feat: ownable2step realm (#3594)

Addresses: #3520

Add a ownable variant realm to have a transfer of ownership with two
functions where the new owner needs to accept ownership to be sure no
mistake can be made.

---------

Co-authored-by: Leon Hudak <[email protected]>

examples/gno.land/p/oxtekgrinder/ownable2step/errors.gno

@@ -0,0 +1,10 @@
+package ownable2step
+
+import "errors"
+
+var (
+	ErrNoPendingOwner      = errors.New("ownable2step: no pending owner")
+	ErrUnauthorized        = errors.New("ownable2step: caller is not owner")
+	ErrPendingUnauthorized = errors.New("ownable2step: caller is not pending owner")
+	ErrInvalidAddress      = errors.New("ownable2step: new owner address is invalid")
+)

examples/gno.land/p/oxtekgrinder/ownable2step/gno.mod

@@ -0,0 +1 @@
+module gno.land/p/oxtekgrinder/ownable2step

examples/gno.land/p/oxtekgrinder/ownable2step/ownable.gno

@@ -0,0 +1,98 @@
+package ownable2step
+
+import (
+	"std"
+)
+
+const OwnershipTransferEvent = "OwnershipTransfer"
+
+// Ownable2Step is a two-step ownership transfer package
+// It allows the current owner to set a new owner and the new owner will need to accept the ownership before it is transferred
+type Ownable2Step struct {
+	owner        std.Address
+	pendingOwner std.Address
+}
+
+func New() *Ownable2Step {
+	return &Ownable2Step{
+		owner:        std.PrevRealm().Addr(),
+		pendingOwner: "",
+	}
+}
+
+func NewWithAddress(addr std.Address) *Ownable2Step {
+	return &Ownable2Step{
+		owner:        addr,
+		pendingOwner: "",
+	}
+}
+
+// TransferOwnership initiate the transfer of the ownership to a new address by setting the PendingOwner
+func (o *Ownable2Step) TransferOwnership(newOwner std.Address) error {
+	if !o.CallerIsOwner() {
+		return ErrUnauthorized
+	}
+	if !newOwner.IsValid() {
+		return ErrInvalidAddress
+	}
+
+	o.pendingOwner = newOwner
+	return nil
+}
+
+// AcceptOwnership accepts the pending ownership transfer
+func (o *Ownable2Step) AcceptOwnership() error {
+	if o.pendingOwner.String() == "" {
+		return ErrNoPendingOwner
+	}
+	if std.PrevRealm().Addr() != o.pendingOwner {
+		return ErrPendingUnauthorized
+	}
+
+	o.owner = o.pendingOwner
+	o.pendingOwner = ""
+
+	return nil
+}
+
+// DropOwnership removes the owner, effectively disabling any owner-related actions
+// Top-level usage: disables all only-owner actions/functions,
+// Embedded usage: behaves like a burn functionality, removing the owner from the struct
+func (o *Ownable2Step) DropOwnership() error {
+	if !o.CallerIsOwner() {
+		return ErrUnauthorized
+	}
+
+	prevOwner := o.owner
+	o.owner = ""
+
+	std.Emit(
+		OwnershipTransferEvent,
+		"from", prevOwner.String(),
+		"to", "",
+	)
+
+	return nil
+}
+
+// Owner returns the owner address from Ownable
+func (o *Ownable2Step) Owner() std.Address {
+	return o.owner
+}
+
+// PendingOwner returns the pending owner address from Ownable2Step
+func (o *Ownable2Step) PendingOwner() std.Address {
+	return o.pendingOwner
+}
+
+// CallerIsOwner checks if the caller of the function is the Realm's owner
+func (o *Ownable2Step) CallerIsOwner() bool {
+	return std.PrevRealm().Addr() == o.owner
+}
+
+// AssertCallerIsOwner panics if the caller is not the owner
+func (o *Ownable2Step) AssertCallerIsOwner() {
+	if std.PrevRealm().Addr() != o.owner {
+		panic(ErrUnauthorized)
+	}
+}

