Unify ink_env::{eval_contract, invoke_contract} (#1165)

* Merge contract invoke and eval

* Fix up call builder

* Fmt

* Restore off chain param getters

* Use ReturnType in generated CallBuilder

* No longer need to explicitly wrap return type in ReturnType

* Fmt

* Remove some unused ReturnType usage

* Default to `returns::<()>()`, remove ReturnType usage in api

* Fmt

* Fix UI test

* Another UI test

Author: ascjones

crates/env/src/api.rs

@@ -21,7 +21,6 @@ use crate::{
         TypedEnvBackend,
     },
     call::{
-        utils::ReturnType,
         CallParams,
         CreateParams,
     },
@@ -216,33 +215,7 @@ pub fn clear_contract_storage(key: &Key) {
     })
 }
 
-/// Invokes a contract message.
-///
-/// # Note
-///
-/// - Prefer using this over [`eval_contract`] if possible. [`invoke_contract`]
-///   will generally have a better performance since it won't try to fetch any results.
-/// - This is a low level way to invoke another smart contract.
-///   Prefer to use the ink! guided and type safe approach to using this.
-///
-/// # Errors
-///
-/// - If the called account does not exist.
-/// - If the called account is not a contract.
-/// - If arguments passed to the called contract message are invalid.
-/// - If the called contract execution has trapped.
-/// - If the called contract ran out of gas upon execution.
-pub fn invoke_contract<T, Args>(params: &CallParams<T, Args, ()>) -> Result<()>
-where
-    T: Environment,
-    Args: scale::Encode,
-{
-    <EnvInstance as OnInstance>::on_instance(|instance| {
-        TypedEnvBackend::invoke_contract::<T, Args>(instance, params)
-    })
-}
-
-/// Evaluates a contract message and returns its result.
+/// Invokes a contract message and returns its result.
 ///
 /// # Note
 ///
@@ -257,14 +230,14 @@ where
 /// - If the called contract execution has trapped.
 /// - If the called contract ran out of gas upon execution.
 /// - If the returned value failed to decode properly.
-pub fn eval_contract<T, Args, R>(params: &CallParams<T, Args, ReturnType<R>>) -> Result<R>
+pub fn invoke_contract<T, Args, R>(params: &CallParams<T, Args, R>) -> Result<R>
 where
     T: Environment,
     Args: scale::Encode,
     R: scale::Decode,
 {
     <EnvInstance as OnInstance>::on_instance(|instance| {
-        TypedEnvBackend::eval_contract::<T, Args, R>(instance, params)
+        TypedEnvBackend::invoke_contract::<T, Args, R>(instance, params)
     })
 }
 

crates/env/src/backend.rs

@@ -14,7 +14,6 @@
 
 use crate::{
     call::{
-        utils::ReturnType,
         CallParams,
         CreateParams,
     },
@@ -359,27 +358,14 @@ pub trait TypedEnvBackend: EnvBackend {
         T: Environment,
         Event: Topics + scale::Encode;
 
-    /// Invokes a contract message.
+    /// Invokes a contract message and returns its result.
     ///
     /// # Note
     ///
     /// For more details visit: [`invoke_contract`][`crate::invoke_contract`]
-    fn invoke_contract<T, Args>(
+    fn invoke_contract<T, Args, R>(
         &mut self,
-        call_data: &CallParams<T, Args, ()>,
-    ) -> Result<()>
-    where
-        T: Environment,
-        Args: scale::Encode;
-
-    /// Evaluates a contract message and returns its result.
-    ///
-    /// # Note
-    ///
-    /// For more details visit: [`eval_contract`][`crate::eval_contract`]
-    fn eval_contract<T, Args, R>(
-        &mut self,
-        call_data: &CallParams<T, Args, ReturnType<R>>,
+        call_data: &CallParams<T, Args, R>,
     ) -> Result<R>
     where
         T: Environment,

crates/env/src/call/call_builder.rs

@@ -84,38 +84,17 @@ where
     }
 }
 
-impl<E, Args> CallParams<E, Args, ()>
-where
-    E: Environment,
-    Args: scale::Encode,
-{
-    /// Invokes the contract with the given built-up call parameters.
-    ///
-    /// # Note
-    ///
-    /// Prefer [`invoke`](`Self::invoke`) over [`eval`](`Self::eval`) if the
-    /// called contract message does not return anything because it is more efficient.
-    pub fn invoke(&self) -> Result<(), crate::Error> {
-        crate::invoke_contract(self)
-    }
-}
-
-impl<E, Args, R> CallParams<E, Args, ReturnType<R>>
+impl<E, Args, R> CallParams<E, Args, R>
 where
     E: Environment,
     Args: scale::Encode,
     R: scale::Decode,
 {
-    /// Evaluates the contract with the given built-up call parameters.
+    /// Invokes the contract with the given built-up call parameters.
     ///
     /// Returns the result of the contract execution.
-    ///
-    /// # Note
-    ///
-    /// Prefer [`invoke`](`Self::invoke`) over [`eval`](`Self::eval`) if the
-    /// called contract message does not return anything because it is more efficient.
-    pub fn eval(&self) -> Result<R, crate::Error> {
-        crate::eval_contract(self)
+    pub fn invoke(&self) -> Result<R, crate::Error> {
+        crate::invoke_contract(self)
     }
 }
 
