fix: fix warning messages of checkstyle

build.gradle

@@ -3,6 +3,7 @@ plugins {
     id 'maven-publish'
     id 'signing'
     id 'jacoco'
+    id 'checkstyle'
     id 'com.github.kt3k.coveralls' version '2.12.2'
     id "me.champeau.jmh" version "0.7.1"
     id "com.github.spotbugs" version "5.1.3"
@@ -56,6 +57,17 @@ spotbugsMain {
     }
 }
 
+checkstyle {
+    toolVersion = '10.12.1'
+    configProperties = [
+            "org.checkstyle.google.suppressionxpathfilter.config":
+                    "${projectDir}/config/checkstyle/suppressions-xpath.xml",
+    ]
+    ignoreFailures = false
+    maxWarnings = 0
+    checkstyleTest.enabled = false
+}
+
 task compileModuleInfoJava(type: JavaCompile, dependsOn: compileJava) {
     classpath = files()
     source = 'src/main/java9/module-info.java'

config/checkstyle/suppressions-xpath.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionXpathFilter Experimental Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2_xpath_experimental.dtd">
+
+<suppressions>
+    <suppress-xpath files="Keyboard\.java" checks="MemberName" query="//VARIABLE_DEF/IDENT[@text='x']"/>
+    <suppress-xpath files="Keyboard\.java" checks="MemberName" query="//VARIABLE_DEF/IDENT[@text='y']"/>
+    <suppress-xpath files="Match\.java" checks="MemberName" query="//VARIABLE_DEF/IDENT[@text='i']"/>
+    <suppress-xpath files="Match\.java" checks="MemberName" query="//VARIABLE_DEF/IDENT[@text='j']"/>
+</suppressions>

src/main/java/com/nulabinc/zxcvbn/Scoring.java

@@ -55,7 +55,7 @@ public Strength mostGuessableMatchSequence(
     for (int k = 0; k < n; k++) {
       for (Match m : matchesByJ.get(k)) {
         if (m.i > 0) {
-          for (Map.Entry<Integer, Match> entry : optimal.m.get(m.i - 1).entrySet()) {
+          for (Map.Entry<Integer, Match> entry : optimal.matches.get(m.i - 1).entrySet()) {
             int l = entry.getKey();
             update(password, m, l + 1, optimal, excludeAdditive);
           }
@@ -67,7 +67,7 @@ public Strength mostGuessableMatchSequence(
     }
     List<Match> optimalMatchSequence = unwind(n, optimal);
     Integer optimalL = optimalMatchSequence.size();
-    double guesses = password.length() == 0 ? 1 : optimal.g.get(n - 1).get(optimalL);
+    double guesses = password.length() == 0 ? 1 : optimal.guesses.get(n - 1).get(optimalL);
     Strength strength = new Strength();
     strength.setPassword(password);
     strength.setGuesses(guesses);
@@ -78,7 +78,6 @@ public Strength mostGuessableMatchSequence(
 
   private void update(
       CharSequence password, Match m, int l, Optimal optimal, boolean excludeAdditive) {
-    int k = m.j;
     double pi = new EstimateGuess(this.context, password).exec(m);
     if (l > 1) {
       pi *= optimal.pi.get(m.i - 1).get(l - 1);
@@ -96,16 +95,17 @@ private void update(
         g = Double.MAX_VALUE;
       }
     }
-    for (Map.Entry<Integer, Double> competing : optimal.g.get(k).entrySet()) {
+    int k = m.j;
+    for (Map.Entry<Integer, Double> competing : optimal.guesses.get(k).entrySet()) {
       if (competing.getKey() > l) {
         continue;
       }
       if (competing.getValue() <= g) {
         return;
       }
     }
-    optimal.g.get(k).put(l, g);
-    optimal.m.get(k).put(l, m);
+    optimal.guesses.get(k).put(l, g);
+    optimal.matches.get(k).put(l, m);
     optimal.pi.get(k).put(l, pi);
   }
 
@@ -115,10 +115,10 @@ private void bruteforceUpdate(
     update(password, m, 1, optimal, excludeAdditive);
     for (int i = 1; i <= k; i++) {
       m = makeBruteforceMatch(password, i, k);
-      for (Map.Entry<Integer, Match> entry : optimal.m.get(i - 1).entrySet()) {
+      for (Map.Entry<Integer, Match> entry : optimal.matches.get(i - 1).entrySet()) {
         int l = entry.getKey();
-        Match last_m = entry.getValue();
-        if (last_m.pattern != Pattern.Bruteforce) {
+        Match lastMatch = entry.getValue();
+        if (lastMatch.pattern != Pattern.Bruteforce) {
           update(password, m, l + 1, optimal, excludeAdditive);
         }
       }
@@ -131,14 +131,14 @@ private static List<Match> unwind(int n, Optimal optimal) {
     if (0 <= k) {
       int l = 0;
       Double g = Double.POSITIVE_INFINITY;
-      for (Map.Entry<Integer, Double> candidate : optimal.g.get(k).entrySet()) {
+      for (Map.Entry<Integer, Double> candidate : optimal.guesses.get(k).entrySet()) {
         if (candidate.getValue() < g) {
           l = candidate.getKey();
           g = candidate.getValue();
         }
       }
       while (k >= 0) {
-        Match m = optimal.m.get(k).get(l);
+        Match m = optimal.matches.get(k).get(l);
         optimalMatchSequence.add(0, m);
         k = m.i - 1;
         l--;
@@ -152,10 +152,16 @@ private static Match makeBruteforceMatch(CharSequence password, int i, int j) {
   }
 
