JS: decomposition of array access

js/js.inliner/src/org/jetbrains/kotlin/js/inline/ExpressionDecomposer.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.js.inline.util
 import com.google.dart.compiler.backend.js.ast.*
 import com.google.dart.compiler.backend.js.ast.metadata.*
 import org.jetbrains.kotlin.js.translate.utils.JsAstUtils.*
+import org.jetbrains.kotlin.js.translate.utils.ast.*
 
 import kotlin.platform.platformStatic
 import kotlin.properties.Delegates
@@ -81,6 +82,21 @@ class ExpressionDecomposer private (
         return false
     }
 
+    override fun visit(x: JsArrayAccess, ctx: JsContext<*>): Boolean {
+        x.process()
+        return false
+    }
+
+    private fun JsArrayAccess.process() {
+        array = accept(array)
+
+        if (array in containsNodeWithSideEffect && index in containsExtractable) {
+            array = array.extractToTemporary()
+        }
+
+        index = accept(index)
+    }
+
     override fun visit(x: JsInvocation, ctx: JsContext<*>): Boolean {
         CallableInvocationAdapter(x).process()
         return false

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/astUtils.kt

@@ -55,3 +55,11 @@ public fun JsNode.any(predicate: (JsNode) -> Boolean): Boolean {
     visitor.accept(this)
     return visitor.matched
 }
+
+public var JsArrayAccess.index: JsExpression
+    get() = getIndexExpression()
+    set(value) = setIndexExpression(value)
+
+public var JsArrayAccess.array: JsExpression
+    get() = getArrayExpression()
+    set(value) = setArrayExpression(value)

js/js.translator/testData/inlineEvaluationOrder/cases/arrayAccess1.kt

@@ -0,0 +1,8 @@
+package foo
+
+fun box(): String {
+    assertEquals(2, fizz(array(1, 2))[buzz(1)])
+    assertEquals("fizz(1,2);buzz(1);", pullLog())
+
+    return "OK"
+}

js/js.translator/testData/inlineEvaluationOrder/cases/arrayAccess2.kt

@@ -0,0 +1,8 @@
+package foo
+
+fun box(): String {
+    assertEquals(2, array(1, 2)[fizz(0) + buzz(1)])
+    assertEquals("fizz(0);buzz(1);", pullLog())
+
+    return "OK"
+}

js/js.translator/testData/inlineEvaluationOrder/cases/arrayAccess3.kt

@@ -0,0 +1,8 @@
+package foo
+
+fun box(): String {
+    assertEquals(2, array(1, fizz(2))[fizz(0) + buzz(1)])
+    assertEquals("fizz(2);fizz(0);buzz(1);", pullLog())
+
+    return "OK"
+}