Add test showing regression wrt #1173 fix (inability to recover from certain parse errors) (#1213)

Author: cowtowncoder

src/test/java/com/fasterxml/jackson/failing/ParserErrorRecovery1173Test.java

@@ -0,0 +1,59 @@
+package com.fasterxml.jackson.failing;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.core.*;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+// Test(s) to see that limited amount of recovery is possible over
+// content: specifically, most single-character problems.
+public class ParserErrorRecovery1173Test
+    extends JUnit5TestBase
+{
+    private final JsonFactory JSON_F = newStreamFactory();
+
+    @Test
+    public void testRecoverNumberBytes() throws Exception {
+        _testRecoverNumber(MODE_INPUT_STREAM);
+        _testRecoverNumber(MODE_INPUT_STREAM_THROTTLED);
+    }
+
+    @Test
+    public void testRecoverNumberDataInput() throws Exception {
+        _testRecoverNumber(MODE_DATA_INPUT);
+    }
+
+    @Test
+    public void testRecoverNumberChars() throws Exception {
+        _testRecoverNumber(MODE_READER);
+        _testRecoverNumber(MODE_READER_THROTTLED);
+    }
+
+    /*
+    /**********************************************************
+    /* Helper methods
+    /**********************************************************
+     */
+
+    private void _testRecoverNumber(int mode) throws Exception
+    {
+        try (JsonParser p = createParser(JSON_F, mode, "1\n[ , ]\n3")) {
+            assertToken(JsonToken.VALUE_NUMBER_INT, p.nextToken());
+            assertEquals(1, p.getIntValue());
+            assertToken(JsonToken.START_ARRAY, p.nextToken());
+            try {
+                JsonToken t = p.nextToken();
+                fail("Should have gotten an exception; instead got token: "+t);
+            } catch (JsonParseException e) {
+                verifyException(e, "Unexpected character (','");
+            }
+
+            // But should essentially "skip" problematic character
+            assertToken(JsonToken.END_ARRAY, p.nextToken());
+            assertToken(JsonToken.VALUE_NUMBER_INT, p.nextToken());
+            assertEquals(3, p.getIntValue());
+            assertNull(p.nextToken());
+}
+    }
+}