move python formatter extensions to python.psi.impl module

GitOrigin-RevId: 452346cbd12e9c21c636dc8dbcab9a29813bc67b

platform/ide-core-impl/resources/META-INF/IdeCore.xml

@@ -9,5 +9,7 @@
                         serviceImplementation="com.intellij.util.download.impl.DownloadableFileServiceImpl"/>
     <applicationService serviceInterface="com.intellij.notification.NotificationGroupManager"
                         serviceImplementation="com.intellij.notification.impl.NotificationGroupManagerImpl"/>
+    <applicationService serviceImplementation="com.intellij.ide.GeneralSettings" preload="notHeadless"/>
+    <applicationService serviceImplementation="com.intellij.openapi.editor.ex.EditorSettingsExternalizable"/>
   </extensions>
 </idea-plugin>

platform/ide-core/src/com/intellij/ide/GeneralSettings.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.ide;
 
 import com.intellij.ide.ui.UINumericRange;
@@ -8,6 +8,7 @@ import com.intellij.openapi.application.Application;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.components.*;
 import com.intellij.openapi.util.Disposer;
+import com.intellij.openapi.util.SystemInfo;
 import com.intellij.util.ObjectUtils;
 import com.intellij.util.PlatformUtils;
 import com.intellij.util.xmlb.XmlSerializerUtil;
@@ -42,7 +43,7 @@ public final class GeneralSettings implements PersistentStateComponent<GeneralSe
 
   private static final String SHOW_TIPS_ON_STARTUP_DEFAULT_VALUE_PROPERTY = "ide.show.tips.on.startup.default.value";
 
-  private String myBrowserPath = BrowserUtil.getDefaultAlternativeBrowserPath();
+  private String myBrowserPath = getDefaultAlternativeBrowserPath();
   private boolean myShowTipsOnStartup = Boolean.parseBoolean(System.getProperty(SHOW_TIPS_ON_STARTUP_DEFAULT_VALUE_PROPERTY, "true"));
   private boolean myReopenLastProject = true;
   private boolean mySupportScreenReaders = ObjectUtils.chooseNotNull(SUPPORT_SCREEN_READERS_OVERRIDDEN, false);
@@ -281,4 +282,19 @@ public final class GeneralSettings implements PersistentStateComponent<GeneralSe
   public void setDefaultProjectDirectory(@SystemDependent String defaultProjectDirectory) {
     myDefaultProjectDirectory = defaultProjectDirectory;
   }
+
+  private static @NotNull String getDefaultAlternativeBrowserPath() {
+    if (SystemInfo.isWindows) {
+      return "C:\\Program Files\\Internet Explorer\\IExplore.exe";
+    }
+    else if (SystemInfo.isMac) {
+      return "open";
+    }
+    else if (SystemInfo.isUnix) {
+      return "/usr/bin/firefox";
+    }
+    else {
+      return "";
+    }
+  }
 }

platform/platform-api/src/com/intellij/ide/BrowserUtil.java

@@ -126,21 +126,6 @@ public final class BrowserUtil {
     return command;
   }
 
-  public static @NotNull String getDefaultAlternativeBrowserPath() {
-    if (SystemInfo.isWindows) {
-      return "C:\\Program Files\\Internet Explorer\\IExplore.exe";
-    }
-    else if (SystemInfo.isMac) {
-      return "open";
-    }
-    else if (SystemInfo.isUnix) {
-      return "/usr/bin/firefox";
-    }
-    else {
-      return "";
-    }
-  }
-
   //<editor-fold desc="Deprecated stuff.">
   /** @deprecated the result is a pain to deal with; please use {@link #getOpenBrowserCommand(String, String, List, boolean)} instead */
   @Deprecated(forRemoval = true)

platform/platform-resources/src/META-INF/PlatformExtensions.xml

@@ -160,8 +160,6 @@
     <virtualFileSystem implementationClass="com.intellij.openapi.vfs.impl.jar.JarFileSystemImpl" key="jar" physical="true"/>
     <virtualFileSystem implementationClass="com.intellij.openapi.vfs.ex.temp.TempFileSystem" key="temp" physical="true"/>
 
