feat: Add get_icp_xdr_conversion_rate to mock cmc

CHANGELOG.md

@@ -4,6 +4,10 @@
 
 ## [Unreleased] - ReleaseDate
 
+## [1.0.2] - 2024-10-28
+* Added `get_icp_xdr_conversion_rate` to mock CMC
+No changes to the cycles ledger. Released because a community project relies on the mock CMC and would like to have this feature available.
+
 ## [1.0.1] - 2024-08-22
 * Update `ic-cdk` dependency to patch a security issue.
 
@@ -28,7 +32,8 @@
 ## [0.1.0] - 2023-07-12
 
 <!-- next-url -->
-[Unreleased]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v1.0.1...HEAD
+[Unreleased]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v1.0.2...HEAD
+[1.0.2]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v1.0.1...cycles-ledger-v1.0.2
 [1.0.1]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v1.0.0...cycles-ledger-v1.0.1
 [1.0.0]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v0.6.0...cycles-ledger-v1.0.0
 [0.6.0]: https://github.com/dfinity/cycles-ledger/compare/cycles-ledger-v0.5.0...cycles-ledger-v0.6.0

fake-cmc/fake-cmc.did

@@ -22,8 +22,21 @@ type SubnetSelection = variant {
     Filter : SubnetFilter;
     Subnet : record { subnet : principal };
 };
+
+type IcpXdrConversionRate = record {
+  timestamp_seconds : nat64;
+  xdr_permyriad_per_icp : nat64;
+};
+
+type IcpXdrConversionRateResponse = record {
+  data : IcpXdrConversionRate;
+  hash_tree : blob;
+  certificate : blob;
+};
+
 service : {
     create_canister : (CmcCreateCanisterArgs) -> (CmcCreateCanisterResult);
     fail_next_create_canister_with : (CmcCreateCanisterError) -> ();
     last_create_canister_args : () -> (CmcCreateCanisterArgs) query;
+    get_icp_xdr_conversion_rate : () -> (IcpXdrConversionRateResponse) query;
 };

fake-cmc/src/lib.rs

@@ -1,8 +1,35 @@
+use candid::CandidType;
 use cycles_ledger::endpoints::{CmcCreateCanisterArgs, CmcCreateCanisterError};
+use ic_cdk::api::time;
 use serde::Deserialize;
 
+const NANOSECONDS_PER_SECOND: u64 = 1_000_000_000;
+
 #[derive(Debug, Deserialize, Eq, PartialEq, Default)]
 pub struct State {
     pub last_create_canister_args: Option<CmcCreateCanisterArgs>,
     pub fail_next_create_canister_with: Option<CmcCreateCanisterError>,
 }
+
+#[derive(CandidType, Deserialize, Default)]
+pub struct IcpXdrConversionRateResponse {
+    pub certificate: Vec<u8>,
+    pub data: IcpXdrConversionRate,
+    pub hash_tree: Vec<u8>,
+}
+
+#[derive(CandidType, Deserialize)]
+pub struct IcpXdrConversionRate {
+    pub xdr_permyriad_per_icp: u64,
+    pub timestamp_seconds: u64,
+}
+
+impl Default for IcpXdrConversionRate {
+    fn default() -> Self {
+        Self {
+            // mocked value
+            xdr_permyriad_per_icp: 50_000,
+            timestamp_seconds: time() / NANOSECONDS_PER_SECOND,
+        }
+    }
+}

fake-cmc/src/main.rs

@@ -1,7 +1,7 @@
 use candid::{candid_method, Principal};
 use core::panic;
 use cycles_ledger::endpoints::{CmcCreateCanisterArgs, CmcCreateCanisterError};
-use fake_cmc::State;
+use fake_cmc::{IcpXdrConversionRateResponse, State};
 use ic_cdk::{
     api::{
         call::{msg_cycles_accept128, msg_cycles_available128},
@@ -75,6 +75,12 @@ fn fail_next_create_canister_with(error: CmcCreateCanisterError) {
     STATE.with(|s| s.borrow_mut().fail_next_create_canister_with = Some(error))
 }
 
+#[candid_method]
+#[query]
+fn get_icp_xdr_conversion_rate() -> IcpXdrConversionRateResponse {
+    Default::default()
+}
+
 #[candid_method]
 #[query]
 fn last_create_canister_args() -> CmcCreateCanisterArgs {