jamin-json-schema-validation v1.0.1

jamin-json-schema-validation

This JSON schema validator allows developers to run a function on each property in a JSON object and test if the JSON is what you expected.

Installing

npm install jamin-json-schema-validation --save

Use

const SchemaValidator = require("jamin-json-schema-validation"),
      validateSchema = SchemaValidator.validateSchema,
      schemaRejection = SchemaValidator.schemaRejection;

let data = {
    name: "ben",
    color: "blue",
    age: 17
}
let schema = {
    name: (name) => {
        if (name.length > 50) {
            throw schemaRejection("Exceeded maximum amount of characters for your name.")
        }
    },
    color: null, //use null if you don't need to validate with a function
    age: (age) =>  {
        if(age < 18){
            throw schemaRejection("You are too young.")
        }
    }
}
validateSchema(data, schema)
    .then((validSchema) => {
        console.log("VALID SCHEMA: ", validSchema)
    })
    .catch((err) => {
        console.log("INVALID SCHEMA: ", err)
    })

Suggested use with Express

app.post("/route", function (req, res) {
    let body = req.body
    /*
    body = {
        name: "ben",
        color: "blue",
        age: 17
    }
    */
   validateSchema(body, schema)
    .then((validSchema) => {
        //validSchema == body
        //Now:
        //Perform ops on database...
    })
    .catch((err) => {
        //err is an object in the form {message: "", key: ""}
        //key may be undefined if the error was not found due to a custom thrown schemaRejection
        if(key === "age"){
            res.send(err.message)
            //sends - You are too young.
        }
    })

})

NOTE: The example with Express uses a body parser for the post data

npm install body-parser --save

Then

app.use(bodyParser.json())
app.use(bodyParser.urlencoded({
    extended: true
}))