fn type_to_schema_expr()

in avro_derive/src/lib.rs [242:283]

• 39 lines of code
• 4 McCabe index (conditional complexity)

fn type_to_schema_expr(ty: &Type) -> Result<TokenStream, Vec<syn::Error>> {
    if let Type::Path(p) = ty {
        let type_string = p.path.segments.last().unwrap().ident.to_string();

        let schema = match &type_string[..] {
            "bool" => quote! {apache_avro::schema::Schema::Boolean},
            "i8" | "i16" | "i32" | "u8" | "u16" => quote! {apache_avro::schema::Schema::Int},
            "u32" | "i64" => quote! {apache_avro::schema::Schema::Long},
            "f32" => quote! {apache_avro::schema::Schema::Float},
            "f64" => quote! {apache_avro::schema::Schema::Double},
            "String" | "str" => quote! {apache_avro::schema::Schema::String},
            "char" => {
                return Err(vec![syn::Error::new_spanned(
                    ty,
                    "AvroSchema: Cannot guarantee successful deserialization of this type",
                )])
            }
            "u64" => {
                return Err(vec![syn::Error::new_spanned(
                ty,
                "Cannot guarantee successful serialization of this type due to overflow concerns",
            )])
            } // Can't guarantee serialization type
            _ => {
                // Fails when the type does not implement AvroSchemaComponent directly
                // TODO check and error report with something like https://docs.rs/quote/1.0.15/quote/macro.quote_spanned.html#example
                type_path_schema_expr(p)
            }
        };
        Ok(schema)
    } else if let Type::Array(ta) = ty {
        let inner_schema_expr = type_to_schema_expr(&ta.elem)?;
        Ok(quote! {apache_avro::schema::Schema::array(#inner_schema_expr)})
    } else if let Type::Reference(tr) = ty {
        type_to_schema_expr(&tr.elem)
    } else {
        Err(vec![syn::Error::new_spanned(
            ty,
            format!("Unable to generate schema for type: {ty:?}"),
        )])
    }
}