join-string 0.3.0

use join_string::{join, join_str, DisplayIter, DisplayWrapper, Join, Joiner};

#[test]
fn basic() {
    let empty: [&str; 0] = [];
    assert_eq!(empty.join(", ").into_string(), "");
    assert_eq!([""].iter().join(", ").into_string(), "");
    assert_eq!(["foo"].iter().join(", ").into_string(), "foo");
    assert_eq!(["", ""].iter().join(", ").into_string(), ", ");
    assert_eq!(
        ["foo", "bar", "baz"].iter().join(", ").into_string(),
        "foo, bar, baz"
    );
}

fn join_as_ref_str(elements: &[impl AsRef<str>], sep: impl AsRef<str>) -> String {
    join_str(elements, sep).into_string()
}

fn join_map_as_ref_str(elements: &[impl AsRef<str>], sep: impl std::fmt::Display) -> String {
    DisplayIter::new(elements).join(sep).into_string()
}

fn join_sep_as_ref_str(elements: &[impl std::fmt::Display], sep: impl AsRef<str>) -> String {
    elements.iter().join(DisplayWrapper::new(sep)).into_string()
}

#[test]
fn types() {
    assert_eq!(
        ['a', 'b', 'c'].iter().join(", ".to_owned()).to_string(),
        "a, b, c"
    );
    let array = [1, 2, 3];
    assert_eq!(array.join("").into_string(), "123");
    assert_eq!(array.join("").into_string(), "123"); // test that it's not moving the array
    assert_eq!(Join::join(&[1.0, 2.0, 3.0], ", ").into_string(), "1, 2, 3");
    assert_eq!(
        ["foo".to_owned(), "bar".to_owned(), "baz".to_owned()]
            .join(", ")
            .into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        vec![format_args!("{:02}", 1), format_args!("{:.1} {}", 3.0, 4)]
            .join(' ')
            .into_string(),
        "01 3.0 4"
    );
    let items: [&dyn std::fmt::Display; 4] = [&Box::new("foo"), &"bar", &'z', &"bla".to_owned()];
    assert_eq!(items.iter().join(", ").into_string(), "foo, bar, z, bla");
    assert_eq!(
        ["".chars().join(""), "".chars().join("bla")]
            .iter()
            .join("ab".chars().join(','))
            .into_string(),
        "a,b"
    );
    assert_eq!(
        join_map_as_ref_str(&["foo", "bar", "baz"], ", "),
        "foo, bar, baz"
    );
    assert_eq!(
        join_sep_as_ref_str(&["foo", "bar", "baz"], ", "),
        "foo, bar, baz"
    );

    let mut set = std::collections::BTreeSet::new();
    set.insert("foo");
    set.insert("bar");
    set.insert("baz");
    assert_eq!(set.iter().join(", ").into_string(), "bar, baz, foo");

    assert_eq!(Some("foo").iter().join(", ").into_string(), "foo");
    assert_eq!(Some("foo").join(", ").into_string(), "foo");

    let ok: std::result::Result<&str, &str> = Ok("ok");
    assert_eq!(ok.iter().join(", ").into_string(), "ok");
    assert_eq!(ok.join(", ").into_string(), "ok");

    let err: std::result::Result<&str, &str> = Err("err");
    assert_eq!(err.iter().join(", ").into_string(), "");
    assert_eq!(err.join(", ").into_string(), "");
}

#[test]
fn test_join_str() {
    assert_eq!(
        join_as_ref_str(&["foo", "bar", "baz"], ", "),
        "foo, bar, baz"
    );
    assert_eq!(
        join_str(&["foo", "bar", "baz"], ", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        join_str(["foo", "bar", "baz"].iter(), ", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        ["foo", "bar", "baz"].join_str(", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        ["foo", "bar", "baz"].iter().join_str(", ").into_string(),
        "foo, bar, baz"
    );
}

#[test]
fn joinable() {
    assert_eq!(
        join(["foo", "bar", "baz"].as_slice(), ", ").into_string(),
        "foo, bar, baz"
    );
    let mut iter = ["foo", "bar", "baz"].iter();
    assert_eq!(join(&mut iter, ", ").into_string(), "foo, bar, baz");
    assert_eq!(join(&mut iter, ", ").into_string(), ""); // iterator is consumed
    assert_eq!(
        join(["foo", "bar", "baz"], ", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        join(["foo", "bar", "baz"].iter().rev(), ", ").into_string(),
        "baz, bar, foo"
    );
    assert_eq!(
        join(&["foo", "bar", "baz"], ", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        join(vec!["foo", "bar", "baz"].as_slice(), ", ").into_string(),
        "foo, bar, baz"
    );
    assert_eq!(
        join(&vec!["foo", "bar", "baz"], ", ").into_string(),
        "foo, bar, baz"
    );
}

