Cargo.toml

[package]
name = "rocket-contrib-test"
version = "0.1.0"
authors = ["bstpierre"]
edition = "2018"

[dependencies]
rocket_contrib = "0.4"

output

   Compiling rocket-contrib-test v0.1.0 (/home/bstpierre/projects/rust/rocket-contrib-test)
warning: unused `#[macro_use]` import
 --> src/lib.rs:1:1
  |
1 | #[macro_use] extern crate rocket_contrib;
  | ^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

error[E0277]: can't compare `serde_json::value::Value` with `rocket_contrib::json::JsonValue`
  --> src/lib.rs:14:2
   |
14 |     assert_eq!(object["B"][0], json!("b"));
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `serde_json::value::Value == rocket_contrib::json::JsonValue`
   |
   = help: the trait `std::cmp::PartialEq<rocket_contrib::json::JsonValue>` is not implemented for `serde_json::value::Value`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error[E0277]: can't compare `serde_json::value::Value` with `rocket_contrib::json::JsonValue`
  --> src/lib.rs:16:2
   |
16 |     assert_eq!(object["D"], json!(null));
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `serde_json::value::Value == rocket_contrib::json::JsonValue`
   |
   = help: the trait `std::cmp::PartialEq<rocket_contrib::json::JsonValue>` is not implemented for `serde_json::value::Value`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error[E0277]: can't compare `serde_json::value::Value` with `rocket_contrib::json::JsonValue`
  --> src/lib.rs:17:2
   |
17 |     assert_eq!(object[0]["x"]["y"]["z"], json!(null));
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ no implementation for `serde_json::value::Value == rocket_contrib::json::JsonValue`
   |
   = help: the trait `std::cmp::PartialEq<rocket_contrib::json::JsonValue>` is not implemented for `serde_json::value::Value`
   = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)

error: aborting due to 3 previous errors

For more information about this error, try `rustc --explain E0277`.
error: Could not compile `rocket-contrib-test`.

To learn more, run the command again with --verbose.

src_lib.rs

#[macro_use] extern crate rocket_contrib;

#[cfg(test)]
mod tests {
//    use rocket_contrib::json::Json;

    #[test]
    fn it_works() {
        let object = json!({
            "A": ["a", "á", "à"],
            "B": ["b", "b́"],
            "C": ["c", "ć", "ć̣", "ḉ"],
        });
        assert_eq!(object["B"][0], json!("b"));

        assert_eq!(object["D"], json!(null));
        assert_eq!(object[0]["x"]["y"]["z"], json!(null));
    }
}