examples/gno.land/p/oxtekgrinder/ownable2step/ownable_test.gno

@@ -0,0 +1,156 @@
+package ownable2step
+
+import (
+	"std"
+	"testing"
+
+	"gno.land/p/demo/testutils"
+	"gno.land/p/demo/uassert"
+	"gno.land/p/demo/urequire"
+)
+
+var (
+	alice = testutils.TestAddress("alice")
+	bob   = testutils.TestAddress("bob")
+)
+
+func TestNew(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigCaller(alice)
+
+	o := New()
+	got := o.Owner()
+	pendingOwner := o.PendingOwner()
+
+	uassert.Equal(t, got, alice)
+	uassert.Equal(t, pendingOwner.String(), "")
+}
+
+func TestNewWithAddress(t *testing.T) {
+	o := NewWithAddress(alice)
+
+	got := o.Owner()
+	pendingOwner := o.PendingOwner()
+
+	uassert.Equal(t, got, alice)
+	uassert.Equal(t, pendingOwner.String(), "")
+}
+
+func TestInitiateTransferOwnership(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigCaller(alice)
+
+	o := New()
+
+	err := o.TransferOwnership(bob)
+	urequire.NoError(t, err)
+
+	owner := o.Owner()
+	pendingOwner := o.PendingOwner()
+
+	uassert.Equal(t, owner, alice)
+	uassert.Equal(t, pendingOwner, bob)
+}
+
+func TestTransferOwnership(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigCaller(alice)
+
+	o := New()
+
+	err := o.TransferOwnership(bob)
+	urequire.NoError(t, err)
+
+	owner := o.Owner()
+	pendingOwner := o.PendingOwner()
+
+	uassert.Equal(t, owner, alice)
+	uassert.Equal(t, pendingOwner, bob)
+
+	std.TestSetRealm(std.NewUserRealm(bob))
+	std.TestSetOrigCaller(bob)
+
+	err = o.AcceptOwnership()
+	urequire.NoError(t, err)
+
+	owner = o.Owner()
+	pendingOwner = o.PendingOwner()
+
+	uassert.Equal(t, owner, bob)
+	uassert.Equal(t, pendingOwner.String(), "")
+}
+
+func TestCallerIsOwner(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigCaller(alice)
+
+	o := New()
+	unauthorizedCaller := bob
+
+	std.TestSetRealm(std.NewUserRealm(unauthorizedCaller))
+	std.TestSetOrigCaller(unauthorizedCaller)
+
+	uassert.False(t, o.CallerIsOwner())
+}
+
+func TestDropOwnership(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+
+	o := New()
+
+	err := o.DropOwnership()
+	urequire.NoError(t, err, "DropOwnership failed")
+
+	owner := o.Owner()
+	uassert.Empty(t, owner, "owner should be empty")
+}
+
+// Errors
+
+func TestErrUnauthorized(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+	std.TestSetOrigCaller(alice)
+
+	o := New()
+
+	std.TestSetRealm(std.NewUserRealm(bob))
+	std.TestSetOrigCaller(bob)
+
+	uassert.ErrorContains(t, o.TransferOwnership(alice), ErrUnauthorized.Error())
+	uassert.ErrorContains(t, o.DropOwnership(), ErrUnauthorized.Error())
+}
+
+func TestErrInvalidAddress(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+
+	o := New()
+
+	err := o.TransferOwnership("")
+	uassert.ErrorContains(t, err, ErrInvalidAddress.Error())
+
+	err = o.TransferOwnership("10000000001000000000100000000010000000001000000000")
+	uassert.ErrorContains(t, err, ErrInvalidAddress.Error())
+}
+
+func TestErrNoPendingOwner(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+
+	o := New()
+
+	err := o.AcceptOwnership()
+	uassert.ErrorContains(t, err, ErrNoPendingOwner.Error())
+}
+
+func TestErrPendingUnauthorized(t *testing.T) {
+	std.TestSetRealm(std.NewUserRealm(alice))
+
+	o := New()
+
+	err := o.TransferOwnership(bob)
+	urequire.NoError(t, err)
+
+	std.TestSetRealm(std.NewUserRealm(alice))
+
+	err = o.AcceptOwnership()
+	uassert.ErrorContains(t, err, ErrPendingUnauthorized.Error())
+}