feat: make MAX_SPONSORS configurable per deployment (#96)

contracts/escrow/src/lib.rs

@@ -24,7 +24,8 @@ pub const BPS_DENOMINATOR: i128 = 10_000;
 /// accumulate. Bounds the per-contributor loops in `refund` and
 /// `extend_deadline` to a small, predictable constant regardless of how
 /// popular a bounty gets. See `docs/escrow-crowdfunding-design.md`.
-pub const MAX_SPONSORS: u32 = 20;
+/// Default maximum number of sponsors if not configured at initialization.
+pub const DEFAULT_MAX_SPONSORS: u32 = 20;
 
 /// Minimum grace period (in seconds) after the deadline before anyone can permissionlessly trigger a refund.
 /// This prevents a race condition where a legitimate release in-flight near the deadline gets front-run by a refund.
@@ -52,6 +53,7 @@ impl EscrowContract {
         admin: Address,
         treasury: Address,
         fee_bps: u32,
+        max_sponsors: Option<u32>,
     ) -> Result<(), Error> {
         admin.require_auth();
 
@@ -65,6 +67,11 @@ impl EscrowContract {
         env.storage().instance().set(&DataKey::Admin, &admin);
         env.storage().instance().set(&DataKey::Treasury, &treasury);
         env.storage().instance().set(&DataKey::FeeBps, &fee_bps);
+        let limit = max_sponsors.unwrap_or(DEFAULT_MAX_SPONSORS);
+        if limit == 0 {
+            return Err(Error::InvalidAmount);
+        }
+        env.storage().instance().set(&DataKey::MaxSponsors, &limit);
         Ok(())
     }
 
@@ -158,7 +165,8 @@ impl EscrowContract {
             EscrowStatus::Funded => {}
         }
 
-        if escrow.contributor_count >= MAX_SPONSORS {
+        let max_sponsors: u32 = env.storage().instance().get(&DataKey::MaxSponsors).unwrap_or(DEFAULT_MAX_SPONSORS);
+        if escrow.contributor_count >= max_sponsors {
             return Err(Error::TooManySponsors);
         }
 

contracts/escrow/src/test.rs

@@ -24,7 +24,7 @@ fn setup(env: &Env) -> (Address, Address, Address, EscrowContractClient<'_>) {
     let treasury = Address::generate(env);
     let contract_id = env.register(EscrowContract, ());
     let client = EscrowContractClient::new(env, &contract_id);
-    client.initialize(&admin, &treasury, &500u32); // 5% fee
+    client.initialize(&admin, &treasury, &500u32, &None); // 5% fee
     (contract_id, admin, treasury, client)
 }
 
@@ -33,7 +33,7 @@ fn test_initialize_rejects_double_init() {
     let env = Env::default();
     env.mock_all_auths();
     let (_, admin, treasury, client) = setup(&env);
-    let err = client.try_initialize(&admin, &treasury, &500u32);
+    let err = client.try_initialize(&admin, &treasury, &500u32, &None);
     assert_eq!(err, Err(Ok(Error::AlreadyInitialized)));
 }
 
@@ -247,7 +247,7 @@ fn test_adversarial_ordering_resistance() {
     let client = crate::EscrowContractClient::new(&env, &contract_id);
 
     // Initialize with 0% fee to simplify fraction/dust calculations
-    client.initialize(&admin, &treasury, &0u32);
+    client.initialize(&admin, &treasury, &0u32, &None);
 
     // 2. Create recipient addresses
     let dev1 = Address::generate(&env);
@@ -312,7 +312,7 @@ fn test_large_split_distributes_dust_by_largest_remainder() {
     let contract_id = env.register(crate::EscrowContract, ());
     let client = crate::EscrowContractClient::new(&env, &contract_id);
     // 0% fee so the whole total is distributable.
-    client.initialize(&admin, &treasury, &0u32);
+    client.initialize(&admin, &treasury, &0u32, &None);
 
     // 60 recipients: 59 with alternating 160/170 bps, the last one receiving
     // the leftover of 10000. All 170-bps recipients share an identical
@@ -400,7 +400,7 @@ fn test_initialize_requires_admin_auth() {
     let contract_id = env.register(EscrowContract, ());
     let client = EscrowContractClient::new(&env, &contract_id);
 
-    let result = client.try_initialize(&admin, &treasury, &500u32);
+    let result = client.try_initialize(&admin, &treasury, &500u32, &None);
     assert!(result.is_err());
 }
 
@@ -732,14 +732,14 @@ fn test_contribute_rejects_beyond_max_sponsors() {
 
     // MAX_SPONSORS is 20; alice's `fund` call above already used slot 0, so
     // 19 more `contribute` calls exactly fill the cap.
-    for _ in 0..(crate::MAX_SPONSORS - 1) {
+    for _ in 0..(crate::DEFAULT_MAX_SPONSORS - 1) {
         let extra = Address::generate(&env);
         asset_client.mint(&extra, &1_000i128);
         client.contribute(&105u64, &extra, &1_000i128);
     }
     assert_eq!(
         client.get_escrow(&105u64).contributor_count,
-        crate::MAX_SPONSORS
+        crate::DEFAULT_MAX_SPONSORS
     );
 
