Merge pull request #347 from gbidsilva/CSV-147

[CSV-147] Error message optimization during faulty CSV record read

Author: garydgregory

src/main/java/org/apache/commons/csv/Lexer.java

@@ -367,8 +367,8 @@ private Token parseEncapsulatedToken(final Token token) throws IOException {
                         }
                         if (!Character.isWhitespace((char)c)) {
                             // error invalid char between token and next delimiter
-                            throw new IOException("(line " + getCurrentLineNumber() +
-                                    ") invalid char between encapsulated token and delimiter");
+                            throw new IOException("Invalid char between encapsulated token and delimiter at line: " +
+                                    getCurrentLineNumber() + ", position: " + getCharacterPosition());
                         }
                     }
                 }

src/test/java/org/apache/commons/csv/CSVParserTest.java

@@ -1642,4 +1642,26 @@ private void validateRecordPosition(final String lineSeparator) throws IOExcepti
         parser.close();
     }
 
+    @Test
+    public void testFaultyCSVShouldThrowExceptionWithLineAndPosition() throws IOException {
+        String csvContent = "col1,col2,col3,col4,col5,col6,col7,col8,col9,col10\n" +
+                "rec1,rec2,rec3,rec4,rec5,rec6,rec7,rec8,\"\"rec9\"\",rec10";
+
+        StringReader stringReader = new StringReader(csvContent);
+        CSVFormat csvFormat = CSVFormat.DEFAULT.builder()
+                .setHeader()
+                .setSkipHeaderRecord(true)
+                .build();
+
+        CSVParser csvParser = csvFormat.parse(stringReader);
+        Exception exception = assertThrows(UncheckedIOException.class, () -> {
+            for (CSVRecord record : csvParser) {
+                // this will result in exception due to parsing issue
+            }
+        });
+        String expectedErrorMessage = "Invalid char between encapsulated token and delimiter at " +
+                "line: 2, position: 94";
+        String actualMessage = exception.getMessage();
+        assertTrue(actualMessage.contains(expectedErrorMessage));
+    }
 }