feat: add function selectors to psp22 trait

pop-api/examples/fungibles/lib.rs

@@ -6,7 +6,7 @@ use pop_api::{
 	v0::fungibles::{
 		self as api,
 		events::{Approval, Created, Transfer},
-		traits::{PSP22Burnable, PSP22Metadata, PSP22Mintable, PSP22},
+		traits::{Psp22, Psp22Burnable, Psp22Metadata, Psp22Mintable},
 		PSP22Error,
 	},
 };
@@ -57,7 +57,7 @@ mod fungibles {
 		}
 	}
 
-	impl PSP22 for Fungible {
+	impl Psp22 for Fungible {
 		/// Returns the total token supply.
 		#[ink(message)]
 		fn total_supply(&self) -> Balance {
@@ -210,7 +210,7 @@ mod fungibles {
 		}
 	}
 
-	impl PSP22Metadata for Fungible {
+	impl Psp22Metadata for Fungible {
 		/// Returns the token name.
 		#[ink(message)]
 		fn token_name(&self) -> Option<String> {
@@ -236,7 +236,7 @@ mod fungibles {
 		}
 	}
 
-	impl PSP22Mintable for Fungible {
+	impl Psp22Mintable for Fungible {
 		/// Creates `value` amount of tokens and assigns them to `account`, increasing the total
 		/// supply.
 		///
@@ -255,7 +255,7 @@ mod fungibles {
 		}
 	}
 
-	impl PSP22Burnable for Fungible {
+	impl Psp22Burnable for Fungible {
 		/// Destroys `value` amount of tokens from `account`, reducing the total supply.
 		///
 		/// # Parameters

pop-api/examples/fungibles/tests.rs

@@ -782,18 +782,18 @@ fn deploy(
 // A set of helper methods to test the contract calls.
 
 fn total_supply(session: &mut Session<Pop>) -> Balance {
-	call::<Pop, Balance, PSP22Error>(session, "PSP22::total_supply", vec![], None).unwrap()
+	call::<Pop, Balance, PSP22Error>(session, "Psp22::total_supply", vec![], None).unwrap()
 }
 
 fn balance_of(session: &mut Session<Pop>, owner: AccountId) -> Balance {
-	call::<Pop, Balance, PSP22Error>(session, "PSP22::balance_of", vec![owner.to_string()], None)
+	call::<Pop, Balance, PSP22Error>(session, "Psp22::balance_of", vec![owner.to_string()], None)
 		.unwrap()
 }
 
 fn allowance(session: &mut Session<Pop>, owner: AccountId, spender: AccountId) -> Balance {
 	call::<Pop, Balance, PSP22Error>(
 		session,
-		"PSP22::allowance",
+		"Psp22::allowance",
 		vec![owner.to_string(), spender.to_string()],
 		None,
 	)
@@ -803,7 +803,7 @@ fn allowance(session: &mut Session<Pop>, owner: AccountId, spender: AccountId) -
 fn transfer(session: &mut Session<Pop>, to: AccountId, amount: Balance) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22::transfer",
+		"Psp22::transfer",
 		vec![to.to_string(), amount.to_string(), serde_json::to_string::<[u8; 0]>(&[]).unwrap()],
 		None,
 	)
@@ -817,7 +817,7 @@ fn transfer_from(
 ) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22::transfer_from",
+		"Psp22::transfer_from",
 		vec![
 			from.to_string(),
 			to.to_string(),
@@ -835,7 +835,7 @@ fn approve(
 ) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22::approve",
+		"Psp22::approve",
 		vec![spender.to_string(), value.to_string()],
 		None,
 	)
@@ -848,7 +848,7 @@ fn increase_allowance(
 ) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22::increase_allowance",
+		"Psp22::increase_allowance",
 		vec![spender.to_string(), value.to_string()],
 		None,
 	)
@@ -861,30 +861,30 @@ fn decrease_allowance(
 ) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22::decrease_allowance",
+		"Psp22::decrease_allowance",
 		vec![spender.to_string(), value.to_string()],
 		None,
 	)
 }
 
