diff --git a/examples/gno.land/r/gnoland/users/v1/users.gno b/examples/gno.land/r/gnoland/users/v1/users.gno
index e1b58cac200..551af2e4120 100644
--- a/examples/gno.land/r/gnoland/users/v1/users.gno
+++ b/examples/gno.land/r/gnoland/users/v1/users.gno
@@ -9,9 +9,6 @@ import (
 
 const (
 	reValidUsername = "^[a-z]{3}[_a-z0-9]{0,14}[0-9]{3}$"
-	RegisterEvent   = "Registered"
-	UpdateNameEvent = "NameUpdated"
-	DeleteUserEvent = "UserDeleted"
 )
 
 var reUsername = regexp.MustCompile(reValidUsername)
@@ -37,7 +34,6 @@ func Register(username string) error {
 		return err
 	}
 
-	std.Emit(RegisterEvent, "registrant", registrant.String(), "username", username)
 	return nil
 }
 
@@ -51,16 +47,19 @@ func UpdateName(newName string) error {
 		return ErrPaused
 	}
 
+	if matched := reUsername.MatchString(newName); !matched {
+		return ErrInvalidUsername
+	}
+
 	registrant := std.PrevRealm().Addr()
 	if err := users.UpdateName(newName, registrant); err != nil {
 		return err
 	}
 
-	std.Emit(UpdateNameEvent, "registrant", registrant.String(), "newName", newName)
 	return nil
 }
 
-// DeleteUser makes all names associated with the PrevRealm() address unresolvable.
+// DeleteUser makes all names associated with the `PrevRealm()` address unresolvable.
 // WARN: After deletion, the same address WILL NOT be able to register a new name.
 func DeleteUser() error {
 	std.AssertOriginCall()
@@ -74,6 +73,5 @@ func DeleteUser() error {
 		return err
 	}
 