     // The 21st distinct contribution is rejected.

contracts/escrow/src/types.rs

@@ -38,6 +38,7 @@ pub enum DataKey {
     Admin,
     Treasury,
     FeeBps,
+    MaxSponsors,
     Escrow(u64),
     Contribution(u64, u32), // (issue_id, contribution_index)
 }

contracts/milestones/src/lib.rs

@@ -28,7 +28,8 @@ pub const BPS_DENOMINATOR: i128 = 10_000;
 /// (and any future timeout-triggered wind-down that reuses
 /// `refund_remaining_budget`) to a small, predictable constant regardless
 /// of how popular a release gets. See `docs/milestones-crowdfunding-design.md`.
-pub const MAX_SPONSORS: u32 = 20;
+/// Default maximum number of sponsors if not configured at initialization.
+pub const DEFAULT_MAX_SPONSORS: u32 = 20;
 
 #[contract]
 pub struct MilestonesContract;
@@ -44,6 +45,7 @@ impl MilestonesContract {
         admin: Address,
         treasury: Address,
         fee_bps: u32,
+        max_sponsors: Option<u32>,
     ) -> Result<(), Error> {
         admin.require_auth();
 
@@ -56,6 +58,11 @@ impl MilestonesContract {
         env.storage().instance().set(&DataKey::Admin, &admin);
         env.storage().instance().set(&DataKey::Treasury, &treasury);
         env.storage().instance().set(&DataKey::FeeBps, &fee_bps);
+        let limit = max_sponsors.unwrap_or(DEFAULT_MAX_SPONSORS);
+        if limit == 0 {
+            return Err(Error::InvalidAmount);
+        }
+        env.storage().instance().set(&DataKey::MaxSponsors, &limit);
         Ok(())
     }
 
@@ -144,7 +151,8 @@ impl MilestonesContract {
         if milestone.closed {
             return Err(Error::MilestoneClosed);
         }
-        if milestone.contributor_count >= MAX_SPONSORS {
+        let max_sponsors: u32 = env.storage().instance().get(&DataKey::MaxSponsors).unwrap_or(DEFAULT_MAX_SPONSORS);
+        if milestone.contributor_count >= max_sponsors {
             return Err(Error::TooManySponsors);
         }
 

contracts/milestones/src/test.rs

@@ -21,7 +21,7 @@ fn setup(env: &Env) -> (Address, Address, MilestonesContractClient<'_>) {
     let treasury = Address::generate(env);
     let contract_id = env.register(MilestonesContract, ());
     let client = MilestonesContractClient::new(env, &contract_id);
-    client.initialize(&admin, &treasury, &500u32); // 5% fee
+    client.initialize(&admin, &treasury, &500u32, &None); // 5% fee
     (admin, treasury, client)
 }
 
@@ -109,7 +109,7 @@ fn test_large_split_distributes_dust_by_largest_remainder() {
     let contract_id = env.register(crate::MilestonesContract, ());
     let client = crate::MilestonesContractClient::new(&env, &contract_id);
     // 0% fee so the whole total is distributable.
-    client.initialize(&admin, &treasury, &0u32);
+    client.initialize(&admin, &treasury, &0u32, &None);
 
     // 60 recipients: 59 with alternating 160/170 bps, the last one receiving
     // the leftover of 10000. All 170-bps recipients share an identical
@@ -261,7 +261,7 @@ fn test_initialize_requires_admin_auth() {
     let contract_id = env.register(MilestonesContract, ());
     let client = MilestonesContractClient::new(&env, &contract_id);
 
-    let result = client.try_initialize(&admin, &treasury, &500u32);
+    let result = client.try_initialize(&admin, &treasury, &500u32, &None);
     assert!(result.is_err());
 }
 
@@ -516,14 +516,14 @@ fn test_contribute_rejects_beyond_max_sponsors() {
 
     // MAX_SPONSORS is 20; alice's `create_milestone` above already used
     // slot 0, so 19 more `contribute` calls exactly fill the cap.
-    for _ in 0..(crate::MAX_SPONSORS - 1) {
+    for _ in 0..(crate::DEFAULT_MAX_SPONSORS - 1) {
         let extra = Address::generate(&env);
         asset_client.mint(&extra, &1_000i128);
         client.contribute(&56u64, &extra, &1_000i128);
     }
     assert_eq!(
         client.get_milestone(&56u64).contributor_count,
-        crate::MAX_SPONSORS
+        crate::DEFAULT_MAX_SPONSORS
     );
 
     // The 21st distinct contribution is rejected.

contracts/milestones/src/types.rs

@@ -59,6 +59,7 @@ pub enum DataKey {
     Admin,
     Treasury,
     FeeBps,
+    MaxSponsors,
     Milestone(u64),
     IssueStatus(u64, u64),  // (milestone_id, issue_id)
     Contribution(u64, u32), // (milestone_id, contribution_index)