Tests: fix gradle tests for script configuration loading

Introduce `testAffectedGradleProjectFiles` property
to avoid full gradle project import in some tests

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/testing.kt

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.scripting.gradle
+
+import com.intellij.openapi.application.Application
+
+// this property is used in tests to avoid full gradle project import and to make those tests more lightweight
+var testAffectedGradleProjectFiles: Boolean = false
+
+internal val Application.isUnitTestModeWithoutAffectedGradleProjectFilesCheck: Boolean
+    get() {
+        if (isUnitTestMode) {
+            return !testAffectedGradleProjectFiles
+        }
+        return false
+    }

idea/idea-gradle/src/org/jetbrains/kotlin/idea/scripting/gradle/utils.kt

@@ -36,8 +36,9 @@ fun isInAffectedGradleProjectFiles(project: Project, filePath: String): Boolean
 }
 
 fun isInAffectedGradleProjectFiles(files: Set<String>, filePath: String): Boolean {
-    // todo: avoid isUnitTestMode usage
-    if (ApplicationManager.getApplication().isUnitTestMode) return true
+    if (ApplicationManager.getApplication().isUnitTestModeWithoutAffectedGradleProjectFilesCheck) {
+        return true
+    }
 
     return filePath in files
 }

idea/idea-gradle/tests/org/jetbrains/kotlin/idea/scripting/gradle/GradleScriptOutOfProjectTest.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.idea.scripting.gradle
 
-import junit.framework.TestCase
 import org.jetbrains.kotlin.idea.core.script.ScriptConfigurationManager
 import org.jetbrains.kotlin.idea.script.AbstractScriptConfigurationLoadingTest
 import org.jetbrains.kotlin.psi.KtFile
@@ -22,7 +21,13 @@ class GradleScriptOutOfProjectTest : AbstractScriptConfigurationLoadingTest() {
 
         configureScriptFile(rootDir, buildGradleKts)
 
-        ScriptConfigurationManager.markFileWithManualConfigurationLoading(myFile.virtualFile)
+        testAffectedGradleProjectFiles = true
+    }
+
+    override fun tearDown() {
+        super.tearDown()
+
+        testAffectedGradleProjectFiles = false
     }
 
     private val loaderForOutOfProjectScripts by lazy {