Add support for Join and Split variable quick actions.

org.eclipse.jdt.ls.core/src/org/eclipse/jdt/ls/core/internal/text/correction/QuickAssistProcessor.java

@@ -115,8 +115,10 @@
 import org.eclipse.jdt.internal.corext.dom.Selection;
 import org.eclipse.jdt.internal.corext.fix.FixMessages;
 import org.eclipse.jdt.internal.corext.fix.IProposableFix;
+import org.eclipse.jdt.internal.corext.fix.JoinVariableFixCore;
 import org.eclipse.jdt.internal.corext.fix.LambdaExpressionAndMethodRefFixCore;
 import org.eclipse.jdt.internal.corext.fix.LinkedProposalModelCore;
+import org.eclipse.jdt.internal.corext.fix.SplitVariableFixCore;
 import org.eclipse.jdt.internal.corext.fix.StringConcatToTextBlockFixCore;
 import org.eclipse.jdt.internal.corext.fix.SwitchExpressionsFixCore;
 import org.eclipse.jdt.internal.corext.refactoring.surround.SurroundWithTryWithResourcesAnalyzer;
@@ -223,6 +225,10 @@ public List<ChangeCorrectionProposal> getAssists(CodeActionParams params, IInvoc
 			if (!problemExists(locations, javaDocCommentProblems)) {
 				JavadocTagsSubProcessor.getMissingJavadocCommentProposals(context, coveringNode, resultingCollections, JavaCodeActionKind.QUICK_ASSIST);
 			}
+
+			// Variable quick fixes
+			getSplitVariableProposal(context, coveringNode, resultingCollections);
+			getJoinVariableProposal(context, coveringNode, resultingCollections);
 			return resultingCollections;
 		}
 		return Collections.emptyList();
@@ -1835,4 +1841,33 @@ private static boolean getStringConcatToTextBlockProposal(IInvocationContext con
 		return false;
 	}
 
+	private boolean getJoinVariableProposal(IInvocationContext context, ASTNode coveringNode, ArrayList<ChangeCorrectionProposal> resultingCollections) {
+		if (resultingCollections != null) {
+			SplitVariableFixCore fix = SplitVariableFixCore.createSplitVariableFix(context.getASTRoot(), coveringNode);
+			if (fix != null) {
+				try {
+					resultingCollections.add(new ChangeCorrectionProposal(fix.getDisplayString(), JavaCodeActionKind.QUICK_ASSIST, fix.createChange(null), IProposalRelevance.SPLIT_VARIABLE_DECLARATION));
+					return true;
+				} catch (CoreException e) {
+					// ignore
+				}
+			}
+		}
+		return false;
+	}
+
+	private boolean getSplitVariableProposal(IInvocationContext context, ASTNode coveringNode, ArrayList<ChangeCorrectionProposal> resultingCollections) {
+		if (resultingCollections != null) {
+			JoinVariableFixCore fix = JoinVariableFixCore.createJoinVariableFix(context.getASTRoot(), coveringNode);
+			if (fix != null) {
+				try {
+					resultingCollections.add(new ChangeCorrectionProposal(fix.getDisplayString(), JavaCodeActionKind.QUICK_ASSIST, fix.createChange(null), IProposalRelevance.JOIN_VARIABLE_DECLARATION));
+					return true;
+				} catch (CoreException e) {
+					// ignore
+				}
+			}
+		}
+		return false;
+	}
 }

org.eclipse.jdt.ls.target/org.eclipse.jdt.ls.tp.target

@@ -29,7 +29,7 @@
             <unit id="org.eclipse.jdt.source.feature.group" version="0.0.0"/>
             <unit id="org.eclipse.sdk.feature.group" version="0.0.0"/>
             <unit id="org.mockito.mockito-core" version="0.0.0"/>
-            <repository location="https://download.eclipse.org/eclipse/updates/4.29-I-builds/I20230625-1800/"/>
+            <repository location="https://download.eclipse.org/eclipse/updates/4.29-I-builds/I20230629-1800/"/>
         </location>
         <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
             <unit id="org.eclipse.xtext.xbase.lib" version="0.0.0"/>

org.eclipse.jdt.ls.tests/src/org/eclipse/jdt/ls/core/internal/correction/VariableQuickFixTest.java

