Align StyleSheetBuilder parameter with other @Composable ContentBuilder and add test (#1112)

web/core/src/jsMain/kotlin/org/jetbrains/compose/web/elements/Elements.kt

@@ -943,8 +943,8 @@ fun Style(
  * @param rulesBuild allows to define the style rules using [StyleSheetBuilder]
  */
 @Composable
-fun Style(
-    applyAttrs: (AttrsBuilder<HTMLStyleElement>.() -> Unit)? = null,
+inline fun Style(
+    noinline applyAttrs: (AttrsBuilder<HTMLStyleElement>.() -> Unit)? = null,
     rulesBuild: StyleSheetBuilder.() -> Unit
 ) {
     val builder = StyleSheetBuilderImpl()

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2020-2021 JetBrains s.r.o. and respective authors and developers.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE.txt file.
+ */
+
+package org.jetbrains.compose.web.core.tests.elements
+
+import androidx.compose.runtime.*
+import org.jetbrains.compose.web.css.*
+import org.jetbrains.compose.web.dom.*
+import org.jetbrains.compose.web.testutils.*
+import org.w3c.dom.*
+import org.w3c.dom.css.*
+import kotlin.test.*
+
+class StyleTest {
+    @Test
+    fun testingComposableStyle() = runTest {
+        var color by mutableStateOf(Color.green)
+        composition {
+            Style {
+                val element = remember { "body" }
+                element {
+                    backgroundColor(color)
+                }
+            }
+        }
+        val element = root.firstChild
+        assertTrue(element is HTMLStyleElement)
+        val sheet = element.sheet
+        assertTrue(sheet is CSSStyleSheet)
+        assertEquals("""body { background-color: green; }""", sheet.cssRules.asList().single().cssText)
+
+        color = Color.red
+        waitForRecompositionComplete()
+        assertEquals("""body { background-color: red; }""", sheet.cssRules.asList().single().cssText)
+    }
+}