refactor checkpoint

veilid-core/src/veilid_api/serialize_helpers.rs

@@ -0,0 +1,24 @@
+use super::*;
+
+pub fn deserialize_json<'a, T: de::Deserialize<'a>>(
+    arg: &'a str,
+) -> Result<T, super::VeilidAPIError> {
+    serde_json::from_str(arg).map_err(|e| VeilidAPIError::ParseError {
+        message: e.to_string(),
+        value: String::new(),
+    })
+}
+
+pub fn deserialize_opt_json<T: de::DeserializeOwned>(
+    arg: Option<String>,
+) -> Result<T, VeilidAPIError> {
+    let arg = arg.ok_or_else(|| VeilidAPIError::ParseError {
+        message: "invalid null string".to_owned(),
+        value: String::new(),
+    })?;
+    deserialize_json(&arg)
+}
+
+pub fn serialize_json<T: Serialize>(val: T) -> String {
+    serde_json::to_string(&val).expect("failed to serialize json value")
+}