Issue checkstyle#10924: Update TrailingCommentCheck to use code points

src/main/java/com/puppycrawl/tools/checkstyle/checks/TrailingCommentCheck.java

@@ -19,6 +19,7 @@
 
 package com.puppycrawl.tools.checkstyle.checks;
 
+import java.util.Arrays;
 import java.util.regex.Pattern;
 
 import com.puppycrawl.tools.checkstyle.StatelessCheck;
@@ -243,8 +244,9 @@ public void visitToken(DetailAST ast) {
     private void checkSingleLineComment(DetailAST ast) {
         final int lineNo = ast.getLineNo();
         final String comment = ast.getFirstChild().getText();
-        final String line = getLines()[lineNo - 1];
-        final String lineBefore = line.substring(0, ast.getColumnNo());
+        final int[] lineBeforeCodePoints =
+                Arrays.copyOfRange(getLineCodePoints(lineNo - 1), 0, ast.getColumnNo());
+        final String lineBefore = new String(lineBeforeCodePoints, 0, lineBeforeCodePoints.length);
 
         if (!format.matcher(lineBefore).find() && !isLegalCommentContent(comment)) {
             log(ast, MSG_KEY);
@@ -261,15 +263,19 @@ private void checkBlockComment(DetailAST ast) {
         final DetailAST firstChild = ast.getFirstChild();
         final DetailAST lastChild = ast.getLastChild();
         final String comment = firstChild.getText();
-        String line = getLines()[lineNo - 1];
+        int[] lineCodePoints = getLineCodePoints(lineNo - 1);
 
-        if (line.length() > lastChild.getColumnNo() + 1) {
-            line = line.substring(lastChild.getColumnNo() + 2);
+        if (lineCodePoints.length > lastChild.getColumnNo() + 1) {
+            lineCodePoints = Arrays.copyOfRange(lineCodePoints,
+                    lastChild.getColumnNo() + 2, lineCodePoints.length);
         }
 
+        String line = new String(lineCodePoints, 0, lineCodePoints.length);
         line = FORMAT_LINE.matcher(line).replaceAll("");
 
-        final String lineBefore = getLines()[lineNo - 1].substring(0, ast.getColumnNo());
+        final int[] lineBeforeCodePoints =
+                Arrays.copyOfRange(getLineCodePoints(lineNo - 1), 0, ast.getColumnNo());
+        final String lineBefore = new String(lineBeforeCodePoints, 0, lineBeforeCodePoints.length);
         final boolean isCommentAtEndOfLine = ast.getLineNo() != lastChild.getLineNo()
                 || CommonUtil.isBlank(line);
         final boolean isLegalBlockComment = isLegalCommentContent(comment)

src/test/java/com/puppycrawl/tools/checkstyle/checks/TrailingCommentCheckTest.java

@@ -119,4 +119,19 @@ public void testLegalCommentWithNoPrecedingWhitespace() throws Exception {
         verifyWithInlineConfigParser(
                 getPath("InputTrailingCommentWithNoPrecedingWhitespace.java"), expected);
     }
+
+    @Test
+    public void testWithEmoji() throws Exception {
+        final String[] expected = {
+            "13:24: " + getCheckMessage(MSG_KEY),
+            "15:27: " + getCheckMessage(MSG_KEY),
+            "21:33: " + getCheckMessage(MSG_KEY),
+            "25:13: " + getCheckMessage(MSG_KEY),
+            "27:16: " + getCheckMessage(MSG_KEY),
+            "28:24: " + getCheckMessage(MSG_KEY),
+            "33:37: " + getCheckMessage(MSG_KEY),
+        };
+        verifyWithInlineConfigParser(
+            getPath("InputTrailingCommentWithEmoji.java"), expected);
+    }
 }

src/test/resources/com/puppycrawl/tools/checkstyle/checks/trailingcomment/InputTrailingCommentWithEmoji.java

@@ -0,0 +1,34 @@
+/*
+TrailingComment
+format = (default)^[\s});]*$
+legalComment = ^ this is ok
+
+
+*/
+
+package com.puppycrawl.tools.checkstyle.checks.trailingcomment;
+
+public class InputTrailingCommentWithEmoji {
+    // violation below
+    String a = "🧐🥳😠😨"; /*string with emoji */
+    // violation below
+    String b = "👌🏻🤞🏻😂😂🎄"; // another string
+
+    /* yet another */String c = "😂😂🎄👍"; /* this is ok */
+    String d = "🧐🥳"; // this is ok
+  /*
+  * 🎄a🎄b🎄c🎄 // violation below
+  * 🎄 👌🏻 🤘🏻 🎄*/  void test1() { /* some
+   🎄  adsad 🎄                  /*comments */
+    }
+    // violation below
+    /*😂 😂*/ // 🤛🏻🤛🏻
+
+    /* 🎃 ☠️ */ // 👿 asd😱 // violation
+    /* 😱 🎄 */ /*🎄 🥶 */ // violation
+
+    /**  // comment
+     * 🤛🏻q🥳w👆🏻e😠r👇🏻t😨y
+     */
+    /* 👆🏻 👇🏻    */  void test2() {} // violation
+}