proc-macro2 0.2.3

A stable implementation of the upcoming new `proc_macro` API. Comes with an option, off by default, to also reimplement itself in terms of the upstream unstable API.
Documentation
extern crate proc_macro2;

use std::str;

use proc_macro2::{Term, Literal, TokenStream};

#[cfg(procmacro2_semver_exempt)]
use proc_macro2::TokenNode;

#[cfg(procmacro2_semver_exempt)]
#[cfg(not(feature = "nightly"))]
use proc_macro2::Span;

#[test]
fn symbols() {
    assert_eq!(Term::intern("foo").as_str(), "foo");
    assert_eq!(Term::intern("bar").as_str(), "bar");
}

#[test]
fn literals() {
    assert_eq!(Literal::string("foo").to_string(), "\"foo\"");
    assert_eq!(Literal::string("\"").to_string(), "\"\\\"\"");
    assert_eq!(Literal::float(10.0).to_string(), "10.0");
}

#[test]
fn roundtrip() {
    fn roundtrip(p: &str) {
        println!("parse: {}", p);
        let s = p.parse::<TokenStream>().unwrap().to_string();
        println!("first: {}", s);
        let s2 = s.to_string().parse::<TokenStream>().unwrap().to_string();
        assert_eq!(s, s2);
    }
    roundtrip("a");
    roundtrip("<<");
    roundtrip("<<=");
    roundtrip("
        /// a
        wut
    ");
    roundtrip("
        1
        1.0
        1f32
        2f64
        1usize
        4isize
        4e10
        1_000
        1_0i32
        8u8
        9
        0
        0xffffffffffffffffffffffffffffffff
    ");
    roundtrip("'a");
    roundtrip("'static");
    roundtrip("'\\u{10__FFFF}'");
    roundtrip("\"\\u{10_F0FF__}foo\\u{1_0_0_0__}\"");
}

#[test]
fn fail() {
    fn fail(p: &str) {
        if p.parse::<TokenStream>().is_ok() {
            panic!("should have failed to parse: {}", p);
        }
    }
    fail("1x");
    fail("1u80");
    fail("1f320");
    fail("' static");
    fail("'mut");
}

#[cfg(procmacro2_semver_exempt)]
#[test]
fn span_test() {
    fn check_spans(p: &str, mut lines: &[(usize, usize, usize, usize)]) {
        let ts = p.parse::<TokenStream>().unwrap();
        check_spans_internal(ts, &mut lines);
    }

    fn check_spans_internal(
        ts: TokenStream,
        lines: &mut &[(usize, usize, usize, usize)],
    ) {
        for i in ts {
            if let Some((&(sline, scol, eline, ecol), rest)) = lines.split_first() {
                *lines = rest;

                let start = i.span.start();
                assert_eq!(start.line, sline, "sline did not match for {}", i);
                assert_eq!(start.column, scol, "scol did not match for {}", i);

                let end = i.span.end();
                assert_eq!(end.line, eline, "eline did not match for {}", i);
                assert_eq!(end.column, ecol, "ecol did not match for {}", i);

                match i.kind {
                    TokenNode::Group(_, stream) =>
                        check_spans_internal(stream, lines),
                    _ => {}
                }
            }
        }
    }

    check_spans("\
/// This is a document comment
testing 123
{
  testing 234
}", &[
    (1, 0, 1, 30),
    (2, 0, 2, 7),
    (2, 8, 2, 11),
    (3, 0, 5, 1),
    (4, 2, 4, 9),
    (4, 10, 4, 13),
]);
}

#[cfg(procmacro2_semver_exempt)]
#[cfg(not(feature = "nightly"))]
#[test]
fn default_span() {
    let start = Span::call_site().start();
    assert_eq!(start.line, 1);
    assert_eq!(start.column, 0);
    let end = Span::call_site().end();
    assert_eq!(end.line, 1);
    assert_eq!(end.column, 0);
    let source_file = Span::call_site().source_file();
    assert_eq!(source_file.path().to_string(), "<unspecified>");
    assert!(!source_file.is_real());
}

#[cfg(procmacro2_semver_exempt)]
#[test]
fn span_join() {
    let source1 =
        "aaa\nbbb".parse::<TokenStream>().unwrap().into_iter().collect::<Vec<_>>();
    let source2 =
        "ccc\nddd".parse::<TokenStream>().unwrap().into_iter().collect::<Vec<_>>();

    assert!(source1[0].span.source_file() != source2[0].span.source_file());
    assert_eq!(source1[0].span.source_file(), source1[1].span.source_file());

    let joined1 = source1[0].span.join(source1[1].span);
    let joined2 = source1[0].span.join(source2[0].span);
    assert!(joined1.is_some());
    assert!(joined2.is_none());

    let start = joined1.unwrap().start();
    let end = joined1.unwrap().end();
    assert_eq!(start.line, 1);
    assert_eq!(start.column, 0);
    assert_eq!(end.line, 2);
    assert_eq!(end.column, 3);

    assert_eq!(joined1.unwrap().source_file(), source1[0].span.source_file());
}

#[test]
fn no_panic() {
    let s = str::from_utf8(b"b\'\xc2\x86  \x00\x00\x00^\"").unwrap();
    assert!(s.parse::<proc_macro2::TokenStream>().is_err());
}

#[test]
fn tricky_doc_commaent() {
    let stream = "/**/".parse::<proc_macro2::TokenStream>().unwrap();
    let tokens = stream.into_iter().collect::<Vec<_>>();
    assert!(tokens.is_empty(), "not empty -- {:?}", tokens);

    let stream = "/// doc".parse::<proc_macro2::TokenStream>().unwrap();
    let tokens = stream.into_iter().collect::<Vec<_>>();
    assert!(tokens.len() == 1, "not length 1 -- {:?}", tokens);
    match tokens[0].kind {
        proc_macro2::TokenNode::Literal(_) => {}
        _ => panic!("wrong token {:?}", tokens[0]),
    }
}