-    <applicationService serviceImplementation="com.intellij.ide.GeneralSettings" preload="notHeadless"/>
-
     <applicationService serviceImplementation="com.intellij.ui.jcef.JBCefStartup" preload="notHeadless" os="mac"/>
     <cachesInvalidator implementation="com.intellij.ui.jcef.JBCefAppCacheInvalidator" order="last" />
 
@@ -638,7 +636,6 @@
     <applicationService serviceInterface="com.intellij.openapi.actionSystem.AbbreviationManager"
                         serviceImplementation="com.intellij.openapi.actionSystem.impl.AbbreviationManagerImpl"/>
 
-    <applicationService serviceImplementation="com.intellij.openapi.editor.ex.EditorSettingsExternalizable"/>
     <applicationService serviceImplementation="com.intellij.openapi.editor.ex.EditorSettingsExternalizable$OsSpecificState"/>
     <applicationConfigurable
         groupId="editor"

python/python-common-tests/com/jetbrains/python/PythonCommonFormatterTest.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2022 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.jetbrains.python;
 
 import com.intellij.formatting.WrapType;
@@ -7,15 +7,16 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.codeStyle.CodeStyleManager;
 import com.intellij.psi.util.PsiTreeUtil;
-import com.jetbrains.python.fixtures.PyTestCase;
+import com.jetbrains.python.fixture.PythonCommonTestCase;
 import com.jetbrains.python.formatter.PyCodeStyleSettings;
 import com.jetbrains.python.psi.LanguageLevel;
 import com.jetbrains.python.psi.PyElementGenerator;
 import com.jetbrains.python.psi.PyStatement;
 import org.jetbrains.annotations.NotNull;
 
+public abstract class PythonCommonFormatterTest extends PythonCommonTestCase {
+  protected static final LanguageLevel LANGUAGE_LEVEL = LanguageLevel.getLatest();
 
-public class PyFormatterTest extends PyTestCase {
   @NotNull
   private PyCodeStyleSettings getPythonCodeStyleSettings() {
     return getCodeStyleSettings().getCustomSettings(PyCodeStyleSettings.class);
@@ -522,7 +523,7 @@ public class PyFormatterTest extends PyTestCase {
   public void testAlignmentOfClosingBraceInDictLiteralWhenNoHangingIndent() {
     doTest();
   }
-  
+
   public void testNoAlignmentClosingBraceInDictLiteralWhenOpeningBraceIsForcedOnNewLine() {
     getPythonCodeStyleSettings().DICT_NEW_LINE_AFTER_LEFT_BRACE = true;
     doTest();
@@ -671,7 +672,7 @@ public class PyFormatterTest extends PyTestCase {
     getPythonCodeStyleSettings().DICT_NEW_LINE_BEFORE_RIGHT_BRACE = true;
     doTest();
   }
-  
+
   public void testForceNewLineAfterLeftParenInMethodParameters() {  // PY-33060
     getCommonCodeStyleSettings().METHOD_PARAMETERS_LPAREN_ON_NEXT_LINE = true;
     doTest();
@@ -714,7 +715,7 @@ public class PyFormatterTest extends PyTestCase {
   public void testHangingIndentDetectionIgnoresComments() {
     doTest();
   }
-  
+
   // PY-15530
   public void testAlignmentInArgumentListWhereFirstArgumentIsEmptyCall() {
     doTest();
@@ -814,7 +815,7 @@ public class PyFormatterTest extends PyTestCase {
     doTest();
   }
 
-  // PY-10182  
+  // PY-10182
   public void testHangClosingParenthesisInFunctionDefinition() {
     getPythonCodeStyleSettings().HANG_CLOSING_BRACKETS = true;
     doTest();
@@ -831,7 +832,7 @@ public class PyFormatterTest extends PyTestCase {
     getPythonCodeStyleSettings().HANG_CLOSING_BRACKETS = false;
     doTest();
   }
-  
+
   // PY-15874
   public void testHangClosingOnComprehensionsAndGeneratorExpressions() {
     getPythonCodeStyleSettings().HANG_CLOSING_BRACKETS = true;
@@ -853,7 +854,7 @@ public class PyFormatterTest extends PyTestCase {
     getCodeStyleSettings().setRightMargin(PythonLanguage.INSTANCE, 35);
     doTest();
   }
-  
+
   // PY-20633
   public void testFromImportParenthesesPlacementHangClosingParenthesis() {
     getPythonCodeStyleSettings().FROM_IMPORT_NEW_LINE_AFTER_LEFT_PARENTHESIS = true;
@@ -1157,17 +1158,17 @@ public class PyFormatterTest extends PyTestCase {
     getPythonCodeStyleSettings().HANG_CLOSING_BRACKETS = true;
     doTest();
   }
-  
+
   // PY-48009
   public void testItemAlignmentInMappingPatterns() {
     doTest();
   }
-  
+
   // PY-48009
   public void testItemIndentInMappingPatterns() {
     doTest();
   }
-  
+
   // PY-48009
   public void testHangingClosingBracketInMappingPatterns() {
     getPythonCodeStyleSettings().HANG_CLOSING_BRACKETS = true;

