feat(examples): wugnot (grc20’s wrapped ugnot) (gnolang#1356)

This PR presents a GNOT wrapper that conforms to the GRC20 interface.

Optimally, the txtar file should be relocated to the wugnot directory,
pending resolution of [issue
gnolang#1269](gnolang#1269 (comment)).

Enabling the use of `gnokey maketx call -func WUGNOT.Transfer` over
`-func Transfer` would streamline the wrapper, reducing it to just the
initial 55 lines.

<!-- please provide a detailed description of the changes made in this
pull request. -->

<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
- [x] Provided any useful hints for running manual tests
- [x] 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>

---------

Signed-off-by: moul <94029+moul@users.noreply.github.com>

examples/gno.land/r/demo/wugnot/gno.mod

@@ -0,0 +1,6 @@
+module gno.land/r/demo/wugnot
+
+require (
+	gno.land/p/demo/grc/grc20 v0.0.0-latest
+	gno.land/p/demo/ufmt v0.0.0-latest
+)

examples/gno.land/r/demo/wugnot/wugnot.gno

@@ -0,0 +1,126 @@
+package wugnot
+
+import (
+	"std"
+	"strings"
+
+	"gno.land/p/demo/grc/grc20"
+	"gno.land/p/demo/ufmt"
+)
+
+var (
+	// wugnot is the admin token, able to mint and burn.
+	wugnot *grc20.AdminToken = grc20.NewAdminToken("wrapped GNOT", "wugnot", 0)
+	// WUGNOT is the banker usable by users directly.
+	WUGNOT = wugnot.GRC20()
+)
+
+const (
+	ugnotMinDeposit  uint64 = 1000
+	wugnotMinDeposit uint64 = 1
+)
+
+// wrapper.
+//
+
+func Deposit() {
+	caller := std.PrevRealm().Addr()
+	sent := std.GetOrigSend()
+	amount := sent.AmountOf("ugnot")
+
+	if uint64(amount) < ugnotMinDeposit {
+		panic(ufmt.Sprintf("Deposit below minimum: %d/%d ugnot.", amount, ugnotMinDeposit))
+	}
+	wugnot.Mint(caller, uint64(amount))
+}
+
+func Withdraw(amount uint64) {
+	if amount < wugnotMinDeposit {
+		panic(ufmt.Sprintf("Deposit below minimum: %d/%d wugnot.", amount, wugnotMinDeposit))
+	}
+
+	caller := std.PrevRealm().Addr()
+	pkgaddr := std.GetOrigPkgAddr()
+
+	callerBal, _ := wugnot.BalanceOf(caller)
+	if callerBal < amount {
+		panic(ufmt.Sprintf("Insufficient balance: %d available, %d needed.", callerBal, amount))
+	}
+
+	// send swapped ugnots to caller
+	banker := std.GetBanker(std.BankerTypeRealmSend)
+	send := std.Coins{{"ugnot", int64(amount)}}
+	banker.SendCoins(pkgaddr, caller, send)
+	wugnot.Burn(caller, amount)
+}
+
+// render.
+//
+
+func Render(path string) string {
+	parts := strings.Split(path, "/")
+	c := len(parts)
+
+	switch {
+	case path == "":
+		return wugnot.RenderHome()
+	case c == 2 && parts[0] == "balance":
+		owner := std.Address(parts[1])
+		balance, _ := wugnot.BalanceOf(owner)
+		return ufmt.Sprintf("%d\n", balance)
+	default:
+		return "404\n"
+	}
+}
+
+// XXX: if we could call WUGNOT.XXX instead of XXX from gnokey, then, all the following lines would not be needed.
+
+// direct getters.
+// XXX: remove them in favor of q_call wugnot.XXX
+
+func TotalSupply() uint64 {
+	return wugnot.TotalSupply()
+}
+
+func BalanceOf(owner std.Address) uint64 {
+	balance, err := wugnot.BalanceOf(owner)
+	if err != nil {
+		panic(err)
+	}
+	return balance
+}
+
+func Allowance(owner, spender std.Address) uint64 {
+	allowance, err := wugnot.Allowance(owner, spender)
+	if err != nil {
+		panic(err)
+	}
+	return allowance
+}
+
+// setters.
+//
+
+func Transfer(to std.Address, amount uint64) {
+	caller := std.PrevRealm().Addr()
+	err := wugnot.Transfer(caller, to, amount)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func Approve(spender std.Address, amount uint64) {
+	caller := std.PrevRealm().Addr()
+	err := wugnot.Approve(caller, spender, amount)
+	if err != nil {
+		panic(err)
+	}
+}
+
+func TransferFrom(from, to std.Address, amount uint64) {
+	caller := std.PrevRealm().Addr()
+	err := wugnot.TransferFrom(caller, from, to, amount)
+	if err != nil {
+		panic(err)
+	}
+}

