Fixed KT-5339 J2K: convert Objects.equals to == and !=

Mock JDK regenerated to add java.util.Objects

 #KT-5339 Fixed

generators/src/org/jetbrains/jet/generators/mockJDK/GenerateMockJdk.java

@@ -252,6 +252,7 @@ public class GenerateMockJdk {
             "java/util/Properties.class",
             "java/util/Random.class",
             "java/util/RandomAccess.class",
+            "java/util/Objects.class",
             "java/util/Set.class",
             "java/util/SortedMap.class",
             "java/util/SortedSet.class",

j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.kt

@@ -235,6 +235,11 @@ open class ExpressionVisitor(private val converter: Converter) : JavaElementVisi
             }
         }
 
+        if (target is PsiMethod && isObjectsEquals(target) && arguments.size == 2) {
+            result = BinaryExpression(converter.convertExpression(arguments[0]), converter.convertExpression(arguments[1]), "==")
+            return
+        }
+
         result = MethodCallExpression(converter.convertExpression(methodExpr),
                                       convertArguments(expression),
                                       typeArguments,
@@ -247,6 +252,12 @@ open class ExpressionVisitor(private val converter: Converter) : JavaElementVisi
                 method.getParameterList().getParameters().single().getType().getCanonicalText() == JAVA_LANG_OBJECT
     }
 
+    private fun isObjectsEquals(method: PsiMethod): Boolean {
+        return method.getName() == "equals" &&
+                method.getParameterList().getParameters().size == 2 &&
+                method.getContainingClass()?.getQualifiedName() == "java.util.Objects"
+    }
+
     override fun visitNewExpression(expression: PsiNewExpression) {
         if (expression.getArrayInitializer() != null) {
             result = converter.convertExpression(expression.getArrayInitializer())

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -1146,6 +1146,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/equals/Equals4.java");
         }
         
+        @TestMetadata("ObjectsEquals.java")
+        public void testObjectsEquals() throws Exception {
+            doTest("j2k/tests/testData/ast/equals/ObjectsEquals.java");
+        }
+        
     }
     
     @TestMetadata("j2k/tests/testData/ast/field")

j2k/tests/testData/ast/equals/ObjectsEquals.java

@@ -0,0 +1,15 @@
+//file
+import java.util.Objects;
+
+interface I {
+}
+
+class C{
+    boolean foo1(I i1, I i2) {
+        return Objects.equals(i1, i2))
+    }
+
+    boolean foo2(I i1, I i2) {
+        return !java.util.Objects.equals(i1, i2)
+    }
+}

j2k/tests/testData/ast/equals/ObjectsEquals.kt

@@ -0,0 +1,13 @@
+import java.util.Objects
+
+trait I
+
+class C {
+    fun foo1(i1: I, i2: I): Boolean {
+        return i1 == i2
+    }
+
+    fun foo2(i1: I, i2: I): Boolean {
+        return i1 != i2
+    }
+}