clap/clap_derive/tests/nested.rs
Aaron Hill c837b28552
fix(clap_derive): Unwrap syn::TypeGroup when checking field types
Due to macro expansions, a `syn` type may be wrapped in multiple
'layers' of `syn::Type::Group`. However, `clap_derive` currently does
not check for `syn::Type::Group`, which will cause an `Option` (along
with other matched types) to fail to be detected when it results from a
macro expansion.

This commit 'unwraps' outer type groups before checking the
user-provided types against well-known types. Currently, these groups
may not be present due to a rustc bug (rust-lang/rust#43081)

However, once https://github.com/rust-lang/rust/pull/73084 is merged,
these groups will be present in more cases. This commit makes `clap`
compatible with both older and newer versions of rustc.
2020-06-29 11:25:55 -04:00

33 lines
1.1 KiB
Rust

// Copyright 2018 Guillaume Pinot (@TeXitoi) <texitoi@texitoi.eu>,
// Kevin Knapp (@kbknapp) <kbknapp@gmail.com>, and
// Andrew Hobden (@hoverbear) <andrew@hoverbear.org>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//
// This work was derived from Structopt (https://github.com/TeXitoi/structopt)
// commit#ea76fa1b1b273e65e3b0b1046643715b49bec51f which is licensed under the
// MIT/Apache 2.0 license.
use clap::Clap;
// Tests that clap_derive properly detects an `Option` field
// that results from a macro expansion
#[test]
fn use_option() {
macro_rules! expand_ty {
($name:ident: $ty:ty) => {
#[derive(Clap)]
struct Outer {
#[clap(short, long)]
#[allow(dead_code)]
$name: $ty,
}
};
}
expand_ty!(my_field: Option<String>);
}