Source code
Revision control
Copy as Markdown
Other Tools
use std::collections::HashSet;
#[cfg(feature = "signed")] use crate::secure::SignedJar;
#[cfg(feature = "private")] use crate::secure::PrivateJar;
#[cfg(any(feature = "signed", feature = "private"))] use crate::secure::Key;
use crate::delta::DeltaCookie;
use crate::Cookie;
/// A collection of cookies that tracks its modifications.
///
/// A `CookieJar` provides storage for any number of cookies. Any changes made
/// to the jar are tracked; the changes can be retrieved via the
/// [delta](#method.delta) method which returns an iterator over the changes.
///
/// # Usage
///
/// A jar's life begins via [new](#method.new) and calls to
/// [`add_original`](#method.add_original):
///
/// ```rust
/// use cookie::{Cookie, CookieJar};
///
/// let mut jar = CookieJar::new();
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add_original(Cookie::new("second", "another"));
/// ```
///
/// Cookies can be added via [add](#method.add) and removed via
/// [remove](#method.remove). Finally, cookies can be looked up via
/// [get](#method.get):
///
/// ```rust
/// # use cookie::{Cookie, CookieJar};
/// let mut jar = CookieJar::new();
/// jar.add(Cookie::new("a", "one"));
/// jar.add(Cookie::new("b", "two"));
///
/// assert_eq!(jar.get("a").map(|c| c.value()), Some("one"));
/// assert_eq!(jar.get("b").map(|c| c.value()), Some("two"));
///
/// jar.remove(Cookie::named("b"));
/// assert!(jar.get("b").is_none());
/// ```
///
/// # Deltas
///
/// A jar keeps track of any modifications made to it over time. The
/// modifications are recorded as cookies. The modifications can be retrieved
/// via [delta](#method.delta). Any new `Cookie` added to a jar via `add`
/// results in the same `Cookie` appearing in the `delta`; cookies added via
/// `add_original` do not count towards the delta. Any _original_ cookie that is
/// removed from a jar results in a "removal" cookie appearing in the delta. A
/// "removal" cookie is a cookie that a server sends so that the cookie is
/// removed from the client's machine.
///
/// Deltas are typically used to create `Set-Cookie` headers corresponding to
/// the changes made to a cookie jar over a period of time.
///
/// ```rust
/// # use cookie::{Cookie, CookieJar};
/// let mut jar = CookieJar::new();
///
/// // original cookies don't affect the delta
/// jar.add_original(Cookie::new("original", "value"));
/// assert_eq!(jar.delta().count(), 0);
///
/// // new cookies result in an equivalent `Cookie` in the delta
/// jar.add(Cookie::new("a", "one"));
/// jar.add(Cookie::new("b", "two"));
/// assert_eq!(jar.delta().count(), 2);
///
/// // removing an original cookie adds a "removal" cookie to the delta
/// jar.remove(Cookie::named("original"));
/// assert_eq!(jar.delta().count(), 3);
///
/// // removing a new cookie that was added removes that `Cookie` from the delta
/// jar.remove(Cookie::named("a"));
/// assert_eq!(jar.delta().count(), 2);
/// ```
#[derive(Default, Debug, Clone)]
pub struct CookieJar {
original_cookies: HashSet<DeltaCookie>,
delta_cookies: HashSet<DeltaCookie>,
}
impl CookieJar {
/// Creates an empty cookie jar.
///
/// # Example
///
/// ```rust
/// use cookie::CookieJar;
///
/// let jar = CookieJar::new();
/// assert_eq!(jar.iter().count(), 0);
/// ```
pub fn new() -> CookieJar {
CookieJar::default()
}
/// Returns a reference to the `Cookie` inside this jar with the name
/// `name`. If no such cookie exists, returns `None`.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
/// assert!(jar.get("name").is_none());
///
/// jar.add(Cookie::new("name", "value"));
/// assert_eq!(jar.get("name").map(|c| c.value()), Some("value"));
/// ```
pub fn get(&self, name: &str) -> Option<&Cookie<'static>> {
self.delta_cookies
.get(name)
.or_else(|| self.original_cookies.get(name))
.and_then(|c| if c.removed { None } else { Some(&c.cookie) })
}
/// Adds an "original" `cookie` to this jar. If an original cookie with the
/// same name already exists, it is replaced with `cookie`. Cookies added
/// with `add` take precedence and are not replaced by this method.
