Update assertj+tests work with other locales

pom.xml

@@ -335,7 +335,7 @@
       </plugin>
       <plugin>
         <artifactId>maven-assembly-plugin</artifactId>
-        <version>3.0.0</version>
+        <version>3.2.0</version>
         <inherited>false</inherited>
         <configuration>
           <descriptorRefs>
@@ -505,7 +505,7 @@
           <dependency>
             <groupId>org.assertj</groupId>
             <artifactId>assertj-core</artifactId>
-            <version>2.9.0</version>
+            <version>3.15.0</version>
           </dependency>
           <dependency>
             <groupId>net.bytebuddy</groupId>

xmlunit-assertj/src/test/java/org/xmlunit/assertj/LocaleModifier.java

@@ -0,0 +1,16 @@
+package org.xmlunit.assertj;
+
+import java.util.Locale;
+
+public class LocaleModifier {
+    private Locale locale;
+
+    public void setEnglish() {
+        locale = Locale.getDefault();
+        Locale.setDefault(new Locale("en"));
+    }
+
+    public void restore() {
+        Locale.setDefault(locale);
+    }
+}

xmlunit-assertj/src/test/java/org/xmlunit/assertj/ValueAssertTest.java

@@ -13,6 +13,8 @@
 */
 package org.xmlunit.assertj;
 
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.mockito.Mockito;
@@ -34,6 +36,18 @@ public class ValueAssertTest {
     @Rule
     public ExpectedException thrown = none();
 
+    private static LocaleModifier locale = new LocaleModifier();
+
+    @BeforeClass
+    public static void overwriteLocale() {
+        locale.setEnglish();
+    }
+
+    @AfterClass
+    public static void restoreLocale() {
+        locale.restore();
+    }
+
     @Test
     public void testAsInt_shouldPass() {
 

xmlunit-assertj/src/test/java/org/xmlunit/assertj/XmlAssertValidationTest.java

@@ -13,6 +13,8 @@
 */
 package org.xmlunit.assertj;
 
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.xmlunit.validation.Languages;
@@ -31,6 +33,18 @@ public class XmlAssertValidationTest {
     @Rule
     public ExpectedException thrown = none();
 
+    private static LocaleModifier locale = new LocaleModifier();
+
+    @BeforeClass
+    public static void overwriteLocale() {
+        locale.setEnglish();
+    }
+
+    @AfterClass
+    public static void restoreLocale() {
+        locale.restore();
+    }
+
     @Test
     public void testIsValidAgainst_shouldPass() {
         StreamSource xml = new StreamSource(new File("../test-resources/BookXsdGenerated.xml"));
@@ -89,7 +103,8 @@ public void testIsValidAgainst_withEmptySourcesArray_shouldPass() {
         StreamSource xml = new StreamSource(new File("../test-resources/BookXsdGenerated.xml"));
 
         assertThat(xml).isValidAgainst();
-        assertThat(xml).isValidAgainst(new Object[0]);
+        final Object[] emptyArray = new Object[0];
+        assertThat(xml).isValidAgainst(emptyArray);
     }
 
     @Test

xmlunit-assertj/src/test/java/org/xmlunit/assertj/XmlAssertValueByXPathTest.java

@@ -13,6 +13,8 @@
 */
 package org.xmlunit.assertj;
 
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 
@@ -25,6 +27,18 @@ public class XmlAssertValueByXPathTest {
     @Rule
     public ExpectedException thrown = none();
 
+    private static LocaleModifier locale = new LocaleModifier();
+
+    @BeforeClass
+    public static void overwriteLocale() {
+        locale.setEnglish();
+    }
+
+    @AfterClass
+    public static void restoreLocale() {
+        locale.restore();
+    }
+
     @Test
     public void testValueByXPath_withNull_shouldFailed() {