valset: update min_weight/max_validators by migrating

contracts/tgrade-valset/src/contract.rs

@@ -5,8 +5,8 @@ use std::convert::TryInto;
 #[cfg(not(feature = "library"))]
 use cosmwasm_std::entry_point;
 use cosmwasm_std::{
-    to_binary, Addr, Binary, BlockInfo, Decimal, Deps, DepsMut, Empty, Env, MessageInfo, Order,
-    Reply, StdResult, Timestamp, WasmMsg,
+    to_binary, Addr, Binary, BlockInfo, Decimal, Deps, DepsMut, Env, MessageInfo, Order, Reply,
+    StdError, StdResult, Timestamp, WasmMsg,
 };
 
 use cw2::set_contract_version;
@@ -24,7 +24,7 @@ use tg_utils::{ensure_from_older_version, JailingDuration, SlashMsg, ADMIN};
 use crate::error::ContractError;
 use crate::msg::{
     EpochResponse, ExecuteMsg, InstantiateMsg, InstantiateResponse, JailingPeriod,
-    ListActiveValidatorsResponse, ListValidatorResponse, ListValidatorSlashingResponse,
+    ListActiveValidatorsResponse, ListValidatorResponse, ListValidatorSlashingResponse, MigrateMsg,
     OperatorResponse, QueryMsg, RewardsDistribution, RewardsInstantiateMsg, ValidatorMetadata,
     ValidatorResponse,
 };
@@ -722,8 +722,19 @@ fn calculate_diff(
 }
 
 #[cfg_attr(not(feature = "library"), entry_point)]
-pub fn migrate(deps: DepsMut, _env: Env, _msg: Empty) -> Result<Response, ContractError> {
+pub fn migrate(deps: DepsMut, _env: Env, msg: MigrateMsg) -> Result<Response, ContractError> {
     ensure_from_older_version(deps.storage, CONTRACT_NAME, CONTRACT_VERSION)?;
+
+    CONFIG.update::<_, StdError>(deps.storage, |mut cfg| {
+        if let Some(min_weight) = msg.min_weight {
+            cfg.min_weight = min_weight;
+        }
+        if let Some(max_validators) = msg.max_validators {
+            cfg.max_validators = max_validators;
+        }
+        Ok(cfg)
+    })?;
+
     Ok(Response::new())
 }
 

contracts/tgrade-valset/src/msg.rs

@@ -416,6 +416,13 @@ pub struct InstantiateResponse {
     pub rewards_contract: Addr,
 }
 
+#[derive(Serialize, Deserialize, Clone, PartialEq, JsonSchema, Debug)]
+#[serde(rename_all = "snake_case")]
+pub struct MigrateMsg {
+    pub min_weight: Option<u64>,
+    pub max_validators: Option<u32>,
+}
+
 #[cfg(test)]
 mod test {
     use super::*;

contracts/tgrade-valset/src/multitest.rs

@@ -3,6 +3,7 @@ mod contract;
 mod double_sign;
 mod helpers;
 mod jailing;
+mod migration;
 mod rewards_split;
 mod slashing;
 mod stake;

contracts/tgrade-valset/src/multitest/migration.rs

@@ -0,0 +1,29 @@
+use super::suite::SuiteBuilder;
+use crate::msg::MigrateMsg;
+
+#[test]
+fn migration_can_alter_cfg() {
+    let mut suite = SuiteBuilder::new()
+        .with_max_validators(6)
+        .with_min_weight(3)
+        .build();
+    let admin = suite.admin().to_string();
+
+    let cfg = suite.config().unwrap();
+    assert_eq!(cfg.max_validators, 6);
+    assert_eq!(cfg.min_weight, 3);
+
+    suite
+        .migrate(
+            &admin,
+            &MigrateMsg {
+                min_weight: Some(5),
+                max_validators: Some(10),
+            },
+        )
+        .unwrap();
+
+    let cfg = suite.config().unwrap();
+    assert_eq!(cfg.max_validators, 10);
+    assert_eq!(cfg.min_weight, 5);
+}

contracts/tgrade-valset/src/multitest/suite.rs

@@ -39,7 +39,8 @@ pub fn contract_valset() -> Box<dyn Contract<TgradeMsg>> {
         crate::contract::query,
     )
     .with_sudo(crate::contract::sudo)
-    .with_reply(crate::contract::reply);
+    .with_reply(crate::contract::reply)
+    .with_migrate(crate::contract::migrate);
 
     Box::new(contract)
 }
@@ -391,6 +392,7 @@ impl SuiteBuilder {
 
         Suite {
             app,
+            valset_code_id: valset_id,
             valset,
             membership,
             distribution_contracts,
@@ -409,6 +411,8 @@ pub struct Suite {
     /// Multitest app
     #[derivative(Debug = "ignore")]
     app: TgradeApp,
+    /// The code id of the valset contract
+    valset_code_id: u64,
     /// tgrade-valset contract address
     valset: Addr,
     /// membership contract address
@@ -734,4 +738,15 @@ impl Suite {
             &[],
         )
     }
+
+    /// Migrates the contract to the same version (same code id), but possibly changing
+    /// some cfg values via MigrateMsg.
+    pub fn migrate(&mut self, addr: &str, msg: &MigrateMsg) -> AnyResult<AppResponse> {
+        self.app.migrate_contract(
+            Addr::unchecked(addr),
+            self.valset.clone(),
+            msg,
+            self.valset_code_id,
+        )
+    }
 }