///
/// Adding an original cookie does not affect the [delta](#method.delta)
/// computation. This method is intended to be used to seed the cookie jar
/// with cookies received from a client's HTTP message.
///
/// For accurate `delta` computations, this method should not be called
/// after calling `remove`.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add_original(Cookie::new("second", "two"));
///
/// assert_eq!(jar.get("name").map(|c| c.value()), Some("value"));
/// assert_eq!(jar.get("second").map(|c| c.value()), Some("two"));
/// assert_eq!(jar.iter().count(), 2);
/// assert_eq!(jar.delta().count(), 0);
/// ```
pub fn add_original(&mut self, cookie: Cookie<'static>) {
self.original_cookies.replace(DeltaCookie::added(cookie));
}
/// Adds `cookie` to this jar. If a cookie with the same name already
/// exists, it is replaced with `cookie`.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
/// jar.add(Cookie::new("name", "value"));
/// jar.add(Cookie::new("second", "two"));
///
/// assert_eq!(jar.get("name").map(|c| c.value()), Some("value"));
/// assert_eq!(jar.get("second").map(|c| c.value()), Some("two"));
/// assert_eq!(jar.iter().count(), 2);
/// assert_eq!(jar.delta().count(), 2);
/// ```
pub fn add(&mut self, cookie: Cookie<'static>) {
self.delta_cookies.replace(DeltaCookie::added(cookie));
}
/// Removes `cookie` from this jar. If an _original_ cookie with the same
/// name as `cookie` is present in the jar, a _removal_ cookie will be
/// present in the `delta` computation. To properly generate the removal
/// cookie, `cookie` must contain the same `path` and `domain` as the cookie
/// that was initially set.
///
/// A "removal" cookie is a cookie that has the same name as the original
/// cookie but has an empty value, a max-age of 0, and an expiration date
/// far in the past. See also [`Cookie::make_removal()`].
///
/// # Example
///
/// Removing an _original_ cookie results in a _removal_ cookie:
///
/// ```rust
/// # extern crate cookie;
/// use cookie::{CookieJar, Cookie};
/// use cookie::time::Duration;
///
/// # fn main() {
/// let mut jar = CookieJar::new();
///
/// // Assume this cookie originally had a path of "/" and domain of "a.b".
/// jar.add_original(Cookie::new("name", "value"));
///
/// // If the path and domain were set, they must be provided to `remove`.
/// jar.remove(Cookie::build("name", "").path("/").domain("a.b").finish());
///
/// // The delta will contain the removal cookie.
/// let delta: Vec<_> = jar.delta().collect();
/// assert_eq!(delta.len(), 1);
/// assert_eq!(delta[0].name(), "name");
/// assert_eq!(delta[0].max_age(), Some(Duration::seconds(0)));
/// # }
/// ```
///
/// Removing a new cookie does not result in a _removal_ cookie unless
/// there's an original cookie with the same name:
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
/// jar.add(Cookie::new("name", "value"));
/// assert_eq!(jar.delta().count(), 1);
///
/// jar.remove(Cookie::named("name"));
/// assert_eq!(jar.delta().count(), 0);
///
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add(Cookie::new("name", "value"));
/// assert_eq!(jar.delta().count(), 1);
///
/// jar.remove(Cookie::named("name"));
/// assert_eq!(jar.delta().count(), 1);
/// ```
pub fn remove(&mut self, mut cookie: Cookie<'static>) {
if self.original_cookies.contains(cookie.name()) {
cookie.make_removal();
self.delta_cookies.replace(DeltaCookie::removed(cookie));
} else {
self.delta_cookies.remove(cookie.name());
}
}
/// Removes `cookie` from this jar completely. This method differs from
/// `remove` in that no delta cookie is created under any condition. Neither
/// the `delta` nor `iter` methods will return a cookie that is removed
/// using this method.
