Extract extra imports provision into an extension, implement one ...

for script in the plugin, drop direct dependency on scripts from
FileScopeFactory

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/ScriptExtraImportsProviderExtension.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. 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.scripting.compiler.plugin
+
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtImportInfo
+import org.jetbrains.kotlin.resolve.ImportPath
+import org.jetbrains.kotlin.resolve.extensions.ExtraImportsProviderExtension
+import org.jetbrains.kotlin.script.ScriptDependenciesProvider
+
+class ScriptExtraImportsProviderExtension : ExtraImportsProviderExtension {
+
+    // initially copied from org.jetbrains.kotlin.resolve.lazy.FileScopeFactory.DefaultImportImpl, but kept separate to simplify dependencies
+    // and allow easier extension
+    private class ScriptExtraImportImpl(private val importPath: ImportPath) : KtImportInfo {
+        override val isAllUnder: Boolean get() = importPath.isAllUnder
+
+        override val importContent = KtImportInfo.ImportContent.FqNameBased(importPath.fqName)
+
+        override val aliasName: String? get() = importPath.alias?.asString()
+
+        override val importedFqName: FqName? get() = importPath.fqName
+    }
+
+    override fun getExtraImports(ktFile: KtFile): Collection<KtImportInfo> =
+        ktFile.takeIf { it.isScript() }?.let { file ->
+            val scriptDependencies = ScriptDependenciesProvider.getInstance(file.project)?.getScriptDependencies(file.originalFile)
+            scriptDependencies?.imports?.map { ScriptExtraImportImpl(ImportPath.fromString(it)) }
+        }.orEmpty()
+}

plugins/scripting/scripting-compiler/src/org/jetbrains/kotlin/scripting/compiler/plugin/pluginRegisrar.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.extensions.CollectAdditionalSourcesExtension
 import org.jetbrains.kotlin.extensions.CompilerConfigurationExtension
+import org.jetbrains.kotlin.resolve.extensions.ExtraImportsProviderExtension
 import org.jetbrains.kotlin.resolve.extensions.SyntheticResolveExtension
 import org.jetbrains.kotlin.script.ScriptDefinitionProvider
 import org.jetbrains.kotlin.script.ScriptDependenciesProvider
@@ -33,6 +34,7 @@ class ScriptingCompilerConfigurationComponentRegistrar : ComponentRegistrar {
             CliScriptDependenciesProvider(project)
         )
         SyntheticResolveExtension.registerExtension(project, ScriptingResolveExtension())
+        ExtraImportsProviderExtension.registerExtension(project, ScriptExtraImportsProviderExtension())
 
         val messageCollector = configuration.get(CLIConfigurationKeys.MESSAGE_COLLECTOR_KEY)
         if (messageCollector != null) {