refactor: error

extension/Cargo.toml

@@ -16,9 +16,6 @@ targets = ["x86_64-unknown-linux-gnu"]
 codec.workspace = true
 log.workspace = true
 
-# Local
-pop-primitives.workspace = true
-
 # Substrate
 frame-support.workspace = true
 frame-system.workspace = true
@@ -33,19 +30,18 @@ rand = "0.8.5"
 [features]
 default = ["std"]
 std = [
- "log/std",
- "codec/std",
- "frame-support/std",
- "frame-system/std",
- "pallet-contracts/std",
- "pop-primitives/std",
- "sp-runtime/std",
- "sp-core/std",
- "sp-std/std",
+    "log/std",
+    "codec/std",
+    "frame-support/std",
+    "frame-system/std",
+    "pallet-contracts/std",
+    "sp-runtime/std",
+    "sp-core/std",
+    "sp-std/std",
 ]
 runtime-benchmarks = [
- "frame-support/runtime-benchmarks",
- "frame-system/runtime-benchmarks",
- "pallet-contracts/runtime-benchmarks",
- "sp-runtime/runtime-benchmarks",
+    "frame-support/runtime-benchmarks",
+    "frame-system/runtime-benchmarks",
+    "pallet-contracts/runtime-benchmarks",
+    "sp-runtime/runtime-benchmarks",
 ]

extension/src/lib.rs

@@ -272,9 +272,7 @@ impl TryFrom<u8> for FuncId {
 }
 
 /// Converts a `DispatchError` to a `u32` status code based on the version of the API the contract uses.
-/// The contract calling the chain extension can optionally convert the status code to the descriptive `Error`.
-///
-/// For `Error` see `pop_primitives::<version>::error::Error`.
+/// The contract calling the chain extension can optionally convert the status code to the descriptive `pop_api::Error`.
 ///
 /// The error encoding can vary per version, allowing for flexible and backward-compatible error handling.
 /// As a result, contracts maintain compatibility across different versions of the runtime.

pop-api/integration-tests/Cargo.toml

@@ -11,6 +11,7 @@ frame-system = { version = "29.0.0", default-features = false }
 pallet-balances = { version = "29.0.2", default-features = false }
 pallet-assets = { version = "30.0.0", default-features = false }
 pallet-contracts = { version = "28.0.0", default-features = false }
+pop-api = { path = "../../pop-api", default-features = false }
 pop-primitives = { path = "../../primitives", default-features = false }
 pop-runtime-devnet = { path = "../../runtime/devnet", default-features = false }
 sp-io = { version = "31.0.0", default-features = false }
@@ -25,6 +26,7 @@ std = [
     "pallet-balances/std",
     "pallet-assets/std",
     "pallet-contracts/std",
+    "pop-api/std",
     "pop-primitives/std",
     "pop-runtime-devnet/std",
     "scale/std",

pop-api/integration-tests/contracts/fungibles/lib.rs

@@ -181,7 +181,7 @@ mod fungibles {
 
 		#[ink::test]
 		fn default_works() {
-			PopApiFungiblesExample::new();
+			Fungibles::new();
 		}
 	}
 }

pop-api/integration-tests/src/fungibles/mod.rs

@@ -1,5 +1,5 @@
 use super::*;
-use pop_primitives::error::{
+use pop_api::{
 	ArithmeticError::*,
 	Error::{self, *},
 	TokenError::*,

pop-api/src/lib.rs

@@ -11,6 +11,7 @@ use constants::DECODING_FAILED;
 use ink::env::chain_extension::{ChainExtensionMethod, FromStatusCode};
 #[cfg(feature = "assets")]
 pub use v0::assets;
+pub use v0::{ArithmeticError, Error, TokenError, TransactionalError};
 
 /// Module providing primitives types.
 pub mod primitives;

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

@@ -11,9 +11,9 @@ use crate::{
 	primitives::{AccountId, AssetId, Balance},
 	Result, StatusCode,
 };
-pub use asset_management::*;
 use constants::*;
 use ink::{env::chain_extension::ChainExtensionMethod, prelude::vec::Vec};
+pub use management::*;
 pub use metadata::*;
 
 // Helper method to build a dispatch call.
@@ -485,13 +485,11 @@ mod tests {
 	use super::FungiblesError;
 	use crate::{
 		constants::{ASSETS, BALANCES},
-		primitives::error::{
-			ArithmeticError::*,
-			Error::{self, *},
-			TokenError::*,
-			TransactionalError::*,
-		},
+		ArithmeticError::*,
+		Error::{self, *},
 		StatusCode,
+		TokenError::*,
+		TransactionalError::*,
 	};
 
 	fn error_into_status_code(error: Error) -> StatusCode {

pop-api/src/v0/mod.rs

@@ -1,23 +1,141 @@
 use crate::{
 	build_extension_method,
 	constants::{DISPATCH, READ_STATE},
-	primitives::error::Error,
 	StatusCode,
 };
-use ink::env::chain_extension::ChainExtensionMethod;
+use ink::{env::chain_extension::ChainExtensionMethod, scale::Decode};
 
