diff --git a/helpmehelpapplication/src/test/java/ntnu/systemutvikling/team6/models/registry/UserRegistryTest.java b/helpmehelpapplication/src/test/java/ntnu/systemutvikling/team6/models/registry/UserRegistryTest.java
new file mode 100644
index 0000000..f4ca625
--- /dev/null
+++ b/helpmehelpapplication/src/test/java/ntnu/systemutvikling/team6/models/registry/UserRegistryTest.java
@@ -0,0 +1,106 @@
+package ntnu.systemutvikling.team6.models.registry;
+
+import ntnu.systemutvikling.team6.models.user.Inbox;
+import ntnu.systemutvikling.team6.models.user.Role;
+import ntnu.systemutvikling.team6.models.user.Settings;
+import ntnu.systemutvikling.team6.models.user.User;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Optional;
+import java.util.UUID;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class UserRegistryTest {
+    User user;
+    UserRegistry userRegistry;
+
+    @BeforeEach
+    void setUp() {
+        String validUsername = "username";
+        String validEmail = "Email@gmail.com";
+        String validPassword = "Password";
+        Role validRole = Role.NORMAL_USER;
+        Settings validSettings = new Settings();
+        Inbox validInbox = new Inbox();
+        this.user =
+                new User(
+                        validUsername,
+                        validEmail,
+                        validPassword,
+                        validRole,
+                        validSettings,
+                        validInbox
+        );
+        userRegistry = new UserRegistry();
+    }
+
+    @Test
+    void userRegistryShouldStartEmpty() {
+        assertEquals(0, userRegistry.getAllUsers().size());
+    }
+
+    @Test
+    void addUserTest() {
+        userRegistry.addUser(user);
+
+        assertEquals(user, userRegistry.getAllUsers().getFirst());
+    }
+
+    @Test
+    void addingNullUserShouldThrow() {
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> userRegistry.addUser(null)
+        );
+    }
+
+    @Test
+    void removeUserTest() {
+        userRegistry.addUser(user);
+
+        userRegistry.removeUserByUUID(user.getId());
+
+        assertEquals(0, userRegistry.getAllUsers().size());
+    }
+
+    @Test
+    void removeNullUserShouldThrow() {
+        userRegistry.addUser(user);
+
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> userRegistry.removeUserByUUID(null)
+        );
+    }
+
+    @Test
+    void getUserByUUIDTest() {
+        userRegistry.addUser(user);
+
+        Optional<User> result = userRegistry.findUserById(user.getId());
+
+        assertTrue(result.isPresent());
+        assertEquals(result.get().getId(), user.getId());
+    }
+
+    @Test
+    void getUserByUUIDNonExistentUserTest() {
+        userRegistry.addUser(user);
+
+        Optional<User> result = userRegistry.findUserById(UUID.randomUUID());
+
+        assertFalse(result.isPresent());
+    }
+
+    @Test
+    void getNullUserByUUIDShouldThrow() {
+        userRegistry.addUser(user);
+
+        assertThrows(
+                IllegalArgumentException.class,
+                () -> userRegistry.findUserById(null)
+        );
+    }
+}
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