From 53aca1d95c51ca66818fefd28ed90150d7f2f2af Mon Sep 17 00:00:00 2001
From: Mateusz Matela <mateusz.matela@gmail.com>
Date: Thu, 25 Jan 2024 20:39:00 +0100
Subject: [PATCH] Java formatter setting for switch arror opening brace
 position (#1473)

---
 .../formatter/FormatterRegressionTests.java   | 25 ++++++++
 .../workspace/Formatter/testGH1473/A_out.java | 58 +++++++++++++++++
 .../workspace/Formatter/testGH1473/B_out.java | 57 +++++++++++++++++
 .../workspace/Formatter/testGH1473/C_out.java | 62 +++++++++++++++++++
 .../workspace/Formatter/testGH1473/in.java    | 53 ++++++++++++++++
 .../DefaultCodeFormatterConstants.java        | 19 +++++-
 .../DefaultCodeFormatterOptions.java          |  6 ++
 .../formatter/LineBreaksPreparator.java       | 19 ++++--
 8 files changed, 291 insertions(+), 8 deletions(-)
 create mode 100644 org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/A_out.java
 create mode 100644 org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/B_out.java
 create mode 100644 org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/C_out.java
 create mode 100644 org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/in.java

diff --git a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/formatter/FormatterRegressionTests.java b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/formatter/FormatterRegressionTests.java
index 7046a5e5042..53df77fa9e1 100644
--- a/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/formatter/FormatterRegressionTests.java
+++ b/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/formatter/FormatterRegressionTests.java
@@ -16329,4 +16329,29 @@ void foo(int i) {
 		}
 		""");
 }
+
+/**
+ * https://github.com/eclipse-jdt/eclipse.jdt/issues/1473 - Java formatter setting for switch arror opening brace position
+ */
+public void testGH1473a() throws JavaModelException {
+	setComplianceLevel(CompilerOptions.VERSION_14);
+	this.formatterPrefs.brace_position_for_block_in_case = DefaultCodeFormatterConstants.NEXT_LINE;
+	this.formatterPrefs.brace_position_for_block_in_case_after_arrow = DefaultCodeFormatterConstants.END_OF_LINE;
+	String input = getCompilationUnit("Formatter", "", "testGH1473", "in.java").getSource();
+	formatSource(input, getCompilationUnit("Formatter", "", "testGH1473", "A_out.java").getSource());
+}
+public void testGH1473b() throws JavaModelException {
+	setComplianceLevel(CompilerOptions.VERSION_14);
+	this.formatterPrefs.brace_position_for_block_in_case = DefaultCodeFormatterConstants.END_OF_LINE;
+	this.formatterPrefs.brace_position_for_block_in_case_after_arrow = DefaultCodeFormatterConstants.NEXT_LINE;
+	String input = getCompilationUnit("Formatter", "", "testGH1473", "in.java").getSource();
+	formatSource(input, getCompilationUnit("Formatter", "", "testGH1473", "B_out.java").getSource());
+}
+public void testGH1473c() throws JavaModelException {
+	setComplianceLevel(CompilerOptions.VERSION_14);
+	this.formatterPrefs.brace_position_for_block_in_case = DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED;
+	this.formatterPrefs.brace_position_for_block_in_case_after_arrow = DefaultCodeFormatterConstants.NEXT_LINE_SHIFTED;
+	String input = getCompilationUnit("Formatter", "", "testGH1473", "in.java").getSource();
+	formatSource(input, getCompilationUnit("Formatter", "", "testGH1473", "C_out.java").getSource());
+}
 }
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/A_out.java b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/A_out.java
new file mode 100644
index 00000000000..544ca351fa3
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/A_out.java
@@ -0,0 +1,58 @@
+class Test {
+	void foo(int i) {
+		int k = switch (i) {
+		case 1, 2, 3:
+		{
+			yield 33;
+		}
+		case 4:
+			yield 44;
+		case 5:
+		{
+		}
+			yield 55;
+		default:
