/// <summary>
/// compare two snapshots with each other
/// </summary>
/// <param name="newshot"></param>
/// <param name="savedshot"></param>
/// <param name="options">the options</param>
/// <returns></returns>
public SnapshotResult Compare(Snapshot newshot, Snapshot savedshot, SnapshotOptions options)
{
if (newshot == null || savedshot == null)
{
return(SnapshotResult.SnapshotDoesNotExist(savedshot));
}
var count = newshot.Count;
if (count < savedshot.Count)
{
count = savedshot.Count;
}
var comparer = options.Comparer ?? LineCompare.Default;
for (var i = 0; i < count; i++)
{
if (!comparer.Compare(newshot[i], savedshot[i]))
{
return(SnapshotResult.SnapshotsDoNotMatch(newshot, savedshot, i));
}
}
return(SnapshotResult.SnapshotsMatch(newshot, savedshot));
}
/// <summary>
/// Create a new instance of the snapshot exception
/// </summary>
/// <param name="message"></param>
/// <param name="result"></param>
public SnapshotMatchException(string message, SnapshotResult result)
: base(message)
{
SnapshotResult = result;
OldSnapshot = result.OldSnapshot?.ToString();
NewSnapshot = result.NewSnapshot?.ToString();
}
/// <summary>
/// assert invalid snapshots
/// </summary>
/// <param name="snapshotResult"></param>
public static void AssertSnapshot(SnapshotResult snapshotResult)
{
switch (snapshotResult.Status)
{
case SnapshotStatus.SnapshotsDoNotMatch:
Throw(snapshotResult, s => new SnapshotMatchException(s, snapshotResult));
break;
case SnapshotStatus.SnapshotDoesNotExist:
case SnapshotStatus.SnapshotUpdated:
case SnapshotStatus.SnapshotsMatch:
default:
return;
}
}
public static void MatchSnapshot(this Snapshot snapshot, SnapshotOptions options)
{
options = options.MergeDefault();
var resolver = new SnapshotSetupResolver();
var setup = resolver.ResolveSnapshotSetup();
var client = GetClient();
var result = client.Validate(snapshot, setup, options);
if (result.Status == SnapshotStatus.SnapshotDoesNotExist || result.Status == SnapshotStatus.UpdateSnapshot)
{
client.Write(snapshot, setup);
result = SnapshotResult.SnapshotUpdated(snapshot, null);
}
SnapshotAsserter.AssertSnapshot(result);
}
private static void Throw <T>(SnapshotResult result, Func <string, T> exception) where T : Exception
{
var(saved, actual, index) = Difference(result.OldSnapshot[result.Index].Value, result.NewSnapshot[result.Index].Value);
var message = new StringBuilder();
message.Append(Environment.NewLine);
message.AppendLine($"Snapshots do not match");
message.AppendLine($" - Line {result.Index + 1} position {index}");
message.AppendLine($"Expected - {saved}");
message.AppendLine($"Actual - {actual}");
message.AppendLine(string.Empty);
message.AppendLine("Line:");
message.AppendLine($"Expected - {result.OldSnapshot[result.Index]}");
message.AppendLine($"Actual - {result.NewSnapshot[result.Index]}");
message.AppendLine(string.Empty);
message.AppendLine("Original snapshot:");
message.AppendLine(result.OldSnapshot.ToString());
message.AppendLine(string.Empty);
message.AppendLine("New snapshot:");
message.Append(result.NewSnapshot.ToString());
throw exception(message.ToString());
}
