PY-2980 Unresolved reference for ForeignKey defined as string

python/psi-api/src/com/jetbrains/python/nameResolver/FQNamesProvider.java

@@ -12,4 +12,9 @@ public interface FQNamesProvider {
    */
   @NotNull
   String[] getNames();
+
+  /**
+   * @return is name of class (true) or function (false)
+   */
+  boolean isClass();
 }

python/psi-api/src/com/jetbrains/python/nameResolver/NameResolverTools.java

@@ -2,14 +2,13 @@ package com.jetbrains.python.nameResolver;
 
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiReference;
+import com.jetbrains.python.psi.PyClass;
 import com.jetbrains.python.psi.PyElement;
+import com.jetbrains.python.psi.PyFunction;
 import com.jetbrains.python.psi.PyQualifiedNameOwner;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Set;
+import java.util.*;
 
 /**
  * @author Ilya.Kazakevich
@@ -52,25 +51,28 @@ public final class NameResolverTools {
         elementToCheck = (PyElement)resolvedElement;
       }
     }
+    String qualifiedName = null;
     if (elementToCheck instanceof PyQualifiedNameOwner) {
-      final String qualifiedName = ((PyQualifiedNameOwner)elementToCheck).getQualifiedName();
-      return getNames(namesProviders).contains(qualifiedName);
+      qualifiedName = ((PyQualifiedNameOwner)elementToCheck).getQualifiedName();
+    }
+    String className = null;
+    if (elementToCheck instanceof PyFunction) {
+      final PyClass aClass = ((PyFunction)elementToCheck).getContainingClass();
+      if (aClass != null) {
+        className = aClass.getQualifiedName();
+      }
+    }
+
+    for (final FQNamesProvider provider : namesProviders) {
+      final List<String> names = Arrays.asList(provider.getNames());
+      if (qualifiedName != null && names.contains(qualifiedName)) {
+        return true;
+      }
+      if (className != null && provider.isClass() && names.contains(className)) {
+        return true;
+      }
     }
     return false;
   }
 
-  /**
-   * Returns set of names all providers provide
-   *
-   * @param providers providers to check
-   * @return set of names
-   */
-  @NotNull
-  private static Collection<String> getNames(@NotNull final FQNamesProvider... providers) {
-    final Set<String> result = new HashSet<String>();
-    for (final FQNamesProvider provider : providers) {
-      result.addAll(Arrays.asList(provider.getNames()));
-    }
-    return result;
-  }
 }

python/psi-api/src/com/jetbrains/python/psi/PyCallExpression.java

@@ -16,6 +16,7 @@
 package com.jetbrains.python.psi;
 
 import com.intellij.psi.PsiElement;
+import com.jetbrains.python.FunctionParameter;
 import com.jetbrains.python.nameResolver.FQNamesProvider;
 import com.jetbrains.python.psi.resolve.PyResolveContext;
 import org.jetbrains.annotations.NotNull;
@@ -66,6 +67,16 @@ public interface PyCallExpression extends PyExpression {
   @Nullable
   <T extends PsiElement> T getArgument(int index, String keyword, Class<T> argClass);
 
+  /**
+   * Returns the argument if one is present in the list.
+   *
+   * @param parameter parameter
+   * @param argClass argument expected type
+   * @return the argument or null
+   */
+  @Nullable
+  <T extends PsiElement> T getArgument(@NotNull final FunctionParameter parameter, @NotNull Class<T> argClass);
+
   @Nullable
   PyExpression getKeywordArgument(String keyword);
 

python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java

@@ -21,6 +21,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiReference;
 import com.intellij.psi.ResolveResult;
 import com.intellij.psi.util.PsiTreeUtil;
+import com.jetbrains.python.FunctionParameter;
 import com.jetbrains.python.PyNames;
 import com.jetbrains.python.nameResolver.FQNamesProvider;
 import com.jetbrains.python.nameResolver.NameResolverTools;
@@ -361,6 +362,27 @@ public class PyCallExpressionHelper {
     return false;
   }
 
+
+  /**
+   * Returns argument if it exists and has appropriate type
+   * @param parameter argument
+   * @param argClass expected class
+   * @param expression call expression
+   * @param <T> expected class
+   * @return argument expression or null if has wrong type of does not exist
+   */
+  @Nullable
+  public static  <T extends PsiElement> T getArgument(
+    @NotNull final FunctionParameter parameter,
+    @NotNull final Class<T> argClass,
+    @NotNull final PyCallExpression expression) {
+    final PyArgumentList list = expression.getArgumentList();
+    if (list == null) {
+      return null;
+    }
+    return PyUtil.as(list.getValueExpressionForParam(parameter), argClass);
+  }
+
   @Nullable
   public static PyExpression getKeywordArgument(PyCallExpression expr, String keyword) {
     for (PyExpression arg : expr.getArguments()) {

python/src/com/jetbrains/python/psi/impl/PyCallExpressionImpl.java

@@ -18,6 +18,7 @@ package com.jetbrains.python.psi.impl;
 import com.intellij.lang.ASTNode;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.util.PsiTreeUtil;
+import com.jetbrains.python.FunctionParameter;
 import com.jetbrains.python.nameResolver.FQNamesProvider;
 import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.resolve.PyResolveContext;
@@ -72,6 +73,12 @@ public class PyCallExpressionImpl extends PyElementImpl implements PyCallExpress
     return getArgument(index, argClass);
   }
 
+  @Nullable
+  @Override
+  public <T extends PsiElement> T getArgument(@NotNull final FunctionParameter parameter, @NotNull final Class<T> argClass) {
+    return PyCallExpressionHelper.getArgument(parameter, argClass, this);
+  }
+
   @Override
   public PyExpression getKeywordArgument(String keyword) {
     return PyCallExpressionHelper.getKeywordArgument(this, keyword);

python/src/com/jetbrains/python/psi/impl/PyDecoratorImpl.java

@@ -21,6 +21,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.QualifiedName;
 import com.intellij.util.IncorrectOperationException;
+import com.jetbrains.python.FunctionParameter;
 import com.jetbrains.python.PyElementTypes;
 import com.jetbrains.python.PyTokenTypes;
 import com.jetbrains.python.PythonDialectsTokenSetProvider;
@@ -128,6 +129,12 @@ public class PyDecoratorImpl extends StubBasedPsiElementBase<PyDecoratorStub> im
     return getArgument(index, argClass);
   }
 
+  @Nullable
+  @Override
+  public <T extends PsiElement> T getArgument(@NotNull final FunctionParameter parameter, @NotNull final Class<T> argClass) {
+    return PyCallExpressionHelper.getArgument(parameter, argClass, this);
+  }
+
   @Override
   public PyExpression getKeywordArgument(String keyword) {
     return PyCallExpressionHelper.getKeywordArgument(this, keyword);