
-				break;
+		if (useCode) {
+			msg.append(code);
+			switch (type) {
+				case WARNING:
+					msg.append("W");
+					break;
+				case ERROR:
+					msg.append("E");
+					break;
+			}
+			msg.append(":");
 		}
-		msg.append(":");
 		if (position != -1) {
 			msg.append("(pos ").append(position).append("): ");
 		}