address PR feedback: filter empty env vars per-candidate, add JSON wire-format test, rename tests

- build.rs: push empty-string filter into each candidate of build_id/commit_sha chains so an explicitly-set-but-empty primary var (e.g. PET_COMMIT_SHA from an unset GitHub Actions context) doesn't short-circuit fallbacks.
- jsonrpc.rs: add test_info_response_serializes_camel_case_and_omits_none covering camelCase rename + skip_serializing_if without requiring CI env vars at compile time.
- rename existing tests to ..._optional_build_metadata for accurate scope.

Author: StellaHuang95

crates/pet/build.rs

@@ -8,20 +8,34 @@ fn main() {
     println!("cargo:rerun-if-env-changed=BUILD_SOURCEVERSION");
     println!("cargo:rerun-if-env-changed=GITHUB_SHA");
 
+    // Filter empties per-candidate so an explicitly-set-but-empty primary var
+    // doesn't short-circuit the fallback chain (e.g., `PET_BUILD_ID=""`).
     if let Some(build_id) = std::env::var("PET_BUILD_ID")
         .ok()
-        .or_else(|| std::env::var("BUILD_BUILDID").ok())
         .filter(|value| !value.is_empty())
+        .or_else(|| {
+            std::env::var("BUILD_BUILDID")
+                .ok()
+                .filter(|value| !value.is_empty())
+        })
     {
         println!("cargo:rustc-env=PET_BUILD_ID={build_id}");
     }
 
     // BUILD_SOURCEVERSION is set by Azure Pipelines; GITHUB_SHA by GitHub Actions.
     if let Some(commit_sha) = std::env::var("PET_COMMIT_SHA")
         .ok()
-        .or_else(|| std::env::var("BUILD_SOURCEVERSION").ok())
-        .or_else(|| std::env::var("GITHUB_SHA").ok())
         .filter(|value| !value.is_empty())
+        .or_else(|| {
+            std::env::var("BUILD_SOURCEVERSION")
+                .ok()
+                .filter(|value| !value.is_empty())
+        })
+        .or_else(|| {
+            std::env::var("GITHUB_SHA")
+                .ok()
+                .filter(|value| !value.is_empty())
+        })
     {
         println!("cargo:rustc-env=PET_COMMIT_SHA={commit_sha}");
     }

crates/pet/src/jsonrpc.rs

@@ -1542,7 +1542,7 @@ mod tests {
     }
 
     #[test]
-    fn test_info_response_uses_package_version_and_optional_build_id() {
+    fn test_info_response_uses_package_version_and_optional_build_metadata() {
         let info = InfoResponse::current();
 
         assert_eq!(info.pet_version, env!("CARGO_PKG_VERSION"));
@@ -1558,6 +1558,31 @@ mod tests {
             .is_none_or(|commit_sha| !commit_sha.is_empty()));
     }
 
+    #[test]
+    fn test_info_response_serializes_camel_case_and_omits_none() {
+        // Guards the JSON wire format (camelCase rename + skip_serializing_if)
+        // independently of whether CI env vars were set at compile time.
+        let json = serde_json::to_value(InfoResponse {
+            pet_version: "1.2.3".to_string(),
+            build_id: Some("42".to_string()),
+            commit_sha: Some("abc123".to_string()),
+        })
+        .unwrap();
+        assert_eq!(json["petVersion"], "1.2.3");
+        assert_eq!(json["buildId"], "42");
+        assert_eq!(json["commitSha"], "abc123");
+
+        let json = serde_json::to_value(InfoResponse {
+            pet_version: "1.2.3".to_string(),
+            build_id: None,
+            commit_sha: None,
+        })
+        .unwrap();
+        assert_eq!(json["petVersion"], "1.2.3");
+        assert!(json.get("buildId").is_none());
+        assert!(json.get("commitSha").is_none());
+    }
+
     #[test]
     fn test_parse_refresh_options_rejects_non_empty_array() {
         assert!(parse_refresh_options(json!([{"searchKind": "Conda"}])).is_err());

crates/pet/tests/jsonrpc_server_test.rs

@@ -111,7 +111,7 @@ fn assert_single_environment(
 }
 
 #[test]
-fn info_reports_pet_version_and_optional_build_id() {
+fn info_reports_pet_version_and_optional_build_metadata() {
     let client = PetJsonRpcClient::spawn().expect("failed to spawn PET server");
 
     let info = client.info().expect("info request failed");