LMBQ-113: During element screenshot, add 1px tolerance

Lombiq.Tests.UI.Samples/Lombiq.Tests.UI.Samples.csproj

@@ -12,7 +12,7 @@
     <None Remove=".htmlvalidate.json" />
     <None Remove="xunit.runner.json" />
   </ItemGroup>
-  
+
   <ItemGroup>
     <Content Include=".htmlvalidate.json">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
@@ -21,14 +21,6 @@
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>
   </ItemGroup>
-
-  <ItemGroup>
-    <EmbeddedResource Include="Tests\BasicVisualVerificationTests_VerifyBlogImage_By_ClassName[Contains]_-field-name-blog-image.png" />
-    <EmbeddedResource Include="Tests\BasicVisualVerificationTests_VerifyNavbar_By_ClassName[Contains]_-navbar-brand_Unix_chrome.png" />
-    <EmbeddedResource Include="Tests\BasicVisualVerificationTests_VerifyNavbar_By_ClassName[Contains]_-navbar-brand_Unix_msedge.png" />
-    <EmbeddedResource Include="Tests\BasicVisualVerificationTests_VerifyNavbar_By_ClassName[Contains]_-navbar-brand_Win32NT_chrome.png" />
-    <EmbeddedResource Include="Tests\BasicVisualVerificationTests_VerifyNavbar_By_ClassName[Contains]_-navbar-brand_Win32NT_msedge.png" />
-  </ItemGroup>
 
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />

Lombiq.Tests.UI/Exceptions/VisualVerificationBaselineImageNotFoundException.cs

@@ -7,12 +7,7 @@ namespace Lombiq.Tests.UI.Exceptions;
 public class VisualVerificationBaselineImageNotFoundException : Exception
 #pragma warning restore CA1032 // Implement standard exception constructors
 {
-    public VisualVerificationBaselineImageNotFoundException(string path)
-        : this(path, innerException: null)
-    {
-    }
-
-    public VisualVerificationBaselineImageNotFoundException(string path, Exception innerException)
+    public VisualVerificationBaselineImageNotFoundException(string path, Exception innerException = null)
         : base(
             $"Baseline image file not found, thus it was created automatically under the path {path}."
             + " Please set its \"Build action\" to \"Embedded resource\" if you want to deploy a self-contained"

Lombiq.Tests.UI/Extensions/ScreenshotUITestContextExtensions.cs

@@ -70,8 +70,8 @@ public static Image TakeFullPageScreenshot(this UITestContext context)
             var height = images.Keys.Sum(
                 position =>
                     position.Y % viewportSize.Height == 0
-                    ? viewportSize.Height
-                    : (position.Y + viewportSize.Height) % viewportSize.Height);
+                        ? viewportSize.Height
+                        : (position.Y + viewportSize.Height) % viewportSize.Height);
 
             var screenshot = new SixLabors.ImageSharp.Image<Argb32>(viewportSize.Width, height);
 
@@ -105,27 +105,48 @@ public static Image TakeElementScreenshot(this UITestContext context, IWebElemen
     {
         using var screenshot = context.TakeFullPageScreenshot();
 
-        var elementAbsoluteSize = new Size(
-            element.Location.X + element.Size.Width,
-            element.Location.Y + element.Size.Height);
+        var elementLocation = element.Location;
+        var elementSize = element.Size;
 
