Stupid-Linq-Tricks-Record-Rollup

Stupid-Linq-Tricks-Record-Rollup01.cs

//Source object where depending on the length of the text
public class RawRecords
{
  public int Id { get; set; }
  public int Sequence { get; set; }
  public DateTime Timestamp { get; set; }
  public string Comment { get; set; }
}

//Destination object where you want the multiple comment lines to be rolled up into the destination CommentText property.
public class Comment
{
  public int CommentId { get; set; }
  public DateTime CommentTimestamp { get; set; }
  public string CommentText { get; set; }
}

[TestMethod]
public void single_comment_rollup()
{
    IEnumerable<RawRecords> rawRecords = GetSampleRow();
    const string EXPECTED = "Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.";
 
    var actualComment = new Comment
    {
        CommentId = rawRecords.First().Id,
        CommentTimestamp = rawRecords.First().Timestamp,
        CommentText = string.Join("", rawRecords.OrderBy(ord => ord.Sequence).Select(x => x.Comment))
    };
 
    Assert.AreEqual(EXPECTED, actualComment.CommentText);
}