serde/test_suite/tests/test_borrow.rs

#[macro_use]
extern crate serde_derive;

extern crate serde;
use serde::{Deserialize, Deserializer};

extern crate serde_test;
use serde_test::{
    Error,
    Token,
    assert_de_tokens,
    assert_de_tokens_error,
};

use std::borrow::Cow;

#[test]
fn test_borrowed_str() {
    assert_de_tokens(
        &"borrowed",
        &[
            Token::BorrowedStr("borrowed"),
        ]
    );
}

#[test]
fn test_borrowed_str_from_string() {
    assert_de_tokens_error::<&str>(
        &[
            Token::String("borrowed"),
        ],
        Error::Message("invalid type: string \"borrowed\", expected a borrowed string".to_owned()),
    );
}

#[test]
fn test_borrowed_str_from_str() {
    assert_de_tokens_error::<&str>(
        &[
            Token::Str("borrowed"),
        ],
        Error::Message("invalid type: string \"borrowed\", expected a borrowed string".to_owned()),
    );
}

#[test]
fn test_string_from_borrowed_str() {
    assert_de_tokens(
        &"owned".to_owned(),
        &[
            Token::BorrowedStr("owned"),
        ]
    );
}

#[test]
fn test_borrowed_bytes() {
    assert_de_tokens(
        &&b"borrowed"[..],
        &[
            Token::BorrowedBytes(b"borrowed"),
        ]
    );
}

#[test]
fn test_borrowed_bytes_from_bytebuf() {
    assert_de_tokens_error::<&[u8]>(
        &[
            Token::ByteBuf(b"borrowed"),
        ],
        Error::Message("invalid type: byte array, expected a borrowed byte array".to_owned()),
    );
}

#[test]
fn test_borrowed_bytes_from_bytes() {
    assert_de_tokens_error::<&[u8]>(
        &[
            Token::Bytes(b"borrowed"),
        ],
        Error::Message("invalid type: byte array, expected a borrowed byte array".to_owned()),
    );
}

#[test]
fn test_tuple() {
    assert_de_tokens(
        &("str", &b"bytes"[..]),
        &[
            Token::Tuple(2),
            Token::BorrowedStr("str"),
            Token::BorrowedBytes(b"bytes"),
            Token::TupleEnd,
        ]
    );
}

#[test]
fn test_struct() {
    #[derive(Deserialize, Debug, PartialEq)]
    struct Borrowing<'a, 'b> {
        bs: &'a str,
        bb: &'b [u8],
    }

    assert_de_tokens(
        &Borrowing { bs: "str", bb: b"bytes" },
        &[
            Token::Struct("Borrowing", 2),

            Token::BorrowedStr("bs"),
            Token::BorrowedStr("str"),

            Token::BorrowedStr("bb"),
            Token::BorrowedBytes(b"bytes"),

            Token::StructEnd,
        ]
    );
}

#[test]
fn test_cow() {
    #[derive(Deserialize)]
    struct Cows<'a, 'b> {
        copied: Cow<'a, str>,

        #[serde(borrow)]
        borrowed: Cow<'b, str>,
    }

    let tokens = &[
        Token::Struct("Cows", 2),

        Token::Str("copied"),
        Token::BorrowedStr("copied"),

        Token::Str("borrowed"),
        Token::BorrowedStr("borrowed"),

        Token::StructEnd,
    ];

    let mut de = serde_test::Deserializer::new(tokens);
    let cows = Cows::deserialize(&mut de).unwrap();
    assert_eq!(de.next_token(), None);

    match cows.copied {
        Cow::Owned(ref s) if s == "copied" => {}
        _ => panic!("expected a copied string"),
    }

    match cows.borrowed {
        Cow::Borrowed("borrowed") => {}
        _ => panic!("expected a borrowed string"),
    }
}

#[test]
fn test_lifetimes() {
    #[derive(Deserialize)]
    struct Cows<'a, 'b> {
        _copied: Cow<'a, str>,

        #[serde(borrow)]
        _borrowed: Cow<'b, str>,
    }

    // Tests that `'de: 'a` is not required by the Deserialize impl.
    fn _cows_lifetimes<'de: 'b, 'a, 'b, D>(deserializer: D) -> Cows<'a, 'b>
        where D: Deserializer<'de>
    {
        Deserialize::deserialize(deserializer).unwrap()
    }

    #[derive(Deserialize)]
    struct Wrap<'a, 'b> {
        #[serde(borrow = "'b")]
        _cows: Cows<'a, 'b>,
    }

    // Tests that `'de: 'a` is not required by the Deserialize impl.
    fn _wrap_lifetimes<'de: 'b, 'a, 'b, D>(deserializer: D) -> Wrap<'a, 'b>
        where D: Deserializer<'de>
    {
        Deserialize::deserialize(deserializer).unwrap()
    }
}