python/python-common-tests/com/jetbrains/python/fixture/PythonCommonCodeInsightTestFixture.kt

@@ -26,6 +26,8 @@ interface PythonCommonCodeInsightTestFixture {
 
   val testRootDisposable: Disposable
 
+  val caretOffset: Int
+
   fun setUp() {
   }
 

python/python-common-tests/com/jetbrains/python/fixture/PythonCommonTestCase.java

@@ -1,5 +1,6 @@
 package com.jetbrains.python.fixture;
 
+import com.intellij.application.options.CodeStyle;
 import com.intellij.openapi.application.WriteAction;
 import com.intellij.openapi.projectRoots.Sdk;
 import com.intellij.openapi.projectRoots.SdkModificator;
@@ -8,6 +9,9 @@ import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VfsUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiFile;
+import com.intellij.psi.codeStyle.CodeStyleSettings;
+import com.intellij.psi.codeStyle.CommonCodeStyleSettings;
+import com.jetbrains.python.PythonLanguage;
 import com.jetbrains.python.documentation.PyDocumentationSettings;
 import com.jetbrains.python.documentation.docstrings.DocStringFormat;
 import com.jetbrains.python.psi.LanguageLevel;
@@ -90,6 +94,21 @@ public abstract class PythonCommonTestCase extends TestCase {
     }
   }
 
+  @NotNull
+  protected CommonCodeStyleSettings getCommonCodeStyleSettings() {
+    return getCodeStyleSettings().getCommonSettings(PythonLanguage.getInstance());
+  }
+
+  @NotNull
+  protected CodeStyleSettings getCodeStyleSettings() {
+    return CodeStyle.getSettings(myFixture.getProject());
+  }
+
+  @NotNull
+  protected CommonCodeStyleSettings.IndentOptions getIndentOptions() {
+    return getCommonCodeStyleSettings().getIndentOptions();
+  }
+
   protected void assertProjectFilesNotParsed(@NotNull PsiFile currentFile) {
     assertRootNotParsed(currentFile, myFixture.getTempDirRoot(), null);
   }

python/python-common-tests/intellij.python.commonTests.iml

@@ -18,5 +18,7 @@
     <orderEntry type="library" scope="TEST" name="Guava" level="project" />
     <orderEntry type="library" scope="TEST" name="StreamEx" level="project" />
     <orderEntry type="module" module-name="intellij.platform.analysis.impl" scope="TEST" />
+    <orderEntry type="module" module-name="intellij.platform.codeStyle" scope="TEST" />
+    <orderEntry type="module" module-name="intellij.platform.editor" scope="TEST" />
   </component>
 </module>

python/python-psi-impl/resources/META-INF/PythonPsiImpl.xml

@@ -51,6 +51,14 @@
                              implementationClass="com.jetbrains.python.psi.impl.references.PyKeywordPatternManipulator"/>
     <lang.parserDefinition language="Python" implementationClass="com.jetbrains.python.PythonParserDefinition"/>
 
