feat: improve r/gnoland/valopers implementation (gnolang#2509)

## Description

This PR improves the gno implementation of the `valopers` Realm.

Waiting on gnolang#2380 to add a context-based Govdao pattern before merging.

<details><summary>Contributors' checklist...</summary>

- [x] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

---------

Co-authored-by: Manfred Touron <94029+moul@users.noreply.github.com>

examples/gno.land/r/gnoland/valopers/gno.mod

@@ -1,6 +1,11 @@
 module gno.land/r/gnoland/valopers
 
 require (
-	gno.land/p/demo/ownable v0.0.0-latest
+	gno.land/p/demo/avl v0.0.0-latest
+	gno.land/p/demo/testutils v0.0.0-latest
+	gno.land/p/demo/uassert v0.0.0-latest
+	gno.land/p/demo/ufmt v0.0.0-latest
+	gno.land/p/sys/validators v0.0.0-latest
 	gno.land/r/gov/dao v0.0.0-latest
+	gno.land/r/sys/validators v0.0.0-latest
 )

examples/gno.land/r/gnoland/valopers/init.gno

@@ -0,0 +1,7 @@
+package valopers
+
+import "gno.land/p/demo/avl"
+
+func init() {
+	valopers = avl.NewTree()
+}

examples/gno.land/r/gnoland/valopers/valopers.gno

@@ -5,35 +5,177 @@ package valopers
 import (
 	"std"
 
-	"gno.land/p/demo/ownable"
+	"gno.land/p/demo/avl"
+	"gno.land/p/demo/ufmt"
+	pVals "gno.land/p/sys/validators"
 	govdao "gno.land/r/gov/dao"
+	"gno.land/r/sys/validators"
 )
 
-// Valoper represents a validator operator profile.
+const (
+	errValoperExists        = "valoper already exists"
+	errValoperMissing       = "valoper does not exist"
+	errInvalidAddressUpdate = "valoper updated address exists"
+	errValoperNotCaller     = "valoper is not the caller"
+)
+
+// valopers keeps track of all the active validator operators
+var valopers *avl.Tree // Address -> Valoper
+
+// Valoper represents a validator operator profile
 type Valoper struct {
-	ownable.Ownable // Embedding the Ownable type for ownership management.
+	Name        string // the display name of the valoper
+	Description string // the description of the valoper
+
+	Address      std.Address // The bech32 gno address of the validator
+	PubKey       string      // the bech32 public key of the validator
+	P2PAddresses []string    // the publicly reachable P2P addresses of the validator
+	Active       bool        // flag indicating if the valoper is active
+}
+
+// Register registers a new valoper
+func Register(v Valoper) {
+	// Check if the valoper is already registered
+	if isValoper(v.Address) {
+		panic(errValoperExists)
+	}
+
+	// TODO add address derivation from public key
+	// (when the laws of gno make it possible)
+
+	// Save the valoper to the set
+	valopers.Set(v.Address.String(), v)
+}
 
-	DisplayName   string      // The display name of the valoper.
-	ValidatorAddr std.Address // The address of the validator.
-	// TODO: Add other valoper metadata as needed.
+// Update updates an existing valoper
+func Update(address std.Address, v Valoper) {
+	// Check if the valoper is present
+	if !isValoper(address) {
+		panic(errValoperMissing)
+	}
+
+	// Check that the valoper wouldn't be
+	// overwriting an existing one
+	isAddressUpdate := address != v.Address
+	if isAddressUpdate && isValoper(v.Address) {
+		panic(errInvalidAddressUpdate)
+	}
+
+	// Remove the old valoper info
+	// in case the address changed
+	if address != v.Address {
+		valopers.Remove(address.String())
+	}
+
+	// Save the new valoper info
+	valopers.Set(v.Address.String(), v)
 }
 
-// Register registers a new valoper.
-// TODO: Define the parameters and implement the function.
-func Register( /* TBD */ ) {
-	panic("not implemented")
+// GetByAddr fetches the valoper using the address, if present
+func GetByAddr(address std.Address) Valoper {
+	valoperRaw, exists := valopers.Get(address.String())
+	if !exists {
+		panic(errValoperMissing)
+	}
+
+	return valoperRaw.(Valoper)
 }
 
-// Update updates an existing valoper.
-// TODO: Define the parameters and implement the function.
-func Update( /* TBD */ ) {
-	panic("not implemented")
+// Render renders the current valoper set
+func Render(_ string) string {
+	if valopers.Size() == 0 {
+		return "No valopers to display."
+	}
+
+	output := "Valset changes to apply:\n"
+	valopers.Iterate("", "", func(_ string, value interface{}) bool {
+		valoper := value.(Valoper)
+
+		output += valoper.Render()
+
+		return false
+	})
+
+	return output
 }
 
