[JS IR] Drop last null arguments in calls of external functions

^KT-40090 fixed
JetBrains · Nov 23, 2020 · fe3030c · fe3030c
1 parent 5c731c6
commit fe3030c
Showing 1 changed file with 21 additions and 12 deletions.
diff --git a/...er/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt b/...er/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/transformers/irToJs/jsAstUtils.kt
@@ -198,26 +198,35 @@ fun translateCall(
     }
 }
 
-fun translateCallArguments(expression: IrMemberAccessExpression<*>, context: JsGenerationContext, transformer: IrElementToJsExpressionTransformer): List<JsExpression> {
+fun translateCallArguments(
+    expression: IrMemberAccessExpression<*>,
+    context: JsGenerationContext,
+    transformer: IrElementToJsExpressionTransformer,
+): List<JsExpression> {
     val size = expression.valueArgumentsCount
 
-    val arguments = (0 until size).mapTo(ArrayList(size)) { index ->
-        val argument = expression.getValueArgument(index)
-        val result = argument?.accept(transformer, context)
-        if (result == null) {
-            if (context.staticContext.backendContext.es6mode) return@mapTo JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(2))
-
-            assert(expression is IrFunctionAccessExpression && expression.symbol.owner.isExternalOrInheritedFromExternal())
-            JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(1))
-        } else
-            result
-    }
+    val validWithNullArgs = expression.validWithNullArgs()
+    val arguments = (0 until size)
+        .mapTo(ArrayList(size)) { index ->
+            val argument = expression.getValueArgument(index)
+            argument?.accept(transformer, context)
+        }
+        .onEach { result ->
+            if (result == null) {
+                assert(validWithNullArgs)
+            }
+        }
+        .dropLastWhile { it == null }
+        .map { it ?: JsPrefixOperation(JsUnaryOperator.VOID, JsIntLiteral(1)) }
 
     return if (expression.symbol.isSuspend) {
         arguments + context.continuation
     } else arguments
 }
 
+private fun IrMemberAccessExpression<*>.validWithNullArgs() =
+    this is IrFunctionAccessExpression && symbol.owner.isExternalOrInheritedFromExternal()
+
 fun JsStatement.asBlock() = this as? JsBlock ?: JsBlock(this)
 
 fun defineProperty(receiver: JsExpression, name: String, value: () -> JsExpression): JsInvocation {