IPP: keep escaping when joining string literals (IDEA-239079)

in "Join concatenated string literals" intention

GitOrigin-RevId: 67c08f332be1d78a3019cb45824c7405b104552c

plugins/IntentionPowerPak/src/com/siyeh/ipp/concatenation/JoinConcatenatedStringLiteralsIntention.java

@@ -69,32 +69,36 @@ public class JoinConcatenatedStringLiteralsIntention extends Intention {
   }
 
   private static void merge(PsiLiteralExpression left, PsiLiteralExpression right, StringBuilder newExpression) {
-    String leftText = Objects.requireNonNull(left.getValue()).toString();
-    String rightText = Objects.requireNonNull(right.getValue()).toString();
+    final String leftText = getLiteralExpressionText(left);
+    final String rightText = getLiteralExpressionText(right);
     if (left.isTextBlock()) {
-      String indent = StringUtil.repeat(" ", PsiLiteralUtil.getTextBlockIndent(left));
-      newExpression.append("\"\"\"").append('\n').append(indent);
-      newExpression.append(leftText.replaceAll("\n", "\n" + indent));
-      if (right.isTextBlock()) {
-        newExpression.append(rightText.replaceAll("\n", "\n" + indent));
-      }
-      else {
-        newExpression.append(StringUtil.escapeStringCharacters(rightText));
-      }
-      newExpression.append("\"\"\"");
+      newExpression.append("\"\"\"\n").append(leftText)
+        .append(right.isTextBlock() ? rightText : PsiLiteralUtil.escapeTextBlockCharacters(rightText)).append("\"\"\"");
     }
     else if (right.isTextBlock()) {
-      String indent = StringUtil.repeat(" ", PsiLiteralUtil.getTextBlockIndent(right));
-      newExpression.append("\"\"\"").append('\n').append(indent);
-      newExpression.append(StringUtil.escapeStringCharacters(leftText));
-      newExpression.append(rightText.replaceAll("\n", "\n" + indent));
-      newExpression.append("\"\"\"");
+      newExpression.append("\"\"\"\n").append(PsiLiteralUtil.escapeTextBlockCharacters(leftText)).append(rightText).append("\"\"\"");
     }
     else {
-      newExpression.append('"');
-      newExpression.append(StringUtil.escapeStringCharacters(leftText));
-      newExpression.append(StringUtil.escapeStringCharacters(rightText));
-      newExpression.append('"');
+      newExpression.append('"').append(leftText).append(rightText).append('"');
+    }
+  }
+
+  private static String getLiteralExpressionText(PsiLiteralExpression expression) {
+    final PsiType type = expression.getType();
+    if (PsiType.CHAR.equals(type)) {
+      final String result = StringUtil.unquoteString(expression.getText());
+      if (result.equals("\"")) return "\\\"";
+      if (result.equals("\\'")) return "'";
+      return result;
+    }
+    else if (type instanceof PsiPrimitiveType) {
+      return Objects.requireNonNull(expression.getValue()).toString();
+    }
+    else if (expression.isTextBlock()) {
+      return PsiLiteralUtil.getTextBlockText(expression);
+    }
+    else {
+      return PsiLiteralUtil.getStringLiteralContent(expression);
     }
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/join_concat/KeepEscapes.java

@@ -0,0 +1,3 @@
+class KeepEscapes {{
+  System.out.println("\u1234" +<caret> "\u5678");
+}}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/join_concat/KeepEscapes_after.java

@@ -0,0 +1,3 @@
+class KeepEscapes {{
+  System.out.println("\u1234\u5678");
+}}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/join_concat/TextBlocksAndStringLiteral_after.java

@@ -4,6 +4,7 @@ class TextBlocks {
       System.out.println("""
               first
                second
-                third \\forth\""<caret>"");
+                third\
+               \\forth\""<caret>"");
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/join_concat/TextBlocksTailingLineBreak_after.java

@@ -6,6 +6,6 @@ class TextBlocks {
                second
                 third
               forth
-<caret>              """);
+              <caret>""");
   }
 }

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/join_concat/TextBlocks_after.java

@@ -2,8 +2,9 @@ class TextBlocks {
   static {
       //c1
       System.out.println("""
-              first   second
+              first  \s\
+              second
                 third_no space
-<caret>              """);
+              <caret>""");
   }
 }

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/concatenation/JoinConcatenatedStringLiteralsIntentionTest.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2020 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 com.siyeh.ipp.concatenation;
 
 import com.intellij.testFramework.LightProjectDescriptor;
@@ -31,11 +17,12 @@ public class JoinConcatenatedStringLiteralsIntentionTest extends IPPTestCase {
     public void testTextBlocks() { doTest(); }
     public void testTextBlocksTailingLineBreak() { doTest(); }
     public void testTextBlocksAndStringLiteral() { doTest(); }
+    public void testKeepEscapes() { doTest(); }
 
     @NotNull
     @Override
     protected LightProjectDescriptor getProjectDescriptor() {
-        return JAVA_13;
+        return JAVA_14;
     }
 
     @Override