fix linter errors

Signed-off-by: Kirill Mokevnin <mokevnin@gmail.com>

Author: mokevnin

README.md

@@ -7,8 +7,8 @@
 ```java
 import static io.hexlet.utils.ArraysAsSets;
 
-String[] firstNames = { "Vasya", "Kolya", "Petya" };
-String[] secondNames = { "Igor", "Petya", "Sergey", "Vasya", "Sasha" };
+String[] firstNames = {"Vasya", "Kolya", "Petya"};
+String[] secondNames = {"Igor", "Petya", "Sergey", "Vasya", "Sasha"};
 
 intersection(firstNames, secondNames);
 // ["Vasya", "Petya"]
@@ -19,8 +19,8 @@ intersection(firstNames, secondNames);
 ```java
 import static io.hexlet.utils.ArraysAsSets;
 
-String[] firstNames = { "Vasya", "Kolya", "Petya" };
-String[] secondNames = { "Igor", "Petya", "Sergey", "Vasya", "Sasha" };
+String[] firstNames = {"Vasya", "Kolya", "Petya"};
+String[] secondNames = {"Igor", "Petya", "Sergey", "Vasya", "Sasha"};
 
 union(firstNames, secondNames);
 // ["Petya", "Sasha", "Igor", "Kolya", "Vasya", "Sergey"]
@@ -31,8 +31,8 @@ union(firstNames, secondNames);
 ```java
 import static io.hexlet.utils.ArraysAsSets;
 
-String[] firstNames = { "Vasya", "Kolya", "Petya" };
-String[] secondNames = { "Igor", "Petya", "Sergey", "Vasya", "Sasha" };
+String[] firstNames = {"Vasya", "Kolya", "Petya"};
+String[] secondNames = {"Igor", "Petya", "Sergey", "Vasya", "Sasha"};
 difference(firstNames, secondNames);
 // ["Kolya"]
 ```

config/checkstyle/checkstyle.xml

@@ -1,30 +1,42 @@
 <?xml version="1.0"?>
 <!DOCTYPE module PUBLIC
-        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
-        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+          "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+          "https://checkstyle.org/dtds/configuration_1_3.dtd">
 
 <!--
+
   Checkstyle configuration that checks the sun coding conventions from:
+
     - the Java Language Specification at
       https://docs.oracle.com/javase/specs/jls/se11/html/index.html
+
     - the Sun Code Conventions at https://www.oracle.com/technetwork/java/codeconvtoc-136057.html
+
     - the Javadoc guidelines at
       https://www.oracle.com/technetwork/java/javase/documentation/index-137868.html
+
     - the JDK Api documentation https://docs.oracle.com/en/java/javase/11/
+
     - some best practices
+
   Checkstyle is very configurable. Be sure to read the documentation at
   https://checkstyle.org (or in your downloaded distribution).
+
   Most Checks are configurable, be sure to consult the documentation.
+
   To completely disable a check, just comment it out or delete it from the file.
   To suppress certain violations please review suppression filters.
+
   Finally, it is worth reading the documentation.
+
 -->
 
 <module name="Checker">
     <!--
         If you set the basedir property below, then all reported file
         names will be relative to the specified directory. See
         https://checkstyle.org/5.x/config.html#Checker
+
         <property name="basedir" value="${basedir}"/>
     -->
     <property name="severity" value="error"/>
@@ -60,8 +72,8 @@
     <!-- See https://checkstyle.org/config_sizes.html -->
     <module name="FileLength"/>
     <module name="LineLength">
-        <property name="fileExtensions" value="java"/>
-        <property name="max" value="120"/>
+      <property name="fileExtensions" value="java"/>
+      <property name="max" value="120"/>
     </module>
 
     <!-- Checks for whitespace                               -->
@@ -71,10 +83,10 @@
     <!-- Miscellaneous other checks.                   -->
     <!-- See https://checkstyle.org/config_misc.html -->
     <module name="RegexpSingleline">
-        <property name="format" value="\s+$"/>
-        <property name="minimum" value="0"/>
-        <property name="maximum" value="0"/>
-        <property name="message" value="Line has trailing spaces."/>
+       <property name="format" value="\s+$"/>
+       <property name="minimum" value="0"/>
+       <property name="maximum" value="0"/>
+       <property name="message" value="Line has trailing spaces."/>
     </module>
 
