OSOE-111: Detect visual errors (visual verification testing) in the UI Testing Toolbox

[dministro]

Fixes GH-85

OSOE-111

[Piedone]

In any case, please check how the number of allocations can be reduced here, because there's both a stream and an array here.

________________________________ From: Horváth József ***@***.***> Sent: Friday, June 3, 2022 10:15:45 AM To: Lombiq/UI-Testing-Toolbox ***@***.***> Cc: Zoltán Lehóczky ***@***.***>; Comment ***@***.***> Subject: Re: [Lombiq/UI-Testing-Toolbox] OSOE-111: Detect visual errors (visual verification testing) in the UI Testing Toolbox (PR #166) @dministro commented on this pull request.

________________________________ In Lombiq.Tests.UI/Extensions/ReliabilityUITestContextExtensions.cs<#166 (comment)>:

+ using var elementImage = context.TakeElementScreenshot(element);

+ using var elementImageStream = new MemoryStream(); + + elementImage.Save(elementImageStream, ImageFormat.Bmp); + var elementImageRaw = elementImageStream.ToArray(); + return ComputeSha256Hash(elementImageRaw); + } + + private static string ComputeSha256Hash(byte[] raw) + { + using var sha256Hash = SHA256.Create(); + + return string.Concat( + sha256Hash.ComputeHash(raw) + .Select(item => item.ToString("x2", CultureInfo.InvariantCulture))); elementImageStream.GetHashCode() is not enough to check the equality. (here <https://docs.microsoft.com/en-us/dotnet/api/system.object.gethashcode?view=net-6.0#:~:text=Two%20objects%20that%20are%20equal%20return%20hash%20codes%20that%20are%20equal.%20However%2C%20the%20reverse%20is%20not%20true%3A%20equal%20hash%20codes%20do%20not%20imply%20object%20equality%2C%20because%20different%20(unequal)%20objects%20can%20have%20identical%20hash%20codes.> you can read more) If I remember good (in FW3.5) the GetHashCode(...) didn't generated position sensitive hash. — Reply to this email directly, view it on GitHub<#166 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AAPCSR5FEBOKT6Z67YP5AXLVNG5LDANCNFSM5W2YC26Q>. You are receiving this because you commented.Message ID: ***@***.***>