improve code + mutation coverage in HsAdminPersonEntity

src/test/java/net/hostsharing/hsadminng/hs/admin/person/HsAdminPersonEntityUnitTest.java

@@ -0,0 +1,32 @@
+package net.hostsharing.hsadminng.hs.admin.person;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HsAdminPersonEntityUnitTest {
+
+    @Test
+    void getDisplayReturnsTradeNameIfAvailable() {
+        final var givenPersonEntity = HsAdminPersonEntity.builder()
+                .tradeName("some trade name")
+                .build();
+
+        final var actualDisplay = givenPersonEntity.getDisplayName();
+
+        assertThat(actualDisplay).isEqualTo("some trade name");
+    }
+
+    @Test
+    void getDisplayReturnsFamilyAndGivenNameIfNoTradeNameAvailable() {
+        final var givenPersonEntity = HsAdminPersonEntity.builder()
+                .familyName("some family name")
+                .givenName("some given name")
+                .build();
+
+        final var actualDisplay = givenPersonEntity.getDisplayName();
+
+        assertThat(actualDisplay).isEqualTo("some family name, some given name");
+    }
+
+}