/// <inheritdoc />
public List <string> Scan(string input)
=> digitSeparator.GetDigitsByLine(input)
// Transform each line by...
.Select(
line => {
// Parsing every 3x3 chunk into digits
var digitsInLine = line.Select(digit => digitScanner.Parse(digit)).ToList();
// If all digits are valid, concatenate them into a string, otherwise => null
return(digitsInLine.All(digit => digit != null)
? digitsInLine.Cast <char>().JoinToString()
: null);
})
.ToList();
public void Parse_ScansDigitCorrectly(string value, char expected) => scanner.Parse(value).Should().Be(expected);