+		{
+			throw new RuntimeException();
+		}
+		};
+
+		switch (k) {
+		case 1, 2, 3:
+		{
+			k += 4;
+		} {
+			k += 55;
+			break;
+		}
+		case 4:
+			k += 43;
+			break;
+		default:
+		{
+			throw new RuntimeException();
+		}
+		}
+
+		int m = switch (i) {
+		case 1, 2, 3 -> {
+			k++;
+			yield 33;
+		}
+		case 4 -> 66;
+		default -> {
+			throw new RuntimeException();
+		}
+		};
+
+		switch (m) {
+		case 1, 2, 3 -> {
+			k += 4;
+		}
+		case 4 -> k += 55;
+		default -> {
+			throw new RuntimeException();
+		}
+		}
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/B_out.java b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/B_out.java
new file mode 100644
index 00000000000..97522a6cae0
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/B_out.java
@@ -0,0 +1,57 @@
+class Test {
+	void foo(int i) {
+		int k = switch (i) {
+		case 1, 2, 3: {
+			yield 33;
+		}
+		case 4:
+			yield 44;
+		case 5: {
+		}
+			yield 55;
+		default: {
+			throw new RuntimeException();
+		}
+		};
+
+		switch (k) {
+		case 1, 2, 3: {
+			k += 4;
+		} {
+			k += 55;
+			break;
+		}
+		case 4:
+			k += 43;
+			break;
+		default: {
+			throw new RuntimeException();
+		}
+		}
+
+		int m = switch (i) {
+		case 1, 2, 3 ->
+		{
+			k++;
+			yield 33;
+		}
+		case 4 -> 66;
+		default ->
+		{
+			throw new RuntimeException();
+		}
+		};
+
+		switch (m) {
+		case 1, 2, 3 ->
+		{
+			k += 4;
+		}
+		case 4 -> k += 55;
+		default ->
+		{
+			throw new RuntimeException();
+		}
+		}
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/C_out.java b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/C_out.java
new file mode 100644
index 00000000000..6cad3e95244
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/C_out.java
@@ -0,0 +1,62 @@
+class Test {
+	void foo(int i) {
+		int k = switch (i) {
+		case 1, 2, 3:
+			{
+				yield 33;
+			}
+		case 4:
+			yield 44;
+		case 5:
+			{
+			}
+			yield 55;
+		default:
+			{
+				throw new RuntimeException();
+			}
+		};
+
+		switch (k) {
+		case 1, 2, 3:
+			{
+				k += 4;
+			} {
+			k += 55;
+			break;
+		}
+		case 4:
+			k += 43;
+			break;
+		default:
+			{
+				throw new RuntimeException();
+			}
+		}
+
+		int m = switch (i) {
+		case 1, 2, 3 ->
+			{
+				k++;
+				yield 33;
+			}
+		case 4 -> 66;
+		default ->
+			{
+				throw new RuntimeException();
+			}
+		};
+
+		switch (m) {
+		case 1, 2, 3 ->
+			{
+				k += 4;
+			}
+		case 4 -> k += 55;
+		default ->
+			{
+				throw new RuntimeException();
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/in.java b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/in.java
new file mode 100644
index 00000000000..d8c9c301f29
--- /dev/null
+++ b/org.eclipse.jdt.core.tests.model/workspace/Formatter/testGH1473/in.java
@@ -0,0 +1,53 @@
+class Test {
+	void foo(int i) {
+		int k = switch(i) {
+		case 1,2,3: {
+			yield 33;
+		}
+		case 4:
+			yield 44;
+		case 5:{}
+			yield 55;
+		default: {
+			throw new RuntimeException();
+		}
+		};
+		
+		switch(k) {
+		case 1,2,3: {
+			k += 4;
+		}
+		{
+			k += 55;
+			break;
+		}
+		case 4:
+			k += 43;
+			break;
+		default: {
+			throw new RuntimeException();
+		}
+		}
+		
+		int m = switch(i) {
+		case 1,2,3 -> {
+			k++;
+			yield 33;
+		}
+		case 4 -> 66;
+		default -> {
+			throw new RuntimeException();
+		}
+		};
+		
+		switch (m) {
+		case 1,2,3 -> {
+			k += 4;
+		}
+		case 4 -> k +=55;
+		default -> {
+			throw new RuntimeException();
+		}
+		}
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/core/formatter/DefaultCodeFormatterConstants.java b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/core/formatter/DefaultCodeFormatterConstants.java
index 770d1209abb..477caa8d2ac 100644
--- a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/core/formatter/DefaultCodeFormatterConstants.java