@@ -179,7 +158,7 @@ where
 /// # use ::ink_env::{
 /// #     Environment,
 /// #     DefaultEnvironment,
-/// #     call::{build_call, Selector, ExecutionInput, utils::ReturnType},
+/// #     call::{build_call, Selector, ExecutionInput},
 /// # };
 /// # type AccountId = <DefaultEnvironment as Environment>::AccountId;
 /// let my_return_value: i32 = build_call::<DefaultEnvironment>()
@@ -192,7 +171,7 @@ where
 ///             .push_arg(true)
 ///             .push_arg(&[0x10; 32])
 ///     )
-///     .returns::<ReturnType<i32>>()
+///     .returns::<i32>()
 ///     .fire()
 ///     .unwrap();
 /// ```
@@ -328,18 +307,6 @@ where
     }
 }
 
-mod seal {
-    /// Used to prevent users from implementing `IndicateReturnType` for their own types.
-    pub trait Sealed {}
-    impl Sealed for () {}
-    impl<T> Sealed for super::ReturnType<T> {}
-}
-
-/// Types that can be used in [`CallBuilder::returns`] to signal return type.
-pub trait IndicateReturnType: Default + self::seal::Sealed {}
-impl IndicateReturnType for () {}
-impl<T> IndicateReturnType for ReturnType<T> {}
-
 impl<E, Callee, GasLimit, TransferredValue, Args>
     CallBuilder<E, Callee, GasLimit, TransferredValue, Args, Unset<ReturnType<()>>>
 where
@@ -350,14 +317,11 @@ where
     /// # Note
     ///
     /// Either use `.returns::<()>` to signal that the call does not return a value
-    /// or use `.returns::<ReturnType<T>>` to signal that the call returns a value of
-    /// type `T`.
+    /// or use `.returns::<T>` to signal that the call returns a value of type `T`.
     #[inline]
     pub fn returns<R>(
         self,
-    ) -> CallBuilder<E, Callee, GasLimit, TransferredValue, Args, Set<R>>
-    where
-        R: IndicateReturnType,
+    ) -> CallBuilder<E, Callee, GasLimit, TransferredValue, Args, Set<ReturnType<R>>>
     {
         CallBuilder {
             env: Default::default(),
@@ -414,7 +378,7 @@ impl<E, GasLimit, TransferredValue, Args, RetType>
         GasLimit,
         TransferredValue,
         Set<ExecutionInput<Args>>,
-        Set<RetType>,
+        Set<ReturnType<RetType>>,
     >
 where
     E: Environment,
@@ -465,27 +429,6 @@ where
     }
 }
 
-impl<E, GasLimit, TransferredValue, Args>
-    CallBuilder<
-        E,
-        Set<E::AccountId>,
-        GasLimit,
-        TransferredValue,
-        Set<ExecutionInput<Args>>,
-        Set<()>,
-    >
-where
-    E: Environment,
-    GasLimit: Unwrap<Output = u64>,
-    Args: scale::Encode,
-    TransferredValue: Unwrap<Output = E::Balance>,
-{
-    /// Invokes the cross-chain function call.
-    pub fn fire(self) -> Result<(), Error> {
-        self.params().invoke()
-    }
-}
-
 impl<E, GasLimit, TransferredValue>
     CallBuilder<
         E,
@@ -524,6 +467,6 @@ where
 {
     /// Invokes the cross-chain function call and returns the result.
     pub fn fire(self) -> Result<R, Error> {
-        self.params().eval()
+        self.params().invoke()
     }
 }

crates/env/src/call/common.rs

@@ -18,7 +18,7 @@ use core::marker::PhantomData;
 
 /// Represents a return type.
 ///
-/// Used as a marker type to differentiate at compile-time between invoke and evaluate.
+/// Used as a marker type to define the return type of an ink! message in call builders.
 #[derive(Debug)]
 pub struct ReturnType<T>(PhantomData<fn() -> T>);
 

crates/env/src/call/mod.rs

@@ -23,7 +23,6 @@ mod selector;
 /// Utility types for the cross-contract calling API.
 pub mod utils {
     pub use super::{
-        call_builder::IndicateReturnType,
         common::{
             ReturnType,
             Set,

crates/env/src/engine/off_chain/impls.rs

@@ -15,7 +15,6 @@
 use super::EnvInstance;
 use crate::{
     call::{
-        utils::ReturnType,
         CallParams,
         CreateParams,
     },
@@ -387,10 +386,14 @@ impl TypedEnvBackend for EnvInstance {
         self.engine.deposit_event(&enc_topics[..], enc_data);
     }
 
-    fn invoke_contract<T, Args>(&mut self, params: &CallParams<T, Args, ()>) -> Result<()>
+    fn invoke_contract<T, Args, R>(
+        &mut self,
+        params: &CallParams<T, Args, R>,
+    ) -> Result<R>
     where
         T: Environment,
         Args: scale::Encode,
+        R: scale::Decode,
     {
         let _gas_limit = params.gas_limit();
         let _callee = params.callee();
@@ -400,18 +403,6 @@ impl TypedEnvBackend for EnvInstance {
         unimplemented!("off-chain environment does not support contract invocation")
     }
 
-    fn eval_contract<T, Args, R>(
-        &mut self,
-        _call_params: &CallParams<T, Args, ReturnType<R>>,
-    ) -> Result<R>
-    where
-        T: Environment,
-        Args: scale::Encode,
-        R: scale::Decode,
-    {
-        unimplemented!("off-chain environment does not support contract evaluation")
-    }
-
     fn instantiate_contract<T, Args, Salt, C>(
         &mut self,
         params: &CreateParams<T, Args, Salt, C>,