Prevent PrivilegeText from rendering masked value when there is no content

Author: pwelter34

src/Privileged.Components/PrivilegeText.cs

@@ -254,6 +254,19 @@ public class PrivilegeText : ComponentBase
     /// </remarks>
     protected bool? IsAllowed { get; set; }
 
+    /// <summary>
+    /// Gets or sets whether the component has content to display.
+    /// </summary>
+    /// <value>
+    /// <c>true</c> if either <see cref="ChildContent"/> is not null or <see cref="Text"/> is not null/empty/whitespace;
+    /// <c>false</c> otherwise.
+    /// </value>
+    /// <remarks>
+    /// This property is calculated in <see cref="OnParametersSet"/> and is used to determine
+    /// whether to render the toggle button and masked content.
+    /// </remarks>
+    protected bool HasContent { get; set; }
+
     /// <summary>
     /// Gets or sets whether the content is currently shown (unmasked) by user interaction.
     /// </summary>
@@ -293,6 +306,8 @@ protected override void OnParametersSet()
 
         IsAllowed = string.IsNullOrWhiteSpace(Subject)
             || PrivilegeContext?.Allowed(Action, Subject, Qualifier) == true;
+
+        HasContent = ChildContent != null || !string.IsNullOrWhiteSpace(Text);
     }
 
     /// <summary>
@@ -318,6 +333,9 @@ protected override void OnParametersSet()
     /// </remarks>
     protected override void BuildRenderTree(RenderTreeBuilder builder)
     {
+        if (!HasContent)
+            return;
+
         // Container
         builder.OpenElement(0, "div");
         builder.AddAttribute(1, "style", ContainerStyle);

test/Privileged.Components.Tests/PrivilegeTextTests.cs

@@ -18,7 +18,7 @@ public void AuthorizedWithText_ShowsMaskedText()
 
         var button = cut.Find("button");
         Assert.NotNull(button);
-        
+
         cut.Find("div div").MarkupMatches("<div>••••••</div>");
     }
 
@@ -340,4 +340,95 @@ public void DefaultAction_IsRead()
         var button = cut.Find("button");
         Assert.NotNull(button);
     }
+
+    [Fact]
+    public void NoContent_NullTextAndChildContent_RendersNothing()
+    {
+        var context = new PrivilegeBuilder()
+            .Allow("read", "Secret")
+            .Build();
+
+        var cut = Render<PrivilegeText>(parameters => parameters
+            .AddCascadingValue(context)
+            .Add(p => p.Action, "read")
+            .Add(p => p.Subject, "Secret")
+            .Add(p => p.Text, (string?)null)
+        );
+
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("button"));
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("div"));
+    }
+
+    [Fact]
+    public void NoContent_EmptyText_RendersNothing()
+    {
+        var context = new PrivilegeBuilder()
+            .Allow("read", "Secret")
+            .Build();
+
+        var cut = Render<PrivilegeText>(parameters => parameters
+            .AddCascadingValue(context)
+            .Add(p => p.Action, "read")
+            .Add(p => p.Subject, "Secret")
+            .Add(p => p.Text, "")
+        );
+
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("button"));
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("div"));
+    }
+
+    [Fact]
+    public void NoContent_WhitespaceText_RendersNothing()
+    {
+        var context = new PrivilegeBuilder()
+            .Allow("read", "Secret")
+            .Build();
+
+        var cut = Render<PrivilegeText>(parameters => parameters
+            .AddCascadingValue(context)
+            .Add(p => p.Action, "read")
+            .Add(p => p.Subject, "Secret")
+            .Add(p => p.Text, "   ")
+        );
+
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("button"));
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("div"));
+    }
+
+    [Fact]
+    public void NoContent_UnauthorizedWithNoContent_RendersNothing()
+    {
+        var context = new PrivilegeBuilder()
+            .Forbid("read", "Secret")
+            .Build();
+
+        var cut = Render<PrivilegeText>(parameters => parameters
+            .AddCascadingValue(context)
+            .Add(p => p.Action, "read")
+            .Add(p => p.Subject, "Secret")
+            .Add(p => p.Text, "")
+        );
+
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("button"));
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("div"));
+    }
+
+    [Fact]
+    public void NoContent_WithMaskedContent_StillRendersNothing()
+    {
+        var context = new PrivilegeBuilder()
+            .Allow("read", "Secret")
+            .Build();
+
+        var cut = Render<PrivilegeText>(parameters => parameters
+            .AddCascadingValue(context)
+            .Add(p => p.Action, "read")
+            .Add(p => p.Subject, "Secret")
+            .Add(p => p.Text, "")
+            .Add(p => p.MaskedContent, "<em>Hidden</em>")
+        );
+
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("button"));
+        Assert.Throws<Bunit.ElementNotFoundException>(() => cut.Find("div"));
+    }
 }