fn derive_avro_schema()

in avro_derive/src/lib.rs [62:112]

• 51 lines of code
• 5 McCabe index (conditional complexity)

fn derive_avro_schema(input: &mut DeriveInput) -> Result<TokenStream, Vec<syn::Error>> {
    let named_type_options =
        NamedTypeOptions::from_attributes(&input.attrs[..]).map_err(darling_to_syn)?;
    let full_schema_name = vec![named_type_options.namespace, Some(input.ident.to_string())]
        .into_iter()
        .flatten()
        .collect::<Vec<String>>()
        .join(".");
    let schema_def = match &input.data {
        syn::Data::Struct(s) => get_data_struct_schema_def(
            &full_schema_name,
            named_type_options
                .doc
                .or_else(|| extract_outer_doc(&input.attrs)),
            named_type_options.alias,
            s,
            input.ident.span(),
        )?,
        syn::Data::Enum(e) => get_data_enum_schema_def(
            &full_schema_name,
            named_type_options
                .doc
                .or_else(|| extract_outer_doc(&input.attrs)),
            named_type_options.alias,
            e,
            input.ident.span(),
        )?,
        _ => {
            return Err(vec![syn::Error::new(
                input.ident.span(),
                "AvroSchema derive only works for structs and simple enums ",
            )])
        }
    };
    let ident = &input.ident;
    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
    Ok(quote! {
        impl #impl_generics apache_avro::schema::derive::AvroSchemaComponent for #ident #ty_generics #where_clause {
            fn get_schema_in_ctxt(named_schemas: &mut std::collections::HashMap<apache_avro::schema::Name, apache_avro::schema::Schema>, enclosing_namespace: &Option<String>) -> apache_avro::schema::Schema {
                let name =  apache_avro::schema::Name::new(#full_schema_name).expect(&format!("Unable to parse schema name {}", #full_schema_name)[..]).fully_qualified_name(enclosing_namespace);
                let enclosing_namespace = &name.namespace;
                if named_schemas.contains_key(&name) {
                    apache_avro::schema::Schema::Ref{name: name.clone()}
                } else {
                    named_schemas.insert(name.clone(), apache_avro::schema::Schema::Ref{name: name.clone()});
                    #schema_def
                }
            }
        }
    })
}