+    <lang.formatter language="Python" implementationClass="com.jetbrains.python.formatter.PythonFormattingModelBuilder"/>
+    <preFormatProcessor implementation="com.jetbrains.python.formatter.PyPreFormatProcessor"/>
+    <postFormatProcessor implementation="com.jetbrains.python.formatter.PyTrailingBlankLinesPostFormatProcessor"/>
+    <postFormatProcessor implementation="com.jetbrains.python.formatter.PyFromImportPostFormatProcessor"/>
+    <lang.whiteSpaceFormattingStrategy language="Python"
+                                       implementationClass="com.jetbrains.python.formatter.PyWhiteSpaceFormattingStrategy"/>
+    <lang.lineWrapStrategy language="Python" implementationClass="com.jetbrains.python.formatter.PyLineWrapPositionStrategy"/>
+
     <!-- PyFunctionTypeAnnotation -->
     <lang.parserDefinition language="PyFunctionTypeComment"
                            implementationClass="com.jetbrains.python.codeInsight.functionTypeComments.PyFunctionTypeAnnotationParserDefinition"/>

python/python-psi-impl/src/com/jetbrains/python/editor/PyWhiteSpaceUtil.java

@@ -0,0 +1,166 @@
+package com.jetbrains.python.editor;
+
+import com.intellij.lang.ASTNode;
+import com.intellij.psi.*;
+import com.intellij.psi.impl.source.tree.TreeUtil;
+import com.intellij.psi.util.PsiTreeUtil;
+import com.jetbrains.python.PyTokenTypes;
+import com.jetbrains.python.psi.*;
+import com.jetbrains.python.psi.impl.PyPsiUtils;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class PyWhiteSpaceUtil {
+  public static boolean needInsertBackslash(PsiFile file, int offset, boolean autoWrapInProgress) {
+    if (offset > 0) {
+      final PsiElement beforeCaret = file.findElementAt(offset - 1);
+      if (beforeCaret instanceof PsiWhiteSpace && beforeCaret.getText().indexOf('\\') >= 0) {
+        // we've got a backslash at EOL already, don't need another one
+        return false;
+      }
+    }
+    PsiElement atCaret = file.findElementAt(offset);
+    if (atCaret == null) {
+      return false;
+    }
+    ASTNode nodeAtCaret = atCaret.getNode();
+    return needInsertBackslash(nodeAtCaret, autoWrapInProgress);
+  }
+
+  public static boolean needInsertBackslash(ASTNode nodeAtCaret, boolean autoWrapInProgress) {
+    if (PsiTreeUtil.getParentOfType(nodeAtCaret.getPsi(), PyFStringFragment.class) != null) {
+      return false;
+    }
+
+    PsiElement statementBefore = findStatementBeforeCaret(nodeAtCaret);
+    PsiElement statementAfter = findStatementAfterCaret(nodeAtCaret);
+    if (statementBefore != statementAfter) {  // Enter pressed at statement break
+      return false;
+    }
+    if (statementBefore == null) {  // empty file
+      return false;
+    }
+
+    if (PsiTreeUtil.hasErrorElements(statementBefore)) {
+      if (!autoWrapInProgress) {
+        // code is already bad, don't mess it up even further
+        return false;
+      }
+      // if we're in middle of typing, it's expected that we will have error elements
+    }
+
+    final int offset = nodeAtCaret.getTextRange().getStartOffset();
+    if (inFromImportParentheses(statementBefore, offset) || inWithItemsParentheses(statementBefore, offset)) {
+      return false;
+    }
+
+    PsiElement wrappableBefore = findWrappable(nodeAtCaret, true);
+    PsiElement wrappableAfter = findWrappable(nodeAtCaret, false);
+    if (!(wrappableBefore instanceof PsiComment)) {
+      while (wrappableBefore != null) {
+        PsiElement next = PsiTreeUtil.getParentOfType(wrappableBefore, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
+        if (next == null) {
+          break;
+        }
+        wrappableBefore = next;
+      }
+    }
+    if (!(wrappableAfter instanceof PsiComment)) {