#[test]
fn complex_exprs() {
    assert_eq!(
        "a bcd ef"
            .split_whitespace()
            .map(str::len)
            .join(", ")
            .into_string(),
        "1, 3, 2"
    );

    assert_eq!(
        "foo bar baz"
            .split_whitespace()
            .map(|s| s.chars().rev().join(""))
            .join(" ")
            .into_string(),
        "oof rab zab"
    );
}

#[test]
fn into_impl() {
    let str: String = [1, 2, 3].join(" + ").into();
    assert_eq!(str, "1 + 2 + 3");
    assert_eq!(
        <Joiner<_, _> as Into<String>>::into("äüö".chars().join(' ')),
        "ä ü ö"
    );
}

#[test]
fn from_impl() {
    let str = String::from([1, 2, 3].join(" + "));
    assert_eq!(str, "1 + 2 + 3");
    assert_eq!(String::from("äüö".chars().join(' ')), "ä ü ö");
}

#[test]
fn display_impl() {
    assert_eq!(
        format!("<{}>", ["foo", "bar", "baz"].iter().join(", ")),
        "<foo, bar, baz>"
    );
    assert_eq!(
        format!("<{}>", [1, 2, 3].iter().cycle().take(5).join(", ")),
        "<1, 2, 3, 1, 2>"
    );
}

#[test]
fn write_fmt() -> std::fmt::Result {
    let mut buffer = String::new();
    ["foo", "bar", "baz"]
        .iter()
        .join(", ")
        .write_fmt(&mut buffer)?;
    assert_eq!(buffer, "foo, bar, baz");

    Ok(())
}

#[test]
fn write_io() -> std::io::Result<()> {
    let mut buffer: Vec<u8> = Vec::new();
    ["foo", "bar", "baz"]
        .iter()
        .join(", ")
        .write_io(&mut buffer)?;
    assert_eq!(buffer, b"foo, bar, baz");

    Ok(())
}

#[derive(Debug)]
struct MyItem(String);

impl std::fmt::Display for MyItem {
    #[inline]
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.0.fmt(f)
    }
}

struct MyContainer {
    items: Vec<MyItem>,
}

impl std::iter::IntoIterator for MyContainer {
    type Item = MyItem;
    type IntoIter = <Vec<MyItem> as std::iter::IntoIterator>::IntoIter;

    #[inline]
    fn into_iter(self) -> Self::IntoIter {
        self.items.into_iter()
    }
}

#[test]
fn custom_impl() {
    let cont = MyContainer {
        items: vec![
            MyItem("foo".to_string()),
            MyItem("bar".to_string()),
            MyItem("baz".to_string()),
        ],
    };

    assert_eq!(cont.join(", ").into_string(), "foo, bar, baz");
}

struct MyOtherContainer {
    items: Vec<MyItem>,
}

impl MyOtherContainer {
    #[inline]
    fn join<'a, S>(&'a self, sep: S) -> Joiner<std::slice::Iter<'a, MyItem>, S>
    where
        S: std::fmt::Display,
    {
        Joiner::new(self.items.iter(), sep)
    }
}

#[test]
fn joiner_new() {
    let cont = MyOtherContainer {
        items: vec![
            MyItem("foo".to_string()),
            MyItem("bar".to_string()),
            MyItem("baz".to_string()),
        ],
    };

    assert_eq!(cont.join(", ").into_string(), "foo, bar, baz");
}

#[test]
fn debug() {
    #[derive(Debug)]
    struct MyStruct {
        #[allow(unused)]
        value: u32
    }

    assert_eq!(format!("{:?}", ['a', 'b', 'c'].join(", ")), "'a', 'b', 'c'");
    assert_eq!(format!("{:?}", [
        &MyStruct { value: 1 },
        &MyStruct { value: 2 },
        &MyStruct { value: 3 },
    ].join(", ")), "MyStruct { value: 1 }, MyStruct { value: 2 }, MyStruct { value: 3 }");
}