 /// APIs for asset-related use cases.
 #[cfg(feature = "assets")]
 pub mod assets;
 
 pub(crate) const V0: u8 = 0;
 
+/// Reason why a Pop API call failed.
+#[derive(Debug, Eq, PartialEq)]
+#[ink::scale_derive(Encode, Decode, TypeInfo)]
+#[repr(u8)]
+#[allow(clippy::unnecessary_cast)]
+pub enum Error {
+	/// An unknown error occurred. This variant captures any unexpected errors that the
+	/// contract cannot specifically handle. It is useful for cases where there are breaking
+	/// changes in the runtime or when an error falls outside the predefined categories. The
+	/// variant includes:
+	Other {
+		/// The index within the `DispatchError`.
+		dispatch_error_index: u8,
+		/// The index within the `DispatchError` variant (e.g. a `TokenError`).
+		error_index: u8,
+		/// The specific error code or sub-index, providing additional context (e.g.
+		/// error` in `ModuleError`).
+		error: u8,
+	} = 0,
+	/// Failed to lookup some data.
+	CannotLookup = 1,
+	/// A bad origin.
+	BadOrigin = 2,
+	/// A custom error in a module.
+	///
+	Module {
+		/// The pallet index.
+		index: u8,
+		/// The error within the pallet.
+		error: u8,
+	} = 3,
+	/// At least one consumer is remaining so the account cannot be destroyed.
+	ConsumerRemaining = 4,
+	/// There are no providers so the account cannot be created.
+	NoProviders = 5,
+	/// There are too many consumers so the account cannot be created.
+	TooManyConsumers = 6,
+	/// An error to do with tokens.
+	Token(TokenError) = 7,
+	/// An arithmetic error.
+	Arithmetic(ArithmeticError) = 8,
+	/// The number of transactional layers has been reached, or we are not in a transactional
+	/// layer.
+	Transactional(TransactionalError) = 9,
+	/// Resources exhausted, e.g. attempt to read/write data which is too large to manipulate.
+	Exhausted = 10,
+	/// The state is corrupt; this is generally not going to fix itself.
+	Corruption = 11,
+	/// Some resource (e.g. a preimage) is unavailable right now. This might fix itself later.
+	Unavailable = 12,
+	/// Root origin is not allowed.
+	RootNotAllowed = 13,
+	/// Unknown call.
+	UnknownCall = 254,
+	/// Decoding failed.
+	DecodingFailed = 255,
+}
+
 impl From<StatusCode> for Error {
 	fn from(value: StatusCode) -> Self {
 		value.0.into()
 	}
 }
 
+impl From<u32> for Error {
+	/// Converts a `u32` status code into an `Error`.
+	///
+	/// This conversion maps a raw status code returned by the runtime into the more
+	/// descriptive `Error` enum variant, providing better context and understanding of the
+	/// error.
+	fn from(value: u32) -> Self {
+		let encoded = value.to_le_bytes();
+		Error::decode(&mut &encoded[..]).unwrap_or(Error::DecodingFailed)
+	}
+}
+
+/// Description of what went wrong when trying to complete an operation on a token.
+#[derive(Debug, Eq, PartialEq)]
+#[ink::scale_derive(Encode, Decode, TypeInfo)]
+pub enum TokenError {
+	/// Funds are unavailable.
+	FundsUnavailable,
+	/// Some part of the balance gives the only provider reference to the account and thus cannot
+	/// be (re)moved.
+	OnlyProvider,
+	/// Account cannot exist with the funds that would be given.
+	BelowMinimum,
+	/// Account cannot be created.
+	CannotCreate,
+	/// The asset in question is unknown.
+	UnknownAsset,
+	/// Funds exist but are frozen.
+	Frozen,
+	/// Operation is not supported by the asset.
+	Unsupported,
+	/// Account cannot be created for a held balance.
+	CannotCreateHold,
+	/// Withdrawal would cause unwanted loss of account.
+	NotExpendable,
+	/// Account cannot receive the assets.
+	Blocked,
+}
+
+/// Arithmetic errors.
+#[derive(Debug, Eq, PartialEq)]
+#[ink::scale_derive(Encode, Decode, TypeInfo)]
+pub enum ArithmeticError {
+	/// Underflow.
+	Underflow,
+	/// Overflow.
+	Overflow,
+	/// Division by zero.
+	DivisionByZero,
+}
+
+/// Errors related to transactional storage layers.
+#[derive(Debug, Eq, PartialEq)]
+#[ink::scale_derive(Encode, Decode, TypeInfo)]
+pub enum TransactionalError {
+	/// Too many transactional layers have been spawned.
+	LimitReached,
+	/// A transactional layer was expected, but does not exist.
+	NoLayer,
+}
+
 // Helper method to build a dispatch call.
 //
 // Parameters:

primitives/Cargo.toml

@@ -5,13 +5,6 @@ license = "GPL-3.0-only"
 version = "0.0.0"
 edition = "2021"
 
-[dependencies]
-codec.workspace = true
-scale-info.workspace = true
-
 [features]
 default = ["std"]
-std = [
-    "codec/std",
-    "scale-info/std",
-]
+std = []