examples/gno.land/r/demo/wugnot/z0_filetest.gno

@@ -0,0 +1,75 @@
+// PKGPATH: gno.land/r/demo/wugnot_test
+package wugnot_test
+
+import (
+	"fmt"
+	"std"
+
+	"gno.land/p/demo/testutils"
+	"gno.land/r/demo/wugnot"
+)
+
+var (
+	addr1 = testutils.TestAddress("test1")
+	addrc = std.DerivePkgAddr("gno.land/r/demo/wugnot")
+	addrt = std.DerivePkgAddr("gno.land/r/demo/wugnot_test")
+)
+
+func main() {
+	std.TestSetOrigPkgAddr(addrc)
+	std.TestIssueCoins(addrc, std.Coins{{"ugnot", 100000001}}) // TODO: remove this
+
+	// issue ugnots
+	std.TestIssueCoins(addr1, std.Coins{{"ugnot", 100000001}})
+
+	// print initial state
+	printBalances()
+	// println(wugnot.Render("queues"))
+	// println("A -", wugnot.Render(""))
+
+	std.TestSetOrigCaller(addr1)
+	std.TestSetOrigSend(std.Coins{{"ugnot", 123_400}}, nil)
+	wugnot.Deposit()
+	printBalances()
+	wugnot.Withdraw(4242)
+	printBalances()
+}
+
+func printBalances() {
+	printSingleBalance := func(name string, addr std.Address) {
+		wugnotBal := wugnot.BalanceOf(addr)
+		std.TestSetOrigCaller(addr)
+		abanker := std.GetBanker(std.BankerTypeOrigSend)
+		acoins := abanker.GetCoins(addr).AmountOf("ugnot")
+		bbanker := std.GetBanker(std.BankerTypeRealmIssue)
+		bcoins := bbanker.GetCoins(addr).AmountOf("ugnot")
+		cbanker := std.GetBanker(std.BankerTypeRealmSend)
+		ccoins := cbanker.GetCoins(addr).AmountOf("ugnot")
+		dbanker := std.GetBanker(std.BankerTypeReadonly)
+		dcoins := dbanker.GetCoins(addr).AmountOf("ugnot")
+		fmt.Printf("| %-13s | addr=%s | wugnot=%-5d | ugnot=%-9d %-9d %-9d %-9d |\n",
+			name, addr, wugnotBal, acoins, bcoins, ccoins, dcoins)
+	}
+	println("-----------")
+	printSingleBalance("wugnot_test", addrt)
+	printSingleBalance("wugnot", addrc)
+	printSingleBalance("addr1", addr1)
+	println("-----------")
+}
+
+// Output:
+// -----------
+// | wugnot_test   | addr=g19rmydykafrqyyegc8uuaxxpzqwzcnxraj2dev9 | wugnot=0     | ugnot=200000000 200000000 200000000 200000000 |
+// | wugnot        | addr=g1pf6dv9fjk3rn0m4jjcne306ga4he3mzmupfjl6 | wugnot=0     | ugnot=100000001 100000001 100000001 100000001 |
+// | addr1         | addr=g1w3jhxap3ta047h6lta047h6lta047h6l4mfnm7 | wugnot=0     | ugnot=100000001 100000001 100000001 100000001 |
+// -----------
+// -----------
+// | wugnot_test   | addr=g19rmydykafrqyyegc8uuaxxpzqwzcnxraj2dev9 | wugnot=123400 | ugnot=200000000 200000000 200000000 200000000 |
+// | wugnot        | addr=g1pf6dv9fjk3rn0m4jjcne306ga4he3mzmupfjl6 | wugnot=0     | ugnot=100000001 100000001 100000001 100000001 |
+// | addr1         | addr=g1w3jhxap3ta047h6lta047h6lta047h6l4mfnm7 | wugnot=0     | ugnot=100000001 100000001 100000001 100000001 |
+// -----------
+// -----------
+// | wugnot_test   | addr=g19rmydykafrqyyegc8uuaxxpzqwzcnxraj2dev9 | wugnot=119158 | ugnot=200004242 200004242 200004242 200004242 |
+// | wugnot        | addr=g1pf6dv9fjk3rn0m4jjcne306ga4he3mzmupfjl6 | wugnot=0     | ugnot=99995759  99995759  99995759  99995759  |
+// | addr1         | addr=g1w3jhxap3ta047h6lta047h6lta047h6l4mfnm7 | wugnot=0     | ugnot=100000001 100000001 100000001 100000001 |
+// -----------

gno.land/cmd/gnoland/testdata/wugnot.txtar

@@ -0,0 +1,43 @@
+gnoland start
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -args '' -broadcast -chainid=tendermint_test test1
+stdout '# wrapped GNOT \(\$wugnot\)'
+stdout 'Decimals..: 0'
+stdout 'Total supply..: 0'
+stdout 'Known accounts..: 0'
+stdout 'OK!'
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Deposit -send 12345678ugnot -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout 'OK!'
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -args '' -broadcast -chainid=tendermint_test test1
+stdout 'Total supply..: 12345678'
+stdout 'Known accounts..: 1'
+stdout 'OK!'
+
+# XXX: use test2 instead (depends on https://github.com/gnolang/gno/issues/1269#issuecomment-1806386069)
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Deposit -send 12345678ugnot -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout 'OK!'
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -args '' -broadcast -chainid=tendermint_test test1
+stdout 'Total supply..: 24691356'
+stdout 'Known accounts..: 1' # should be 2 once we can use test2
+stdout 'OK!'
+
+# XXX: replace hardcoded address with test3
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Transfer -gas-fee 1000000ugnot -gas-wanted 2000000 -args 'g1u7y667z64x2h7vc6fmpcprgey4ck233jaww9zq' -args '10000000' -broadcast -chainid=tendermint_test test1
+stdout 'OK!'
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -args '' -broadcast -chainid=tendermint_test test1
+stdout 'Total supply..: 24691356'
+stdout 'Known accounts..: 2' # should be 3 once we can use test2
+stdout 'OK!'
+
+# XXX: use test3 instead (depends on https://github.com/gnolang/gno/issues/1269#issuecomment-1806386069)
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Withdraw -args 10000000 -gas-fee 1000000ugnot -gas-wanted 2000000 -broadcast -chainid=tendermint_test test1
+stdout 'OK!'
+
+gnokey maketx call -pkgpath gno.land/r/demo/wugnot -func Render -gas-fee 1000000ugnot -gas-wanted 2000000 -args '' -broadcast -chainid=tendermint_test test1
+stdout 'Total supply..: 14691356'
+stdout 'Known accounts..: 2' # should be 3 once we can use test2
+stdout 'OK!'