Issue #14689: Resolve Javadoc summary false positives

src/it/resources/com/google/checkstyle/test/chapter7javadoc/rule72thesummaryfragment/InputIncorrectSummaryJavaDocCheck.java

@@ -7,7 +7,7 @@
 class InputIncorrectSummaryJavaDocCheck {
 
     /**
-     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}
+     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}.
      */
     void foo3() {}
 

src/main/java/com/puppycrawl/tools/checkstyle/Main.java

@@ -503,7 +503,7 @@ private static AuditListener createListener(OutputFormat format, Path outputLoca
     }
 
     /**
-     * Create output stream or return System.out
+     * Create output stream or return System.out.
      *
      * @param outputPath output location
      * @return output stream

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

@@ -72,7 +72,7 @@ public class SuppressWarningsHolder
      */
     private static final String CHECKSTYLE_PREFIX = "checkstyle:";
 
-    /** Java.lang namespace prefix, which is stripped from SuppressWarnings */
+    /** Java.lang namespace prefix, which is stripped from SuppressWarnings. */
     private static final String JAVA_LANG_PREFIX = "java.lang.";
 
     /** Suffix to be removed from subclasses of Check. */

src/main/java/com/puppycrawl/tools/checkstyle/checks/coding/ModifiedControlVariableCheck.java

@@ -408,7 +408,7 @@ private static Set<String> getForIteratorVariables(DetailAST ast) {
     }
 
     /**
-     * Find all child of given AST of type TokenType.EXPR
+     * Find all child of given AST of type TokenType.EXPR.
      *
      * @param ast parent of expressions to find
      * @return all child of given ast

src/main/java/com/puppycrawl/tools/checkstyle/checks/imports/PkgImportControl.java

@@ -29,13 +29,13 @@
  * be a sub-package, a class, or an allow/disallow rule.
  */
 class PkgImportControl extends AbstractImportControl {
-    /** The package separator: "." */
+    /** The package separator: ".". */
     private static final String DOT = ".";
 
     /** The regex for the package separator: "\\.". */
     private static final String DOT_REGEX = "\\.";
 
-    /** A pattern matching the package separator: "\." */
+    /** A pattern matching the package separator: "\.". */
     private static final Pattern DOT_REGEX_PATTERN = Pattern.compile(DOT_REGEX);
 
     /** The regex for the escaped package separator: "\\\\.". */

src/main/java/com/puppycrawl/tools/checkstyle/checks/javadoc/SummaryJavadocCheck.java

@@ -218,13 +218,11 @@ private void validateUntaggedSummary(DetailNode ast) {
             log(ast.getLineNumber(), MSG_SUMMARY_JAVADOC_MISSING);
         }
         else if (!period.isEmpty()) {
-            final String firstSentence = getFirstSentence(ast);
-            final int endOfSentence = firstSentence.lastIndexOf(period);
-            if (!summaryDoc.contains(period)) {
+            final String firstSentence = getFirstSentence(ast, period);
+            if (!summaryDoc.contains(period) || firstSentence.isEmpty()) {
                 log(ast.getLineNumber(), MSG_SUMMARY_FIRST_SENTENCE);
             }
-            if (endOfSentence != -1
-                    && containsForbiddenFragment(firstSentence.substring(0, endOfSentence))) {
+            else if (containsForbiddenFragment(firstSentence)) {
                 log(ast.getLineNumber(), MSG_SUMMARY_JAVADOC);
             }
         }
@@ -579,28 +577,70 @@ private static String getStringInsideTag(String result, DetailNode detailNode) {
      * Finds and returns first sentence.
      *
      * @param ast Javadoc root node.
+     * @param period Period character.
      * @return first sentence.
      */
-    private static String getFirstSentence(DetailNode ast) {
+    private static String getFirstSentence(DetailNode ast, String period) {
         final StringBuilder result = new StringBuilder(256);
-        final String periodSuffix = DEFAULT_PERIOD + ' ';
-        for (DetailNode child : ast.getChildren()) {
-            final String text;
-            if (child.getChildren().length == 0) {
-                text = child.getText();
+        final boolean foundEnd = appendFirstSentence(ast, period, result);
+        if (!foundEnd) {
+            result.setLength(0);
+        }
+        return result.toString();
+    }
+
+    /**
+     * Finds and appends first sentence to result.
+     *
+     * @param ast Javadoc node to append.
+     * @param period Period character.
+     * @param result Builder to append to.
+     * @return true if the period character was found, false otherwise
+     */
+    private static boolean appendFirstSentence(
+            DetailNode ast, String period, StringBuilder result) {
+        boolean foundEnd = false;
+        if (ast.getChildren().length == 0) {
+            final String text = ast.getText();
+            final int periodIndex = findEndingPeriod(text, period);
+            if (periodIndex >= 0) {
+                result.append(text, 0, periodIndex);
+                foundEnd = true;
             }
             else {
-                text = getFirstSentence(child);
+                result.append(text);
             }
-
-            if (text.contains(periodSuffix)) {
-                result.append(text, 0, text.indexOf(periodSuffix) + 1);
+        }
+        for (DetailNode child : ast.getChildren()) {
+            if (appendFirstSentence(child, period, result)) {
+                foundEnd = true;
                 break;
             }
+        }
+        return foundEnd;
+    }
 