+      while (wrappableAfter != null) {
+        PsiElement next = PsiTreeUtil.getParentOfType(wrappableAfter, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
+        if (next == null) {
+          break;
+        }
+        wrappableAfter = next;
+      }
+    }
+    if (wrappableBefore instanceof PsiComment || wrappableAfter instanceof PsiComment) {
+      return false;
+    }
+    if (wrappableAfter == null) {
+      return !(wrappableBefore instanceof PyDecoratorList);
+    }
+    return wrappableBefore != wrappableAfter;
+  }
+
+  @Nullable
+  private static PsiElement findWrappable(ASTNode nodeAtCaret, boolean before) {
+    PsiElement wrappable = before
+                                 ? findBeforeCaret(nodeAtCaret, PyEditorHandlerConfig.WRAPPABLE_CLASSES)
+                                 : findAfterCaret(nodeAtCaret, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
+    if (wrappable == null) {
+      PsiElement emptyTuple = before
+                              ? findBeforeCaret(nodeAtCaret, PyTupleExpression.class)
+                              : findAfterCaret(nodeAtCaret, PyTupleExpression.class);
+      if (emptyTuple != null && emptyTuple.getNode().getFirstChildNode().getElementType() == PyTokenTypes.LPAR) {
+        wrappable = emptyTuple;
+      }
+    }
+    return wrappable;
+  }
+
+  @Nullable
+  private static PsiElement findStatementBeforeCaret(ASTNode node) {
+    return findBeforeCaret(node, PyStatement.class, PyStatementPart.class);
+  }
+
+  @Nullable
+  private static PsiElement findStatementAfterCaret(ASTNode node) {
+    return findAfterCaret(node, PyStatement.class, PyStatementPart.class);
+  }
+
+  private static PsiElement findBeforeCaret(ASTNode atCaret, Class<? extends PsiElement>... classes) {
+    while (atCaret != null) {
+      atCaret = TreeUtil.prevLeaf(atCaret);
+      if (atCaret != null && atCaret.getElementType() != TokenType.WHITE_SPACE) {
+        return getNonStrictParentOfType(atCaret.getPsi(), classes);
+      }
+    }
+    return null;
+  }
+
+  private static PsiElement findAfterCaret(ASTNode atCaret, Class<? extends PsiElement>... classes) {
+    while (atCaret != null) {
+      if (atCaret.getElementType() != TokenType.WHITE_SPACE) {
+        return getNonStrictParentOfType(atCaret.getPsi(), classes);
+      }
+      atCaret = TreeUtil.nextLeaf(atCaret);
+    }
+    return null;
+  }
+
+  @Nullable
+  private static <T extends PsiElement> T getNonStrictParentOfType(@NotNull PsiElement element, Class<? extends T> @NotNull ... classes) {
+    PsiElement run = element;
+    while (run != null) {
+      for (Class<? extends T> aClass : classes) {
+        if (aClass.isInstance(run)) return (T)run;
+      }
+      if (run instanceof PsiFile || run instanceof PyStatementList) break;
+      run = run.getParent();
+    }
+
+    return null;
+  }
+
+  private static boolean inFromImportParentheses(PsiElement statement, int offset) {
+    if (!(statement instanceof PyFromImportStatement)) {
+      return false;
+    }
+    PyFromImportStatement fromImportStatement = (PyFromImportStatement)statement;
+    PsiElement leftParen = fromImportStatement.getLeftParen();
+    if (leftParen != null && offset >= leftParen.getTextRange().getEndOffset()) {
+      return true;
+    }
+    return false;
+  }
+
+  private static boolean inWithItemsParentheses(@NotNull PsiElement statement, int offset) {
+    if (!(statement instanceof PyWithStatement)) {
+      return false;
+    }
+
+    final PsiElement leftParen = PyPsiUtils.getFirstChildOfType(statement, PyTokenTypes.LPAR);
+    return leftParen != null && offset >= leftParen.getTextRange().getEndOffset();
+  }
+}