   private static long factorial(int n) {
-    if (n < 2) return 1;
-    if (n > 19) return JS_NUMBER_MAX;
+    if (n < 2) {
+      return 1;
+    }
+    if (n > 19) {
+      return JS_NUMBER_MAX;
+    }
     long f = 1;
-    for (int i = 2; i <= n; i++) f *= i;
+    for (int i = 2; i <= n; i++) {
+      f *= i;
+    }
     return f;
   }
 
@@ -170,17 +176,17 @@ public int compare(Match m1, Match m2) {
 
   private static class Optimal {
 
-    public final List<Map<Integer, Match>> m = new ArrayList<>();
+    public final List<Map<Integer, Match>> matches = new ArrayList<>();
 
     public final List<Map<Integer, Double>> pi = new ArrayList<>();
 
-    public final List<Map<Integer, Double>> g = new ArrayList<>();
+    public final List<Map<Integer, Double>> guesses = new ArrayList<>();
 
     public Optimal(int n) {
       for (int i = 0; i < n; i++) {
-        m.add(new HashMap<Integer, Match>());
+        matches.add(new HashMap<Integer, Match>());
         pi.add(new HashMap<Integer, Double>());
-        g.add(new HashMap<Integer, Double>());
+        guesses.add(new HashMap<Integer, Double>());
       }
     }
   }

src/main/java/com/nulabinc/zxcvbn/TimeEstimates.java

@@ -45,7 +45,8 @@ public static int guessesToScore(double guesses) {
     }
     if (guesses < 1e10 + DELTA) {
       return 3;
-    } else return 4;
+    }
+    return 4;
   }
 
   public static String displayTime(final double seconds) {

src/main/java/com/nulabinc/zxcvbn/WipeableString.java

@@ -152,7 +152,8 @@ public static int parseInt(CharSequence s, int radix) throws NumberFormatExcepti
 
     int result = 0;
     boolean negative = false;
-    int i = 0, len = s.length();
+    int i = 0;
+    int len = s.length();
     int limit = -Integer.MAX_VALUE;
     int multmin;
     int digit;
@@ -163,11 +164,12 @@ public static int parseInt(CharSequence s, int radix) throws NumberFormatExcepti
         if (firstChar == '-') {
           negative = true;
           limit = Integer.MIN_VALUE;
-        } else if (firstChar != '+')
+        } else if (firstChar != '+') {
           throw new NumberFormatException("For input string: \"" + s + "\"");
-
-        if (len == 1) // Cannot have lone "+" or "-"
-        throw new NumberFormatException("For input string: \"" + s + "\"");
+        }
+        if (len == 1) { // Cannot have lone "+" or "-"
+          throw new NumberFormatException("For input string: \"" + s + "\"");
+        }
         i++;
       }
       multmin = limit / radix;
@@ -202,7 +204,7 @@ public int hashCode() {
     // Reproduce the same hash as String
     int h = hash;
     if (h == 0 && content.length > 0) {
-      char val[] = content;
+      char[] val = content;
 
       for (int i = 0; i < content.length; i++) {
         h = 31 * h + val[i];
@@ -243,7 +245,9 @@ public boolean equals(Object obj) {
    * not readOnly)
    */
   public static void wipeIfPossible(CharSequence text) {
-    if (text == null) return;
+    if (text == null) {
+      return;
+    }
     if (text instanceof WipeableString) {
       ((WipeableString) text).wipe();
     } else if (text instanceof StringBuilder) {

src/main/java/com/nulabinc/zxcvbn/guesses/BaseGuess.java

@@ -15,7 +15,7 @@ protected Context getContext() {
     return context;
   }
 
-  protected static int nCk(int n, int k) {
+  protected static int calculateBinomialCoefficient(int n, int k) {
     // http://blog.plover.com/math/choose.html
     if (k > n) {
       return 0;

src/main/java/com/nulabinc/zxcvbn/guesses/DictionaryGuess.java

@@ -46,7 +46,7 @@ public int uppercaseVariations(Match match) {
     }
     int variations = 0;
     for (int i = 1; i <= Math.min(upperCount, lowerCount); i++) {
-      variations += nCk(upperCount + lowerCount, i);
+      variations += calculateBinomialCoefficient(upperCount + lowerCount, i);
     }
     lowercaseToken.wipe();
     return variations;
@@ -77,7 +77,7 @@ public int l33tVariations(Match match) {
         int minCount = Math.min(originalCount, substitutedCount);
         int possibleCombinations = 0;
         for (int i = 1; i <= minCount; i++) {
-          possibleCombinations += nCk(originalCount + substitutedCount, i);
+          possibleCombinations += calculateBinomialCoefficient(originalCount + substitutedCount, i);
         }
         totalVariations *= possibleCombinations;
       }

