fix: add missing support for templ.SafeCSS in optional CSS class expr…

…essions, fixes #162

generator/test-css-usage/expected.html

@@ -8,3 +8,5 @@
 <div class="a c"></div>
 <div class="a"></div>
 <input type="email" id="email" name="email" class="a b" placeholder="[email protected]" autocomplete="off"/>
+<button class="bg-violet-500 hover:bg-violet-600">Save changes</button>
+

generator/test-css-usage/template.templ

@@ -26,11 +26,16 @@ templ KVExample() {
 	<input type="email" id="email" name="email" class={ "a", "b", "c", templ.KV("c", false) } placeholder="[email protected]" autocomplete="off"/>
 }
 
+templ PsuedoAttributes() {
+	<button class={ "bg-violet-500", templ.KV(templ.SafeClass("hover:bg-violet-600"), true) }>Save changes</button>
+}
+
 templ ThreeButtons() {
 	{! Button("A") }
 	{! Button("B") }
 	<button class={ templ.Classes(green) } type="button">{ "Green" }</button>
 	{! MapCSSExample() }
 	{! KVExample() }
+	{! PsuedoAttributes() }
 }
 

runtime.go

@@ -191,6 +191,12 @@ func (cp *cssProcessor) Add(item any) {
 		}
 	case KeyValue[string, bool]:
 		cp.AddUnsanitized(c.Key, c.Value)
+	case []KeyValue[CSSClass, bool]:
+		for _, kv := range c {
+			cp.AddSanitized(kv.Key.ClassName(), kv.Value)
+		}
+	case KeyValue[CSSClass, bool]:
+		cp.AddSanitized(c.Key.ClassName(), c.Value)
 	case CSSClasses:
 		for _, item := range c {
 			cp.Add(item)

runtime_test.go

@@ -331,8 +331,10 @@ func TestClassesFunction(t *testing.T) {
 				templ.KV("b", true),
 				"c",
 				templ.KV("c", false),
+				templ.KV(templ.SafeClass("d"), true),
+				templ.KV(templ.SafeClass("e"), false),
 			},
-			expected: "a b",
+			expected: "a b d",
 		},
 		{
 			name: "an array of KV types can be used to show or hide classes",