fixed PY-5588 Compatibility inspection: highlight using keyword argument in the list of base classes as errors under py2

python/src/com/jetbrains/python/inspections/PyCompatibilityInspection.java

@@ -1,6 +1,7 @@
 package com.jetbrains.python.inspections;
 
 import com.intellij.codeInspection.LocalQuickFix;
+import com.intellij.codeInspection.ProblemHighlightType;
 import com.intellij.codeInspection.ProblemsHolder;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.roots.ProjectFileIndex;
@@ -115,9 +116,10 @@ public class PyCompatibilityInspection extends PyInspection {
       myHolder = holder;
     }
 
+    @Override
     protected final void registerProblem(@Nullable final PsiElement element,
                                        @NotNull final String message,
-                                       final LocalQuickFix quickFix, boolean asError){
+                                       @Nullable final LocalQuickFix quickFix, final boolean asError){
       if (element == null || element.getTextLength() == 0){
           return;
       }
@@ -215,5 +217,23 @@ public class PyCompatibilityInspection extends PyInspection {
                               len, source, null, false);
       }
     }
+
+    @Override
+    public void visitPyArgumentList(final PyArgumentList node) { //PY-5588
+      final List<PyElement> problemElements = new ArrayList<PyElement>();
+      if (node.getParent() instanceof PyClass) {
+        for (final PyExpression expression : node.getArguments()) {
+          if (expression instanceof PyKeywordArgument)
+            problemElements.add(expression);
+        }
+      }
+      final String errorMessage = "This syntax available only since py3";
+      final boolean isPy3 = LanguageLevel.forElement(node).isPy3K();
+      if (compatibleWithPy2() || !isPy3) {
+        for (final PyElement problemElement : problemElements)
+          myHolder.registerProblem(problemElement, errorMessage, isPy3? ProblemHighlightType.GENERIC_ERROR_OR_WARNING :
+                                                          ProblemHighlightType.GENERIC_ERROR);
+      }
+    }
   }
-}
+}

python/src/com/jetbrains/python/validation/CompatibilityVisitor.java

@@ -12,6 +12,7 @@ import com.jetbrains.python.PyTokenTypes;
 import com.jetbrains.python.actions.*;
 import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.impl.PyQualifiedName;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.HashSet;
 import java.util.List;
@@ -455,13 +456,13 @@ public abstract class CompatibilityVisitor extends PyAnnotator {
     return false;
   }
 
-  protected abstract void registerProblem(PsiElement node, String s, LocalQuickFix localQuickFix, boolean asError);
+  protected abstract void registerProblem(PsiElement node, String s, @Nullable LocalQuickFix localQuickFix, boolean asError);
 
-  protected void registerProblem(PsiElement node, String s, LocalQuickFix localQuickFix) {
+  protected void registerProblem(final PsiElement node, final String s, @Nullable final LocalQuickFix localQuickFix) {
     registerProblem(node, s, localQuickFix, true);
   }
 
-  protected void registerProblem(PsiElement node, String s) {
+  protected void registerProblem(final PsiElement node, final String s) {
     registerProblem(node, s, null);
   }
 
@@ -492,10 +493,14 @@ public abstract class CompatibilityVisitor extends PyAnnotator {
   }
 
   @Override
-  public void visitPyNonlocalStatement(PyNonlocalStatement node) {
-    if (myVersionsToProcess.contains(LanguageLevel.PYTHON24) || myVersionsToProcess.contains(LanguageLevel.PYTHON25) ||
-        myVersionsToProcess.contains(LanguageLevel.PYTHON26) || myVersionsToProcess.contains(LanguageLevel.PYTHON27)) {
+  public void visitPyNonlocalStatement(final PyNonlocalStatement node) {
+    if (compatibleWithPy2()) {
       registerProblem(node, "nonlocal keyword available only since py3", null, false);
     }
   }
+
+  protected boolean compatibleWithPy2() {
+    return myVersionsToProcess.contains(LanguageLevel.PYTHON24) || myVersionsToProcess.contains(LanguageLevel.PYTHON25) ||
+           myVersionsToProcess.contains(LanguageLevel.PYTHON26) || myVersionsToProcess.contains(LanguageLevel.PYTHON27);
+  }
 }

python/testData/inspections/PyCompatibilityInspection/classBaseList.py

@@ -0,0 +1,8 @@
+class Foo(base1, base2, <error descr="This syntax available only since py3">metaclass=mymeta</error>):
+  pass
+
+class Foo(base1, base2):
+  pass
+
+def foo(base1, base2, metaclass=mymeta):
+  pass

python/testSrc/com/jetbrains/python/inspections/PyCompatibilityInspectionTest.java

@@ -110,6 +110,10 @@ public class PyCompatibilityInspectionTest extends PyTestCase {
     doTest();
   }
 
+  public void testClassBaseList() {
+    doTest();
+  }
+
   private void doTest() {
     myFixture.configureByFile("inspections/PyCompatibilityInspection/" + getTestName(true) + ".py");
     myFixture.enableInspections(PyCompatibilityInspection.class);