Add row counter accurate row reporting on errors with chunked parsing (#509)

papaparse.js

@@ -957,6 +957,7 @@
 
 		var self = this;
 		var _stepCounter = 0;	// Number of times step was called (number of rows parsed)
+		var _rowCounter = 0;	// Number of rows that have been parsed so far
 		var _input;				// The input being parsed
 		var _parser;			// The core parser being used
 		var _paused = false;	// Whether we are paused or not
@@ -1172,14 +1173,16 @@
 				if (_config.header)
 				{
 					if (j > _fields.length)
-						addError('FieldMismatch', 'TooManyFields', 'Too many fields: expected ' + _fields.length + ' fields but parsed ' + j, i);
+						addError('FieldMismatch', 'TooManyFields', 'Too many fields: expected ' + _fields.length + ' fields but parsed ' + j, _rowCounter + i);
 					else if (j < _fields.length)
-						addError('FieldMismatch', 'TooFewFields', 'Too few fields: expected ' + _fields.length + ' fields but parsed ' + j, i);
+						addError('FieldMismatch', 'TooFewFields', 'Too few fields: expected ' + _fields.length + ' fields but parsed ' + j, _rowCounter + i);
 				}
 			}
 
 			if (_config.header && _results.meta)
 				_results.meta.fields = _fields;
+
+			_rowCounter += _results.data.length;
 			return _results;
 		}
 

tests/node-tests.js

@@ -59,6 +59,43 @@ describe('PapaParse', function() {
 		});
 	});
 
+	it('reports the correct row number on FieldMismatch errors', function(done) {
+		Papa.parse(fs.createReadStream(__dirname + '/verylong-sample.csv'), {
+			header: true,
+			fastMode: true,
+			complete: function(parsedCsv) {
+				assert.deepEqual(parsedCsv.errors, [
+					{
+						"type": "FieldMismatch",
+						"code": "TooFewFields",
+						"message": "Too few fields: expected 3 fields but parsed 2",
+						"row": 498
+					},
+					{
+						"type": "FieldMismatch",
+						"code": "TooFewFields",
+						"message": "Too few fields: expected 3 fields but parsed 2",
+						"row": 998
+					},
+					{
+						"type": "FieldMismatch",
+						"code": "TooFewFields",
+						"message": "Too few fields: expected 3 fields but parsed 2",
+						"row": 1498
+					},
+					{
+						"type": "FieldMismatch",
+						"code": "TooFewFields",
+						"message": "Too few fields: expected 3 fields but parsed 2",
+						"row": 1998
+					}
+				]);
+				assert.strictEqual(2000, parsedCsv.data.length);
+				done();
+			},
+		});
+	});
+
 	it('piped streaming CSV should be correctly parsed', function(done) {
 		var data = [];
 		var readStream = fs.createReadStream(__dirname + '/long-sample.csv', 'utf8');