feat: Add serialization traits to Status (#499)

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 * Changed the return type of `stored_chunks` to a struct.
 * Added a prime256v1-based `Identity` impl to complement the ed25519 and secp256k1 `Identity` impls.
+* Added serde and candid serialization traits to the `Status` type.
 
 ## [0.32.0] - 2024-01-18
 

ic-agent/Cargo.toml

@@ -76,6 +76,7 @@ web-sys = { version = "0.3", features = ["Window"], optional = true }
 
 [dev-dependencies]
 serde_json = "1.0.79"
+candid = { workspace = true, features = ["value"]}
 
 [target.'cfg(not(target_family = "wasm"))'.dev-dependencies]
 tokio = { version = "1.24.2", features = ["full"] }

ic-agent/src/agent/status.rs

@@ -1,11 +1,15 @@
 //! Types for interacting with the status endpoint of a replica. See [`Status`] for details.
 
+use candid::{CandidType, Deserialize};
+use serde::Serialize;
 use std::{collections::BTreeMap, fmt::Debug};
 
 /// Value returned by the status endpoint of a replica. This is a loose mapping to CBOR values.
 /// Because the agent should not return [`serde_cbor::Value`] directly across API boundaries,
 /// we reimplement it as [`Value`] here.
-#[derive(Debug, Ord, PartialOrd, Eq, PartialEq, Clone, Hash)]
+#[derive(
+    Debug, Ord, PartialOrd, Eq, PartialEq, Clone, Hash, CandidType, Serialize, Deserialize,
+)]
 pub enum Value {
     /// See [`Null`](serde_cbor::Value::Null).
     Null,
@@ -40,7 +44,7 @@ impl std::fmt::Display for Value {
 
 /// The structure returned by [`super::Agent::status`], containing the information returned
 /// by the status endpoint of a replica.
-#[derive(Debug, Ord, PartialOrd, PartialEq, Eq)]
+#[derive(Debug, Ord, PartialOrd, PartialEq, Eq, CandidType, Deserialize, Serialize)]
 pub struct Status {
     /// Optional. The precise git revision of the Internet Computer Protocol implementation.
     pub impl_version: Option<String>,
@@ -55,6 +59,47 @@ pub struct Status {
     pub values: BTreeMap<String, Box<Value>>,
 }
 
+#[test]
+fn can_serilaize_status_as_json() {
+    let status = Status {
+        impl_version: None,
+        replica_health_status: None,
+        root_key: None,
+        values: BTreeMap::new(),
+    };
+    let expected_json =
+        r#"{"impl_version":null,"replica_health_status":null,"root_key":null,"values":{}}"#;
+    let actual_json = serde_json::to_string(&status).expect("Failed to serialize as JSON");
+    assert_eq!(expected_json, actual_json);
+}
+#[test]
+fn can_serialize_status_as_idl() {
+    use candid::types::value::IDLValue;
+    use candid::{Encode, IDLArgs, Result as CandidResult, TypeEnv};
+    let status = Status {
+        impl_version: Some("Foo".to_string()),
+        replica_health_status: None,
+        root_key: None,
+        values: BTreeMap::new(),
+    };
+    // Expresses data as IDLValue.  Then use .to_string() to convert to text-form candid.
+    // TODO: This function has been added to the Candid library and will be available in the next
+    // release.  Then, this definition here can be deleted.
+    pub fn try_from_candid_type<T>(data: &T) -> CandidResult<IDLValue>
+    where
+        T: CandidType,
+    {
+        let blob = Encode!(data)?;
+        let args = IDLArgs::from_bytes_with_types(&blob, &TypeEnv::default(), &[T::ty()])?;
+        Ok(args.args[0].clone())
+    }
+    let expected_idl = "record {\n  values = vec {};\n  replica_health_status = null;\n  impl_version = opt \"Foo\";\n  root_key = null;\n}";
+    let actual_idl = try_from_candid_type(&status)
+        .expect("Failed to convert to idl")
+        .to_string();
+    assert_eq!(expected_idl, actual_idl);
+}
+
 impl std::fmt::Display for Status {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.write_str("{\n")?;