src/tools/rustfmt/tests/target/chains_with_comment.rs

// Chains with comment.

fn main() {
    let x = y // comment
        .z;

    foo // foo
        // comment after parent
        .x
        .y
        // comment 1
        .bar() // comment after bar()
        // comment 2
        .foobar
        // comment after
        // comment 3
        .baz(x, y, z);

    self.rev_dep_graph
        .iter()
        // Remove nodes that are not dirty
        .filter(|&(unit, _)| dirties.contains(&unit))
        // Retain only dirty dependencies of the ones that are dirty
        .map(|(k, deps)| {
            (
                k.clone(),
                deps.iter()
                    .cloned()
                    .filter(|d| dirties.contains(&d))
                    .collect(),
            )
        });

    let y = expr /* comment */
        .kaas()?
        // comment
        .test();
    let loooooooooooooooooooooooooooooooooooooooooong = does_this?
        .look?
        .good?
        .should_we_break?
        .after_the_first_question_mark?;
    let zzzz = expr? // comment after parent
        // comment 0
        .another??? // comment 1
        .another???? // comment 2
        .another? // comment 3
        .another?;

    let y = a
        .very
        .loooooooooooooooooooooooooooooooooooooong() /* comment */
        .chain()
        .inside() /* comment */
        .weeeeeeeeeeeeeee()?
        .test()
        .0
        .x;

    parameterized(f, substs, def_id, Ns::Value, &[], |tcx| {
        tcx.lookup_item_type(def_id).generics
    })?;
    fooooooooooooooooooooooooooo()?
        .bar()?
        .baaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaz()?;

    // #2559
    App::new("cargo-cache")
        .version(crate_version!())
        .bin_name("cargo")
        .about("Manage cargo cache")
        .author("matthiaskrgr")
        .subcommand(
            SubCommand::with_name("cache")
                .version(crate_version!())
                .bin_name("cargo-cache")
                .about("Manage cargo cache")
                .author("matthiaskrgr")
                .arg(&list_dirs)
                .arg(&remove_dir)
                .arg(&gc_repos)
                .arg(&info)
                .arg(&keep_duplicate_crates)
                .arg(&dry_run)
                .arg(&auto_clean)
                .arg(&auto_clean_expensive),
        ) // subcommand
        .arg(&list_dirs);
}

// #2177
impl Foo {
    fn dirty_rev_dep_graph(
        &self,
        dirties: &HashSet<UnitKey>,
    ) -> HashMap<UnitKey, HashSet<UnitKey>> {
        let dirties = self.transitive_dirty_units(dirties);
        trace!("transitive_dirty_units: {:?}", dirties);

        self.rev_dep_graph
            .iter()
            // Remove nodes that are not dirty
            .filter(|&(unit, _)| dirties.contains(&unit))
            // Retain only dirty dependencies of the ones that are dirty
            .map(|(k, deps)| {
                (
                    k.clone(),
                    deps.iter()
                        .cloned()
                        .filter(|d| dirties.contains(&d))
                        .collect(),
                )
            })
    }
}

// #2907
fn foo() {
    let x = foo
        .bar??? // comment
        .baz;
    let x = foo
        .bar???
        // comment
        .baz;
    let x = foo
        .bar??? // comment
        // comment
        .baz;
    let x = foo
        .bar??????????????? // comment
        // comment
        // comment
        // comment
        // comment
        .baz;

    parent /* comment */
        .child;
    parent /* comment1 */     /* comment2 */
        .child;
    parent /* comment1 */   // comment 2
        .child;
    parent??? /* ???no tries here */ // nor ??? here ????
        .child;
    parent /*
            some interesting shaped comment
        */
        .child;

    parent /* comment */
        // another comment
        .child1(some, args) /* comment */ // again
        .await /* longer
             comment
        */ // more comments!
        .use // here's a comment that reaches right to the default width limit aaaaaaaaaaaaaaaaaaaa
        .end;

    parent?? /* spacing is interesting */       /* blah */
        .child;

    // NB: recording the current state of things
    // but is possibly a bug: rustfmt/issues/6433
    parent //comment
        .1
         .2
         .3;
}