JS backend: add the support function expression

#KT-7242 Fixed

compiler/testData/codegen/box/functions/functionExpression/functionExpression.kt

@@ -18,12 +18,12 @@ fun box() : String {
     if(  1.(fun Int.(i: Int) = i + this)(1) != 2) return "test 6 failed";
     if(  (fooT1<String>()("mama")) != "mama")  return "test 7 failed";
 
-    val a = [A] fun Int.() = this + 1 // 
+    val a = [A] fun Int.() = this + 1
     if (1.a() != 2) return "test 8 failed"
     val b = ( fun Int.() = this + 1)
-    if (1.a() != 2) return "test 9 failed"
+    if (1.b() != 2) return "test 9 failed"
     val c = (@c fun Int.() = this + 1)
-    if (1.a() != 2) return "test 10 failed"
+    if (1.c() != 2) return "test 10 failed"
 
     val d = @d fun (): Int { return@d 4}
     if (d() != 4) return "test 11 failed"

compiler/testData/codegen/box/functions/functionExpression/functionExpressionWithName.kt

@@ -21,9 +21,9 @@ fun box() : String {
     val a = [A] fun Int.name() = this + 1 // name
     if (1.a() != 2) return "test 8 failed"
     val b = ( fun Int.name() = this + 1)
-    if (1.a() != 2) return "test 9 failed"
+    if (1.b() != 2) return "test 9 failed"
     val c = (@c fun Int.name() = this + 1)
-    if (1.a() != 2) return "test 10 failed"
+    if (1.c() != 2) return "test 10 failed"
 
     val d = fun name(): Int { return@name 4}
     if (d() != 4) return "test 11 failed"

compiler/testData/codegen/box/functions/functionExpression/functionLiteralExpression.kt

@@ -10,6 +10,8 @@ fun fooT1<T>(t : T) = { t.toString() }
 
 fun fooT2<T>(t: T) = { x:T -> t.toString() + x.toString() }
 
+object t
+
 fun box() : String {
   if( (10.foo1())() != "23910") return "foo1 fail"
   if( (10.foo2())(1) != 11 ) return "foo2 fail"
@@ -18,7 +20,7 @@ fun box() : String {
   if(  {1}() != 1)  return "test 4 failed";
   if(  {x : Int -> x}(1) != 1)  return "test 5 failed";
   if(  1.(fun Int.(x: Int) = x + this)(1) != 2) return "test 6 failed";
-  if(  1.(fun Int.() = this)() != 1)  return "test 7 failed";
+  if(  t.(fun Any.() = this)() != t)  return "test 7 failed";
   if(  (fooT1<String>("mama"))() != "mama")  return "test 8 failed";
   if(  (fooT2<String>("mama"))("papa") != "mamapapa")  return "test 9 failed";
   return "OK"

generators/src/org/jetbrains/kotlin/generators/tests/GenerateTests.kt

@@ -843,6 +843,11 @@ fun main(args: Array<String>) {
         testClass(javaClass<AbstractCompanionObjectTest>()) {
             model("codegen/box/objectIntrinsics", targetBackend = TargetBackend.JS)
         }
+
+        testClass(javaClass<AbstractFunctionExpressionTest>()) {
+            model("codegen/box/functions/functionExpression", targetBackend = TargetBackend.JS)
+        }
+
     }
 }
 

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

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.js.test.semantics;
+
+import com.intellij.testFramework.TestDataPath;
+import org.jetbrains.kotlin.test.JUnit3RunnerWithInners;
+import org.jetbrains.kotlin.test.JetTestUtils;
+import org.jetbrains.kotlin.test.TestMetadata;
+import org.junit.runner.RunWith;
+
+import java.io.File;
+import java.util.regex.Pattern;
+
+/** This class is generated by {@link org.jetbrains.kotlin.generators.tests.TestsPackage}. DO NOT MODIFY MANUALLY */
+@SuppressWarnings("all")
+@TestMetadata("compiler/testData/codegen/box/functions/functionExpression")
+@TestDataPath("$PROJECT_ROOT")
+@RunWith(JUnit3RunnerWithInners.class)
+public class FunctionExpressionTestGenerated extends AbstractFunctionExpressionTest {
+    public void testAllFilesPresentInFunctionExpression() throws Exception {
+        JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/functions/functionExpression"), Pattern.compile("^(.+)\\.kt$"), true);
+    }
+
+    @TestMetadata("functionExpression.kt")
+    public void testFunctionExpression() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/functionExpression/functionExpression.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("functionExpressionWithName.kt")
+    public void testFunctionExpressionWithName() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/functionExpression/functionExpressionWithName.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("functionExpressionWithThisReference.kt")
+    public void testFunctionExpressionWithThisReference() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/functionExpression/functionExpressionWithThisReference.kt");
+        doTest(fileName);
+    }
+
+    @TestMetadata("functionLiteralExpression.kt")
+    public void testFunctionLiteralExpression() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/functionExpression/functionLiteralExpression.kt");
+        doTest(fileName);
+    }
+}

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/abstarctClassesForGeneratedTests.kt

@@ -20,16 +20,20 @@ import org.jetbrains.kotlin.js.test.AbstractSingleFileTranslationWithDirectivesT
 import org.jetbrains.kotlin.js.test.MultipleModulesTranslationTest
 import org.jetbrains.kotlin.js.test.SingleFileTranslationTest
 
-public abstract class AbstractBridgeTest : SingleFileTranslationTest("bridges/") {
+private abstract class AbstractBlackBoxTest(d: String) : SingleFileTranslationTest(d) {
     override fun doTest(filename: String) = checkBlackBoxIsOkByPath(filename)
 }
 
+public abstract class AbstractBridgeTest : AbstractBlackBoxTest("bridges/")
+
 public abstract class AbstractCallableReferenceTest(main: String) : SingleFileTranslationTest("callableReference/" + main)
 
 public abstract class AbstractCompanionObjectTest : SingleFileTranslationTest("objectIntrinsics/")
 
 public abstract class AbstractDynamicTest : SingleFileTranslationTest("dynamic/")
 
+public abstract class AbstractFunctionExpressionTest : AbstractBlackBoxTest("functionExpression/")
+
 public abstract class AbstractInlineEvaluationOrderTest : AbstractSingleFileTranslationWithDirectivesTest("inlineEvaluationOrder/")
 
 public abstract class AbstractInlineJsStdlibTest : AbstractSingleFileTranslationWithDirectivesTest("inlineStdlib/")

js/js.translator/src/org/jetbrains/kotlin/js/translate/expression/ExpressionVisitor.java

@@ -417,7 +417,10 @@ public final class ExpressionVisitor extends TranslatorVisitor<JsNode> {
             MetadataPackage.setStaticRef(name, alias);
         }
 
-        return new JsVars(new JsVars.JsVar(name, alias)).source(expression);
+        boolean isExpression = BindingContextUtilPackage.isUsedAsExpression(expression, context.bindingContext());
+        JsNode result = isExpression ? alias : JsAstUtils.newVar(name, alias);
+
+        return result.source(expression);
     }
 
     @Override