Place the trailing """ of a text block to appear on its own line

PiperOrigin-RevId: 690618067

Author: cushon

core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java

@@ -65,6 +65,9 @@
 
 /** Wraps string literals that exceed the column limit. */
 public final class StringWrapper {
+
+  public static final String TEXT_BLOCK_DELIMITER = "\"\"\"";
+
   /** Reflows long string literals in the given Java source code. */
   public static String wrap(String input, Formatter formatter) throws FormatterException {
     return StringWrapper.wrap(Formatter.MAX_LINE_LENGTH, input, formatter);
@@ -162,7 +165,7 @@ public Void visitLiteral(LiteralTree literalTree, Void aVoid) {
           return null;
         }
         int pos = getStartPosition(literalTree);
-        if (input.substring(pos, min(input.length(), pos + 3)).equals("\"\"\"")) {
+        if (input.substring(pos, min(input.length(), pos + 3)).equals(TEXT_BLOCK_DELIMITER)) {
           textBlocks.add(literalTree);
           return null;
         }
@@ -206,7 +209,7 @@ private void indentTextBlocks(
                 ? ""
                 : " ".repeat(startColumn - 1);
 
-        StringBuilder output = new StringBuilder("\"\"\"");
+        StringBuilder output = new StringBuilder(TEXT_BLOCK_DELIMITER);
         for (int i = 0; i < lines.size(); i++) {
           String line = lines.get(i);
           String trimmed = line.stripLeading().stripTrailing();
@@ -215,11 +218,16 @@ private void indentTextBlocks(
             // Don't add incidental leading whitespace to empty lines
             output.append(prefix);
           }
-          if (i == lines.size() - 1 && trimmed.equals("\"\"\"")) {
-            // If the trailing line is just """, indenting is more than the prefix of incidental
+          if (i == lines.size() - 1) {
+            String withoutDelimiter =
+                trimmed.substring(0, trimmed.length() - TEXT_BLOCK_DELIMITER.length());
+            if (!withoutDelimiter.isEmpty()) {
+              output.append(withoutDelimiter).append('\\').append(separator).append(prefix);
+            }
+            // If the trailing line is just """, indenting it more than the prefix of incidental
             // whitespace has no effect, and results in a javac text-blocks warning that 'trailing
             // white space will be removed'.
-            output.append("\"\"\"");
+            output.append(TEXT_BLOCK_DELIMITER);
           } else {
             output.append(line);
           }
@@ -482,7 +490,7 @@ private static boolean needWrapping(int columnLimit, String input) {
     Iterator<String> it = Newlines.lineIterator(input);
     while (it.hasNext()) {
       String line = it.next();
-      if (line.length() > columnLimit || line.contains("\"\"\"")) {
+      if (line.length() > columnLimit || line.contains(TEXT_BLOCK_DELIMITER)) {
         return true;
       }
     }

core/src/test/java/com/google/googlejavaformat/java/StringWrapperTest.java

@@ -65,7 +65,8 @@ public void textBlock() throws Exception {
             "    String str =",
             "        \"\"\"",
             "{\"sourceEndpoint\":\"ri.something.1-1.object-internal.1\",\"targetEndpoint"
-                + "\":\"ri.something.1-1.object-internal.2\",\"typeId\":\"typeId\"}\"\"\";",
+                + "\":\"ri.something.1-1.object-internal.2\",\"typeId\":\"typeId\"}\\",
+            "\"\"\";",
             "    myString = str;",
             "  }",
             "}");

core/src/test/resources/com/google/googlejavaformat/java/testdata/RSLs.output

@@ -23,7 +23,8 @@ class RSLs {
       """;
   String f =
       """
-      ipsum""";
+      ipsum\
+      """;
   String g =
       """
       lorem\