Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/eomm/header-constraint-strategy
A general purpose find-my-way custom constraint strategy
https://github.com/eomm/header-constraint-strategy
constraints fastify fastify-plugin find-my-way routing
Last synced: 13 days ago
JSON representation
A general purpose find-my-way custom constraint strategy
- Host: GitHub
- URL: https://github.com/eomm/header-constraint-strategy
- Owner: Eomm
- License: mit
- Created: 2021-07-05T16:28:04.000Z (over 3 years ago)
- Default Branch: main
- Last Pushed: 2024-08-14T00:31:45.000Z (3 months ago)
- Last Synced: 2024-10-24T12:28:00.183Z (22 days ago)
- Topics: constraints, fastify, fastify-plugin, find-my-way, routing
- Language: JavaScript
- Homepage:
- Size: 29.3 KB
- Stars: 6
- Watchers: 2
- Forks: 0
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# header-constraint-strategy
[](https://standardjs.com)
[](https://github.com/Eomm/header-constraint-strategy/actions)
A general purpose [`find-my-way`](https://github.com/delvedor/find-my-way) custom [constraint strategy](https://www.fastify.io/docs/latest/Routes/#constraints).
Tested for [Fastify](https://github.com/fastify/fastify) ✅!
This module let you to drive the incoming HTTP request into a route based on the header's strict content.
Doing so, if a request has a specific string header, it can reach a route hide behind a constraint.
Go to the _Usage_ section to get a complete overview of this feature!
## Install
```
npm install header-constraint-strategy
```
## Usage with Fastify
Here all the constraint types you can define with this module!
This setup shows you all the settings `header-constraint-strategy` provides to you.
```js
const headerConstraintStrategy = require('header-constraint-strategy')
const Fastify = require('fastify')
// STEP 1: setup the constraints into your fastify instance
const app = Fastify({
constraints: {
// basic usage
foo: headerConstraintStrategy('foo'),
// strict usage
mustBeIn: headerConstraintStrategy({ header: 'mustBeIn', mustMatchWhenDerived: true }),
// custom header usage
appOption: headerConstraintStrategy({ name: 'appOption', header: 'x-my-app' })
}
})
// STEP 2: use the constraint where you need them
app.get('/', {
handler: reply('no constraint')
})
app.get('/', {
handler: reply('foo'),
constraints: {
foo: 'bar'
}
})
app.get('/', {
handler: reply('mustBeIn'),
constraints: {
mustBeIn: '123'
}
})
app.get('/', {
handler: reply('appOption'),
constraints: {
appOption: 'ABC'
}
})
app.get('/', {
handler: reply('mustBeIn and appOption'),
constraints: {
mustBeIn: '123',
appOption: 'ABC'
}
})
app.listen(80)
```
The routes can be reached via an HTTP request with these headers.
| # | `foo` header | `mustBeIn` header | `x-my-app` header | response |
|---|--------------|-------------------|-------------------|----------|
|1| - | - | - | 200 - no constraint
|2| `bar` | - | - | 200 - foo
|3| `hello` | - | - | 200 - no constraint
|4| - | `123` | - | 200 - mustBeIn
|5| - | `456` | - | 404
|6| - | - | `ABC` | 200 - appOption
|7| - | `123` | `ABC` | 200 - mustBeIn and appOption
|8| - | `ops` | `ABC` | 404
|9| `bar` | `123` | `ABC` | 200 - mustBeIn and appOption
|10| `bar` | `ops` | `ABC` | 404
### Cases explanation
1) When the is not headers that meets the constraint, the route without constraint will be used if set. Otherwise 404
2) The `foo` constraint is matched
3) The `foo` constraint is not matched so the route without constraint is used
4) The `mustBeIn` constraint is matched
5) Like the 4), but this time the route without constraint is no used because of the flag `mustMatchWhenDerived: true`
6) The `appOption` constraint is matched
7) Multiple constraint matches
8) Regardless the `appOption` constraint is matched, the `mustBeIn` constraint with `mustMatchWhenDerived=true` forces the handler to be used
9) When there are multiple matches _(the route with `foo` and route with `mustBeIn` and `appOption`)_, the route with more fulfilled constraint wins!
10) As the 8), the `mustBeIn` constraint is not fulfilled
## Options
You can pass the following options during the registration:
| Option | Default | Description |
|--------|---------|-------------|
|`name`| as the header if not set | The name of the JSON property that you will set in the route's `constraints` option
|`header`| as the name if not set | The HTTP header where read the input to match the constraint
|`mustMatchWhenDerived`| `false` | Define if the same route without constraint must be evaluated for the routing. You can translate it as: is this constraint mandatory?
## License
Copyright [Manuel Spigolon](https://github.com/Eomm), Licensed under [MIT](./LICENSE).