RUBY-21803 Dedent is preserving now

IDEA-CR-34795

plugins/yaml/resources/META-INF/plugin.xml

@@ -12,6 +12,7 @@
     <additionalTextAttributes scheme="Darcula" file="colorSchemes/YAMLDarcula.xml"/>
 
     <lang.formatter language="yaml" implementationClass="org.jetbrains.yaml.formatter.YAMLFormattingModelBuilder"/>
+    <enterHandlerDelegate implementation="org.jetbrains.yaml.formatter.YAMLEnterAtIndentHandler" order="first"/>
     <lang.parserDefinition language="yaml" implementationClass="org.jetbrains.yaml.YAMLParserDefinition"/>
     <lang.commenter language="yaml" implementationClass="org.jetbrains.yaml.YAMLCommenter"/>
     <lang.syntaxHighlighterFactory language="yaml" implementationClass="org.jetbrains.yaml.YAMLSyntaxHighlighterFactory"/>

plugins/yaml/src/org/jetbrains/yaml/formatter/YAMLEnterAtIndentHandler.java

@@ -0,0 +1,34 @@
+// Copyright 2000-2018 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 org.jetbrains.yaml.formatter;
+
+import com.intellij.codeInsight.editorActions.BackspaceHandler;
+import com.intellij.codeInsight.editorActions.enter.EnterHandlerDelegateAdapter;
+import com.intellij.openapi.actionSystem.DataContext;
+import com.intellij.openapi.editor.Editor;
+import com.intellij.openapi.editor.actionSystem.EditorActionHandler;
+import com.intellij.openapi.util.Ref;
+import com.intellij.psi.PsiFile;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.yaml.psi.YAMLFile;
+
+public class YAMLEnterAtIndentHandler extends EnterHandlerDelegateAdapter {
+  @Override
+  public Result preprocessEnter(@NotNull PsiFile file,
+                                @NotNull Editor editor,
+                                @NotNull Ref<Integer> caretOffset,
+                                @NotNull Ref<Integer> caretAdvance,
+                                @NotNull DataContext dataContext,
+                                EditorActionHandler originalHandler) {
+    //if (true) return Result.Continue;
+    if (!(file instanceof YAMLFile)) {
+      return Result.Continue;
+    }
+
+    // honor dedent (RUBY-21803)
+    // The solutions is copied from com.jetbrains.python.editor.PyEnterAtIndentHandler
+    if (BackspaceHandler.isWhitespaceBeforeCaret(editor)) {
+      return Result.DefaultSkipIndent;
+    }
+    return Result.Continue;
+  }
+}

plugins/yaml/testSrc/org/jetbrains/yaml/editing/YAMLTypingTest.java

@@ -42,6 +42,14 @@ public class YAMLTypingTest extends LightPlatformCodeInsightFixtureTestCase {
     doTest("\n");
   }
 
+  public void testPreserveDedent() {
+    doTest("\n");
+  }
+
+  public void testPreserveDedentAfterInlinedMap() {
+    doTest("\n");
+  }
+
   @SuppressWarnings("SameParameterValue")
   private void doTest(String insert) {
     String testName = getTestName(true);

plugins/yaml/testSrc/org/jetbrains/yaml/editing/data/preserveDedent.txt

@@ -0,0 +1,5 @@
+top:
+  hello:
+    country: Australia
+  
+  <caret>

plugins/yaml/testSrc/org/jetbrains/yaml/editing/data/preserveDedent.yml

@@ -0,0 +1,4 @@
+top:
+  hello:
+    country: Australia
+  <caret>

plugins/yaml/testSrc/org/jetbrains/yaml/editing/data/preserveDedentAfterInlinedMap.txt

@@ -0,0 +1,4 @@
+top:
+  - country: Australia
+  
+  <caret>

plugins/yaml/testSrc/org/jetbrains/yaml/editing/data/preserveDedentAfterInlinedMap.yml

@@ -0,0 +1,3 @@
+top:
+  - country: Australia
+  <caret>