Formatter places opening """ of text block on same line as ? / : operators in ternary expressions

まず、提供された /tmp/TernaryBug.java を /tmp/google-java-format.jar でフォーマットし、表示された diff と比較します。テキストブロックを含む三項式を formatter がどのように処理するかを追跡し、その後、各開始 triple quote がその行で空白以外の唯一の内容であること、また期待される出力が Checkstyle の TextBlockGoogleStyleFormatting チェックと競合しなくなっていることを確認します。

Description

google-java-format formats ternary expressions containing text blocks such that the opening """ is placed on the same line as the ? and : operators. This appears to violate Google Java Style Guide Section 4.8.9, which states:

The opening """ of a text block is always on a new line. That line may either follow the same indentation rules as other constructs, or it may have no indentation at all (so it starts at the left margin). The closing """ is on a new line with the same indentation as the opening """, and may be followed on the same line by further code. Each line of text in the text block is indented at least as much as the opening and closing """. (If a line is indented further, then the string literal defined by the text block will have space at the start of that line.)

The key requirement is that the """ must be on a new line, but the formatter places an operator (? or :) immediately before it on the same line, meaning the """ is no longer on the new line.

Reproduction

vivek@Viveks-MacBook-Air checkstyle % cat > /tmp/TernaryBug.java << 'EOF'
class TernaryBug {
    boolean flag = true;

    String a = flag
        ? """
          yes
          """
        : """
          no
          """;
}
EOF

vivek@Viveks-MacBook-Air checkstyle % java -jar /tmp/google-java-format.jar /tmp/TernaryBug.java > /tmp/TernaryBug_formatted.java
diff -u /tmp/TernaryBug.java /tmp/TernaryBug_formatted.java
--- /tmp/TernaryBug.java        2026-04-18 18:43:21
+++ /tmp/TernaryBug_formatted.java      2026-04-18 18:43:26
@@ -1,11 +1,12 @@

 class TernaryBug {
-    boolean flag = true;
+  boolean flag = true;
 
-    String a = flag
-        ? """
+  String a =
+      flag
+          ? """
           yes
           """
-        : """
+          : """
           no
           """;
 }

vivek@Viveks-MacBook-Air checkstyle % cat > /tmp/TernaryBug.java << 'EOF'
class TernaryBug {
    boolean flag = true;

    String d = flag ?
        """
        yes
        """
        :
        """
        no
        """;
}
EOF

vivek@Viveks-MacBook-Air checkstyle % java -jar /tmp/google-java-format.jar /tmp/TernaryBug.java > /tmp/TernaryBug_formatted.java
diff -u /tmp/TernaryBug.java /tmp/TernaryBug_formatted.java
--- /tmp/TernaryBug.java        2026-04-18 18:45:14
+++ /tmp/TernaryBug_formatted.java      2026-04-18 18:45:19
@@ -1,12 +1,12 @@

 class TernaryBug {
-    boolean flag = true;
+  boolean flag = true;
 
-    String d = flag ?
-        """
-        yes
-        """
-        :
-        """
-        no
-        """;
+  String d =
+      flag
+          ? """
+          yes
+          """
+          : """
+          no
+          """;
 }

Expected Behavior

The formatter should place the opening"""on its own line, separate from the ? and : operators. For example:

class TernaryBug {
  boolean flag = true;

  String a =
      flag
          ?
              """
              yes
              """
          :
              """
              no
              """;
}

Or any equivalent layout where """ is the only non-whitespace content on its starting line.

Why This Matters

Checkstyle's TextBlockGoogleStyleFormatting check enforces the Google Java Style Guide rule that the opening """ must be on its own line. The current formatter output directly conflicts with this check, code formatted by google-java-format produces Checkstyle violations. This creates a situation where developers cannot simultaneously satisfy both the formatter and the style checker, which are both intended to enforce the same Google Java Style Guide.