///
/// # Example
///
/// Removing an _original_ cookie; no _removal_ cookie is generated:
///
/// ```rust
/// # extern crate cookie;
/// use cookie::{CookieJar, Cookie};
/// use cookie::time::Duration;
///
/// # fn main() {
/// let mut jar = CookieJar::new();
///
/// // Add an original cookie and a new cookie.
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add(Cookie::new("key", "value"));
/// assert_eq!(jar.delta().count(), 1);
/// assert_eq!(jar.iter().count(), 2);
///
/// // Now force remove the original cookie.
/// jar.force_remove(&Cookie::named("name"));
/// assert_eq!(jar.delta().count(), 1);
/// assert_eq!(jar.iter().count(), 1);
///
/// // Now force remove the new cookie.
/// jar.force_remove(&Cookie::named("key"));
/// assert_eq!(jar.delta().count(), 0);
/// assert_eq!(jar.iter().count(), 0);
/// # }
/// ```
pub fn force_remove<'a>(&mut self, cookie: &Cookie<'a>) {
self.original_cookies.remove(cookie.name());
self.delta_cookies.remove(cookie.name());
}
/// Removes all delta cookies, i.e. all cookies not added via
/// [`CookieJar::add_original()`], from this `CookieJar`. This undoes any
/// changes from [`CookieJar::add()`] and [`CookieJar::remove()`]
/// operations.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
///
/// // Only original cookies will remain after calling `reset_delta`.
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add_original(Cookie::new("language", "Rust"));
///
/// // These operations, represented by delta cookies, will be reset.
/// jar.add(Cookie::new("language", "C++"));
/// jar.remove(Cookie::named("name"));
///
/// // All is normal.
/// assert_eq!(jar.get("name"), None);
/// assert_eq!(jar.get("language").map(Cookie::value), Some("C++"));
/// assert_eq!(jar.iter().count(), 1);
/// assert_eq!(jar.delta().count(), 2);
///
/// // Resetting undoes delta operations.
/// jar.reset_delta();
/// assert_eq!(jar.get("name").map(Cookie::value), Some("value"));
/// assert_eq!(jar.get("language").map(Cookie::value), Some("Rust"));
/// assert_eq!(jar.iter().count(), 2);
/// assert_eq!(jar.delta().count(), 0);
/// ```
pub fn reset_delta(&mut self) {
self.delta_cookies = HashSet::new();
}
/// Returns an iterator over cookies that represent the changes to this jar
/// over time. These cookies can be rendered directly as `Set-Cookie` header
/// values to affect the changes made to this jar on the client.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add_original(Cookie::new("second", "two"));
///
/// // Add new cookies.
/// jar.add(Cookie::new("new", "third"));
/// jar.add(Cookie::new("another", "fourth"));
/// jar.add(Cookie::new("yac", "fifth"));
///
/// // Remove some cookies.
/// jar.remove(Cookie::named("name"));
/// jar.remove(Cookie::named("another"));
///
/// // Delta contains two new cookies ("new", "yac") and a removal ("name").
/// assert_eq!(jar.delta().count(), 3);
/// ```
pub fn delta(&self) -> Delta {
Delta { iter: self.delta_cookies.iter() }
}
/// Returns an iterator over all of the cookies present in this jar.
