From e4150e0d4e05e4aac5c0465bc8068270ae901ef4 Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <bas.leijdekkers@jetbrains.com>
Date: Fri, 19 Dec 2025 12:16:31 +0100
Subject: [PATCH] IDEA-383426 [java]: normalize strings with leading newlines
 when replacing with text block

GitOrigin-RevId: a31195746d6d797f217d13c7351179fa12adb6ae
---
 .../TextBlockMigrationInspection.java         | 22 +++++++++++--------
 .../afterLeadingNewlines.java                 | 12 ++++++++++
 .../beforeLeadingNewlines.java                | 10 +++++++++
 3 files changed, 35 insertions(+), 9 deletions(-)
 create mode 100644 java/java-tests/testData/inspection/textBlockMigration/afterLeadingNewlines.java
 create mode 100644 java/java-tests/testData/inspection/textBlockMigration/beforeLeadingNewlines.java

diff --git a/java/java-impl-inspections/src/com/intellij/codeInspection/TextBlockMigrationInspection.java b/java/java-impl-inspections/src/com/intellij/codeInspection/TextBlockMigrationInspection.java
index 6f1dec1564f1..70d1220405c6 100644
--- a/java/java-impl-inspections/src/com/intellij/codeInspection/TextBlockMigrationInspection.java
+++ b/java/java-impl-inspections/src/com/intellij/codeInspection/TextBlockMigrationInspection.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+// Copyright 2000-2025 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
 package com.intellij.codeInspection;
 
 import com.intellij.codeInspection.options.OptPane;
@@ -115,17 +115,15 @@ public final class TextBlockMigrationInspection extends AbstractBaseJavaLocalIns
       if (expression == null) return;
       Document document = expression.getContainingFile().getViewProvider().getDocument();
       if (document == null) return;
-      PsiLiteralExpression literalExpression = tryCast(expression, PsiLiteralExpression.class);
-      if (literalExpression != null) {
-        replaceWithTextBlock(new PsiExpression[]{literalExpression}, literalExpression);
-        return;
+      if (expression instanceof PsiLiteralExpression literalExpression) {
+        replaceWithTextBlock(literalExpression, new PsiExpression[]{literalExpression});
+      }
+      else if (expression instanceof PsiPolyadicExpression polyadicExpression && ExpressionUtils.hasStringType(polyadicExpression)) {
+        replaceWithTextBlock(polyadicExpression, polyadicExpression.getOperands());
       }
-      PsiPolyadicExpression polyadicExpression = tryCast(expression, PsiPolyadicExpression.class);
-      if (polyadicExpression == null || !ExpressionUtils.hasStringType(polyadicExpression)) return;
-      replaceWithTextBlock(polyadicExpression.getOperands(), polyadicExpression);
     }
 
-    private static void replaceWithTextBlock(PsiExpression @NotNull [] operands, @NotNull PsiExpression toReplace) {
+    private static void replaceWithTextBlock(@NotNull PsiExpression toReplace, PsiExpression @NotNull [] operands) {
       String[] lines = getContentLines(operands);
       if (lines == null) return;
       CommentTracker tracker = new CommentTracker();
@@ -139,6 +137,12 @@ public final class TextBlockMigrationInspection extends AbstractBaseJavaLocalIns
         // append \ + newline at the end of the last line, so we can use closing """ to indent
         lines[lines.length - 1] += "\\\n";
       }
+      for (int i = 0; i < lines.length - 1; i++) {
+        String line = lines[i];
+        if (line.endsWith("\\\n") && lines[i + 1].equals("\n")) {
+          lines[i] = line.substring(0, line.length() - 2); // normalize strings with leading newlines
+        }
+      }
       String content = StringUtil.join(lines);
       if (content.endsWith(" ")) {
         content = content.substring(0, content.length() - 1) + "\\s";
diff --git a/java/java-tests/testData/inspection/textBlockMigration/afterLeadingNewlines.java b/java/java-tests/testData/inspection/textBlockMigration/afterLeadingNewlines.java
new file mode 100644
index 000000000000..88bd461722e1
--- /dev/null
+++ b/java/java-tests/testData/inspection/textBlockMigration/afterLeadingNewlines.java
@@ -0,0 +1,12 @@
+// "Replace with text block" "true-preview"
+
+class LeadingNewlines {
+
+  public static void main(String[] args) {
+    String text = """
+            
+            +---------------------------- ------------------------------------------------------------+
+            | Unable to authenticate the microservice. Administrative functions will not be available |
+            +-----------------------------------------------------------------------------------------+""";
+  }
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/inspection/textBlockMigration/beforeLeadingNewlines.java b/java/java-tests/testData/inspection/textBlockMigration/beforeLeadingNewlines.java
new file mode 100644
index 000000000000..20a0fcd0d697
--- /dev/null
+++ b/java/java-tests/testData/inspection/textBlockMigration/beforeLeadingNewlines.java
@@ -0,0 +1,10 @@
+// "Replace with text block" "true-preview"
+
+class LeadingNewlines {
+
+  public static void main(String[] args) {
+    String text = "\n<caret>+---------------------------- ------------------------------------------------------------+" +
+                  "\n| Unable to authenticate the microservice. Administrative functions will not be available |" +
+                  "\n+-----------------------------------------------------------------------------------------+";
+  }
+}
\ No newline at end of file