-	std.Emit(DeleteUserEvent, "address", addr.String())
 	return nil
 }
diff --git a/examples/gno.land/r/gnoland/users/v1/users_test.gno b/examples/gno.land/r/gnoland/users/v1/users_test.gno
new file mode 100644
index 00000000000..cf556ced9fa
--- /dev/null
+++ b/examples/gno.land/r/gnoland/users/v1/users_test.gno
@@ -0,0 +1,104 @@
+package v1
+
+import (
+	"std"
+	"testing"
+
+	"gno.land/p/demo/testutils"
+	"gno.land/p/demo/uassert"
+	"gno.land/p/demo/urequire"
+
+	"gno.land/r/sys/users"
+)
+
+var (
+	alice     = "alice123"
+	bob       = "bob123"
+	aliceAddr = testutils.TestAddress(alice)
+	bobAddr   = testutils.TestAddress(bob)
+)
+
+func TestRegister_Valid(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(aliceAddr))
+	std.TestSetOrigCaller(aliceAddr)
+
+	uassert.NoError(t, Register(alice))
+	res, latest := users.ResolveName(alice)
+
+	uassert.NotEqual(t, nil, res)
+	uassert.Equal(t, alice, res.Name())
+	uassert.Equal(t, aliceAddr, res.Addr())
+	uassert.False(t, res.IsDeleted())
+	uassert.True(t, latest)
+}
+
+func TestRegister_Invalid(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(bobAddr))
+	std.TestSetOrigCaller(bobAddr)
+
+	// Invalid usernames
+	uassert.Error(t, Register("alice"), ErrInvalidUsername.Error())      // vanity
+	uassert.Error(t, Register(""), ErrInvalidUsername.Error())           // empty
+	uassert.Error(t, Register("   "), ErrInvalidUsername.Error())        // empty
+	uassert.Error(t, Register("123"), ErrInvalidUsername.Error())        // only numbers
+	uassert.Error(t, Register("alice&#($)"), ErrInvalidUsername.Error()) // non-allowed chars
+	uassert.Error(t, Register("Alice123"), ErrInvalidUsername.Error())   // upper-case
+	uassert.Error(t, Register("toolongusernametoolongusernametoolongusername123"),
+		ErrInvalidUsername.Error()) // too long
+
+	// Name taken
+	urequire.NoError(t, Register(bob))
+	uassert.Error(t, Register(bob), users.ErrNameTaken.Error())
+}
+
+func TestUpdateName_Valid(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(aliceAddr))
+	std.TestSetOrigCaller(aliceAddr)
+
+	newalice := "newalice123"
+	// resolve old name
+	urequire.NoError(t, UpdateName(newalice))
+
+	res, latest := users.ResolveName(alice)
+	uassert.NotEqual(t, nil, res)
+	uassert.Equal(t, newalice, res.Name())
+	uassert.Equal(t, aliceAddr, res.Addr())
+	uassert.False(t, res.IsDeleted())
+	uassert.False(t, latest)
+}
+
+func TestUpdateName_Invalid(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(aliceAddr))
+	std.TestSetOrigCaller(aliceAddr)
+
+	// Invalid names
+	uassert.Error(t, UpdateName("alice"), ErrInvalidUsername.Error())      // vanity
+	uassert.Error(t, UpdateName(""), ErrInvalidUsername.Error())           // empty
+	uassert.Error(t, UpdateName("   "), ErrInvalidUsername.Error())        // empty
+	uassert.Error(t, UpdateName("123"), ErrInvalidUsername.Error())        // only numbers
+	uassert.Error(t, UpdateName("alice&#($)"), ErrInvalidUsername.Error()) // non-allowed chars
+	uassert.Error(t, UpdateName("Alice123"), ErrInvalidUsername.Error())   // upper-case
+	uassert.Error(t, UpdateName("toolongusernametoolongusernametoolongusername123"),
+		ErrInvalidUsername.Error()) // too long
+
+	urequire.Error(t, UpdateName(bob), users.ErrNameTaken.Error())
+}
+
+func TestDeleteUser(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(aliceAddr))
+	std.TestSetOrigCaller(aliceAddr)
+
+	urequire.NoError(t, DeleteUser())
+	res, _ := users.ResolveName(alice)
+	uassert.Equal(t, nil, res)
+	res = users.ResolveAddress(aliceAddr)
+	uassert.Equal(t, nil, res)
+}
+
+func TestDeleteUser_Invalid(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(aliceAddr))
+	std.TestSetOrigCaller(aliceAddr)
+
+	// Already deleted user
+	urequire.Error(t, DeleteUser(), users.ErrUserNotExist.Error())
+}
diff --git a/examples/gno.land/r/sys/users/errors.gno b/examples/gno.land/r/sys/users/errors.gno
index 86da596faff..41d9bd7e464 100644
--- a/examples/gno.land/r/sys/users/errors.gno
+++ b/examples/gno.land/r/sys/users/errors.gno
@@ -17,7 +17,6 @@ var (
 
 	ErrAlreadyHasName  = errors.New(prefix + "username for this address already registered - try creating an Alias")
 	ErrDeletedUser     = errors.New(prefix + "cannot register a new username after deleting")
-	ErrAlreadyDeleted  = errors.New(prefix + "cannot delete same user twice")
 	ErrAliasBeforeName = errors.New(prefix + "cannot register Alias before a username")
 
 	ErrUserNotExist = errors.New(prefix + "this user has not been registered before")
diff --git a/examples/gno.land/r/sys/users/store.gno b/examples/gno.land/r/sys/users/store.gno
index 8e6eaf0c5a7..dfc5ce9fa9f 100644
--- a/examples/gno.land/r/sys/users/store.gno
+++ b/examples/gno.land/r/sys/users/store.gno
@@ -16,9 +16,9 @@ var (
 )
 
 const (
-	RegisterUserEvent  = "UserRegistered"
-	RegisterAliasEvent = "AliasRegistered"
-	DeleteUserEvent    = "UserDeleted"
+	RegisterUserEvent = "Registered"
+	UpdateNameEvent   = "NameUpdated"
+	DeleteUserEvent   = "Deleted"
 
 	maxUsernameLen = 64
 )
@@ -117,7 +117,7 @@ func UpdateName(newName string, address std.Address) error {
 	userData.username = newName
 	nameStore.Set(newName, userData)
 
-	std.Emit(RegisterAliasEvent, "Alias", newName, "address", address.String())
+	std.Emit(UpdateNameEvent, "Alias", newName, "address", address.String())
 	return nil
 }