fix(solc): when compiler-out metadata is empty and there's no `internalType` (#1182)

* add another compiler-out with fixes

* update changelog

CHANGELOG.md

@@ -111,6 +111,7 @@
 - Add support for library linking and make `Bytecode`'s `object` filed an
   `enum BytecodeObject` [#656](https://github.com/gakonst/ethers-rs/pull/656).
 - Nit: remove accidentally doubled double-quotes in an error message
+- Fix when compiler-out metadata is empty and there's no internalType [#1182](https://github.com/gakonst/ethers-rs/pull/1182)
 
 ### 0.6.0
 

ethers-solc/src/artifacts/mod.rs

@@ -761,7 +761,7 @@ pub struct SolcAbi {
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Item {
     #[serde(rename = "internalType")]
-    pub internal_type: String,
+    pub internal_type: Option<String>,
     pub name: String,
     #[serde(rename = "type")]
     pub put_type: String,
@@ -1081,7 +1081,13 @@ pub struct UserDoc {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub kind: Option<String>,
     #[serde(default, skip_serializing_if = "::std::collections::BTreeMap::is_empty")]
-    pub methods: BTreeMap<String, BTreeMap<String, String>>,
+    pub methods: BTreeMap<String, MethodNotice>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub notice: Option<String>,
+}
+
+#[derive(Clone, Debug, Default, Serialize, Deserialize, Eq, PartialEq)]
+pub struct MethodNotice {
     #[serde(default, skip_serializing_if = "Option::is_none")]
     pub notice: Option<String>,
 }

ethers-solc/src/artifacts/serde_helpers.rs

@@ -63,6 +63,10 @@ pub mod json_string_opt {
         T: DeserializeOwned,
     {
         if let Some(s) = Option::<String>::deserialize(deserializer)? {
+            if s.is_empty() {
+                return Ok(None)
+            }
+
             serde_json::from_str(&s).map_err(de::Error::custom).map(Some)
         } else {
             Ok(None)