feat: Issuer Tests

* Written tests to test functionality of Issuer implementations

Refs: #3

src/test/java/org/snturk/petition/IssuerTest.java

@@ -0,0 +1,57 @@
+package org.snturk.petition;
+
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.snturk.petition.exceptions.InvalidIssuerException;
+import org.snturk.petition.model.Issuer;
+import org.snturk.petition.model.Organization;
+import org.snturk.petition.model.Person;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class IssuerTest {
+
+
+    @Test @DisplayName("Should create person") void shouldCreatePerson() {
+        Issuer issuerPerson = new Person("Muratcan", "Şentürk");
+        assertEquals("Muratcan Şentürk", issuerPerson.getCompleteName());
+
+        Issuer issuerPerson2 = new Person("Muratcan", "Example", "Şentürk");
+        assertEquals("Muratcan Example Şentürk", issuerPerson2.getCompleteName());
+
+        assertThrows(InvalidIssuerException.class, () -> new Person(null, "Şentürk"));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", null));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", "Example", null));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", null, "Şentürk"));
+        assertThrows(InvalidIssuerException.class, () -> new Person(null, "Example", "Şentürk"));
+        assertThrows(InvalidIssuerException.class, () -> new Person("", "Şentürk"));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", ""));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", "Example", ""));
+        assertThrows(InvalidIssuerException.class, () -> new Person("Muratcan", "", "Şentürk"));
+        assertThrows(InvalidIssuerException.class, () -> new Person("", "Example", "Şentürk"));
+    }
+
+
+    @Test @DisplayName("Should create organization") void shouldCreateOrganization() {
+        Issuer issuerOrganization = new Organization("Example");
+        assertEquals("Example", issuerOrganization.getCompleteName());
+
+        Issuer issuerOrganization2 = new Organization("Example", "Ltd.");
+        assertEquals("Example (Ltd.)", issuerOrganization2.getCompleteName());
+
+        assertThrows(InvalidIssuerException.class, () -> new Organization(null));
+        assertThrows(InvalidIssuerException.class, () -> new Organization(""));
+        assertThrows(InvalidIssuerException.class, () -> new Organization("Example", null));
+        assertThrows(InvalidIssuerException.class, () -> new Organization("Example", ""));
+    }
+
+
+    @Test @DisplayName("Should create issuer") void shouldCreateIssuer() {
+        Issuer issuerPerson = new Person("Muratcan", "Şentürk");
+        assertEquals("Muratcan Şentürk", issuerPerson.getCompleteName());
+
+        Issuer issuerOrganization = new Organization("Example");
+        assertEquals("Example", issuerOrganization.getCompleteName());
+    }
+}