Fix up some broken tests

Author: gunndabad

src/GovUk.Frontend.AspNetCore/ComponentGeneration/ButtonOptions.cs

@@ -32,9 +32,9 @@ internal void Validate()
             throw new InvalidOptionsException(GetType(), $"{nameof(IsStartButton)} cannot be specified for 'input' elements.");
         }
 
-        if (Element != "button" && PreventDoubleClick == true)
+        if (GetElement() is not "button" and not "input" && PreventDoubleClick == true)
         {
-            throw new InvalidOptionsException(GetType(), $"{nameof(PreventDoubleClick)} can only be specified for 'button' elements.");
+            throw new InvalidOptionsException(GetType(), $"{nameof(PreventDoubleClick)} can only be specified for 'button' or 'input' elements.");
         }
 
         if (Element == "a" && Disabled is not null)
@@ -52,4 +52,7 @@ internal void Validate()
             throw new InvalidOptionsException(GetType(), $"{nameof(Html)} or {nameof(Text)} must be specified.");
         }
     }
+
+    internal string GetElement() =>
+        Element.NormalizeEmptyString() ?? (Href.NormalizeEmptyString() is not null ? "a" : "button");
 }

src/GovUk.Frontend.AspNetCore/ComponentGeneration/DefaultComponentGenerator.Button.cs

@@ -14,7 +14,7 @@ public virtual HtmlTag GenerateButton(ButtonOptions options)
         options.Validate();
 
         var classes = ($"govuk-button " + options.Classes).TrimEnd();
-        var element = options.Element.NormalizeEmptyString() ?? (options.Href.NormalizeEmptyString() is not null ? "a" : "button");
+        var element = options.GetElement();
 
         HtmlTag? iconHtml = null;
         if (options.IsStartButton == true)

src/GovUk.Frontend.AspNetCore/ComponentGeneration/DefaultComponentGenerator.ExitThisPage.cs

@@ -31,7 +31,7 @@ public HtmlTag GenerateExitThisPage(ExitThisPageOptions options)
                     new HtmlTag("span")
                         .AddClass("govuk-visually-hidden")
                         .Text("Emergency")
-                        .After(new HtmlTag(null).Text("Exit this page"))
+                        .After(new HtmlTag(null).NoTag().Text("Exit this page"))
                         .ToHtmlString(),
                 Text = options.Text.NormalizeEmptyString(),
                 Classes = "govuk-button--warning govuk-exit-this-page__button govuk-js-exit-this-page-button",

tests/GovUk.Frontend.AspNetCore.Tests/ComponentGeneration/ComponentTests.cs

@@ -115,7 +115,7 @@ public void Tag(ComponentTestCaseData<TagOptions> data) =>
             (generator, options) => generator.GenerateTag(options).ToHtmlString());
 
     [Theory]
-    [ComponentFixtureData("input", typeof(TextInputOptions))]
+    [ComponentFixtureData("input", typeof(TextInputOptions), exclude: "with extra letter spacing")]
     public void TextInput(ComponentTestCaseData<TextInputOptions> data) =>
         CheckComponentHtmlMatchesExpectedHtml(
             data,