TextBlockMigrationInspection: preserve meaningful spaces at the beginning of each line (IDEA-226395)

GitOrigin-RevId: a204f736a29271ebe83fd5f5222d0b1ebd28ddbf

java/java-impl/src/com/intellij/codeInspection/TextBlockMigrationInspection.java

@@ -46,6 +46,7 @@ public class TextBlockMigrationInspection extends AbstractBaseJavaLocalInspectio
         for (PsiExpression operand : operands) {
           PsiLiteralExpressionImpl literal = getLiteralExpression(operand);
           if (literal == null) return;
+          if (nNewLines > 1) continue;
           String text = literal.getText();
           int newLineIdx = getNewLineIndex(text, 0);
           if (newLineIdx == -1) continue;
@@ -57,7 +58,6 @@ public class TextBlockMigrationInspection extends AbstractBaseJavaLocalInspectio
             nNewLines++;
             newLineIdx = getNewLineIndex(text, newLineIdx + 1);
           }
-          if (nNewLines > 1) break;
         }
         if (nNewLines <= 1) return;
         holder.registerProblem(expression, firstNewLineTextRange,
@@ -106,22 +106,55 @@ public class TextBlockMigrationInspection extends AbstractBaseJavaLocalInspectio
     }
 
     private static void replaceWithTextBlock(@NotNull PsiExpression[] operands, @NotNull PsiExpression toReplace) {
-      StringBuilder textBlock = new StringBuilder();
-      textBlock.append("\"\"\"\n");
+      String[] lines = getContentLines(operands);
+      if (lines == null) return;
+      String textBlock = getTextBlock(lines);
+      PsiReplacementUtil.replaceExpression(toReplace, textBlock, new CommentTracker());
+    }
+
+    @NotNull
+    private static String getTextBlock(@NotNull String[] lines) {
+      int indent = PsiLiteralUtil.getTextBlockIndent(lines);
+      // we need additional indent call only when significant trailing line is missing
+      if (indent > 0 && lines.length > 0 && lines[lines.length - 1].endsWith("\n")) indent = 0;
+      String content = getTextBlockContent(lines, indent);
+      return "\"\"\"\n" + content + "\"\"\"" + (indent > 0 ? ".indent(" + indent + ")" : "");
+    }
+
+    @NotNull
+    private static String getTextBlockContent(@NotNull String[] lines, int indent) {
+      StringBuilder content = new StringBuilder();
       boolean escapeStartQuote = false;
+      for (int i = 0; i < lines.length; i++) {
+        String line = lines[i];
+        boolean isLastLine = i == lines.length - 1;
+        if (indent < line.length()) line = line.substring(indent);
+        line = PsiLiteralUtil.escapeTextBlockCharacters(line, escapeStartQuote, isLastLine, isLastLine);
+        escapeStartQuote = line.endsWith("\"");
+        content.append(line);
+      }
+      return content.toString();
+    }
+
+    @Nullable
+    private static String[] getContentLines(@NotNull PsiExpression[] operands) {
+      String[] lines = new String[operands.length];
       for (int i = 0; i < operands.length; i++) {
         PsiExpression operand = operands[i];
         PsiLiteralExpressionImpl literal = getLiteralExpression(operand);
-        if (literal == null) return;
-        String text = getLiteralText(literal);
-        if (text == null) return;
-        boolean isLastLine = i == operands.length - 1;
-        text = PsiLiteralUtil.escapeTextBlockCharacters(text, escapeStartQuote, isLastLine, isLastLine);
-        escapeStartQuote = text.endsWith("\"");
-        textBlock.append(text);
+        if (literal == null) return null;
+        String line = getLiteralText(literal);
+        if (line == null) return null;
+        lines[i] = line;
       }
-      textBlock.append("\"\"\"");
-      PsiReplacementUtil.replaceExpression(toReplace, textBlock.toString(), new CommentTracker());
+      return lines;
+    }
+
+    @Nullable
+    private static String getLiteralText(@NotNull PsiLiteralExpressionImpl literal) {
+      if (literal.getLiteralElementType() == JavaTokenType.STRING_LITERAL) return literal.getInnerText();
+      Object value = literal.getValue();
+      return value == null ? null : value.toString();
     }
   }
 
