json-data-structure-validator

Validates the keys required for an object and the type of its value.

Example

Basic usage

The validate() function validates the JSON object passed as its first argument with the format object passed as its second argument.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	alice: {
		height: 123,
		gender: "girl"
	},
	bob: {
		height: 116,
		weight: 35,
		gender: "boy"
	}
};

validate(json, {
	alice: {
		height: ValidType.Number,
		gender: ValidType.String
	},
	bob: {
		height: ValidType.Number,
		weight: ValidType.Number,
		gender: ValidType.String
	}
});

If a problem occurs during validation, such as a different type or missing key required by the format object, a "ValidationError" exception is raised.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	alice: {
		height: 123,
		gender: "girl"
	},
};

validate(json, {
	alice: {
		height: ValidType.Number,
		weight: ValidType.Number,
		gender: ValidType.String
	},
});
# ValidationError Need key: {weight}

Option key

"?" in the key name in the format object. in the key name in the format object makes it an optional key.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	alice: {
		height: 123,
		gender: "girl"
	},
};

validate(json, {
	alice: {
		height: ValidType.Number,
		"weight?": ValidType.Number,
		gender: ValidType.String
	},
});
# Exceptions disappear

Array data

The "[]" in the key name indicates an array.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	people: [
		"debbie",
		"eliza",
		"flora"
	],
	"high people": [
		{
			name: "alice",
			age: 20
		},
		{
			name: "bob",
			age: 21
		},
		{
			name: "charlie",
			age: 22
		},
	]
};

validate(json, {
	"people[]": ValidType.String,
	"high people[]": {
		name: ValidType.String,
		age: ValidType.Number
	},
});

Regexp key

Key names can be specified by regular expressions.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	"100": "hundred",
	"150": "one hundred and fifty",
	"1000": "thousand",
};

validate(json, {
	"/\\d+/": ValidType.String
});

User type

Since ValidType is a normal function, you may specify your own conversion function.

After validation by the validate() function, the contents of json.ids are replaced with the return value of the original function.

import { ValidationError, ValidType, validate } from "./json-data-structure-validator/index.js";

const json = {
	ids: "1,2,3,4,5"
};

validate(json, {
	ids: (v, nodePath) => {
		if (typeof v !== "string")
			throw new ValidationError(`${nodePath}Need ids '${JSON.stringify(v)}'`);
		return v.split(",");
	}
});
# json.ids: "1,2,3,4,5" => json.ids: [1,2,3,4,5]

The first argument is the value to be verified. This is required.

The second argument "nodePath" is the node path being verified. It is not required, but is effective when an exception occurs in a deep object.

emurenMRz / json-data-structure-validator