Implement downcasting for Api trait

Author: chipshort

Cargo.lock

@@ -74,6 +74,7 @@ serde-json-wasm = { version = "1.0.1", default-features = false, features = [
 static_assertions = "1.1.0"
 thiserror = "1.0.26"
 rmp-serde = "1.3.0"
+downcast-rs = { version = "2.0.1", default-features = false }
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 bech32 = "0.11.0"

packages/std/Cargo.toml

@@ -2756,4 +2756,15 @@ mod tests {
         // we are not interested in the exact humanization, just that it works
         mock_api.addr_humanize(&canonical_addr).unwrap();
     }
+
+    #[test]
+    fn mock_api_downcast() {
+        let mut deps = mock_dependencies();
+        let deps_mut = deps.as_mut();
+
+        let mock_api = deps_mut.api.downcast_ref::<MockApi>().unwrap();
+
+        let addr = mock_api.addr_make("input");
+        assert_eq!(mock_api.addr_validate(addr.as_str()).unwrap(), addr);
+    }
 }

packages/std/src/testing/mock.rs

@@ -1,5 +1,6 @@
 use core::marker::PhantomData;
 use core::ops::Deref;
+use downcast_rs::{impl_downcast, Downcast};
 use serde::{de::DeserializeOwned, Serialize};
 
 use crate::coin::Coin;
@@ -130,7 +131,7 @@ pub trait Storage {
 ///
 /// We can use feature flags to opt-in to non-essential methods
 /// for backwards compatibility in systems that don't have them all.
-pub trait Api {
+pub trait Api: Downcast {
     /// Takes a human readable address and validates if it is valid.
     /// If it the validation succeeds, a `Addr` containing the same data as the input is returned.
     ///
@@ -329,6 +330,7 @@ pub trait Api {
     /// Those messages are not persisted to chain.
     fn debug(&self, message: &str);
 }
+impl_downcast!(Api);
 
 /// A short-hand alias for the two-level query result (1. accessing the contract, 2. executing query in the contract)
 pub type QuerierResult = SystemResult<ContractResult<Binary>>;