standard json output: skip serializing keys instead of emitting a nul…

…l object (#52)

Signed-off-by: Cyrill Leutwiler <[email protected]>

crates/solidity/src/solc/standard_json/output/contract/evm/mod.rs

@@ -20,15 +20,17 @@ use self::extra_metadata::ExtraMetadata;
 #[serde(rename_all = "camelCase")]
 pub struct EVM {
     /// The contract EVM legacy assembly code.
-    #[serde(rename = "legacyAssembly")]
+    #[serde(rename = "legacyAssembly", skip_serializing_if = "Option::is_none")]
     pub assembly: Option<Assembly>,
     /// The contract PolkaVM assembly code.
-    #[serde(rename = "assembly")]
+    #[serde(rename = "assembly", skip_serializing_if = "Option::is_none")]
     pub assembly_text: Option<String>,
     /// The contract bytecode.
     /// Is reset by that of PolkaVM before yielding the compiled project artifacts.
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub bytecode: Option<Bytecode>,
     /// The contract deployed bytecode.
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub deployed_bytecode: Option<DeployedBytecode>,
     /// The contract function signatures.
     #[serde(default, skip_serializing_if = "Option::is_none")]