 fn token_name(session: &mut Session<Pop>) -> Option<String> {
-	call::<Pop, Option<String>, PSP22Error>(session, "PSP22Metadata::token_name", vec![], None)
+	call::<Pop, Option<String>, PSP22Error>(session, "Psp22Metadata::token_name", vec![], None)
 		.unwrap()
 }
 
 fn token_symbol(session: &mut Session<Pop>) -> Option<String> {
-	call::<Pop, Option<String>, PSP22Error>(session, "PSP22Metadata::token_symbol", vec![], None)
+	call::<Pop, Option<String>, PSP22Error>(session, "Psp22Metadata::token_symbol", vec![], None)
 		.unwrap()
 }
 
 fn token_decimals(session: &mut Session<Pop>) -> u8 {
-	call::<Pop, u8, PSP22Error>(session, "PSP22Metadata::token_decimals", vec![], None).unwrap()
+	call::<Pop, u8, PSP22Error>(session, "Psp22Metadata::token_decimals", vec![], None).unwrap()
 }
 
 fn mint(session: &mut Session<Pop>, account: AccountId, amount: Balance) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22Mintable::mint",
+		"Psp22Mintable::mint",
 		vec![account.to_string(), amount.to_string()],
 		None,
 	)
@@ -893,7 +893,7 @@ fn mint(session: &mut Session<Pop>, account: AccountId, amount: Balance) -> Resu
 fn burn(session: &mut Session<Pop>, account: AccountId, amount: Balance) -> Result<(), PSP22Error> {
 	call::<Pop, (), PSP22Error>(
 		session,
-		"PSP22Burnable::burn",
+		"Psp22Burnable::burn",
 		vec![account.to_string(), amount.to_string()],
 		None,
 	)

pop-api/src/v0/fungibles/traits.rs

@@ -1,29 +1,34 @@
 //! Traits that can be used by contracts. Including standard compliant traits.
 
-use super::*;
 use core::result::Result;
+
 use ink::prelude::string::String;
 
+use super::*;
+
+/// Function selectors as per the PSP22 standard: https://github.com/w3f/PSPs/blob/master/PSPs/psp-22.md.
+/// The mint and burn selectors are not defined in the standard, but have been created in the same way.
+
 /// The PSP22 trait.
 #[ink::trait_definition]
-pub trait PSP22 {
+pub trait Psp22 {
 	/// Returns the total token supply.
-	#[ink(message)]
+	#[ink(message, selector = 0x162df8c2)]
 	fn total_supply(&self) -> Balance;
 
 	/// Returns the account balance for the specified `owner`.
 	///
 	/// # Parameters
 	/// - `owner` - The account whose balance is being queried.
-	#[ink(message)]
+	#[ink(message, selector = 0x6568382f)]
 	fn balance_of(&self, owner: AccountId) -> Balance;
 
 	/// Returns the allowance for a `spender` approved by an `owner`.
 	///
 	/// # Parameters
 	/// - `owner` - The account that owns the tokens.
 	/// - `spender` - The account that is allowed to spend the tokens.
-	#[ink(message)]
+	#[ink(message, selector = 0x4d47d921)]
 	fn allowance(&self, owner: AccountId, spender: AccountId) -> Balance;
 
 	/// Transfers `value` amount of tokens from the caller's account to account `to`
@@ -33,7 +38,7 @@ pub trait PSP22 {
 	/// - `to` - The recipient account.
 	/// - `value` - The number of tokens to transfer.
 	/// - `data` - Additional data in unspecified format.
-	#[ink(message)]
+	#[ink(message, selector = 0xdb20f9f5)]
 	fn transfer(&mut self, to: AccountId, value: Balance, data: Vec<u8>) -> Result<(), PSP22Error>;
 
