"Move file/symbol" refactoring does not permute updated imports

Previously new imports were always inserted after all other imports in
containing statement list, even if they were intended to replace
another existing import. I've changed meaning of "anchor" parameter a
bit, so that it can be used to specify exact insertion place for
new import.

python/src/com/jetbrains/python/codeInsight/imports/AddImportHelper.java

@@ -180,7 +180,9 @@ public class AddImportHelper {
    * @param file   where to operate
    * @param name   which to import (qualified is OK)
    * @param asName optional name for 'as' clause
-   * @param anchor place where the imported name was used
+   * @param anchor place where the imported name was used. It will be used to determine proper block where new import should be inserted,
+   *               e.g. inside conditional block or try/except statement. Also if anchor is another import statement, new import statement
+   *               will be inserted right after it.
    * @return whether import statement was actually added
    */
   public static boolean addImportStatement(@NotNull PsiFile file,
@@ -208,7 +210,12 @@ public class AddImportHelper {
     final PsiElement insertParent = importStatement != null && importStatement.getContainingFile() == file ?
                                     importStatement.getParent() : file;
     try {
-      insertParent.addBefore(importNodeToInsert, getInsertPosition(insertParent, name, priority));
+      if (anchor instanceof PyImportStatementBase) {
+        insertParent.addAfter(importNodeToInsert, anchor);
+      }
+      else {
+        insertParent.addBefore(importNodeToInsert, getInsertPosition(insertParent, name, priority));
+      }
     }
     catch (IncorrectOperationException e) {
       LOG.error(e);
@@ -217,14 +224,16 @@ public class AddImportHelper {
   }
 
   /**
-   * Adds a new {@link com.jetbrains.python.psi.PyFromImportStatement} statement below other top-level imports.
+   * Adds a new {@link com.jetbrains.python.psi.PyFromImportStatement} statement below other top-level imports or as specified by anchor.
    *
    * @param file   where to operate
    * @param from   import source (reference after {@code from} keyword)
    * @param name   imported name (identifier after {@code import} keyword)
    * @param asName optional alias (identifier after {@code as} keyword)
-   * @param anchor place where the imported name was used. It's used to determine proper block where new import should be inserted,
-   *               e.g. inside conditional block or try/except statement.
+   * @param anchor place where the imported name was used. It will be used to determine proper block where new import should be inserted,
+   *               e.g. inside conditional block or try/except statement. Also if anchor is another import statement, new import statement
+   *               will be inserted right after it.
+   * @see #addOrUpdateFromImportStatement
    */
   public static void addFromImportStatement(@NotNull PsiFile file,
                                             @NotNull String from,
@@ -253,7 +262,12 @@ public class AddImportHelper {
         insertParent.addBefore(whitespace, element);
       }
       else {
-        insertParent.addBefore(nodeToInsert, getInsertPosition(insertParent, from, priority));
+        if (anchor instanceof PyImportStatementBase) {
+          insertParent.addAfter(nodeToInsert, anchor);
+        }
+        else {
+          insertParent.addBefore(nodeToInsert, getInsertPosition(insertParent, from, priority));
+        }
       }
     }
     catch (IncorrectOperationException e) {
@@ -270,7 +284,9 @@ public class AddImportHelper {
    * @param name     imported name (identifier after {@code import} keyword)
    * @param asName   optional alias (identifier after {@code as} keyword)
    * @param priority optional import priority used to sort imports
-   * @param anchor   used to determine insert position for new import statement
+   * @param anchor   place where the imported name was used. It will be used to determine proper block where new import should be inserted,
+   *                 e.g. inside conditional block or try/except statement. Also if anchor is another import statement, new import statement
+   *                 will be inserted right after it.
    * @return whether import was actually added
    * @see #addFromImportStatement
    */
@@ -312,6 +328,8 @@ public class AddImportHelper {
    * @param file    file where import will be inserted
    * @param element used to determine where to insert import
    * @see com.jetbrains.python.codeInsight.PyCodeInsightSettings#PREFER_FROM_IMPORT
+   * @see #addImportStatement
+   * @see #addOrUpdateFromImportStatement
    */
   public static void addImport(final PsiNamedElement target, final PsiFile file, final PyElement element) {
     final boolean useQualified = !PyCodeInsightSettings.getInstance().PREFER_FROM_IMPORT;

python/testData/refactoring/move/relativeImportsInsideMovedModule/after/src/subpkg1/mod1.py

@@ -1,6 +1,7 @@
 from pkg1 import subpkg2
 from pkg1.subpkg2 import mod2
 from pkg1.subpkg2.mod2 import VAR
+from subpkg1 import mod3
 
 # malformed imports
 from
@@ -10,6 +11,5 @@ from pkg1.subpkg2 import
 # absolute imports
 import pkg1.subpkg2 as foo
 from pkg1 import subpkg2 as bar
-from subpkg1 import mod3
 
 print(subpkg2, mod3, mod2, foo, bar, VAR)