249 lines
7.7 KiB
Markdown
249 lines
7.7 KiB
Markdown
[](https://travis-ci.org/gcanti/tcomb)
|
|
[](https://david-dm.org/gcanti/tcomb)
|
|

|
|
|
|
> "Si vis pacem, para bellum" - (Vegetius 5th century)
|
|
|
|
tcomb is a library for Node.js and the browser which allows you to **check the types** of JavaScript values at runtime with a simple and concise syntax. It's great for **Domain Driven Design** and for adding safety to your internal code.
|
|
|
|
# TypeScript / Flowtype users
|
|
|
|
You may want to check out [io-ts](https://github.com/gcanti/io-ts)
|
|
|
|
# IMPORTANT: Running in production
|
|
|
|
tcomb is supposed to be used in **development** and is **disabled in production**.
|
|
If you want type checks in production you may use
|
|
- [tcomb-validation](https://github.com/gcanti/tcomb-validation)
|
|
- [io-ts](https://github.com/gcanti/io-ts)
|
|
|
|
# Setup
|
|
|
|
```sh
|
|
npm install tcomb --save
|
|
```
|
|
|
|
**Code example**
|
|
|
|
A type-checked function:
|
|
|
|
```js
|
|
import t from 'tcomb';
|
|
|
|
function sum(a, b) {
|
|
t.Number(a);
|
|
t.Number(b);
|
|
return a + b;
|
|
}
|
|
|
|
sum(1, 's'); // throws '[tcomb] Invalid value "s" supplied to Number'
|
|
|
|
// using babel-plugin-tcomb
|
|
function sum(a: number, b: number) {
|
|
return a + b;
|
|
}
|
|
```
|
|
|
|
A user defined type:
|
|
|
|
```js
|
|
const Integer = t.refinement(t.Number, (n) => n % 1 === 0, 'Integer');
|
|
```
|
|
|
|
A type-checked class:
|
|
|
|
```js
|
|
const Person = t.struct({
|
|
name: t.String, // required string
|
|
surname: t.maybe(t.String), // optional string
|
|
age: t.Integer, // required integer
|
|
tags: t.list(t.String) // a list of strings
|
|
}, 'Person');
|
|
|
|
// methods are defined as usual
|
|
Person.prototype.getFullName = function () {
|
|
return `${this.name} ${this.surname}`;
|
|
};
|
|
|
|
const person = Person({
|
|
surname: 'Canti'
|
|
}); // throws '[tcomb] Invalid value undefined supplied to Person/name: String'
|
|
```
|
|
|
|
Chrome DevTools:
|
|
|
|

|
|
|
|
# Docs
|
|
|
|
- [API](docs/API.md)
|
|
- [A little guide to runtime type checking and runtime type introspection](docs/GUIDE.md) (Work in progress)
|
|
|
|
# Features
|
|
|
|
**Lightweight**
|
|
|
|
3KB gzipped, no dependencies.
|
|
|
|
**Type safety**
|
|
|
|
All models defined with `tcomb` are type-checked.
|
|
|
|
**Note**. Instances *are not boxed*, this means that `tcomb` works great with lodash, Ramda, etc. And you can of course use them as props to React components.
|
|
|
|
**Based on set theory**
|
|
|
|
- Blog post: [JavaScript, Types and Sets - Part I](https://gcanti.github.io/2014/09/29/javascript-types-and-sets.html)
|
|
- Blog post: [JavaScript, Types and Sets - Part II](https://gcanti.github.io/2014/10/07/javascript-types-and-sets-part-II.html)
|
|
|
|
**Domain Driven Design**
|
|
|
|
Write complex domain models in a breeze and with a small code footprint. Supported types / combinators:
|
|
|
|
* user defined types
|
|
* structs
|
|
* lists
|
|
* enums
|
|
* refinements
|
|
* unions
|
|
* intersections
|
|
* the option type
|
|
* tuples
|
|
* dictionaries
|
|
* functions
|
|
* recursive and mutually recursive types
|
|
* interfaces
|
|
|
|
**Immutability and immutability helpers**
|
|
|
|
Instances are immutable using `Object.freeze`. This means you can use standard JavaScript objects and arrays. You don't have to change how you normally code. You can update an immutable instance with the provided `update(instance, spec)` function:
|
|
|
|
```js
|
|
const person2 = Person.update(person, {
|
|
name: { $set: 'Guido' }
|
|
});
|
|
```
|
|
|
|
where `spec` is an object containing *commands*. The following commands are compatible with the [Facebook Immutability Helpers](http://facebook.github.io/react/docs/update.html):
|
|
|
|
* `$push`
|
|
* `$unshift`
|
|
* `$splice`
|
|
* `$set`
|
|
* `$apply`
|
|
* `$merge`
|
|
|
|
See [Updating immutable instances](docs/API.md#updating-immutable-instances) for details.
|
|
|
|
**Speed**
|
|
|
|
`Object.freeze` calls and asserts are executed only in development and stripped out in production (using `process.env.NODE_ENV !== 'production'` tests).
|
|
|
|
**Runtime type introspection**
|
|
|
|
All models are inspectable at runtime. You can read and reuse the information stored in your types (in the `meta` static member). See [The meta object](docs/GUIDE.md#the-meta-object) in the docs for details.