-            result.append(text);
+    /**
+     * Find position of an ending period in the text. Ignores any period not followed by
+     * whitespace.
+     *
+     * @param text text to search
+     * @param period period character
+     * @return position of period character, or -1 if there is no ending period
+     */
+    private static int findEndingPeriod(String text, String period) {
+        int periodIndex = text.indexOf(period);
+        while (periodIndex >= 0) {
+            final int afterPeriodIndex = periodIndex + period.length();
+            if (afterPeriodIndex >= text.length()
+                || Character.isWhitespace(text.charAt(afterPeriodIndex))) {
+                break;
+            }
+            else {
+                periodIndex = text.indexOf(period, afterPeriodIndex);
+            }
         }
-        return result.toString();
+        return periodIndex;
     }
 
 }

src/main/java/com/puppycrawl/tools/checkstyle/checks/metrics/AbstractClassCouplingCheck.java

@@ -49,7 +49,7 @@
 @FileStatefulCheck
 public abstract class AbstractClassCouplingCheck extends AbstractCheck {
 
-    /** A package separator - "." */
+    /** A package separator - ".". */
     private static final char DOT = '.';
 
     /** Class names to ignore. */

src/test/java/com/puppycrawl/tools/checkstyle/checks/javadoc/SummaryJavadocCheckTest.java

@@ -113,6 +113,9 @@ public void testPeriod() throws Exception {
             "14: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
             "19: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
             "37: " + getCheckMessage(MSG_SUMMARY_MISSING_PERIOD),
+            "42: " + getCheckMessage(MSG_SUMMARY_JAVADOC),
+            "49: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
+            "55: " + getCheckMessage(MSG_SUMMARY_JAVADOC),
         };
 
         verifyWithInlineConfigParser(
@@ -230,6 +233,7 @@ public void testPeriodAtEnd() throws Exception {
             "33: " + getCheckMessage(MSG_SUMMARY_JAVADOC_MISSING),
             "40: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
             "60: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
+            "70: " + getCheckMessage(MSG_SUMMARY_FIRST_SENTENCE),
         };
 
         verifyWithInlineConfigParser(

src/test/resources/com/puppycrawl/tools/checkstyle/checks/javadoc/summaryjavadoc/InputSummaryJavadocCorrect.java

@@ -2,7 +2,7 @@
 SummaryJavadoc
 violateExecutionOnNonTightHtml = (default)false
 forbiddenSummaryFragments = ^@return the *|^This method returns *|^A \
-                            [{]@code [a-zA-Z0-9]+[}]( is a )
+                            [{]@code [a-zA-Z0-9]+[}]( is a )|fail-summary-fragment
 period = (default).
 
 
@@ -89,6 +89,14 @@ void foo14() {}
      */
     void foo15() {}
 
+    /**
+     * Summary sentence on its own line.
+     * <p>
+     * Another sentence that is not part of the summary,
+     * so this should not matter: fail-summary-fragment.
+     */
+    void foo16() {}
+
     /**
      * This is summary java doc.
      * <a href="mailto:vlad@htmlbook.ru"/>

src/test/resources/com/puppycrawl/tools/checkstyle/checks/javadoc/summaryjavadoc/InputSummaryJavadocIncorrect.java

@@ -17,7 +17,7 @@
 class InputSummaryJavadocIncorrect {
 
     /**
-     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}
+     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}.
      */
     void foo3() {}
     // violation below 'Summary javadoc is missing.'

src/test/resources/com/puppycrawl/tools/checkstyle/checks/javadoc/summaryjavadoc/InputSummaryJavadocIncorrect2.java

@@ -16,7 +16,7 @@
 class InputSummaryJavadocIncorrect2 {
 
     /**
-     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}
+     * As of JDK 1.1, replaced by {@link #setBounds(int,int,int,int)}.
      */
     void foo3() {}
     // violation below 'Summary javadoc is missing.'

src/test/resources/com/puppycrawl/tools/checkstyle/checks/javadoc/summaryjavadoc/InputSummaryJavadocPeriod.java

@@ -1,7 +1,7 @@
 /*
 SummaryJavadoc
 violateExecutionOnNonTightHtml = (default)false
-forbiddenSummaryFragments = (default)^$
+forbiddenSummaryFragments = ^$|fail-summary-fragment
 period = _
 
 
@@ -37,4 +37,24 @@ void foo7(){}
      * {@summary An especially short bit of Javadoc}
      */ // violation above 'Summary .* missing an ending period.'
     void foo8() {}
+
+    // violation below 'Forbidden summary fragment.'
+    /**
+     * Summary sentence containing default period mentioning version 1.1, then ending with correct
+     * period after disallowed words, fail-summary-fragment_
+     */
+    void foo9() {}
+
+    // violation below 'First sentence .* missing an ending period.'
+    /**
+     * Summary sentence containing correct period mid_word, but not at the end
+     */
+    void foo10() throws Exception {}
+
+    // violation below 'Forbidden summary fragment.'
+    /**
+     * Summary sentence containing correct period mid_word, then ending with correct period after
+     * disallowed words, fail-summary-fragment_
+     */
+    void foo11() {}
 }

src/test/resources/com/puppycrawl/tools/checkstyle/checks/javadoc/summaryjavadoc/InputSummaryJavadocPeriodAtEnd.java

@@ -12,7 +12,7 @@
 
 public class InputSummaryJavadocPeriodAtEnd {
     /**
-     * JAXB 1.0 only default validation event handler
+     * JAXB 1.0 only default validation event handler.
      */
     public static final byte NUL = 0;
     // violation below 'Summary javadoc is missing.'
@@ -66,4 +66,9 @@ public void foo5(){
     public void foo6() {
 
     }
+    // violation below 'First sentence .* missing an ending period.'
+    /**
+     * JAXB 1.0 missing end period
+     */
+    public static final byte ONE = 1;
 }