///
/// # Example
///
/// ```rust
/// use cookie::{CookieJar, Cookie};
///
/// let mut jar = CookieJar::new();
///
/// jar.add_original(Cookie::new("name", "value"));
/// jar.add_original(Cookie::new("second", "two"));
///
/// jar.add(Cookie::new("new", "third"));
/// jar.add(Cookie::new("another", "fourth"));
/// jar.add(Cookie::new("yac", "fifth"));
///
/// jar.remove(Cookie::named("name"));
/// jar.remove(Cookie::named("another"));
///
/// // There are three cookies in the jar: "second", "new", and "yac".
/// # assert_eq!(jar.iter().count(), 3);
/// for cookie in jar.iter() {
/// match cookie.name() {
/// "second" => assert_eq!(cookie.value(), "two"),
/// "new" => assert_eq!(cookie.value(), "third"),
/// "yac" => assert_eq!(cookie.value(), "fifth"),
/// _ => unreachable!("there are only three cookies in the jar")
/// }
/// }
/// ```
pub fn iter(&self) -> Iter {
Iter {
delta_cookies: self.delta_cookies.iter()
.chain(self.original_cookies.difference(&self.delta_cookies)),
}
}
/// Returns a read-only `PrivateJar` with `self` as its parent jar using the
/// key `key` to verify/decrypt cookies retrieved from the child jar. Any
/// retrievals from the child jar will be made from the parent jar.
///
/// # Example
///
/// ```rust
/// use cookie::{Cookie, CookieJar, Key};
///
/// // Generate a secure key.
/// let key = Key::generate();
///
/// // Add a private (signed + encrypted) cookie.
/// let mut jar = CookieJar::new();
/// jar.private_mut(&key).add(Cookie::new("private", "text"));
///
/// // The cookie's contents are encrypted.
/// assert_ne!(jar.get("private").unwrap().value(), "text");
///
/// // They can be decrypted and verified through the child jar.
/// assert_eq!(jar.private(&key).get("private").unwrap().value(), "text");
///
/// // A tampered with cookie does not validate but still exists.
/// let mut cookie = jar.get("private").unwrap().clone();
/// jar.add(Cookie::new("private", cookie.value().to_string() + "!"));
/// assert!(jar.private(&key).get("private").is_none());
/// assert!(jar.get("private").is_some());
/// ```
#[cfg(feature = "private")]
#[cfg_attr(all(nightly, doc), doc(cfg(feature = "private")))]
pub fn private<'a>(&'a self, key: &Key) -> PrivateJar<&'a Self> {
PrivateJar::new(self, key)
}
/// Returns a read/write `PrivateJar` with `self` as its parent jar using
/// the key `key` to sign/encrypt and verify/decrypt cookies added/retrieved
/// from the child jar.
///
/// Any modifications to the child jar will be reflected on the parent jar,
/// and any retrievals from the child jar will be made from the parent jar.
///
/// # Example
///
/// ```rust
/// use cookie::{Cookie, CookieJar, Key};
///
/// // Generate a secure key.
/// let key = Key::generate();
///
/// // Add a private (signed + encrypted) cookie.
/// let mut jar = CookieJar::new();
/// jar.private_mut(&key).add(Cookie::new("private", "text"));
///
/// // Remove a cookie using the child jar.
/// jar.private_mut(&key).remove(Cookie::named("private"));
/// ```
#[cfg(feature = "private")]
#[cfg_attr(all(nightly, doc), doc(cfg(feature = "private")))]
pub fn private_mut<'a>(&'a mut self, key: &Key) -> PrivateJar<&'a mut Self> {
PrivateJar::new(self, key)
}
/// Returns a read-only `SignedJar` with `self` as its parent jar using the
/// key `key` to verify cookies retrieved from the child jar. Any retrievals
/// from the child jar will be made from the parent jar.
///
/// # Example
///
/// ```rust
/// use cookie::{Cookie, CookieJar, Key};
///
/// // Generate a secure key.
/// let key = Key::generate();
///
/// // Add a signed cookie.
/// let mut jar = CookieJar::new();
/// jar.signed_mut(&key).add(Cookie::new("signed", "text"));
///
/// // The cookie's contents are signed but still in plaintext.