 	/// Transfers `value` tokens on behalf of `from` to the account `to`
@@ -44,7 +49,7 @@ pub trait PSP22 {
 	/// - `to` - The recipient account.
 	/// - `value` - The number of tokens to transfer.
 	/// - `data` - Additional data with unspecified format.
-	#[ink(message)]
+	#[ink(message, selector = 0x54b3c76e)]
 	fn transfer_from(
 		&mut self,
 		from: AccountId,
@@ -60,62 +65,68 @@ pub trait PSP22 {
 	/// # Parameters
 	/// - `spender` - The account that is allowed to spend the tokens.
 	/// - `value` - The number of tokens to approve.
-	#[ink(message)]
+	#[ink(message, selector = 0xb20f1bbd)]
 	fn approve(&mut self, spender: AccountId, value: Balance) -> Result<(), PSP22Error>;
 
 	/// Increases the allowance of `spender` by `value` amount of tokens.
 	///
 	/// # Parameters
 	/// - `spender` - The account that is allowed to spend the tokens.
 	/// - `value` - The number of tokens to increase the allowance by.
-	#[ink(message)]
+	#[ink(message, selector = 0x96d6b57a)]
 	fn increase_allowance(&mut self, spender: AccountId, value: Balance) -> Result<(), PSP22Error>;
 
 	/// Decreases the allowance of `spender` by `value` amount of tokens.
 	///
 	/// # Parameters
 	/// - `spender` - The account that is allowed to spend the tokens.
 	/// - `value` - The number of tokens to decrease the allowance by.
-	#[ink(message)]
+	#[ink(message, selector = 0xfecb57d5)]
 	fn decrease_allowance(&mut self, spender: AccountId, value: Balance) -> Result<(), PSP22Error>;
 }
 
 /// The PSP22 Metadata trait.
 #[ink::trait_definition]
-pub trait PSP22Metadata {
+pub trait Psp22Metadata {
 	/// Returns the token name.
-	#[ink(message)]
+	#[ink(message, selector = 0x3d261bd4)]
 	fn token_name(&self) -> Option<String>;
 
 	/// Returns the token symbol.
-	#[ink(message)]
+	#[ink(message, selector = 0x34205be5)]
 	fn token_symbol(&self) -> Option<String>;
 
 	/// Returns the token decimals.
-	#[ink(message)]
+	#[ink(message, selector = 0x7271b782)]
 	fn token_decimals(&self) -> u8;
 }
 
 /// The PSP22 Mintable trait.
 #[ink::trait_definition]
-pub trait PSP22Mintable {
+pub trait Psp22Mintable {
 	/// Creates `value` amount of tokens and assigns them to `account`, increasing the total supply.
 	///
+	/// The selector for this message is `0xfc3c75d4` (first 4 bytes of
+	/// `blake2b_256("PSP22Mintable::mint")`).
+	///
 	/// # Parameters
 	/// - `account` - The account to be credited with the created tokens.
 	/// - `value` - The number of tokens to mint.
-	#[ink(message)]
+	#[ink(message, selector = 0xfc3c75d4)]
 	fn mint(&mut self, account: AccountId, value: Balance) -> Result<(), PSP22Error>;
 }
 
 /// The PSP22 Burnable trait.
 #[ink::trait_definition]
-pub trait PSP22Burnable {
+pub trait Psp22Burnable {
 	/// Destroys `value` amount of tokens from `account`, reducing the total supply.
 	///
+	/// The selector for this message is `0x7a9da510` (first 4 bytes of
+	/// `blake2b_256("PSP22Burnable::burn")`).
+	///
 	/// # Parameters
 	/// - `account` - The account from which the tokens will be destroyed.
 	/// - `value` - The number of tokens to destroy.
-	#[ink(message)]
+	#[ink(message, selector = 0x7a9da510)]
 	fn burn(&mut self, account: AccountId, value: Balance) -> Result<(), PSP22Error>;
 }