@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * Copyright (c) 2023 Gayan Perera and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Gayan Perera - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jdt.ls.core.internal.correction;
+
+import java.util.Hashtable;
+import java.util.List;
+
+import org.eclipse.jdt.core.ICompilationUnit;
+import org.eclipse.jdt.core.IJavaProject;
+import org.eclipse.jdt.core.IPackageFragment;
+import org.eclipse.jdt.core.IPackageFragmentRoot;
+import org.eclipse.jdt.ls.core.internal.CodeActionUtil;
+import org.eclipse.jdt.ls.core.internal.JavaCodeActionKind;
+import org.eclipse.lsp4j.CodeAction;
+import org.eclipse.lsp4j.CodeActionKind;
+import org.eclipse.lsp4j.Command;
+import org.eclipse.lsp4j.jsonrpc.messages.Either;
+import org.junit.Before;
+import org.junit.Test;
+
+public class VariableQuickFixTest extends AbstractSelectionTest {
+
+	private IJavaProject fJProject1;
+
+	private IPackageFragmentRoot fSourceFolder;
+
+	@Before
+	public void setup() throws Exception {
+		fJProject1 = newEmptyProject();
+		Hashtable<String, String> options = TestOptions.getDefaultOptions();
+		fJProject1.setOptions(options);
+		fSourceFolder = fJProject1.getPackageFragmentRoot(fJProject1.getProject().getFolder("src"));
+		setOnly(CodeActionKind.QuickFix);
+	}
+
+	@Test
+	public void testSplitVariableExpectDeclarationAndAssignment() throws Exception {
+		setOnly(JavaCodeActionKind.QUICK_ASSIST);
+		IPackageFragment pack1 = fSourceFolder.createPackageFragment("test1", false, null);
+		//@formatter:off
+		String contents = "package test1;\r\n"
+				+ "public class V {\r\n"
+				+ "    public void foo() {\r\n"
+				+ "        int maxCount = 10;\r\n"
+				+ "    }\r\n"
+				+ "}";
+		//@formatter:on
+		ICompilationUnit cu = pack1.createCompilationUnit("V.java", contents, false, null);
+		//@formatter:off
+		String expected = "package test1;\r\n"
+				+ "public class V {\r\n"
+				+ "    public void foo() {\r\n"
+				+ "        int maxCount;\r\n"
+				+ "        maxCount = 10;\r\n"
+				+ "    }\r\n"
+				+ "}";
+		//@formatter:on
+		List<Either<Command, CodeAction>> codeActions = evaluateCodeActions(cu, CodeActionUtil.getRange(cu, "maxCount"));
+		Expected e1 = new Expected("Split variable declaration", expected, JavaCodeActionKind.QUICK_ASSIST);
+		assertCodeActions(codeActions, e1);
+	}
+
+	@Test
+	public void testJoinVariableExpectDeclarationAndAssignment() throws Exception {
+		setOnly(JavaCodeActionKind.QUICK_ASSIST);
+		IPackageFragment pack1 = fSourceFolder.createPackageFragment("test1", false, null);
+		//@formatter:off
+		String contents = "package test1;\r\n"
+				+ "public class V {\r\n"
+				+ "    public void foo() {\r\n"
+				+ "        int maxCount;\r\n"
+				+ "        maxCount = 10;\r\n"
+				+ "    }\r\n"
+				+ "}";
+		//@formatter:on
+		ICompilationUnit cu = pack1.createCompilationUnit("V.java", contents, false, null);
+		//@formatter:off
+		String expected = "package test1;\r\n"
+				+ "public class V {\r\n"
+				+ "    public void foo() {\r\n"
+				+ "        int maxCount = 10;\r\n"
+				+ "    }\r\n"
+				+ "}";
+		//@formatter:on
+		List<Either<Command, CodeAction>> codeActions = evaluateCodeActions(cu, CodeActionUtil.getRange(cu, "maxCount"));
+		Expected e1 = new Expected("Join variable declaration", expected, JavaCodeActionKind.QUICK_ASSIST);
+		assertCodeActions(codeActions, e1);
+	}
+}