koajv
v2.1.0
Published
Koa middleware for AJV validation on query string, body payload and params
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Koajv
Koa middleware factory to validate, querystring, body payload, route params
You can find examples of how to use this library. You can also look at the tests scenarios in the tests directory to get running examples to use.
Breaking changes :
- v1.0.0 -> v2.0.0 : The validation error format has changed
Minor changes :
- v2.0.0 -> v2.1.0 : Add support for custom keywords
Body validation :
In this example the call can looks like : POST http://host.com/example/body
const koajv = require('koajv')
const ajvOptions = {
allErrors: true,
useDefaults: true,
schemaId: 'auto',
keywords: {
trim: {
type: 'string',
modifying: true,
compile: function (sch, parentSchema) {
return function(data, dataPath, parentData, property) {
if(typeof data === 'string') {
if(sch) {
parentData[property] = data.trim()
}
return true
}
return false
}
}
}
}
}
const schema = {
id: 'userSchema',
type: 'object',
additionalProperties: false,
properties: {
id: { type: 'integer' },
name: { type: 'string' },
category: { type: 'string', pattern: '^Teacher|Student$' },
}
}
const bodyValidatorMiddleware = koajv.bodyValidator(schema) // Wille check ctx.request.body
const validator = koajv.createValidator(schema) // return a method
try {
validator({ invalid: 'test' }) // If the object is not matching the schema an execption is thrown
} catch (err) {
}
router.post('/example/body', bodyValidatorMiddleware, routeHandler)
Querystring validation :
In this example the call can looks like : GET http://host.com/example/query?name=test&category=Student
const koajv = require('koajv')
const ajvOptions = {
allErrors: true,
useDefaults: true,
schemaId: 'auto',
}
const schema = {
id: 'querySchema',
type: 'object',
additionalProperties: false,
properties: {
name: { type: 'string' },
category: { type: 'string', pattern: '^Teacher|Student$' },
}
}
const queryValidatorMiddleware = koajv.queryValidator(schema, ajvOptions) // Will check ctx.request.query
router.get('/example/query', queryValidatorMiddleware, routeHandler)
Params validation :
In this example the call can looks like : GET http://host.com/example/params/teacher
const koajv = require('koajv')
const ajvOptions = {
allErrors: true,
useDefaults: true,
schemaId: 'auto',
}
const schema = {
id: 'paramsSchema',
type: 'object',
additionalProperties: false,
properties: {
category: { type: 'string', pattern: `^teacher|student$`},
}
}
const paramsValidatorMiddleware = koajv.paramsValidator(schema, ajvOptions) // Will check ctx.params
router.get('/example/params/:category', paramsValidatorMiddleware, routeHandler)
Generic validation :
You can also instantiate a validator function by using the facotry method `koajv.createValidator()'
const koajv = require('koajv')
const ajvOptions = {
allErrors: true,
useDefaults: true,
schemaId: 'auto',
}
const schema = {
id: 'userSchema',
type: 'object',
additionalProperties: false,
properties: {
id: { type: 'integer' },
name: { type: 'string' },
category: { type: 'string', pattern: '^Teacher|Student$' },
}
}
const validator = koajv.createValidator(schema, ajvOptions) // return a method
try {
validator({ invalid: 'test' }) // If the object is not matching the schema an execption is thrown
} catch (err) {
}
Error Handling :
Here is a simple example of middleware to catch koajv errors :
app.use(async(ctx, next) => {
try {
await next()
} catch (err) {
ctx.status = err.status
ctx.body = {
message: err.message,
code: err.code || 'UNKNOWN_ERROR',
}
}
})
Custom keywords :
To add custom keywords you can pass it as an options
const koajv = require('koajv')
const ajvOptions = {
allErrors: true,
useDefaults: true,
schemaId: 'auto',
keywords: {
trim: {
type: 'string',
modifying: true,
compile: function (sch, parentSchema) {
return function(data, dataPath, parentData, property) {
if(typeof data === 'string') {
if(sch) {
parentData[property] = data.trim()
}
return true
}
return false
}
}
}
}
}
Tests
To Launch the tests :
- run :
$ npm install
- run :
$ npm test
- run :
$ npm run watch
: It launch test when you change the code
(The tests will run a koa app on port 9000 be sure that this port is available)
Code Coverage
After running $ npm test
you can access the code coverage report here : ./coverage/index.html