src/main/java/com/nulabinc/zxcvbn/guesses/SpatialGuess.java

@@ -30,7 +30,10 @@ private double calculateBaseGuesses(Match match, int startingPositions, double a
     for (int i = 2; i <= tokenLength; i++) {
       int possibleTurns = Math.min(turns, i - 1);
       for (int j = 1; j <= possibleTurns; j++) {
-        guesses += nCk(i - 1, j - 1) * startingPositions * Math.pow(averageDegree, j);
+        guesses +=
+            calculateBinomialCoefficient(i - 1, j - 1)
+                * startingPositions
+                * Math.pow(averageDegree, j);
       }
     }
     return guesses;
@@ -50,7 +53,7 @@ private double calculateShiftedVariations(Match match) {
     int shiftedVariations = 0;
     int minCount = Math.min(shiftedCount, unshiftedCount);
     for (int i = 1; i <= minCount; i++) {
-      shiftedVariations += nCk(shiftedCount + unshiftedCount, i);
+      shiftedVariations += calculateBinomialCoefficient(shiftedCount + unshiftedCount, i);
     }
     return shiftedVariations;
   }

src/main/java/com/nulabinc/zxcvbn/io/ClasspathResource.java

@@ -30,18 +30,16 @@ public InputStream getInputStream() throws IOException {
    * Finally, if even the system ClassLoader could not access resource as stream, return null.
    */
   private InputStream getResourceAsStreamWithFallback(String path) {
-    // 0. try loading the resource from the same artifact as this class
-    {
-      InputStream in = getClass().getResourceAsStream(path);
-      if (in != null) {
-        return in;
-      }
-    } // no exceptions thrown
+    // Try loading the resource from the same artifact as this class
+    InputStream in = getClass().getResourceAsStream(path);
+    if (in != null) {
+      return in;
+    }
 
     // 1. try to get resource with thread context ClassLoader
     try {
       ClassLoader cl = Thread.currentThread().getContextClassLoader();
-      InputStream in = this.getResourceAsStream(cl, path);
+      in = this.getResourceAsStream(cl, path);
       if (in != null) {
         return in;
       }
@@ -52,7 +50,7 @@ private InputStream getResourceAsStreamWithFallback(String path) {
     // 2. try to get resource with this class context ClassLoader
     try {
       ClassLoader cl = this.getClass().getClassLoader();
-      InputStream in = this.getResourceAsStream(cl, path);
+      in = this.getResourceAsStream(cl, path);
       if (in != null) {
         return in;
       }
@@ -63,7 +61,7 @@ private InputStream getResourceAsStreamWithFallback(String path) {
     // 3. try to get resource with this class context ClassLoader
     try {
       ClassLoader cl = ClassLoader.getSystemClassLoader();
-      InputStream in = this.getResourceAsStream(cl, path);
+      in = this.getResourceAsStream(cl, path);
       if (in != null) {
         return in;
       }

src/main/java/com/nulabinc/zxcvbn/matchers/BaseMatcher.java

@@ -3,7 +3,9 @@
 import com.nulabinc.zxcvbn.Context;
 import com.nulabinc.zxcvbn.Matcher;
 import java.io.Serializable;
-import java.util.*;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
 
 public abstract class BaseMatcher implements Matcher {
 

src/main/java/com/nulabinc/zxcvbn/matchers/DateMatcher.java

@@ -3,8 +3,10 @@
 import com.nulabinc.zxcvbn.Context;
 import com.nulabinc.zxcvbn.Scoring;
 import com.nulabinc.zxcvbn.WipeableString;
-import java.util.*;
-import java.util.regex.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.regex.Pattern;
 
 /*
  * a "date" is recognized as:

src/main/java/com/nulabinc/zxcvbn/matchers/Keyboard.java

@@ -148,7 +148,8 @@ private Map<Position, String> buildPositionTable(final String layout) {
     private static List<String> split(final String str, final SplitMatcher splitMatcher) {
       final int len = str.length();
       final List<String> list = new ArrayList<>();
-      int i = 0, start = 0;
+      int i = 0;
+      int start = 0;
       boolean match = false;
       while (i < len) {
         if (splitMatcher.match(str.charAt(i))) {
@@ -208,8 +209,12 @@ public int hashCode() {
 
       @Override
       public boolean equals(Object o) {
-        if (this == o) return true;
-        if (!(o instanceof Position)) return false;
+        if (this == o) {
+          return true;
+        }
+        if (!(o instanceof Position)) {
+          return false;
+        }
 
         final Position position = (Position) o;
 

src/main/java/com/nulabinc/zxcvbn/matchers/L33tMatcher.java

@@ -2,7 +2,13 @@
 
 import com.nulabinc.zxcvbn.Context;
 import com.nulabinc.zxcvbn.WipeableString;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
 
 public class L33tMatcher extends BaseMatcher {
 

src/main/java/com/nulabinc/zxcvbn/matchers/RegexMatcher.java

@@ -6,7 +6,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.regex.*;
+import java.util.regex.Pattern;
 
 public class RegexMatcher extends BaseMatcher {