python/python-psi-impl/src/com/jetbrains/python/formatter/PyWhiteSpaceFormattingStrategy.java

@@ -6,7 +6,7 @@ import com.intellij.openapi.util.text.Strings;
 import com.intellij.psi.PsiElement;
 import com.intellij.psi.codeStyle.CodeStyleSettings;
 import com.intellij.psi.formatter.StaticSymbolWhiteSpaceDefinitionStrategy;
-import com.jetbrains.python.editor.PythonEnterHandler;
+import com.jetbrains.python.editor.PyWhiteSpaceUtil;
 import it.unimi.dsi.fastutil.ints.Int2IntMap;
 import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import it.unimi.dsi.fastutil.ints.IntIterator;
@@ -25,7 +25,7 @@ public class PyWhiteSpaceFormattingStrategy extends StaticSymbolWhiteSpaceDefini
                                                   CodeStyleSettings codeStyleSettings) {
     CharSequence whiteSpace =  super.adjustWhiteSpaceIfNecessary(whiteSpaceText, startElement, startOffset, endOffset, codeStyleSettings);
     if (whiteSpace.length() > 0 && whiteSpace.charAt(0) == '\n' && !Strings.contains(whiteSpace, 0, whiteSpace.length(), '\\') &&
-        PythonEnterHandler.needInsertBackslash(startElement.getContainingFile(), startOffset, false)) {
+        PyWhiteSpaceUtil.needInsertBackslash(startElement.getContainingFile(), startOffset, false)) {
       return addBackslashPrefix(whiteSpace, codeStyleSettings);
     }
     return whiteSpace;
@@ -60,7 +60,7 @@ public class PyWhiteSpaceFormattingStrategy extends StaticSymbolWhiteSpaceDefini
     Int2IntMap initialBackSlashes = countBackSlashes(text, startOffset, endOffset);
     if (initialBackSlashes.isEmpty()) {
       if (nodeAfter != null && whiteSpaceText.length() > 0 && whiteSpaceText.charAt(0) == '\n' &&
-        PythonEnterHandler.needInsertBackslash(nodeAfter, false)) {
+        PyWhiteSpaceUtil.needInsertBackslash(nodeAfter, false)) {
         return addBackslashPrefix(whiteSpaceText, codeStyleSettings);
       }
       return whiteSpaceText;

python/src/META-INF/python-core-common.xml

@@ -46,13 +46,6 @@
     <lang.commenter language="Python" implementationClass="com.jetbrains.python.PythonCommenter"/>
     <lang.foldingBuilder language="Python" implementationClass="com.jetbrains.python.PythonFoldingBuilder"/>
     <lang.findUsagesProvider language="Python" implementationClass="com.jetbrains.python.findUsages.PythonFindUsagesProvider"/>
-    <lang.formatter language="Python" implementationClass="com.jetbrains.python.formatter.PythonFormattingModelBuilder"/>
-    <preFormatProcessor implementation="com.jetbrains.python.formatter.PyPreFormatProcessor"/>
-    <postFormatProcessor implementation="com.jetbrains.python.formatter.PyTrailingBlankLinesPostFormatProcessor"/>
-    <postFormatProcessor implementation="com.jetbrains.python.formatter.PyFromImportPostFormatProcessor"/>
-    <lang.whiteSpaceFormattingStrategy language="Python"
-                                       implementationClass="com.jetbrains.python.formatter.PyWhiteSpaceFormattingStrategy"/>
-    <lang.lineWrapStrategy language="Python" implementationClass="com.jetbrains.python.formatter.PyLineWrapPositionStrategy"/>
     <lang.namesValidator language="Python" implementationClass="com.jetbrains.python.refactoring.rename.PythonNamesValidator"/>
     <lang.surroundDescriptor language="Python"
                              implementationClass="com.jetbrains.python.refactoring.surround.PyStatementSurroundDescriptor"/>

python/src/com/jetbrains/python/editor/PythonEnterHandler.java

@@ -17,7 +17,6 @@ import com.intellij.openapi.util.Ref;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.text.LineTokenizer;
 import com.intellij.psi.*;
-import com.intellij.psi.impl.source.tree.TreeUtil;
 import com.intellij.psi.impl.source.tree.injected.InjectedLanguageUtil;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.psi.util.PsiTreeUtil;
@@ -25,9 +24,7 @@ import com.jetbrains.python.PyTokenTypes;
 import com.jetbrains.python.codeInsight.PyCodeInsightSettings;
 import com.jetbrains.python.documentation.docstrings.*;
 import com.jetbrains.python.psi.*;
-import com.jetbrains.python.psi.impl.PyPsiUtils;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 
 import java.util.regex.Matcher;
 
@@ -145,85 +142,13 @@ public class PythonEnterHandler extends EnterHandlerDelegateAdapter {
                                              Document doc) {
     boolean autoWrapInProgress = DataManager.getInstance().loadFromDataContext(dataContext,
                                                                                AutoHardWrapHandler.AUTO_WRAP_LINE_IN_PROGRESS_KEY) != null;
-    if (needInsertBackslash(file, offset, autoWrapInProgress)) {
+    if (PyWhiteSpaceUtil.needInsertBackslash(file, offset, autoWrapInProgress)) {
       doc.insertString(offset, "\\");
       caretOffset.set(caretOffset.get() + 1);
     }
     return Result.Continue;
   }
 