+++ b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/core/formatter/DefaultCodeFormatterConstants.java
@@ -1053,8 +1053,8 @@ public class DefaultCodeFormatterConstants {
 	public static final String FORMATTER_BRACE_POSITION_FOR_BLOCK = JavaCore.PLUGIN_ID + ".formatter.brace_position_for_block";	//$NON-NLS-1$
 	/**
 	 * <pre>
-	 * FORMATTER / Option to position the braces of a block in a case statement when the block is the first statement following
-	 *             the case
+	 * FORMATTER / Option to position the braces of a block in a switch statement/expression when the block
+	 *             is the first statement following a case with colon
 	 *     - option id:         "org.eclipse.jdt.core.formatter.brace_position_for_block_in_case"
 	 *     - possible values:   { END_OF_LINE, NEXT_LINE, NEXT_LINE_SHIFTED, NEXT_LINE_ON_WRAP }
 	 *     - default:           END_OF_LINE
@@ -1066,6 +1066,21 @@ public class DefaultCodeFormatterConstants {
 	 * @since 3.0
 	 */
 	public static final String FORMATTER_BRACE_POSITION_FOR_BLOCK_IN_CASE = JavaCore.PLUGIN_ID + ".formatter.brace_position_for_block_in_case";	//$NON-NLS-1$
+	/**
+	 * <pre>
+	 * FORMATTER / Option to position the braces of a block in a switch statement/expression when the block
+	 *             is the first statement following a case with arrow
+	 *     - option id:         "org.eclipse.jdt.core.formatter.brace_position_for_block_in_case_after_arrow"
+	 *     - possible values:   { END_OF_LINE, NEXT_LINE, NEXT_LINE_SHIFTED, NEXT_LINE_ON_WRAP }
+	 *     - default:           END_OF_LINE
+	 * </pre>
+	 * @see #END_OF_LINE
+	 * @see #NEXT_LINE
+	 * @see #NEXT_LINE_SHIFTED
+	 * @see #NEXT_LINE_ON_WRAP
+	 * @since 3.37
+	 */
+	public static final String FORMATTER_BRACE_POSITION_FOR_BLOCK_IN_CASE_AFTER_ARROW = JavaCore.PLUGIN_ID + ".formatter.brace_position_for_block_in_case_after_arrow";	//$NON-NLS-1$
 	/**
 	 * <pre>
 	 * FORMATTER / Option to position the braces of a constructor declaration
diff --git a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/DefaultCodeFormatterOptions.java b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/DefaultCodeFormatterOptions.java
index 14325ad9311..8dda1ac2055 100644
--- a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/DefaultCodeFormatterOptions.java
+++ b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/DefaultCodeFormatterOptions.java
@@ -186,6 +186,7 @@ public static DefaultCodeFormatterOptions getJavaConventionsSettings() {
 	public String brace_position_for_array_initializer;
 	public String brace_position_for_block;
 	public String brace_position_for_block_in_case;
+	public String brace_position_for_block_in_case_after_arrow;
 	public String brace_position_for_constructor_declaration;
 	public String brace_position_for_enum_constant;
 	public String brace_position_for_enum_declaration;
@@ -637,6 +638,7 @@ public Map<String, String> getMap() {
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_ARRAY_INITIALIZER, this.brace_position_for_array_initializer);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK, this.brace_position_for_block);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK_IN_CASE, this.brace_position_for_block_in_case);
+		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK_IN_CASE_AFTER_ARROW, this.brace_position_for_block_in_case_after_arrow);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_CONSTRUCTOR_DECLARATION, this.brace_position_for_constructor_declaration);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_ENUM_CONSTANT, this.brace_position_for_enum_constant);
 		options.put(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_ENUM_DECLARATION, this.brace_position_for_enum_declaration);
@@ -1326,6 +1328,8 @@ public void set(Map<String, String> settings) {
