A easy and declarative way to test JSON input in Rust.

Overview

assert_json

ci Crates.io docs.rs

A easy and declarative way to test JSON input in Rust. assert_json is a Rust macro heavily inspired by serde json macro. Instead of creating a JSON value from a JSON literal, assert_json makes sure the JSON input conforms to the validation rules specified.

assert_json also output beautiful error message when a validation error occurs.

How to use

0 { Ok(())} else { Err(String::from("id should be greater than 0")) }), "name": name, } } ); } ">
use assert_json::assert_json;
use assert_json::validators;

#[test]
fn test_json_ok() {
    let json = r#"
        {
            "status": "success",
            "result": {
                "id": 5,
                "name": "charlesvdv"
            }
        }
    "#;

    let name = "charlesvdv";

    assert_json!(json, {
            "status": "success",
            "result": {
                "id": validators::u64(|&v| if v > 0 { Ok(())} else { Err(String::from("id should be greater than 0")) }),
                "name": name,
            }
        }
    );
}

Any variables or expressions are interpoled as validation rules matching the type and value of the variable/expression passed to the macro.

Now, if JSON input is changed to something incorrect like this:

    let json = r#"
        {
            "status": "success",
            "result": {
                "id": 5,
-                "name": "charlesvdv"
+                "name": "incorrect name"
            }
        }
    "#;

You will get an comprehensible error message like this one:

thread 'xxxx' panicked at 'error: Invalid JSON
  ┌─ :4:17
  │
4 │         "name": "incorrect name"
  │                 ^^^^^^^^^^^^^^^^ Invalid value. Expected "charlesvdv" but got "incorrect name".

Custom validators

A set of validators are already implemented in the validators module. If required, one can also creates its own validation routine by implementing the Validator trait.

use assert_json::{assert_json, Error, Validator, Value};

fn optional_string(expected: Option<String>) -> impl Validator {
    OptionalStringValidator { expected }
}

/// Matches a null JSON value if expected is None, else check if the strings
/// are equals
struct OptionalStringValidator {
    expected: Option<String>,
}

impl Validator for OptionalStringValidator {
    fn validate<'a>(&self, value: &'a Value) -> Result<(), Error<'a>> {
        if let Some(expected_str) = &self.expected {
            let string_value = value
                .as_str()
                .ok_or_else(|| Error::InvalidType(value, String::from("string")))?;

            if expected_str == string_value {
                Ok(())
            } else {
                Err(Error::InvalidValue(value, expected_str.clone()))
            }
        } else {
            value.as_null()
                .ok_or_else(|| Error::InvalidType(value, String::from("null")))
        }
    }
}

let json = r#"
    {
        "key": "value",
        "none": null
    }
"#;
assert_json!(json, {
    "key": optional_string(Some(String::from("value"))),
    "none": optional_string(None),
});

Alternatives

Acknowledgments

Thanks a lot to the serde-rs/json project members and especially those who contributed to the json! macro.

Owner
Charles Vandevoorde
Software engineer from Brussels . Passionate about software engineering. Love open-source. Sometimes, I develop side-projects.
Charles Vandevoorde
Get JSON values quickly - JSON parser for Rust

get json values quickly GJSON is a Rust crate that provides a fast and simple way to get values from a json document. It has features such as one line

Josh Baker 131 Nov 23, 2021
A fast and simple command-line tool for common operations over JSON-lines files

rjp: Rapid JSON-lines processor A fast and simple command-line tool for common operations over JSON-lines files, such as: converting to and from text

Ales Tamchyna 2 Nov 14, 2021
JSON parser which picks up values directly without performing tokenization in Rust

Pikkr JSON parser which picks up values directly without performing tokenization in Rust Abstract Pikkr is a JSON parser which picks up values directl

Pikkr 582 Nov 7, 2021
Strongly typed JSON library for Rust

Serde JSON   Serde is a framework for serializing and deserializing Rust data structures efficiently and generically. [dependencies] serde_json = "1.0

null 2.5k Nov 25, 2021
JSON implementation in Rust

json-rust Parse and serialize JSON with ease. Changelog - Complete Documentation - Cargo - Repository Why? JSON is a very loose format where anything

Maciej Hirsz 425 Nov 21, 2021
Rust port of gjson,get JSON value by dotpath syntax

A-JSON Read JSON values quickly - Rust JSON Parser change name to AJSON, see issue Inspiration comes from gjson in golang Installation Add it to your

Chen Jiaju 83 Nov 28, 2021
A rust script to convert a better bibtex json file from Zotero into nice organised notes in Obsidian

Zotero to Obsidian script This is a script that takes a better bibtex JSON file exported by Zotero and generates an organised collection of reference

Sashin Exists 3 Nov 3, 2021
CLI tool to convert HOCON into valid JSON or YAML written in Rust.

{hocon:vert} CLI Tool to convert HOCON into valid JSON or YAML. Under normal circumstances this is mostly not needed because hocon configs are parsed

Mathias Oertel 15 Nov 1, 2021
Typify - Compile JSON Schema documents into Rust types.