/// assert_ne!(jar.get("signed").unwrap().value(), "text");
/// assert!(jar.get("signed").unwrap().value().contains("text"));
///
/// // They can be verified through the child jar.
/// assert_eq!(jar.signed(&key).get("signed").unwrap().value(), "text");
///
/// // A tampered with cookie does not validate but still exists.
/// let mut cookie = jar.get("signed").unwrap().clone();
/// jar.add(Cookie::new("signed", cookie.value().to_string() + "!"));
/// assert!(jar.signed(&key).get("signed").is_none());
/// assert!(jar.get("signed").is_some());
/// ```
#[cfg(feature = "signed")]
#[cfg_attr(all(nightly, doc), doc(cfg(feature = "signed")))]
pub fn signed<'a>(&'a self, key: &Key) -> SignedJar<&'a Self> {
SignedJar::new(self, key)
}
/// Returns a read/write `SignedJar` with `self` as its parent jar using the
/// key `key` to sign/verify cookies added/retrieved from the child jar.
///
/// Any modifications to the child jar will be reflected on the parent jar,
/// and any retrievals from the child jar will be made from the parent jar.
///
/// # Example
///
/// ```rust
/// use cookie::{Cookie, CookieJar, Key};
///
/// // Generate a secure key.
/// let key = Key::generate();
///
/// // Add a signed cookie.
/// let mut jar = CookieJar::new();
/// jar.signed_mut(&key).add(Cookie::new("signed", "text"));
///
/// // Remove a cookie.
/// jar.signed_mut(&key).remove(Cookie::named("signed"));
/// ```
#[cfg(feature = "signed")]
#[cfg_attr(all(nightly, doc), doc(cfg(feature = "signed")))]
pub fn signed_mut<'a>(&'a mut self, key: &Key) -> SignedJar<&'a mut Self> {
SignedJar::new(self, key)
}
}
use std::collections::hash_set::Iter as HashSetIter;
/// Iterator over the changes to a cookie jar.
pub struct Delta<'a> {
iter: HashSetIter<'a, DeltaCookie>,
}
impl<'a> Iterator for Delta<'a> {
type Item = &'a Cookie<'static>;
fn next(&mut self) -> Option<&'a Cookie<'static>> {
self.iter.next().map(|c| &c.cookie)
}
}
use std::collections::hash_set::Difference;
use std::collections::hash_map::RandomState;
use std::iter::Chain;
/// Iterator over all of the cookies in a jar.
pub struct Iter<'a> {
delta_cookies: Chain<HashSetIter<'a, DeltaCookie>, Difference<'a, DeltaCookie, RandomState>>,
}
impl<'a> Iterator for Iter<'a> {
type Item = &'a Cookie<'static>;
fn next(&mut self) -> Option<&'a Cookie<'static>> {
for cookie in self.delta_cookies.by_ref() {
if !cookie.removed {
return Some(&*cookie);
}
}
None
}
}
#[cfg(test)]
mod test {
use super::CookieJar;
use crate::Cookie;
#[test]
#[allow(deprecated)]
fn simple() {
let mut c = CookieJar::new();
c.add(Cookie::new("test", ""));
c.add(Cookie::new("test2", ""));
c.remove(Cookie::named("test"));
assert!(c.get("test").is_none());
assert!(c.get("test2").is_some());
c.add(Cookie::new("test3", ""));
c.remove(Cookie::named("test2"));
c.remove(Cookie::named("test3"));
assert!(c.get("test").is_none());
assert!(c.get("test2").is_none());
assert!(c.get("test3").is_none());
}
#[test]
fn jar_is_send() {
fn is_send<T: Send>(_: T) -> bool {
true
}
assert!(is_send(CookieJar::new()))
}
#[test]
#[cfg(all(feature = "signed", feature = "private"))]
fn iter() {
let key = crate::Key::generate();
let mut c = CookieJar::new();
c.add_original(Cookie::new("original", "original"));
c.add(Cookie::new("test", "test"));
c.add(Cookie::new("test2", "test2"));
c.add(Cookie::new("test3", "test3"));
assert_eq!(c.iter().count(), 4);
c.signed_mut(&key).add(Cookie::new("signed", "signed"));
c.private_mut(&key).add(Cookie::new("encrypted", "encrypted"));
