SHL-136: Report syntax error location to the user

* Fix tests

src/main/java/org/springframework/shell/core/SimpleParser.java

@@ -160,6 +160,11 @@ public class SimpleParser implements Parser {
 			try {
 				options = new Tokenizer(methodTarget.getRemainingBuffer()).getTokens();
 			}
+			catch (TokenizingException te) {
+				String commandKey = methodTarget.getKey();
+				reportTokenizingException(commandKey, te);
+				return null;
+			}
 			catch (IllegalArgumentException e) {
 				LOGGER.warning(ExceptionUtils.extractRootCause(e).getMessage());
 				return null;
@@ -310,6 +315,16 @@ public class SimpleParser implements Parser {
 		}
 	}
 
+	private void reportTokenizingException(String commandKey, TokenizingException te) {
+		StringBuilder caret = new StringBuilder();
+		for (int i = 0; i < te.getOffendingOffset() + commandKey.length() + 1; i++) {
+			caret.append(" ");
+		}
+		LOGGER.warning(commandKey + " " + te.getBuffer());
+		LOGGER.warning(caret + "^");
+		LOGGER.warning(te.getReason());
+	}
+
 	/**
 	 * @param cliOptions
 	 * @param options
@@ -597,8 +612,13 @@ public class SimpleParser implements Parser {
 			try {
 				tokenizer = new Tokenizer(methodTarget.getRemainingBuffer(), true);
 			}
+			catch (TokenizingException e) {
+				// Make sure we don't crash the main shell loop just
+				// because the user specified some option twice
+				return -1;
+			}
 			catch (IllegalArgumentException e) {
-				// Make sure we don't crash the mail shell loop just
+				// Make sure we don't crash the main shell loop just
 				// because the user specified some option twice
 				return -1;
 			}

src/main/java/org/springframework/shell/core/Tokenizer.java

@@ -113,26 +113,35 @@ public class Tokenizer {
 			eatKeyEqualsValue();
 		}
 		else {
+			int offsetInCaseOfFailure = pos;
 			String value = eatValue(true);
-			store("", value);
+			store("", value, offsetInCaseOfFailure);
 		}
 
 	}
 
-	private void store(String key, String value) {
+	/**
+	 * Store a command key/value pair, reporting a failure if a mapping with the same key is already present.
+	 * @param key the command key
+	 * @param value the command value
+	 * @param failureOffset the buffer offset at which the mapping we're trying to store was tokenized
+	 */
+	private void store(String key, String value, int failureOffset) {
 		String alreadyThere = result.put(key, value);
 		if (alreadyThere != null) {
 			if ("".equals(key)) {
-				throw new IllegalArgumentException(String.format(
+				String explanation = String.format(
 						"You cannot specify '%s' as another value for the default ('') option in a single command.%n"
 								+ "You already provided '%s' earlier.%n"
 								+ "Did you forget to add quotes around the value of another option?", value,
-						alreadyThere));
+						alreadyThere);
+				throw new TokenizingException(failureOffset, buffer, explanation);
 			}
 			else {
-				throw new IllegalArgumentException(String.format(
+				String explanation = String.format(
 						"You cannot specify '%s' as another value for the '--%s' option in a single command.%n"
-								+ "You already provided '%s' earlier.", value, key, alreadyThere));
+								+ "You already provided '%s' earlier.", value, key, alreadyThere);
+				throw new TokenizingException(failureOffset, buffer, explanation);
 			}
 		}
 	}
@@ -189,7 +198,7 @@ public class Tokenizer {
 				return sb.toString();
 			}
 			else {
-				throw new IllegalArgumentException("Cannot have an unbalanced number of quotation marks");
+				throw new TokenizingException(pos, buffer, "Cannot have an unbalanced number of quotation marks");
 			}
 		}
 		// Eat our delim
@@ -205,7 +214,7 @@ public class Tokenizer {
 	private char processCharacterEscapeCodes(char endDelimiter) {
 		pos++;
 		if (pos >= buffer.length) {
-			throw new IllegalArgumentException("Ran out of input in escape sequence");
+			throw new TokenizingException(buffer.length, buffer, "Ran out of input in escape sequence");
 		}
 		switch (buffer[pos]) {
 		case ESCAPE_CHAR:
@@ -225,7 +234,7 @@ public class Tokenizer {
 			return '\f';
 		case 'u':
 			if (pos + 5 > buffer.length) {
-				throw new IllegalArgumentException("Ran out input in unicode escape sequence");
+				throw new TokenizingException(buffer.length, buffer, "Ran out of input in unicode escape sequence");
 			}
 			String hex = new String(buffer, pos + 1, 4);
 			try {
@@ -234,7 +243,8 @@ public class Tokenizer {
 				return code;
 			}
 			catch (NumberFormatException e) {
-				throw new IllegalArgumentException("Illegal unicode escape sequence: " + ESCAPE_CHAR + "u" + hex);
+				throw new TokenizingException(pos - 1, buffer, "Illegal unicode escape sequence: " + ESCAPE_CHAR + "u"
+						+ hex);
 			}
 
 		default:
@@ -303,6 +313,8 @@ public class Tokenizer {
 	 * in which case allow for just {@code --key}, using "" for the value.
 	 */
 	private void eatKeyEqualsValue() {
+		// We already consumed '--'
+		int offsetInCaseOfFailure = pos - 2;
 		String key = eatKey();
 		eatWhiteSpace();
 		String value;
@@ -320,7 +332,7 @@ public class Tokenizer {
 		if (key.equals("") && value.equals("")) {
 			return;
 		}
-		store(key, value);
+		store(key, value, offsetInCaseOfFailure);
 	}
 
 	private String eatKey() {

src/main/java/org/springframework/shell/core/TokenizingException.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2014 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 org.springframework.shell.core;
+
+@SuppressWarnings("serial")
+public class TokenizingException extends RuntimeException {
+
+	private final int offendingOffset;
+
+	private final char[] buffer;
+
+	private final String reason;
+
+	public TokenizingException(int offendingOffset, char[] buffer, String reason) {
+		super();
+		this.offendingOffset = offendingOffset;
+		this.buffer = buffer;
+		this.reason = reason;
+	}
+
+	public int getOffendingOffset() {
+		return offendingOffset;
+	}
+
+	public String getBuffer() {
+		return new String(buffer);
+	}
+
+	public String getReason() {
+		return reason;
+	}
+
+}

src/test/java/org/springframework/shell/core/TokenizerTests.java

@@ -79,7 +79,7 @@ public class TokenizerTests {
 		assertEquals(expected, result);
 	}
 
-	@Test(expected = IllegalArgumentException.class)
+	@Test(expected = TokenizingException.class)
 	public void testTwoOptionsSameKey() {
 		tokenize("--foo bar --foo buzz");
 	}
@@ -97,7 +97,7 @@ public class TokenizerTests {
 		assertThat(result.get("woot"), equalTo("cool"));
 	}
 
-	@Test(expected = IllegalArgumentException.class)
+	@Test(expected = TokenizingException.class)
 	public void testDisallowTwoOptionsSameEmptyKeyIfNotNextToEachOther() {
 		tokenize("bar --foo wizz buzz");
 	}
@@ -118,7 +118,7 @@ public class TokenizerTests {
 		assertEquals(expected, result);
 	}
 
-	@Test(expected = IllegalArgumentException.class)
+	@Test(expected = TokenizingException.class)
 	public void testValueQuotationUnbalanced() {
 		Map<String, String> result = tokenize("--foo \"bar fizz");
 		assertEquals(singletonMap("foo", "bar fizz"), result);