#[macro_use] mod macros; use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree}; use quote::{quote, ToTokens}; use std::iter::FromIterator; use syn::{parse_quote, Expr, Type, TypePath}; #[test] fn parse_interpolated_leading_component() { // mimics the token stream corresponding to `$mod::rest` let tokens = TokenStream::from_iter(vec![ TokenTree::Group(Group::new(Delimiter::None, quote! { first })), TokenTree::Punct(Punct::new(':', Spacing::Joint)), TokenTree::Punct(Punct::new(':', Spacing::Alone)), TokenTree::Ident(Ident::new("rest", Span::call_site())), ]); snapshot!(tokens.clone() as Expr, @r###" Expr::Path { path: Path { segments: [ PathSegment { ident: "first", arguments: None, }, PathSegment { ident: "rest", arguments: None, }, ], }, } "###); snapshot!(tokens as Type, @r###" Type::Path { path: Path { segments: [ PathSegment { ident: "first", arguments: None, }, PathSegment { ident: "rest", arguments: None, }, ], }, } "###); } #[test] fn print_incomplete_qpath() { // qpath with `as` token let mut ty: TypePath = parse_quote!(::Q); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self as A > :: Q`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self as A > ::`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self >`) "###); assert!(ty.path.segments.pop().is_none()); // qpath without `as` token let mut ty: TypePath = parse_quote!(::A::B); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self > :: A :: B`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self > :: A ::`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`< Self > ::`) "###); assert!(ty.path.segments.pop().is_none()); // normal path let mut ty: TypePath = parse_quote!(Self::A::B); snapshot!(ty.to_token_stream(), @r###" TokenStream(`Self :: A :: B`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`Self :: A ::`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(`Self ::`) "###); assert!(ty.path.segments.pop().is_some()); snapshot!(ty.to_token_stream(), @r###" TokenStream(``) "###); assert!(ty.path.segments.pop().is_none()); } #[test] fn parse_parenthesized_path_arguments_with_disambiguator() { #[rustfmt::skip] let tokens = quote!(FnOnce::() -> !); snapshot!(tokens as Type, @r###" Type::Path { path: Path { segments: [ PathSegment { ident: "FnOnce", arguments: PathArguments::Parenthesized { output: Type( Type::Never, ), }, }, ], }, } "###); }