-        if (elementAbsoluteSize.Width > screenshot.Width || elementAbsoluteSize.Height > screenshot.Height)
+        var expectedSize = new Size(elementLocation.X + elementSize.Width, elementLocation.Y + elementSize.Height);
+
+        var widthDifference = expectedSize.Width - screenshot.Width;
+        var heightDifference = expectedSize.Height - screenshot.Height;
+
+        if (widthDifference > 0 || heightDifference > 0)
         {
-            throw new InvalidOperationException(
-                "The captured screenshot size is smaller then the size required by the selected element. This can occur"
-                + " if there was an unsuccessful scrolling operation while capturing page parts."
-                + $"Captured size: {screenshot.Width.ToTechnicalString()} x {screenshot.Height.ToTechnicalString()}. "
-                + $"Required size: {elementAbsoluteSize.Width.ToTechnicalString()} x "
-                + $"{elementAbsoluteSize.Height.ToTechnicalString()}.");
+            // A difference of 1px can occur when both element.Location and element.Size were rounded to the next
+            // integer from exactly 0.5px, e.g. 212.5px + 287.5px = 500px in the browser, but due to both Size and Point
+            // using int for their coordinates, this will become 213px + 288px = 501px, which will be caught as an error
+            // here. In that case, we keep the elementSize as is, but reduce the Location coordinate by 1 so that
+            // cropping the full page screenshot to the desired region will not fail due to too large dimensions.
+            if (widthDifference <= 1 && heightDifference <= 1)
+            {
+                elementLocation.X -= widthDifference;
+                elementLocation.Y -= heightDifference;
+            }
+            else
+            {
+                throw new InvalidOperationException(
+                    "The captured screenshot size is smaller then the size required by the selected element. This can"
+                    + " occur if there was an unsuccessful scrolling operation while capturing page parts."
+                    + $" Captured size: {AsDimensions(screenshot)}. Expected size: {AsDimensions(expectedSize)}.");
+            }
         }
 
-        var bounds = new Rectangle(element.Location.X, element.Location.Y, element.Size.Width, element.Size.Height);
-        return screenshot.Clone(ctx => ctx.Crop(bounds));
+        var cropRectangle = new Rectangle(elementLocation.X, elementLocation.Y, elementSize.Width, elementSize.Height);
+        return screenshot.Clone(image => image.Crop(cropRectangle));
     }
 
     /// <summary>
     /// Takes a screenshot of an element region only.
     /// </summary>
     public static Image TakeElementScreenshot(this UITestContext context, By elementSelector) =>
         context.TakeElementScreenshot(context.Get(elementSelector));
+
+    private static string AsDimensions(IImageInfo image) =>
+        $"{image.Width.ToTechnicalString()} x {image.Height.ToTechnicalString()}";
+
+    private static string AsDimensions(Size size) =>
+        $"{size.Width.ToTechnicalString()} x {size.Height.ToTechnicalString()}";
 }

Lombiq.Tests.UI/Services/OrchardCoreUITestExecutorConfiguration.cs

@@ -21,6 +21,41 @@ public enum Browser
 
 public class OrchardCoreUITestExecutorConfiguration
 {
+    public static readonly Func<IWebApplicationInstance, Task> AssertAppLogsAreEmptyAsync = app =>
+        app.LogsShouldBeEmptyAsync();
+
+    public static readonly Func<IWebApplicationInstance, Task> AssertAppLogsCanContainWarningsAsync =
+        app => app.LogsShouldBeEmptyAsync(canContainWarnings: true);
+
+    public static readonly Action<IEnumerable<LogEntry>> AssertBrowserLogIsEmpty =
+        logEntries => logEntries.ShouldNotContain(
+            logEntry => IsValidBrowserLogEntry(logEntry),
+            logEntries.Where(IsValidBrowserLogEntry).ToFormattedString());
+
+    public static readonly Func<LogEntry, bool> IsValidBrowserLogEntry =
+        logEntry =>
+            logEntry.Level >= LogLevel.Warning &&
+            // HTML imports are somehow used by Selenium or something but this deprecation notice is always there for
+            // every page.
+            !logEntry.Message.ContainsOrdinalIgnoreCase("HTML Imports is deprecated") &&
+            // The 404 is because of how browsers automatically request /favicon.ico even if a favicon is declared to be
+            // under a different URL.
+            !logEntry.IsNotFoundLogEntry("/favicon.ico");
+
+    /// <summary>
+    /// Gets the global events available during UI test execution.
+    /// </summary>
+    public UITestExecutionEvents Events { get; } = new();
+
+    /// <summary>
+    /// Gets a dictionary storing some custom configuration data.
+    /// </summary>
+    [SuppressMessage(
+        "Design",
+        "MA0016:Prefer return collection abstraction instead of implementation",
+        Justification = "Deliberately modifiable by consumer code.")]
+    public Dictionary<string, object> CustomConfiguration { get; } = new();
+
     public BrowserConfiguration BrowserConfiguration { get; set; } = new();
     public TimeoutConfiguration TimeoutConfiguration { get; set; } = TimeoutConfiguration.Default;
     public AtataConfiguration AtataConfiguration { get; set; } = new();
@@ -53,10 +88,10 @@ public class OrchardCoreUITestExecutorConfiguration
     /// </para>
     /// </remarks>
     public int MaxParallelTests { get; set; } =
-            TestConfigurationManager.GetIntConfiguration(
-                $"{nameof(OrchardCoreUITestExecutorConfiguration)}:{nameof(MaxParallelTests)}") is not { } intValue || intValue == 0
-                ? Environment.ProcessorCount
-                : intValue;
+        TestConfigurationManager.GetIntConfiguration(
+            $"{nameof(OrchardCoreUITestExecutorConfiguration)}:{nameof(MaxParallelTests)}") is { } intValue and > 0
+            ? intValue
+            : Environment.ProcessorCount;
 