-  public static boolean needInsertBackslash(PsiFile file, int offset, boolean autoWrapInProgress) {
-    if (offset > 0) {
-      final PsiElement beforeCaret = file.findElementAt(offset - 1);
-      if (beforeCaret instanceof PsiWhiteSpace && beforeCaret.getText().indexOf('\\') >= 0) {
-        // we've got a backslash at EOL already, don't need another one
-        return false;
-      }
-    }
-    PsiElement atCaret = file.findElementAt(offset);
-    if (atCaret == null) {
-      return false;
-    }
-    ASTNode nodeAtCaret = atCaret.getNode();
-    return needInsertBackslash(nodeAtCaret, autoWrapInProgress);
-  }
-
-  public static boolean needInsertBackslash(ASTNode nodeAtCaret, boolean autoWrapInProgress) {
-    if (PsiTreeUtil.getParentOfType(nodeAtCaret.getPsi(), PyFStringFragment.class) != null) {
-      return false;
-    }
-    
-    PsiElement statementBefore = findStatementBeforeCaret(nodeAtCaret);
-    PsiElement statementAfter = findStatementAfterCaret(nodeAtCaret);
-    if (statementBefore != statementAfter) {  // Enter pressed at statement break
-      return false;
-    }
-    if (statementBefore == null) {  // empty file
-      return false;
-    }
-
-    if (PsiTreeUtil.hasErrorElements(statementBefore)) {
-      if (!autoWrapInProgress) {
-        // code is already bad, don't mess it up even further
-        return false;
-      }
-      // if we're in middle of typing, it's expected that we will have error elements
-    }
-
-    final int offset = nodeAtCaret.getTextRange().getStartOffset();
-    if (inFromImportParentheses(statementBefore, offset) || inWithItemsParentheses(statementBefore, offset)) {
-      return false;
-    }
-
-    PsiElement wrappableBefore = findWrappable(nodeAtCaret, true);
-    PsiElement wrappableAfter = findWrappable(nodeAtCaret, false);
-    if (!(wrappableBefore instanceof PsiComment)) {
-      while (wrappableBefore != null) {
-        PsiElement next = PsiTreeUtil.getParentOfType(wrappableBefore, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
-        if (next == null) {
-          break;
-        }
-        wrappableBefore = next;
-      }
-    }
-    if (!(wrappableAfter instanceof PsiComment)) {
-      while (wrappableAfter != null) {
-        PsiElement next = PsiTreeUtil.getParentOfType(wrappableAfter, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
-        if (next == null) {
-          break;
-        }
-        wrappableAfter = next;
-      }
-    }
-    if (wrappableBefore instanceof PsiComment || wrappableAfter instanceof PsiComment) {
-      return false;
-    }
-    if (wrappableAfter == null) {
-      return !(wrappableBefore instanceof PyDecoratorList);
-    }
-    return wrappableBefore != wrappableAfter;
-  }
-
   private static void insertDocStringStub(Editor editor, PsiElement element, DocstringState state) {
     PyDocStringOwner docOwner = PsiTreeUtil.getParentOfType(element, PyDocStringOwner.class);
     if (docOwner != null) {
@@ -244,87 +169,6 @@ public class PythonEnterHandler extends EnterHandlerDelegateAdapter {
     }
   }
 
