Migrating to v21.0.0

CsvHelper 21 has one breaking change: CsvConfiguration.NewLine is a string instead of a char?. You can now write any line ending, including \r\n, which 20 could only write where it is Environment.NewLine. When you set it, the parser uses it too, in every mode. The NewLine enum and the NewLines constants, unused since 20, are removed. The target frameworks don't change.

Line endings

Give NewLine a string instead of a character.

var config = new CsvConfiguration(CultureInfo.InvariantCulture)
{
    NewLine = '\n',
};

var config = new CsvConfiguration(CultureInfo.InvariantCulture)
{
    NewLine = "\n",
};

• The default when writing: 21.0.0 writes Environment.NewLine, as 20 did. 21.0.2 and later write \r\n.
• IsNewLineSet is new: it tells whether NewLine was set or is the default. If you implement IParserConfiguration or IWriterConfiguration, change NewLine to a string and add IsNewLineSet.

Behavior changes

• A NewLine you set is used for reading too, in every mode. In 20, the default mode ignored it and ended a record at \r\n, \r or \n. In 21, only NewLine ends a record. If you set NewLine = "\n" to write files and read with the same configuration, a file with \r\n line endings keeps the \r at the end of the last field of each record (or, when that field is quoted, it is bad data). Read with a configuration that doesn't set NewLine.
• The Visual Basic constructor that 21.0.5 adds, with every setting as an optional argument, sets NewLine even when you don't pass it, so a configuration created with it reads only \r\n as a line ending. 22.1.1 fixes this.
• ParserMode.Escape without NewLine ends a record at \r\n, \r or \n. In 20 it used \n by default. Before 21.1.1, it reads \r\n as \r followed by a blank line, which IgnoreBlankLines (on by default) skips.
• Quoting: the default ShouldQuote quotes a field that contains \r or \n when NewLine isn't set, and a field that contains NewLine when it is.