private static IReadOnlyCollection <RowMatchingResult> ListDataMismatches <TRowType>(
TableRows expectedRows,
IEnumerable <TRowType> actualRows,
Func <TRowType, string, object> getCellValue)
{
var firstColumnName = expectedRows.First().Keys.First();
var expectedRowsWithIndexAndKey = expectedRows.Select((row, index) => new { row, index, key = row[0] }).AsImmutable();
var actualRowsWithKey = actualRows.Select((row, index) => new { row, index, key = getCellValue(row, firstColumnName).ToString() }).AsImmutable();
var mismatchedAndMissingRows =
from expectedRow in expectedRowsWithIndexAndKey
join actualRow in actualRowsWithKey on expectedRow.key equals actualRow.key into matchedActualRows
from matchedActualRow in matchedActualRows.DefaultIfEmpty()
let rowMatchingResult = matchedActualRow != null
? MatchRows(expectedRow.row, matchedActualRow.row, expectedRow.index, getCellValue)
: new MissingRow(expectedRow.key, expectedRow.index)
where rowMatchingResult != null
select rowMatchingResult;
var unnecessaryRows =
from actualRow in actualRowsWithKey
where expectedRowsWithIndexAndKey.All(row => row.key != actualRow.key)
select new UnnecessaryRow(actualRow.key);
return(mismatchedAndMissingRows.Concat(unnecessaryRows).AsImmutable());
}