-  @Nullable
-  private static PsiElement findWrappable(ASTNode nodeAtCaret, boolean before) {
-    PsiElement wrappable = before
-                                 ? findBeforeCaret(nodeAtCaret, PyEditorHandlerConfig.WRAPPABLE_CLASSES)
-                                 : findAfterCaret(nodeAtCaret, PyEditorHandlerConfig.WRAPPABLE_CLASSES);
-    if (wrappable == null) {
-      PsiElement emptyTuple = before
-                              ? findBeforeCaret(nodeAtCaret, PyTupleExpression.class)
-                              : findAfterCaret(nodeAtCaret, PyTupleExpression.class);
-      if (emptyTuple != null && emptyTuple.getNode().getFirstChildNode().getElementType() == PyTokenTypes.LPAR) {
-        wrappable = emptyTuple;
-      }
-    }
-    return wrappable;
-  }
-
-  @Nullable
-  private static PsiElement findStatementBeforeCaret(ASTNode node) {
-    return findBeforeCaret(node, PyStatement.class, PyStatementPart.class);
-  }
-
-  @Nullable
-  private static PsiElement findStatementAfterCaret(ASTNode node) {
-    return findAfterCaret(node, PyStatement.class, PyStatementPart.class);
-  }
-
-  private static PsiElement findBeforeCaret(ASTNode atCaret, Class<? extends PsiElement>... classes) {
-    while (atCaret != null) {
-      atCaret = TreeUtil.prevLeaf(atCaret);
-      if (atCaret != null && atCaret.getElementType() != TokenType.WHITE_SPACE) {
-        return getNonStrictParentOfType(atCaret.getPsi(), classes);
-      }
-    }
-    return null;
-  }
-
-  private static PsiElement findAfterCaret(ASTNode atCaret, Class<? extends PsiElement>... classes) {
-    while (atCaret != null) {
-      if (atCaret.getElementType() != TokenType.WHITE_SPACE) {
-        return getNonStrictParentOfType(atCaret.getPsi(), classes);
-      }
-      atCaret = TreeUtil.nextLeaf(atCaret);
-    }
-    return null;
-  }
-
-  @Nullable
-  private static <T extends PsiElement> T getNonStrictParentOfType(@NotNull PsiElement element, Class<? extends T> @NotNull ... classes) {
-    PsiElement run = element;
-    while (run != null) {
-      for (Class<? extends T> aClass : classes) {
-        if (aClass.isInstance(run)) return (T)run;
-      }
-      if (run instanceof PsiFile || run instanceof PyStatementList) break;
-      run = run.getParent();
-    }
-
-    return null;
-  }
-
-  private static boolean inFromImportParentheses(PsiElement statement, int offset) {
-    if (!(statement instanceof PyFromImportStatement)) {
-      return false;
-    }
-    PyFromImportStatement fromImportStatement = (PyFromImportStatement)statement;
-    PsiElement leftParen = fromImportStatement.getLeftParen();
-    if (leftParen != null && offset >= leftParen.getTextRange().getEndOffset()) {
-      return true;
-    }
-    return false;
-  }
-
-  private static boolean inWithItemsParentheses(@NotNull PsiElement statement, int offset) {
-    if (!(statement instanceof PyWithStatement)) {
-      return false;
-    }
-
-    final PsiElement leftParen = PyPsiUtils.getFirstChildOfType(statement, PyTokenTypes.LPAR);
-    return leftParen != null && offset >= leftParen.getTextRange().getEndOffset();
-  }
-
   @Override
   public Result postProcessEnter(@NotNull PsiFile file,
                                  @NotNull Editor editor,

python/testSrc/com/jetbrains/python/PythonFormatterTest.java

@@ -0,0 +1,13 @@
+// Copyright 2000-2021 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+package com.jetbrains.python;
+
+import com.jetbrains.python.fixture.PythonCommonCodeInsightTestFixture;
+import com.jetbrains.python.fixtures.PythonPlatformCodeInsightTestFixture;
+import com.jetbrains.python.psi.LanguageLevel;
+
+public class PythonFormatterTest extends PythonCommonFormatterTest {
+  @Override
+  protected PythonCommonCodeInsightTestFixture getFixture() {
+    return new PythonPlatformCodeInsightTestFixture(LANGUAGE_LEVEL);
+  }
+}

python/testSrc/com/jetbrains/python/fixtures/PythonPlatformCodeInsightTestFixture.kt

@@ -42,6 +42,8 @@ class PythonPlatformCodeInsightTestFixture(languageLevel: LanguageLevel) : Pytho
     get() = requireNotNull(myDelegateFixture.tempDirFixture.getFile("."))
   override val testRootDisposable: Disposable
     get() = myDelegateFixture.testRootDisposable
+  override val caretOffset: Int
+    get() = myDelegateFixture.caretOffset
 
   override fun setUp() {
     super.setUp()