[mielecloud] Less strict e-mail validation (#10928)

* [mielecloud] Less strict e-mail validation

Signed-off-by: Björn Lange <bjoern.lange@tu-dortmund.de>

* Some more e-mail validation test cases

Signed-off-by: Björn Lange <bjoern.lange@tu-dortmund.de>

Co-authored-by: Björn Lange <bjoern.lange@tu-dortmund.de>

bundles/org.openhab.binding.mielecloud/src/test/java/org/openhab/binding/mielecloud/internal/util/EmailValidatorTest.java

@@ -0,0 +1,46 @@
+/**
+ * Copyright (c) 2010-2021 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.binding.mielecloud.internal.util;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+/**
+ * @author Björn Lange - Initial Contribution
+ */
+@NonNullByDefault
+public class EmailValidatorTest {
+    @ParameterizedTest
+    @ValueSource(strings = { "example@openhab.org", "itsme@test24.com", "my-account@t-online.de", "Some@dDRESs.edu",
+            "min@Length.com" })
+    void validEmailAddress(String emailAddress) {
+        // when:
+        var valid = EmailValidator.isValid(emailAddress);
+
+        // then:
+        assertTrue(valid);
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = { "examp!e@###.org", "to@o.short.com" })
+    void invalidEmailAddress(String emailAddress) {
+        // when:
+        var valid = EmailValidator.isValid(emailAddress);
+
+        // then:
+        assertFalse(valid);
+    }
+}