fix: make get account proof retrieve latest known state

CHANGELOG.md

@@ -21,6 +21,7 @@
 - RPC client now correctly sets `genesis` value in `ACCEPT` header if `version` is unspecified ([#1370](https://github.com/0xMiden/miden-node/pull/1370)).
 - Pin protobuf (`protox`) dependencies to avoid breaking changes in transitive dependency ([#1403](https://github.com/0xMiden/miden-node/pull/1403)).
 - Fixed no-std compatibility for remote prover clients ([#1407](https://github.com/0xMiden/miden-node/pull/1407)).
+- Fixed `AccountProofRequest` to retrieve the latest known state in case specified block number (or chain tip) does not contain account updates ([#1422](https://github.com/0xMiden/miden-node/issues/1422)).
 
 ## v0.12.6
 

crates/proto/src/generated/rpc_store.rs

@@ -18,8 +18,9 @@ pub struct AccountProofRequest {
     /// ID of the account for which we want to get data
     #[prost(message, optional, tag = "1")]
     pub account_id: ::core::option::Option<super::account::AccountId>,
-    /// Block at which we'd like to get this data. If present, must be close to the chain tip.
-    /// If not present, data from the latest block will be returned.
+    /// Optional block height at which to return the proof.
+    ///
+    /// Defaults to current chain tip if unspecified.
     #[prost(message, optional, tag = "2")]
     pub block_num: ::core::option::Option<super::blockchain::BlockNumber>,
     /// Request for additional account details; valid only for public accounts.

crates/store/src/db/models/queries/accounts.rs

@@ -93,8 +93,7 @@ pub(crate) fn select_account(
     Ok(info)
 }
 
-/// Select account details at a specific block number from the DB using the given
-/// [`SqliteConnection`].
+/// Select account details as they are at the given block height.
 ///
 /// # Returns
 ///
@@ -118,7 +117,11 @@ pub(crate) fn select_account(
 ///     account_codes ON accounts.code_commitment = account_codes.code_commitment
 /// WHERE
 ///     account_id = ?1
-///     AND block_num = ?2
+///     AND block_num <= ?2
+/// ORDER BY
+///     block_num DESC
+/// LIMIT
+///     1
 /// ```
 pub(crate) fn select_historical_account_at(
     conn: &mut SqliteConnection,
@@ -134,8 +137,10 @@ pub(crate) fn select_historical_account_at(
     .filter(
         schema::accounts::account_id
             .eq(account_id.to_bytes())
-            .and(schema::accounts::block_num.eq(block_num.to_raw_sql())),
+            .and(schema::accounts::block_num.le(block_num.to_raw_sql())),
     )
+    .order_by(schema::accounts::block_num.desc())
+    .limit(1)
     .get_result::<(AccountRaw, Option<Vec<u8>>)>(conn)
     .optional()?
     .ok_or(DatabaseError::AccountNotFoundInDb(account_id))?;

proto/proto/store/rpc.proto

@@ -147,8 +147,9 @@ message AccountProofRequest {
     // ID of the account for which we want to get data
     account.AccountId account_id = 1;
 
-    // Block at which we'd like to get this data. If present, must be close to the chain tip.
-    // If not present, data from the latest block will be returned.
+    // Optional block height at which to return the proof.
+    //
+    // Defaults to current chain tip if unspecified.
     optional blockchain.BlockNumber block_num = 2;
 
     // Request for additional account details; valid only for public accounts.