JS: throw exception on access to an uninitialized local variable (KT-20248 fixed)

compiler/testData/codegen/box/properties/lateinit/local/uninitializedCapturedMemberAccess.kt

@@ -1,6 +1,6 @@
 // LANGUAGE_VERSION: 1.2
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, NATIVE
+// IGNORE_BACKEND: NATIVE
 
 import kotlin.UninitializedPropertyAccessException
 

compiler/testData/codegen/box/properties/lateinit/local/uninitializedCapturedRead.kt

@@ -1,6 +1,6 @@
 // LANGUAGE_VERSION: 1.2
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, NATIVE
+// IGNORE_BACKEND: NATIVE
 
 import kotlin.UninitializedPropertyAccessException
 

compiler/testData/codegen/box/properties/lateinit/local/uninitializedMemberAccess.kt

@@ -1,6 +1,6 @@
 // LANGUAGE_VERSION: 1.2
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, NATIVE
+// IGNORE_BACKEND: NATIVE
 
 import kotlin.UninitializedPropertyAccessException
 

compiler/testData/codegen/box/properties/lateinit/local/uninitializedRead.kt

@@ -1,6 +1,6 @@
 // LANGUAGE_VERSION: 1.2
 // WITH_RUNTIME
-// IGNORE_BACKEND: JS, NATIVE
+// IGNORE_BACKEND: NATIVE
 
 import kotlin.UninitializedPropertyAccessException
 

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -15087,49 +15087,25 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 @TestMetadata("uninitializedCapturedMemberAccess.kt")
                 public void testUninitializedCapturedMemberAccess() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/properties/lateinit/local/uninitializedCapturedMemberAccess.kt");
-                    try {
+                    doTest(fileName);
-                        doTest(fileName);
-                    }
-                    catch (Throwable ignore) {
-                        return;
-                    }
-                    throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
                 }
 
                 @TestMetadata("uninitializedCapturedRead.kt")
                 public void testUninitializedCapturedRead() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/properties/lateinit/local/uninitializedCapturedRead.kt");
-                    try {
+                    doTest(fileName);
-                        doTest(fileName);
-                    }
-                    catch (Throwable ignore) {
-                        return;
-                    }
-                    throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
                 }
 
                 @TestMetadata("uninitializedMemberAccess.kt")
                 public void testUninitializedMemberAccess() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/properties/lateinit/local/uninitializedMemberAccess.kt");
-                    try {
+                    doTest(fileName);
-                        doTest(fileName);
-                    }
-                    catch (Throwable ignore) {
-                        return;
-                    }
-                    throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
                 }
 
                 @TestMetadata("uninitializedRead.kt")
                 public void testUninitializedRead() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/properties/lateinit/local/uninitializedRead.kt");
-                    try {
+                    doTest(fileName);
-                        doTest(fileName);
-                    }
-                    catch (Throwable ignore) {
-                        return;
-                    }
-                    throw new AssertionError("Looks like this test can be unmuted. Remove IGNORE_BACKEND directive for that.");
                 }
             }
 

js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/VariableAccessTranslator.java

@@ -19,10 +19,10 @@ package org.jetbrains.kotlin.js.translate.reference;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.descriptors.*;
-import org.jetbrains.kotlin.js.backend.ast.JsBinaryOperation;
+import org.jetbrains.kotlin.descriptors.impl.LocalVariableDescriptor;
-import org.jetbrains.kotlin.js.backend.ast.JsExpression;
+import org.jetbrains.kotlin.js.backend.ast.*;
-import org.jetbrains.kotlin.js.backend.ast.JsNameRef;
 import org.jetbrains.kotlin.js.translate.callTranslator.CallTranslator;
+import org.jetbrains.kotlin.js.translate.context.Namer;
 import org.jetbrains.kotlin.js.translate.context.TranslationContext;
 import org.jetbrains.kotlin.js.translate.general.AbstractTranslator;
 import org.jetbrains.kotlin.psi.KtReferenceExpression;
@@ -80,6 +80,14 @@ public class VariableAccessTranslator extends AbstractTranslator implements Acce
                 }
             }
         }
+        else if (original instanceof LocalVariableDescriptor) {
+            LocalVariableDescriptor originalLocal = (LocalVariableDescriptor) original;
+            if (originalLocal.isLateInit()) {
+                JsInvocation throwInvocation = new JsInvocation(Namer.throwUninitializedPropertyAccessExceptionFunRef(),
+                                                                new JsStringLiteral(originalLocal.getName().asString()));
+                return new JsConditional(new JsBinaryOperation(JsBinaryOperator.EQ, e, new JsNullLiteral()), throwInvocation, e);
+            }
+        }
         return e;
     }