updating JSON grammar based on Antlr V4 reference grammar to properly handle escaped newlines

Author: robertpatrick

core/src/main/antlr4/oracle/weblogic/deploy/json/JSON.g4

@@ -39,7 +39,7 @@ value
 
 
 STRING
-   : '"' (ESC | ~ ["\\])* '"'
+   : '"' (ESC | SAFECODEPOINT)* '"'
    ;
 fragment ESC
    : '\\' (["\\/bfnrt] | UNICODE)
@@ -50,6 +50,9 @@ fragment UNICODE
 fragment HEX
    : [0-9a-fA-F]
    ;
+fragment SAFECODEPOINT
+   : ~ ["\\\u0000-\u001F]
+   ;
 NUMBER
    : '-'? INT ('.' [0-9] +)? EXP?
    ;

core/src/test/java/oracle/weblogic/deploy/json/JsonTranslatorTest.java

@@ -11,17 +11,19 @@
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.function.Executable;
+import org.python.core.PyDictionary;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-public class JsonTranslatorTest {
+class JsonTranslatorTest {
 
     /**
      * Verify that a lexical error will throw an Exception
      */
     @Test
-    public void testLexicalError() {
+    void testLexicalError() {
         // Temporarily disable logging for this test. Intended lexical failure will log a stack trace.
         Logger logger = Logger.getLogger("wlsdeploy.json");
         Level originalLevel  = logger.getLevel();
@@ -40,4 +42,36 @@ public void execute() throws Throwable {
 
         logger.setLevel(originalLevel);
     }
+
+    @Test
+    void testMultilineStringsError() {
+        Logger logger = Logger.getLogger("wlsdeploy.json");
+        Level originalLevel  = logger.getLevel();
+        logger.setLevel(Level.OFF);
+
+        String text = "{ \"abc\": \"xyz\n123\" }";
+        InputStream stream = new ByteArrayInputStream(text.getBytes(UTF_8));
+        final JsonStreamTranslator translator = new JsonStreamTranslator("String", stream);
+        assertThrows(JsonException.class, new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                translator.parse();
+            }
+        }, "Test must raise JsonException when model has a value with a newline in it");
+        logger.setLevel(originalLevel);
+    }
+
+    @Test
+    void testEscapedMultilineStrings() throws Exception {
+        Logger logger = Logger.getLogger("wlsdeploy.json");
+        Level originalLevel  = logger.getLevel();
+        logger.setLevel(Level.OFF);
+
+        String text = "{ \"abc\": \"xyz\\n123\" }";
+        InputStream stream = new ByteArrayInputStream(text.getBytes(UTF_8));
+        final JsonStreamTranslator translator = new JsonStreamTranslator("String", stream);
+        PyDictionary actual = translator.parse();
+        assertNotNull(actual, "Escaped Multiline String should parse correctly");
+        logger.setLevel(originalLevel);
+    }
 }