2 unstable releases
0.2.0 | Oct 12, 2023 |
---|---|
0.1.0 | Mar 11, 2023 |
#1142 in Rust patterns
467 downloads per month
40KB
598 lines
not-so-fast
A Rust library for data validation.
Features
- Builder-pattern API for reporting validation errors
- Easy composition of validators
- Derive macro implementing validation traits for structs and enums
- Error display with
jq
-like paths to bad values - Error serialization reflecting input data structure
Installation
cargo add not-so-fast # --features derive serde
Available cargo features:
derive
- enablesValidate
derive macro, disabled by defaultserde
- enablesserde::Serialize
implementation forValidationNode
, disabled by default
Usage
use not_so_fast::{Validate, ValidationNode, ValidationError};
#[derive(Validate)]
struct User {
#[validate(custom = alpha_only, char_length(max = 30))]
nick: String,
#[validate(range(min = 15, max = 100))]
age: u8,
#[validate(length(max = 3), items(char_length(max = 50)))]
cars: Vec<String>,
}
fn alpha_only(s: &str) -> ValidationNode {
ValidationNode::error_if(
s.chars().any(|c| !c.is_alphanumeric()),
|| ValidationError::with_code("alpha_only")
)
}
let user = User {
nick: "**tom1980**".into(),
age: 200,
cars: vec![
"first".into(),
"second".into(),
"third".repeat(11),
"fourth".into(),
],
};
let node = user.validate();
assert!(node.is_err());
assert_eq!(
vec![
".age: range: Number not in range: max=100, min=15, value=200",
".cars: length: Invalid length: max=3, value=4",
".cars[2]: char_length: Invalid character length: max=50, value=55",
".nick: alpha_only",
].join("\n"),
node.to_string()
);
Guides
not-so-fast/examples/manual.rs explains how to write custom validators.
not-so-fast/examples/derive.rs shows how to use Validator derive macro.
Compared to validator
not-so-fast
attempts to fix issues I stumbled upon when working with the popular https://github.com/Keats/validator crate. APIs of the two libraries are similar, but not compatible. Here are the differences of not-so-fast
:
- Validator composition - Composing validators in
not-so-fast
is simple, since all values - numbers, strings, objects, lists - report validation errors using the same type -ValidationNode
. - Essential validators -
not-so-fast
comes with only the essential validators. You're expected to write custom validators to test data against your domain's rules. - Enum support -
Validate
derive macro works with structs and enums. - Duck typing -
Validate
derive macro does not look at field types whatsoever. To validate data inside containers, you give derive macro hints on how to access the data (some
,items
,fields
attributes). In return,not-so-fast
will work with third-party container types, as long as they have std-like API.
TODO
- Add
matches
derive validator for testing strings against regular expressions - Add
is_some
/required
derive validator for testing options - Consider moving derive validators from
not-so-fast-derive
tonot-so-fast
for better code reusability
License
Licensed under either of Apache License, Version 2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
Dependencies
~0–275KB