fix: indent non-block switch rule bodies with leading comments

Author: jtkiesel

packages/prettier-plugin-java/src/printers/blocks-and-statements.ts

@@ -3,6 +3,7 @@ import { builders } from "prettier/doc";
 import {
   call,
   definedKeys,
+  hasLeadingComments,
   indentInParentheses,
   isBinaryExpression,
   isEmptyStatement,
@@ -190,11 +191,13 @@ export default {
       "expression",
       "throwStatement"
     ]);
-    const parts = [
-      call(path, print, "switchLabel"),
-      " -> ",
-      call(path, print, bodyKey)
-    ];
+    const body = call(path, print, bodyKey);
+    const parts = [call(path, print, "switchLabel"), " ->"];
+    if (bodyKey !== "block" && hasLeadingComments(children[bodyKey]![0])) {
+      parts.push(indent([hardline, body]));
+    } else {
+      parts.push(" ", body);
+    }
     if (children.Semicolon) {
       parts.push(";");
     }

packages/prettier-plugin-java/src/printers/helpers.ts

@@ -233,7 +233,7 @@ export function printComment(node: JavaTerminal) {
 }
 
 export function hasLeadingComments(node: JavaNode) {
-  return node.comments?.some(({ leading }) => leading);
+  return node.comments?.some(({ leading }) => leading) ?? false;
 }
 
 export function indentInParentheses(

packages/prettier-plugin-java/test/unit-test/switch/_input.java

@@ -171,4 +171,18 @@ static String shouldFormatSwitchBlocksWithEmptyLastBlock(Object o) {
         log.info("Done !");
 
     }
+
+  void switchRulesWithComments() {
+    switch (a) {
+      case b ->
+        // comment
+        c;
+      case Dd d ->
+        // comment
+        e;
+      case f ->
+        // comment
+        throw new RuntimeException();
+    }
+  }
 }

packages/prettier-plugin-java/test/unit-test/switch/_output.java

@@ -219,4 +219,18 @@ static String shouldFormatSwitchBlocksWithEmptyLastBlock(Object o) {
 
     log.info("Done !");
   }
+
+  void switchRulesWithComments() {
+    switch (a) {
+      case b ->
+        // comment
+        c;
+      case Dd d ->
+        // comment
+        e;
+      case f ->
+        // comment
+        throw new RuntimeException();
+    }
+  }
 }