From 7dfa9675abc5e2e25bb9e5681c7de86a56cfbb30 Mon Sep 17 00:00:00 2001
From: Julianemeka <julianemeka07@gmail.com>
Date: Thu, 4 Jun 2026 02:06:32 +0000
Subject: [PATCH] feat: add ping health check endpoint (#87)

- Implement ping function returning ledger timestamp
- Add unit test for ping
- Document ping in README and CHANGELOG
---
 CHANGELOG.md                                      | 1 +
 README.md                                         | 9 +++++++++
 contracts/payment-processing-contract/src/lib.rs  | 7 +++++++
 contracts/payment-processing-contract/src/test.rs | 9 +++++++++
 4 files changed, 26 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 158407a..70a944b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+- Add `ping` endpoint to return current ledger timestamp for health monitoring.
 - Remove unused `StorageError` variant from the payment contract ABI.
 - Harden payment and refund flows against external token transfer re-entrancy by committing state before external calls.
 - Add best-effort zero/burn admin address validation and test coverage for invalid admin assignment.
diff --git a/README.md b/README.md
index 768eb27..a74922f 100644
--- a/README.md
+++ b/README.md
@@ -216,6 +216,15 @@ stellar contract invoke --id $CONTRACT_ID --source-account <KEY> --network local
   -- get_version
 ```
 
+#### `ping`
+
+Health check endpoint. Returns the current ledger timestamp (u64).
+
+```bash
+stellar contract invoke --id $CONTRACT_ID --source-account <KEY> --network local \
+  -- ping
+```
+
 #### `upgrade`
 
 Upgrades the contract WASM in-place. Admin only. Existing storage and contract address are preserved.
diff --git a/contracts/payment-processing-contract/src/lib.rs b/contracts/payment-processing-contract/src/lib.rs
index abd76c2..7998898 100644
--- a/contracts/payment-processing-contract/src/lib.rs
+++ b/contracts/payment-processing-contract/src/lib.rs
@@ -57,6 +57,13 @@ impl PaymentContract {
         storage::get_contract_version(&env)
     }
 
+    // ── Health check ──────────────────────────────────────────────────────────
+
+    /// Health check endpoint. Returns the current ledger timestamp.
+    pub fn ping(env: Env) -> u64 {
+        env.ledger().timestamp()
+    }
+
     // ── Merchant management ───────────────────────────────────────────────────
 
     pub fn register_merchant(
diff --git a/contracts/payment-processing-contract/src/test.rs b/contracts/payment-processing-contract/src/test.rs
index f6228c5..6607228 100644
--- a/contracts/payment-processing-contract/src/test.rs
+++ b/contracts/payment-processing-contract/src/test.rs
@@ -227,6 +227,15 @@ fn test_get_version_after_set_admin() {
     assert_eq!(client.get_version(), 1);
 }
 
+#[test]
+fn test_ping() {
+    let (env, client) = setup();
+    env.ledger().with_mut(|li| {
+        li.timestamp = 12345;
+    });
+    assert_eq!(client.ping(), 12345);
+}
+
 // ── Merchant tests ────────────────────────────────────────────────────────────
 
 #[test]