-// GovXXX is a placeholder for a function to interact with the governance DAO.
-// TODO: Define a good API and implement it.
-func GovXXX() {
-	// Assert that the caller is a member of the governance DAO.
-	govdao.AssertIsMember(std.PrevRealm().Addr())
-	panic("not implemented")
+// Render renders a single valoper with their information
+func (v Valoper) Render() string {
+	output := ufmt.Sprintf("## %s\n", v.Name)
+	output += ufmt.Sprintf("%s\n\n", v.Description)
+	output += ufmt.Sprintf("- Address: %s\n", v.Address.String())
+	output += ufmt.Sprintf("- PubKey: %s\n", v.PubKey)
+	output += "- P2P Addresses: [\n"
+
+	if len(v.P2PAddresses) == 0 {
+		output += "]\n"
+
+		return output
+	}
+
+	for index, addr := range v.P2PAddresses {
+		output += addr
+
+		if index == len(v.P2PAddresses)-1 {
+			output += "]\n"
+
+			continue
+		}
+
+		output += ",\n"
+	}
+
+	return output
+}
+
+// isValoper checks if the valoper exists
+func isValoper(address std.Address) bool {
+	_, exists := valopers.Get(address.String())
+
+	return exists
+}
+
+// GovDAOProposal creates a proposal to the GovDAO
+// for adding the given valoper to the validator set.
+// This function is meant to serve as a helper
+// for generating the govdao proposal
+func GovDAOProposal(address std.Address) {
+	var (
+		valoper     = GetByAddr(address)
+		votingPower = uint64(1)
+	)
+
+	// Make sure the valoper is the caller
+	if std.GetOrigCaller() != address {
+		panic(errValoperNotCaller)
+	}
+
+	// Determine the voting power
+	if !valoper.Active {
+		votingPower = uint64(0)
+	}
+
+	changesFn := func() []pVals.Validator {
+		return []pVals.Validator{
+			{
+				Address:     valoper.Address,
+				PubKey:      valoper.PubKey,
+				VotingPower: votingPower,
+			},
+		}
+	}
+
+	// Create the executor
+	executor := validators.NewPropExecutor(changesFn)
+
+	// Craft the proposal comment
+	comment := ufmt.Sprintf(
+		"Proposal to add valoper %s (Address: %s; PubKey: %s) to the valset",
+		valoper.Name,
+		valoper.Address.String(),
+		valoper.PubKey,
+	)
+
+	// Create the govdao proposal
+	govdao.Propose(comment, executor)
 }

examples/gno.land/r/gnoland/valopers/valopers_test.gno

@@ -0,0 +1,149 @@
+package valopers
+
+import (
+	"testing"
+
+	"gno.land/p/demo/avl"
+	"gno.land/p/demo/testutils"
+	"gno.land/p/demo/uassert"
+)
+
+func TestValopers_Register(t *testing.T) {
+	t.Parallel()
+
+	t.Run("already a valoper", func(t *testing.T) {
+		t.Parallel()
+
+		// Clear the set for the test
+		valopers = avl.NewTree()
+
+		v := Valoper{
+			Address: testutils.TestAddress("valoper"),
+		}
+
+		// Add the valoper
+		valopers.Set(v.Address.String(), v)
+
+		uassert.PanicsWithMessage(t, errValoperExists, func() {
+			Register(v)
+		})
+	})
+
+	t.Run("successful registration", func(t *testing.T) {
+		t.Parallel()
+
+		// Clear the set for the test
+		valopers = avl.NewTree()
+
+		v := Valoper{
+			Address: testutils.TestAddress("valoper"),
+			Name:    "new valoper",
+			PubKey:  "pub key",
+		}
+
+		uassert.NotPanics(t, func() {
+			Register(v)
+		})
+
+		uassert.NotPanics(t, func() {
+			valoper := GetByAddr(v.Address)
+
+			uassert.Equal(t, v.Address, valoper.Address)
+			uassert.Equal(t, v.Name, valoper.Name)
+			uassert.Equal(t, v.PubKey, valoper.PubKey)
+		})
+	})
+}
+
+func TestValopers_Update(t *testing.T) {
+	t.Parallel()
+
+	t.Run("non-existing valoper", func(t *testing.T) {
+		t.Parallel()
+
+		// Clear the set for the test
+		valopers = avl.NewTree()
+
+		v := Valoper{}
+
+		// Update the valoper
+		uassert.PanicsWithMessage(t, errValoperMissing, func() {
+			Update(v.Address, v)
+		})
+	})
+
+	t.Run("overwrite valoper", func(t *testing.T) {
+		t.Parallel()
+
+		// Clear the set for the test
+		valopers = avl.NewTree()
+
+		one := Valoper{
+			Address: testutils.TestAddress("valoper 1"),
+		}
+
+		// Add the valoper
+		uassert.NotPanics(t, func() {
+			Register(one)
+		})
+
+		initialAddress := testutils.TestAddress("valoper 2")
+		two := Valoper{
+			Address: initialAddress,
+		}
+
+		// Add the valoper
+		uassert.NotPanics(t, func() {
+			Register(two)
+		})
+
+		// Update the valoper address
+		// so it overlaps
+		two = Valoper{
+			Address: one.Address,
+		}
+
+		// Update the valoper
+		uassert.PanicsWithMessage(t, errInvalidAddressUpdate, func() {
+			Update(initialAddress, two)
+		})
+	})
+
+	t.Run("successful update", func(t *testing.T) {
+		t.Parallel()
+
+		// Clear the set for the test
+		valopers = avl.NewTree()
+
+		var (
+			name = "new valoper"
+			v    = Valoper{
+				Address: testutils.TestAddress("valoper"),
+				Name:    name,
+				PubKey:  "pub key",
+			}
+		)
+
+		// Add the valoper
+		uassert.NotPanics(t, func() {
+			Register(v)
+		})
+
+		// Update the valoper name
+		v.Name = "new name"
+		v.Active = false
+
+		// Update the valoper
+		uassert.NotPanics(t, func() {
+			Update(v.Address, v)
+		})
+
+		// Make sure the valoper is updated
+		uassert.NotPanics(t, func() {
+			valoper := GetByAddr(v.Address)
+
+			uassert.Equal(t, v.Name, valoper.Name)
+			uassert.Equal(t, v.Active, valoper.Active)
+		})
+	})
+}