From bd3953c09f42860242c7678057d73abf125018ae Mon Sep 17 00:00:00 2001
From: Svyatoslav Kuzmich <svyatoslav.kuzmich@jetbrains.com>
Date: Thu, 9 May 2019 15:23:53 +0300
Subject: [PATCH] [JS IR BE] Turn on strict mode in generated code.

Fix multiple import of the same javascript module.
---
 .../js/transformers/irToJs/IrModuleToJsTransformer.kt       | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformer.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformer.kt
index eb9e72209b5..26505157821 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformer.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/IrModuleToJsTransformer.kt
@@ -28,7 +28,9 @@ class IrModuleToJsTransformer(
     private val moduleKind = backendContext.configuration[JSConfigurationKeys.MODULE_KIND]!!
 
     private fun generateModuleBody(module: IrModuleFragment, context: JsGenerationContext): List<JsStatement> {
-        val statements = mutableListOf<JsStatement>()
+        val statements = mutableListOf<JsStatement>(
+            JsStringLiteral("use strict").makeStmt()
+        )
 
         // TODO: fix it up with new name generator
         val anyName = context.getNameForClass(backendContext.irBuiltIns.anyClass.owner)
@@ -251,7 +253,7 @@ class IrModuleToJsTransformer(
                 }
         }
 
-        val importedJsModules = declarationLevelJsModules + packageLevelJsModules
+        val importedJsModules = (declarationLevelJsModules + packageLevelJsModules).distinctBy { it.key }
         return Pair(importStatements, importedJsModules)
     }