Typify Compile JSON Schema documents into Rust types. This can be used ... via the macro import_types!("types.json") to generate Rust types directly i

Oxide Computer Company 23 Nov 24, 2021
rurl is like curl but with a json configuration file per request

rurl rurl is a curl-like cli tool made in rust, the difference is that it takes its params from a json file so you can have all different requests sav

Bruno Ribeiro da Silva 5 Nov 20, 2021
A tool for outputs semantic difference of json

jsondiff A tool for outputs semantic difference of json. "semantic" means: sort object key before comparison sort array before comparison (optional, b

niboshi 3 Sep 22, 2021
Easily create dynamic css using json notation

jss! This crate provides an easy way to write dynamic css using json notation. This gives you more convenient than you think. Considering using a dyna

Jovansonlee Cesar 7 Sep 18, 2021
Decode Metaplex mint account metadata into a JSON file.

Simple Metaplex Decoder (WIP) Install From Source Install Rust. curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh Clone the source: git c

Samuel Vanderwaal 4 Oct 23, 2021
A node package based on jsonschema-rs for performing JSON schema validation

A node package based on jsonschema-rs for performing JSON schema validation.

dxd 44 Nov 29, 2021
Tools for working with Twitter JSON data

Twitter stream user info extractor This project lets you parse JSON data from the Twitter API or other sources to extract some basic user information,

Travis Brown 2 Nov 20, 2021
Rust port of simdjson

SIMD Json for Rust   Rust port of extremely fast simdjson JSON parser with serde compatibility. readme (for real!) simdjson version Currently tracking

null 595 Nov 21, 2021
This library is a pull parser for CommonMark, written in Rust

This library is a pull parser for CommonMark, written in Rust. It comes with a simple command-line tool, useful for rendering to HTML, and is also designed to be easy to use from as a library.

Raph Levien 1.2k Nov 21, 2021
Fontdue - The fastest font renderer in the world, written in pure rust.

Fontdue is a simple, no_std (does not use the standard library for portability), pure Rust, TrueType (.ttf/.ttc) & OpenType (.otf) font rasterizer and layout tool. It strives to make interacting with fonts as fast as possible, and currently has the lowest end to end latency for a font rasterizer.

Joe C 723 Nov 24, 2021
A crate to convert bytes to something more useable and the other way around in a way Compatible with the Confluent Schema Registry. Supporting Avro, Protobuf, Json schema, and both async and blocking.

#schema_registry_converter This library provides a way of using the Confluent Schema Registry in a way that is compliant with the Java client. The rel

Gerard Klijs 45 Nov 24, 2021
An efficient way to filter duplicate lines from input, à la uniq.

runiq This project offers an efficient way (in both time and space) to filter duplicate entries (lines) from texual input. This project was born from

Isaac Whitfield 135 Nov 25, 2021
A library that creates a terminal-like window with feature-packed drawing of text and easy input handling. MIRROR.

BearLibTerminal provides a pseudoterminal window with a grid of character cells and a simple yet powerful API for flexible textual output and uncompli

Tommy Ettinger 32 Nov 5, 2021
Some bunch of test scripts to generate a SQLite DB with 1B rows in fastest possible way

To find out the fastest way to create an SQLite DB with 1B random rows.

null 256 Nov 24, 2021
FeignHttp is a declarative HTTP client. Based on rust macros.

FeignHttp is a declarative HTTP client. Based on rust macros. Features Easy to use Asynchronous request Configurable timeout settings Suppor

null 18 Oct 19, 2021
Pretend is a macros-based declarative Rust HTTP client

pretend is a modular, Feign-inspired HTTP, client based on macros. It's goal is to decouple the definition of a REST API from it's implementation.

null 22 Sep 19, 2021
Declarative Testing Framework

Demonstrate allows tests to be written without as a much repetitive code within the demonstrate! macro, which will generate the corresponding full tests.

Austin Baugh 36 Oct 10, 2021
A fast way to minify JSON

COMPACTO (work in progress) A fast way to minify JSON. Usage/Examples # Compress # Input example (~0.11 KB) # { # "id": "123", # "name": "Edua

Eduardo Stuart 1 Nov 28, 2021
Get JSON values quickly - JSON parser for Rust

get json values quickly GJSON is a Rust crate that provides a fast and simple way to get values from a json document. It has features such as one line

Josh Baker 131 Nov 23, 2021
Easy way to write Node.js module using Rust

node-bindgen Easy way to write native Node.js module using idiomatic Rust Features Easy: Just write idiomatic Rust code, node-bindgen take care of gen

InfinyOn 236 Nov 25, 2021
The dead easy way to use config files in your rust project

Configr The dead easy way to use config files in your project This will load a config.toml file if it exists, otherwise it will create the needed fold

Carsten Kragelund Jørgensen 3 May 27, 2021