assert_eq!(c.iter().count(), 6);
c.remove(Cookie::named("test"));
assert_eq!(c.iter().count(), 5);
c.remove(Cookie::named("signed"));
c.remove(Cookie::named("test2"));
assert_eq!(c.iter().count(), 3);
c.add(Cookie::new("test2", "test2"));
assert_eq!(c.iter().count(), 4);
c.remove(Cookie::named("test2"));
assert_eq!(c.iter().count(), 3);
}
#[test]
fn delta() {
use std::collections::HashMap;
use time::Duration;
let mut c = CookieJar::new();
c.add_original(Cookie::new("original", "original"));
c.add_original(Cookie::new("original1", "original1"));
c.add(Cookie::new("test", "test"));
c.add(Cookie::new("test2", "test2"));
c.add(Cookie::new("test3", "test3"));
c.add(Cookie::new("test4", "test4"));
c.remove(Cookie::named("test"));
c.remove(Cookie::named("original"));
assert_eq!(c.delta().count(), 4);
let names: HashMap<_, _> = c.delta()
.map(|c| (c.name(), c.max_age()))
.collect();
assert!(names.get("test2").unwrap().is_none());
assert!(names.get("test3").unwrap().is_none());
assert!(names.get("test4").unwrap().is_none());
assert_eq!(names.get("original").unwrap(), &Some(Duration::seconds(0)));
}
#[test]
fn replace_original() {
let mut jar = CookieJar::new();
jar.add_original(Cookie::new("original_a", "a"));
jar.add_original(Cookie::new("original_b", "b"));
assert_eq!(jar.get("original_a").unwrap().value(), "a");
jar.add(Cookie::new("original_a", "av2"));
assert_eq!(jar.get("original_a").unwrap().value(), "av2");
}
#[test]
fn empty_delta() {
let mut jar = CookieJar::new();
jar.add(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 1);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().count(), 0);
jar.add_original(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 0);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().count(), 1);
jar.add(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 1);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().count(), 1);
}
#[test]
fn add_remove_add() {
let mut jar = CookieJar::new();
jar.add_original(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 0);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().count(), 1);
// The cookie's been deleted. Another original doesn't change that.
jar.add_original(Cookie::new("name", "val"));
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().count(), 1);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().count(), 1);
jar.add(Cookie::new("name", "val"));
assert_eq!(jar.delta().filter(|c| !c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().count(), 1);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().count(), 1);
}
#[test]
fn replace_remove() {
let mut jar = CookieJar::new();
jar.add_original(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 0);
jar.add(Cookie::new("name", "val"));
assert_eq!(jar.delta().count(), 1);
assert_eq!(jar.delta().filter(|c| !c.value().is_empty()).count(), 1);
jar.remove(Cookie::named("name"));
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
}
#[test]
fn remove_with_path() {
let mut jar = CookieJar::new();
jar.add_original(Cookie::build("name", "val").finish());
assert_eq!(jar.iter().count(), 1);
assert_eq!(jar.delta().count(), 0);
assert_eq!(jar.iter().filter(|c| c.path().is_none()).count(), 1);
jar.remove(Cookie::build("name", "").path("/").finish());
assert_eq!(jar.iter().count(), 0);
assert_eq!(jar.delta().count(), 1);
assert_eq!(jar.delta().filter(|c| c.value().is_empty()).count(), 1);
assert_eq!(jar.delta().filter(|c| c.path() == Some("/")).count(), 1);
}
}