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use crate::util::prelude::*;
pub(crate) trait VisibilityExt {
/// Returns [`syn::Visibility`] that is equivalent to the current visibility
/// but for an item that is inside of the child module. This basically does
/// the following conversions.
///
/// - `pub` -> `pub` (unchanged)
/// - `pub(crate)` -> `pub(crate)` (unchanged)
/// - `pub(self)` or ` ` (default private visibility) -> `pub(super)`
/// - `pub(super)` -> `pub(in super::super)`
/// - `pub(in relative::path)` -> `pub(in super::relative::path)`
/// - `pub(in ::absolute::path)` -> `pub(in ::absolute::path)` (unchanged)
/// - `pub(in crate::path)` -> `pub(in crate::path)` (unchanged)
/// - `pub(in self::path)` -> `pub(in super::path)`
/// - `pub(in super::path)` -> `pub(in super::super::path)`
///
/// Note that absolute paths in `pub(in ...)` are not supported with Rust 2018+,
/// according to the [Rust reference]:
///
/// > Edition Differences: Starting with the 2018 edition, paths for pub(in path)
/// > must start with crate, self, or super. The 2015 edition may also use paths
/// > starting with :: or modules from the crate root.
///
/// # Errors
///
/// This function may return an error if it encounters some unexpected syntax.
/// For example, some syntax that isn't known to the latest version of Rust
/// this code was written for.
///
/// [Rust reference]: https://doc.rust-lang.org/reference/visibility-and-privacy.html#pubin-path-pubcrate-pubsuper-and-pubself
fn into_equivalent_in_child_module(self) -> Result<syn::Visibility>;
}
impl VisibilityExt for syn::Visibility {
fn into_equivalent_in_child_module(mut self) -> Result<syn::Visibility> {
match &mut self {
Self::Public(_) => Ok(self),
Self::Inherited => Ok(syn::parse_quote!(pub(super))),
Self::Restricted(syn::VisRestricted {
path,
in_token: None,
..
}) => {
if path.is_ident("crate") {
return Ok(self);
}
if path.is_ident("super") {
return Ok(syn::parse_quote!(pub(in super::#path)));
}
if path.is_ident("self") {
return Ok(syn::parse_quote!(pub(super)));
}
bail!(
&self,
"Expected either `crate` or `super` or `in some::path` inside of \
`pub(...)` but got something else. This may be because a new \
syntax for visibility was released in a newer Rust version, \
but this crate doesn't support it."
);
}
Self::Restricted(syn::VisRestricted {
path,
in_token: Some(_),
..
}) => {
if path.leading_colon.is_some() {
return Ok(self);
}
if path.starts_with_segment("crate") {
return Ok(self);
}
if let Some(first_segment) = path.segments.first_mut() {
if first_segment.ident == "self" {
let span = first_segment.ident.span();
*first_segment = syn::parse_quote_spanned!(span=>super);
return Ok(self);
}
}
path.segments.insert(0, syn::parse_quote!(super));
Ok(self)
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use syn::parse_quote as pq;
#[test]
fn all_tests() {
#[track_caller]
// One less `&` character to type in assertions
#[allow(clippy::needless_pass_by_value)]
fn test(vis: syn::Visibility, expected: syn::Visibility) {
let actual = vis.into_equivalent_in_child_module().unwrap();
assert!(
actual == expected,
"got:\nactual: {}\nexpected: {}",
actual.to_token_stream(),
expected.to_token_stream()
);
}
test(pq!(pub), pq!(pub));
test(pq!(pub(crate)), pq!(pub(crate)));
test(pq!(pub(self)), pq!(pub(super)));
test(pq!(), pq!(pub(super)));
test(pq!(pub(super)), pq!(pub(in super::super)));
test(
pq!(pub(in relative::path)),
pq!(pub(in super::relative::path)),
);
test(pq!(pub(in crate::path)), pq!(pub(in crate::path)));
test(pq!(pub(in self::path)), pq!(pub(in super::path)));
test(pq!(pub(in super::path)), pq!(pub(in super::super::path)));
test(pq!(pub(in ::absolute::path)), pq!(pub(in ::absolute::path)));
}
}