[Gradle, JS] Css mode instead of boolean flag

#KT-32721 fixed

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpackConfig.kt

@@ -12,6 +12,9 @@ import org.jetbrains.kotlin.gradle.targets.js.NpmVersions
 import org.jetbrains.kotlin.gradle.targets.js.RequiredKotlinJsDependency
 import org.jetbrains.kotlin.gradle.targets.js.appendConfigsFromDir
 import org.jetbrains.kotlin.gradle.targets.js.jsQuoted
+import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpackCssMode.EXTRACT
+import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpackCssMode.IMPORT
+import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpackCssMode.INLINE
 import java.io.File
 import java.io.Serializable
 import java.io.StringWriter
@@ -57,10 +60,12 @@ data class KotlinWebpackConfig(
             if (!cssSettings.enabled) return@also
 
             it.add(versions.cssLoader)
-            if (cssSettings.inline) {
-                it.add(versions.styleLoader)
-            } else {
-                it.add(versions.miniCssExtractPlugin)
+            when (cssSettings.mode) {
+                EXTRACT -> it.add(versions.miniCssExtractPlugin)
+                INLINE -> it.add(versions.styleLoader)
+                IMPORT -> {
+                }
+                else -> cssError()
             }
         }
 
@@ -288,10 +293,12 @@ data class KotlinWebpackConfig(
             |    
             """.trimMargin()
 
-        if (cssSettings.inline) {
-            appendln(inlinedCss)
-        } else {
-            appendln(extractedCss)
+        when (cssSettings.mode) {
+            EXTRACT -> appendln(extractedCss)
+            INLINE -> appendln(inlinedCss)
+            IMPORT -> {
+            }
+            else -> cssError()
         }
 
         appendln(
@@ -351,6 +358,17 @@ data class KotlinWebpackConfig(
         )
     }
 
+    private fun cssError() {
+        throw IllegalStateException(
+            """
+                    Possible values for cssSettings.mode:
+                    - EXTRACT
+                    - INLINE
+                    - IMPORT
+                """.trimIndent()
+        )
+    }
+
 
     private fun json(obj: Any) = StringWriter().also {
         GsonBuilder().setPrettyPrinting().create().toJson(obj, it)

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/webpack/KotlinWebpackCssSettings.kt

@@ -6,11 +6,18 @@
 package org.jetbrains.kotlin.gradle.targets.js.webpack
 
 import org.gradle.api.tasks.Input
+import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpackCssMode.INLINE
 
 data class KotlinWebpackCssSettings(
     @Input
     var enabled: Boolean = true,
 
     @Input
-    var inline: Boolean = true
-)
+    var mode: String = INLINE
+)
+
+object KotlinWebpackCssMode {
+    const val EXTRACT = "extract"
+    const val INLINE = "inline"
+    const val IMPORT = "import"
+}