jest-json-schema-extended

An extension of the popular jest-json-schema package - JSON schema matching for jest.

Example

const {
    dateTime,
    strictObject,
    uuidType,
    numberType,
    booleanType,
    arrayOfItems,
    anyOf,
    exactly,
    stringType,
    stringTypeCanBeEmpty,
    expectToMatchSchema,
    objectWithRequiredProps,
} = require("jest-json-schema-extended")

const objectToTest = {
    id: "47bddd19-e142-45ee-8679-463be8763022",
    enabled: false,
    created: "2019-06-12T15:08:40.292Z",
    requestors: [],
    owners: [
        {
            id: 1,
            lastName: "Robson",
            firstName: "",
            additionalInfo: {
                favouriteTvShow: "The Simpsons",
                goodAtCooking: false,
                propertyThatCanHaveVaryingTypes: "Hello",
            },
        },
        {
            id: 2,
            lastName: "Haroldson",
            firstName: "Doris",
            additionalInfo: {
                favouriteTvShow: "Parks & Recreation",
                married: true,
                propertyThatCanHaveVaryingTypes: 42,
            },
        },
    ],
}

const schema = strictObject({
    id: uuidType,
    enabled: booleanType,
    created: dateTime,
    requestors: exactly([]),
    owners: arrayOfItems(
        strictObject({
            id: numberType,
            lastName: stringType,
            firstName: stringTypeCanBeEmpty,
            additionalInfo: objectWithRequiredProps({
                favouriteTvShow: stringType,
                propertyThatCanHaveVaryingTypes: anyOf([
                    stringType,
                    numberType,
                ]),
            }),
        })
    ),
})

expectToMatchSchema(objectToTest, schema)

Install

npm i --save-dev jest-json-schema-extended

Usage

• In order to be able to use expectToMatchSchema inside jest, you need to call the following inside your test file (or you place it inside a test framework setup file):

const {setup} = require("jest-json-schema-extended");
setup()

Content

objectType

Asserts that the property is an object.

stringType

Asserts that the property is a string. The string is not allowed to be empty - use stringTypeCanBeEmpty instead if emptiness is needed.

stringTypeCanBeEmpty

Asserts that the property is a string. Allows the string to be empty.

urlType

Asserts that the property is a string looking like an URL.

dateTime

Asserts that the property is a string in date-time format.

uuidType

Asserts that the property is a string looking like a UUID.

stringTypePath

Asserts that the property is a string looking like a UNIX path.

numberType

Asserts that the property is a number.

nullType

Asserts that the property holds the value null.

booleanType

Asserts that the property is a boolean.

arrayType

Asserts that the property is an array.

arrayOfObjectsType

Loosely asserts that the property is an array of objects.

expectToMatchSchema(value, schema)

Assert that a value matches a JSON schema. Prints out errors if mismatches found.

Param	Type	Description
value	Object	The JSON object or value (string, boolean etc.) to test.
schema	Object	The JSON schema to test the object against.

strictObject(properties, [options])

Asserts that the object contains all the properties specified - additional properties are not allowed.

Param	Type	Description
properties	Object	Asserts for any key on the object that the property exists. Example: {propOne: stringType, propTwo: numberType}
[options]	Object	Accepts a property optionalProps which can be a list of optional properties that don't need to be present.

objectWithRequiredProps(properties)

Asserts that the object contains all the properties specified - additional properties are allowed.

Param	Type	Description
properties	Object	Asserts for any key on the object that the property exists. Example: {propOne: stringType, propTwo: numberType}

arrayOfItems(itemSchema, options)

Assert a JSON schema against each array item.

Param	Type	Description
itemSchema
options	Object	Accepts an option property minItems which can be used to check that the array contains at least x amount of items.

anyOf(itemSchemas)

Assert that the property is one of the provided JSON schemas.

Param
itemSchemas

stringTypeMatching(regex)

Asserts that the property is a string matching the regular expression provided.

Param	Type
regex	RegExp

stringTypeExact(expStr)

Asserts that the property is exactly the string as specified.

Param	Type
expStr	String

numberTypeGreaterThan(minimum)

Asserts that the property is a number greater than the given number.

Param	Type
minimum	Number

numberTypeLessThan(maximum)

Asserts that the property is a number less than the given number.

Param	Type
maximum	Number

oneOf(valuesExpected)

Asserts that the property received is one of the values given in the array.

Param	Type
valuesExpected	Array.<any>

arrayTypeOfLength(length)

Asserts that the property is an array of the exactly specified length.

Param	Type
length	Number

exactly(valueExpected)

Asserts that the property is exactly the value as specified. Can be anything - an object, an array, a string, a boolean, ...

Param	Type
valueExpected	any

isJsonSchema(toBeDetermined)

Helper function to check whether the passed in object is a JSON schema or a plain object.

Param	Type
toBeDetermined	Object