fix: Felt serde

.github/workflows/ci.yaml

@@ -52,6 +52,10 @@ jobs:
           cd ensure-no_std
           cargo build
 
+      - name: Run cargo build for all workspace
+        run: |
+          cargo build --workspace
+
       - name: Run cargo build ensure-no_std crate for wasm
         run: |
           cd ensure-no_std

examples/merkle-tree-cli/Cargo.toml

@@ -11,7 +11,7 @@ path = "src/main.rs"
 
 [dependencies]
 clap = { version = "4.4.6", features = ["derive"] }
-lambdaworks-crypto = { workspace = true }
+lambdaworks-crypto = { workspace = true, features = ["serde"]}
 lambdaworks-math = { workspace = true, features = ["lambdaworks-serde-string"] }
 serde = { version = "1.0" }
 serde_json = "1"

math/src/field/element.rs

@@ -552,6 +552,7 @@ impl<F: IsPrimeField> Serialize for FieldElement<F> {
     where
         S: Serializer,
     {
+        use crate::alloc::string::ToString;
         let mut state = serializer.serialize_struct("FieldElement", 1)?;
         state.serialize_field("value", &F::representative(self.value()).to_string())?;
         state.end()
@@ -653,7 +654,7 @@ impl<'de, F: IsPrimeField> Deserialize<'de> for FieldElement<F> {
             where
                 M: MapAccess<'de>,
             {
-                let mut value = None;
+                let mut value: Option<&str> = None;
                 while let Some(key) = map.next_key()? {
                     match key {
                         Field::Value => {
@@ -665,22 +666,22 @@ impl<'de, F: IsPrimeField> Deserialize<'de> for FieldElement<F> {
                     }
                 }
                 let value = value.ok_or_else(|| de::Error::missing_field("value"))?;
-                Ok(FieldElement::from_hex(&value).unwrap())
+                FieldElement::from_hex(&value).map_err(|_| de::Error::custom("invalid hex"))
             }
 
             fn visit_seq<S>(self, mut seq: S) -> Result<FieldElement<F>, S::Error>
             where
                 S: SeqAccess<'de>,
             {
-                let mut value = None;
+                let mut value: Option<&str> = None;
                 while let Some(val) = seq.next_element()? {
                     if value.is_some() {
                         return Err(de::Error::duplicate_field("value"));
                     }
                     value = Some(val);
                 }
                 let value = value.ok_or_else(|| de::Error::missing_field("value"))?;
-                Ok(FieldElement::from_hex(&value).unwrap())
+                FieldElement::from_hex(&value).map_err(|_| de::Error::custom("invalid hex"))
             }
         }