feat(query): Introduce non-breaking changes to handle nullable data stated in #2414

Author: BigtoC

packages/std/src/metadata.rs

@@ -23,3 +23,25 @@ pub struct DenomUnit {
     pub exponent: u32,
     pub aliases: Vec<String>,
 }
+
+#[derive(Serialize, Deserialize, Clone, Default, Debug, PartialEq, Eq, JsonSchema)]
+pub struct NullableDenomMetadata {
+    pub description: String,
+    // https://github.com/cosmos/cosmos-sdk/blob/main/api/cosmos/bank/v1beta1/bank.pulsar.go#L4539
+    pub denom_units: Option<Vec<NullableDenomUnit>>,
+    pub base: String,
+    pub display: String,
+    pub name: String,
+    pub symbol: String,
+    pub uri: String,
+    pub uri_hash: String,
+}
+
+/// Replicates the cosmos-sdk bank module DenomUnit type
+#[derive(Serialize, Deserialize, Clone, Default, Debug, PartialEq, Eq, JsonSchema)]
+pub struct NullableDenomUnit {
+    pub denom: String,
+    pub exponent: u32,
+    // https://github.com/cosmos/cosmos-sdk/blob/main/api/cosmos/bank/v1beta1/bank.pulsar.go#L4478
+    pub aliases: Option<Vec<String>>,
+}

packages/std/src/query/bank.rs

@@ -7,7 +7,7 @@ use crate::prelude::*;
 #[cfg(feature = "cosmwasm_1_3")]
 use crate::PageRequest;
 use crate::{Binary, DenomMetadata};
-
+use crate::metadata::NullableDenomMetadata;
 use super::query_response::QueryResponseType;
 
 #[non_exhaustive]
@@ -83,6 +83,14 @@ pub struct DenomMetadataResponse {
     pub metadata: DenomMetadata,
 }
 
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Eq, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+#[non_exhaustive]
+pub struct NullableDenomMetadataResponse {
+    /// The metadata for the queried denom.
+    pub metadata: NullableDenomMetadata,
+}
+
 impl_response_constructor!(DenomMetadataResponse, metadata: DenomMetadata);
 
 impl QueryResponseType for DenomMetadataResponse {}

packages/std/src/traits.rs

@@ -10,9 +10,7 @@ use crate::prelude::*;
 use crate::query::CodeInfoResponse;
 #[cfg(feature = "cosmwasm_1_1")]
 use crate::query::SupplyResponse;
-use crate::query::{
-    AllBalanceResponse, BalanceResponse, BankQuery, CustomQuery, QueryRequest, WasmQuery,
-};
+use crate::query::{AllBalanceResponse, BalanceResponse, BankQuery, CustomQuery, NullableDenomMetadataResponse, QueryRequest, WasmQuery};
 #[cfg(feature = "staking")]
 use crate::query::{
     AllDelegationsResponse, AllValidatorsResponse, BondedDenomResponse, Delegation,
@@ -30,6 +28,7 @@ use crate::{Addr, CanonicalAddr};
 #[cfg(feature = "cosmwasm_1_3")]
 use crate::{DenomMetadata, PageRequest};
 use crate::{RecoverPubkeyError, StdError, StdResult, VerificationError};
+use crate::metadata::NullableDenomMetadata;
 
 #[derive(Clone, Copy, Debug)]
 #[non_exhaustive]
@@ -454,6 +453,16 @@ impl<'a, C: CustomQuery> QuerierWrapper<'a, C> {
         Ok(res.metadata)
     }
 
+    #[cfg(feature = "cosmwasm_1_3")]
+    pub fn query_nullable_denom_metadata(&self, denom: impl Into<String>) -> StdResult<NullableDenomMetadata> {
+        let request = BankQuery::DenomMetadata {
+            denom: denom.into(),
+        }
+            .into();
+        let res: NullableDenomMetadataResponse = self.query(&request)?;
+        Ok(res.metadata)
+    }
+
     #[cfg(feature = "cosmwasm_1_3")]
     pub fn query_all_denom_metadata(
         &self,