Use asHtmlElement helper only in TestUtils

TestUtils is a perfect classic name!

web/core/src/jsTest/kotlin/DomSideEffectTests.kt

@@ -12,12 +12,8 @@ import kotlin.test.assertEquals
 class DomSideEffectTests {
 
     @Test
-    fun canCreateElementsInDomSideEffect() {
-        val root = "div".asHtmlElement()
-
-        renderComposable(
-            root = root
-        ) {
+    fun canCreateElementsInDomSideEffect() = runTest {
+        composition {
             Div {
                 DomSideEffect {
                     it.appendChild(
@@ -28,6 +24,7 @@ class DomSideEffectTests {
                 }
             }
         }
+
         assertEquals(
             expected = "<div><div><p>Hello World!</p></div></div>",
             actual = root.outerHTML

web/core/src/jsTest/kotlin/elements/InputsGenerateCorrectHtmlTests.kt

@@ -505,10 +505,8 @@ class InputsGenerateCorrectHtmlTests {
     }
 
     @Test
-    fun textAreaWithDefaultValueAndWithoutIt() {
-        val root = "div".asHtmlElement()
-
-        renderComposable(root = root) {
+    fun textAreaWithDefaultValueAndWithoutIt() = runTest {
+        composition {
             TextArea()
             TextArea {
                 defaultValue("not-empty-default-value")

web/widgets/src/jsTest/ModifierTests.kt

@@ -12,36 +12,24 @@ import kotlin.test.assertTrue
 
 class ModifierTests {
     @Test
-    fun backgroundModifier() {
-        val root = "div".asHtmlElement()
-        renderComposable(
-            root = root
-        ) {
+    fun backgroundModifier() = runTest {
+         {
             Box(
                 Modifier.background(Color(255, 0, 0))
             ) { }
         }
 
-        val el = root.firstChild
-        assertTrue(el is HTMLElement, "element not found")
-
-        assertEquals("background-color: rgb(255, 0, 0);", el.style.cssText)
+        assertEquals("background-color: rgb(255, 0, 0);", nextChild().style.cssText)
     }
 
     @Test
-    fun size() {
-        val root = "div".asHtmlElement()
-        renderComposable(
-            root = root
-        ) {
+    fun size() = runTest {
+        composition {
             Box(
                 Modifier.size(40.dp)
             ) { }
         }
 
-        val el = root.firstChild
-        assertTrue(el is HTMLElement, "element not found")
-
-        assertEquals("width: 40px; height: 40px;", el.style.cssText)
+        assertEquals("width: 40px; height: 40px;", nextChild().style.cssText)
     }
 }