     public Func<IWebApplicationInstance, Task> AssertAppLogsAsync { get; set; } = AssertAppLogsCanContainWarningsAsync;
     public Action<IEnumerable<LogEntry>> AssertBrowserLog { get; set; } = AssertBrowserLogIsEmpty;
@@ -136,20 +171,6 @@ public class OrchardCoreUITestExecutorConfiguration
     /// </summary>
     public ShortcutsConfiguration ShortcutsConfiguration { get; set; } = new();
 
-    /// <summary>
-    /// Gets the global events available during UI test execution.
-    /// </summary>
-    public UITestExecutionEvents Events { get; } = new();
-
-    /// <summary>
-    /// Gets a dictionary storing some custom configuration data.
-    /// </summary>
-    [SuppressMessage(
-        "Design",
-        "MA0016:Prefer return collection abstraction instead of implementation",
-        Justification = "Deliberately modifiable by consumer code.")]
-    public Dictionary<string, object> CustomConfiguration { get; } = new();
-
     public async Task AssertAppLogsMaybeAsync(IWebApplicationInstance instance, Action<string> log)
     {
         if (instance == null || AssertAppLogsAsync == null) return;
@@ -183,24 +204,4 @@ public void AssertBrowserLogMaybe(IList<LogEntry> browserLogs, Action<string> lo
             throw;
         }
     }
-
-    public static readonly Func<IWebApplicationInstance, Task> AssertAppLogsAreEmptyAsync = app => app.LogsShouldBeEmptyAsync();
-
-    public static readonly Func<IWebApplicationInstance, Task> AssertAppLogsCanContainWarningsAsync =
-        app => app.LogsShouldBeEmptyAsync(canContainWarnings: true);
-
-    public static readonly Action<IEnumerable<LogEntry>> AssertBrowserLogIsEmpty =
-        // HTML imports are somehow used by Selenium or something but this deprecation notice is always there for every
-        // page.
-        logEntries => logEntries.ShouldNotContain(
-            logEntry => IsValidBrowserLogEntry(logEntry),
-            logEntries.Where(IsValidBrowserLogEntry).ToFormattedString());
-
-    public static readonly Func<LogEntry, bool> IsValidBrowserLogEntry =
-        logEntry =>
-            logEntry.Level >= LogLevel.Warning &&
-            !logEntry.Message.ContainsOrdinalIgnoreCase("HTML Imports is deprecated") &&
-            // The 404 is because of how browsers automatically request /favicon.ico even if a favicon is declared to be
-            // under a different URL.
-            !logEntry.IsNotFoundLogEntry("/favicon.ico");
 }