|
|
|
|
Libraries exploiting tcomb's RTI:
|
|
|
|
- [tcomb-validation](https://github.com/gcanti/tcomb-validation)
|
|
- [tcomb-form](https://github.com/gcanti/tcomb-form)
|
|
- Blog post: [JSON API Validation In Node.js](https://gcanti.github.io/2014/09/15/json-api-validation-in-node.html)
|
|
|
|
**Easy JSON serialization / deserialization**
|
|
|
|
Encodes / decodes your domain models to / from JSON for free.
|
|
- Blog post: [JSON Deserialization Into An Object Model](https://gcanti.github.io/2014/09/12/json-deserialization-into-an-object-model.html)
|
|
|
|
**Debugging with Chrome DevTools**
|
|
|
|
You can customize the behavior when an assert fails leveraging the power of Chrome DevTools.
|
|
|
|
```js
|
|
// use the default...
|
|
t.fail = function fail(message) {
|
|
throw new TypeError('[tcomb] ' + message); // set "Pause on exceptions" on the "Sources" panel for a great DX
|
|
};
|
|
|
|
// .. or define your own behavior
|
|
t.fail = function fail(message) {
|
|
console.error(message);
|
|
};
|
|
```
|
|
|
|
**Pattern matching**
|
|
|
|
```js
|
|
const result = t.match(1,
|
|
t.String, () => 'a string',
|
|
t.Number, () => 'a number'
|
|
);
|
|
|
|
console.log(result); // => 'a number'
|
|
```
|
|
|
|
**Babel plugin**
|
|
|
|
Using [babel-plugin-tcomb](https://github.com/gcanti/babel-plugin-tcomb) you can also write (Flow compatible) type annotations:
|
|
|
|
```js
|
|
function sum(a: number, b: number): number {
|
|
return a + b;
|
|
}
|
|
```
|
|
|
|
**TypeScript definition file**
|
|
|
|
[index.d.ts](index.d.ts)
|
|
|
|
# Contributors
|
|
|
|
- [Giulio Canti](https://github.com/gcanti) maintainer
|
|
- [Becky Conning](https://github.com/beckyconning) `func` combinator ideas and documentation
|
|
- [Andrea Lattuada](https://github.com/utaal) `declare` combinator
|
|
|
|
# How to Build a standalone bundle
|
|
|
|
```sh
|
|
git clone git@github.com:gcanti/tcomb.git
|
|
cd tcomb
|
|
npm install
|
|
npm run dist
|
|
```
|
|
|
|
Will output 2 files:
|
|
|
|
- `dist/tcomb.js` (development)
|
|
- `dist/tcomb.min.js` (production) `Object.freeze` calls and asserts stripped out
|
|
|
|
# Related libraries
|
|
|
|
* [tcomb-doc](https://github.com/gcanti/tcomb-doc) Documentation tool for tcomb
|
|
* [tcomb-validation](https://github.com/gcanti/tcomb-validation) Validation library based on type combinators
|
|
* [tcomb-json-schema](https://github.com/gcanti/tcomb-json-schema) Transforms a JSON Schema to a tcomb type
|
|
* [reactuate](https://github.com/reactuate/reactuate) React/Redux stack (not a boilerplate kit)
|
|
* [tcomb-react](https://github.com/gcanti/tcomb-react) Alternative syntax for PropTypes
|
|
* [mongorito-tcomb](https://github.com/xouabita/mongorito-tcomb) Bring schema validation to Mongorito thanks to tcomb
|
|
* [tcomb-form](https://github.com/gcanti/tcomb-form) Forms library for react
|
|
* [tcomb-form-types](https://github.com/Industrial/tcomb-form-types) Adds Types/Validations to tcomb-form
|
|
* [tcomb-form-native](https://github.com/gcanti/tcomb-form-native) Forms library for react-native
|
|
* [tcomb-generate](https://github.com/typeetfunc/tcomb-generate) Generates random data by tcomb type for property-based testing
|
|
* [tcomb-additional-types](http://github.com/eserozvataf/tcomb-additional-types) Provides additional predefined types for your existing tcomb setup
|
|
* [tcomb-builder](https://github.com/cadre/tcomb-builder) An immutable syntax for defining tcomb types and forms
|
|
|
|
# Similar projects
|
|
|
|
* [typed-immutable](https://github.com/Gozala/typed-immutable)
|
|
* [immu](https://github.com/scottcorgan/immu)
|
|
* [immutable](https://github.com/facebook/immutable-js)
|
|
* [mori](https://github.com/swannodette/mori)
|
|
* [seamless-immutable](https://github.com/rtfeldman/seamless-immutable)
|
|
* [deep-freeze](https://www.npmjs.com/package/deep-freeze)
|
|
* [freezer](https://github.com/arqex/freezer)
|
|
* [icedam](https://github.com/winkler1/icedam)
|
|
* [ObjectModel](https://github.com/sylvainpolletvillard/ObjectModel)
|
|
* [rfx](https://github.com/ericelliott/rfx)
|
|
|
|
# License
|
|
|
|
The MIT License (MIT)
|