     <!-- Checks for Headers                                -->
@@ -88,11 +100,11 @@
 
         <!-- Checks for Javadoc comments.                     -->
         <!-- See https://checkstyle.org/config_javadoc.html -->
-        <!--        <module name="InvalidJavadocPosition"/>-->
-        <!--        <module name="JavadocMethod"/>-->
-        <!--        <module name="JavadocType"/>-->
+        <module name="InvalidJavadocPosition"/>
+        <module name="JavadocMethod"/>
+        <module name="JavadocType"/>
         <!-- <module name="JavadocVariable"/> -->
-        <!--        <module name="JavadocStyle"/>-->
+        <module name="JavadocStyle"/>
         <!-- <module name="MissingJavadocMethod"/> -->
 
         <!-- Checks for Naming Conventions.                  -->
@@ -151,18 +163,18 @@
         <!-- See https://checkstyle.org/config_coding.html -->
         <module name="EmptyStatement"/>
         <module name="EqualsHashCode"/>
-        <!--        <module name="HiddenField"/>-->
+        <module name="HiddenField"/>
         <module name="IllegalInstantiation"/>
         <module name="InnerAssignment"/>
-        <!--        <module name="MagicNumber"/>-->
+        <module name="MagicNumber"/>
         <module name="MissingSwitchDefault"/>
         <module name="MultipleVariableDeclarations"/>
         <module name="SimplifyBooleanExpression"/>
         <module name="SimplifyBooleanReturn"/>
 
         <!-- Checks for class design                         -->
         <!-- See https://checkstyle.org/config_design.html -->
-        <!--        <module name="DesignForExtension"/>-->
+        <module name="DesignForExtension"/>
         <module name="FinalClass"/>
         <!-- <module name="HideUtilityClassConstructor"/> -->
         <module name="InterfaceIsType"/>
@@ -172,9 +184,13 @@
         <!-- See https://checkstyle.org/config_misc.html -->
         <module name="ArrayTypeStyle"/>
         <!-- <module name="FinalParameters"/> -->
-        <!-- <module name="TodoComment"/> -->
+        <module name="TodoComment"/>
         <module name="UpperEll"/>
 
+        <module name="Indentation">
+          <property name="basicOffset" value="4"/>
+        </module>
+
         <!-- https://checkstyle.org/config_filters.html#SuppressionXpathFilter -->
         <module name="SuppressionXpathFilter">
             <property name="file" value="${org.checkstyle.sun.suppressionxpathfilter.config}"
@@ -184,4 +200,4 @@
 
     </module>
 
-</module>
+</module>

lib/src/test/java/io/hexlet/utils/ArraysAsSetsTest.java

@@ -6,36 +6,36 @@
 
 public class ArraysAsSetsTest {
 
-    private final String[] strColl1 = { "Vasya", "Kolya", "Petya" };
-    private final String[] strColl2 = { "Igor", "Petya", "Sergey", "Vasya", "Sasha" };
-    private final Integer[] intColl1 = { 13, 22, 14 };
-    private final Integer[] intColl2 = { 12, 13, 45, 22, 99 };
+    private final String[] strColl1 = {"Vasya", "Kolya", "Petya"};
+    private final String[] strColl2 = {"Igor", "Petya", "Sergey", "Vasya", "Sasha"};
+    private final Integer[] intColl1 = {13, 22, 14};
+    private final Integer[] intColl2 = {12, 13, 45, 22, 99};
 
 
     @Test
     void intersectionTest() {
-        final String[] expected = { "Vasya", "Petya" };
+        final String[] expected = {"Vasya", "Petya"};
         assertArrayEquals(ArraysAsSets.intersection(this.strColl1, this.strColl2), expected);
 
-        final Integer[] expected2 = { 13, 22 };
+        final Integer[] expected2 = {13, 22};
         assertArrayEquals(ArraysAsSets.intersection(this.intColl1, this.intColl2), expected2);
     }
 
     @Test
     void unionTest() {
-        final String[] expected = { "Petya", "Sasha", "Igor", "Kolya", "Vasya", "Sergey" };
+        final String[] expected = {"Petya", "Sasha", "Igor", "Kolya", "Vasya", "Sergey"};
         assertArrayEquals(ArraysAsSets.union(this.strColl1, this.strColl2), expected);
 
-        final Integer[] expected2 = { 99, 22, 12, 13, 45, 14 };
+        final Integer[] expected2 = {99, 22, 12, 13, 45, 14};
         assertArrayEquals(ArraysAsSets.union(this.intColl1, this.intColl2), expected2);
     }
 
     @Test
     void differenceTest() {
-        final String[] expected = { "Kolya" };
+        final String[] expected = {"Kolya"};
         assertArrayEquals(ArraysAsSets.difference(this.strColl1, this.strColl2), expected);
 
-        final Integer[] expected2 = { 14 };
+        final Integer[] expected2 = {14};
         assertArrayEquals(ArraysAsSets.difference(this.intColl1, this.intColl2), expected2);
     }
 }