@@ -151,11 +184,4 @@ public class TextBlockMigrationInspection extends AbstractBaseJavaLocalInspectio
     if (literal == null || literal.getLiteralElementType() == JavaTokenType.TEXT_BLOCK_LITERAL) return null;
     return literal;
   }
-
-  @Nullable
-  private static String getLiteralText(@NotNull PsiLiteralExpressionImpl literal) {
-    if (literal.getLiteralElementType() == JavaTokenType.STRING_LITERAL) return literal.getInnerText();
-    Object value = literal.getValue();
-    return value == null ? null : value.toString();
-  }
 }

java/java-psi-api/src/com/intellij/psi/util/PsiLiteralUtil.java

@@ -170,7 +170,7 @@ public class PsiLiteralUtil {
    * <li>All escaped quotes are unescaped.</li>
    * <li>Every third quote is escaped. If escapeStartQuote / escapeEndQuote is set then start / end quote is also escaped.</li>
    * <li>All spaces before \n are converted to \040 escape sequence.
-   * This is required since spaces in the end of the line are trimmed by default (see JEP 355).
+   * This is required since spaces in the end of the line are trimmed by default (see JEP 368).
    * If escapeSpacesInTheEnd is set, then all spaces before the end of the line are converted even if new line in the end is missing. </li>
    * <li> All new line escape sequences are interpreted. </li>
    * <li>Rest of the content is processed as is.</li>
@@ -372,4 +372,22 @@ public class PsiLiteralUtil {
     }
     return -1;
   }
+
+  /**
+   * Determines how many whitespaces would be excluded at the beginning of each line of text block content.
+   * See JEP 368 for more details.
+   *
+   * @param lines text block content
+   */
+  public static int getTextBlockIndent(@NotNull String[] lines) {
+    int prefix = Integer.MAX_VALUE;
+    for (int i = 0; i < lines.length; i++) {
+      String line = lines[i];
+      int indent = 0;
+      while (indent < line.length() && Character.isWhitespace(line.charAt(indent))) indent++;
+      if (indent == line.length() && i < lines.length - 1) lines[i] = "";
+      else if (indent < prefix) prefix = indent;
+    }
+    return prefix;
+  }
 }

java/java-psi-impl/src/com/intellij/psi/impl/source/tree/java/PsiLiteralExpressionImpl.java

@@ -158,7 +158,7 @@ public class PsiLiteralExpressionImpl
     String[] lines = getTextBlockLines();
     if (lines == null) return null;
 
-    int prefix = getTextBlockIndent(lines);
+    int prefix = PsiLiteralUtil.getTextBlockIndent(lines);
 
     StringBuilder sb = new StringBuilder();
     for (int i = 0; i < lines.length; i++) {
@@ -176,19 +176,7 @@ public class PsiLiteralExpressionImpl
   public int getTextBlockIndent() {
     String[] lines = getTextBlockLines();
     if (lines == null) return -1;
-    return getTextBlockIndent(lines);
-  }
-  
-  private static int getTextBlockIndent(String[] lines) {
-    int prefix = Integer.MAX_VALUE;
-    for (int i = 0; i < lines.length; i++) {
-      String line = lines[i];
-      int indent = 0;
-      while (indent < line.length() && Character.isWhitespace(line.charAt(indent))) indent++;
-      if (indent == line.length() && i < lines.length - 1) lines[i] = "";
-      else if (indent < prefix) prefix = indent;
-    }
-    return prefix;
+    return PsiLiteralUtil.getTextBlockIndent(lines);
   }
 
   @Nullable

java/java-tests/testData/inspection/textBlockMigration/afterConcatenationWithSpacesAtTheBeginning.java

@@ -0,0 +1,13 @@
+// "Replace with text block" "true"
+
+class TextBlockMigration {
+
+  void concatenationWithSpacesAtTheBeginning() {
+    String body = """
+            <body>
+              <p>
+              </p>
+            </body>""".indent(2);
+  }
+
+}

java/java-tests/testData/inspection/textBlockMigration/beforeConcatenationWithSpacesAtTheBeginning.java

@@ -0,0 +1,12 @@
+// "Replace with text block" "true"
+
+class TextBlockMigration {
+
+  void concatenationWithSpacesAtTheBeginning() {
+    String body = "  <body>\n<caret>" +
+      "    <p>\n" +
+      "    </p>\n" +
+      "  </body>";
+  }
+
+}

java/java-tests/testData/inspection/textBlockMigration/beforeConcatenationWithTextBlock.java

@@ -0,0 +1,11 @@
+// "Fix all 'Text block can be used' problems in file" "false"
+
+class TextBlockMigration {
+
+  void concatenationWithTextBlock() {
+    String concat = "foo\n<caret>" + "bar\n" +
+                    """
+                    baz""";
+  }
+
+}