 				this.brace_position_for_block_in_case = DefaultCodeFormatterConstants.END_OF_LINE;
 			}
 		}
+		setString(settings, DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_BLOCK_IN_CASE_AFTER_ARROW, BRACE_POSITION_VALUES,
+				v -> this.brace_position_for_block_in_case_after_arrow = v);
 		final Object bracePositionForConstructorDeclarationOption = settings.get(DefaultCodeFormatterConstants.FORMATTER_BRACE_POSITION_FOR_CONSTRUCTOR_DECLARATION);
 		if (bracePositionForConstructorDeclarationOption != null) {
 			try {
@@ -3035,6 +3039,7 @@ public void setDefaultSettings() {
 		this.brace_position_for_array_initializer = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_block = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_block_in_case = DefaultCodeFormatterConstants.END_OF_LINE;
+		this.brace_position_for_block_in_case_after_arrow = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_constructor_declaration = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_enum_constant = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_enum_declaration = DefaultCodeFormatterConstants.END_OF_LINE;
@@ -3439,6 +3444,7 @@ public void setJavaConventionsSettings() {
 		this.brace_position_for_array_initializer = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_block = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_block_in_case = DefaultCodeFormatterConstants.END_OF_LINE;
+		this.brace_position_for_block_in_case_after_arrow = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_constructor_declaration = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_enum_constant = DefaultCodeFormatterConstants.END_OF_LINE;
 		this.brace_position_for_enum_declaration = DefaultCodeFormatterConstants.END_OF_LINE;
diff --git a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/LineBreaksPreparator.java b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/LineBreaksPreparator.java
index 956880c8b7c..4abbb026119 100644
--- a/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/LineBreaksPreparator.java
+++ b/org.eclipse.jdt.core/formatter/org/eclipse/jdt/internal/formatter/LineBreaksPreparator.java
@@ -302,12 +302,10 @@ public boolean visit(Block node) {
 			return true; // braces have been handled in #visit(MethodDeclaration)
 
 		String bracePosition = this.options.brace_position_for_block;
-		if (parent instanceof SwitchStatement) {
-			List<Statement> siblings = ((SwitchStatement) parent).statements();
-			int blockPosition = siblings.indexOf(node);
-			boolean isFirstInCase = blockPosition > 0 && (siblings.get(blockPosition - 1) instanceof SwitchCase);
-			if (isFirstInCase)
-				bracePosition = this.options.brace_position_for_block_in_case;
+		if (parent instanceof SwitchStatement sw) {
+			bracePosition = getBracePositionInSwitch(node, sw.statements());
+		} else if (parent instanceof SwitchExpression se) {
+			bracePosition = getBracePositionInSwitch(node, se.statements());
 		} else if (parent instanceof LambdaExpression) {
 			bracePosition = this.options.brace_position_for_lambda_body;
 		}
@@ -323,6 +321,15 @@ public boolean visit(Block node) {
 		return true;
 	}
 
+	private String getBracePositionInSwitch(Block node, List<Statement> siblings) {
+		int blockPosition = siblings.indexOf(node);
+		if (blockPosition > 0 && siblings.get(blockPosition - 1) instanceof SwitchCase switchCase) {
+			return switchCase.isSwitchLabeledRule() ? this.options.brace_position_for_block_in_case_after_arrow
+					: this.options.brace_position_for_block_in_case;
+		}
+		return this.options.brace_position_for_block;
+	}
+
 	private void blankLinesAroundBlock(ASTNode blockStatement, List<ASTNode> siblings) {
 		putBlankLinesBefore(blockStatement, this.options.blank_lines_before_code_block);
 		if (!this.options.put_empty_statement_on_new_line) {