fluent-schemer

const librarySchema = object({
    dependenciesCount: number().min(0).max(10).integer().optional(),
    name: string().minlength(2).maxlength(10),
    testCoverage: number().min(0).max(100).optional(),
    lastCommitDate: date().after(new Date(new Date().setMonth(new Date().getMonth() - 1))),
    contributors: array(
        object({
            username: string().minlength(5),
            email: string().pattern(/\S+@\S+\.\S+/)
        })
    ),
    issues: array(string()),
    activelyMaintained: bool(),
    license: enumeration('MIT', 'BSD', 'GPL')
});
 
const { errorCounts, errors } = librarySchema.validate(someLibraryRecord);

Incoming:

• default values, something like

const { corrected: pageSize } = number().min(10).max(100).integer().default(10).validate(-5);
console.log(corrected); // 10
 
const { corrected: username } = string()
    .minlength(2)
    .maxlength(10)
    .defaultExpression(value => ('_________' + value).slice(0, 10))
    .validate('1');
console.log(username); // _________1

Aims to provide declarative, expressive and elegant approach to validation, while providing an intuitive, easy-to-use api.

It's cool, because

• it fully embraces ES2015 features such as classes, fat arrow functions, mixins, destructuring statements, modules
• has typescript type definitions - v2.0 comes with typings for enhanced development experience
• has flow libdefs, which will soon be available on flow-typed
• easy to use and pick up, write a little code for a lot of common validation logic
• has a fluent, readable and declarative api
• umd compliant - use in node/browser, with commonjs, umd, script tags, harmony modules, whatever
• no production dependencies, small codebase
• helps developers get rid of imperative code, long if-else's and writing boring validations all over again
• promotes code reuse - easily share code between modules, between clients, servers and across projects
• easy to extends with custom schemas
• statically type checked with latest typescript, checked for correctness with a bunch of unit tests
• throws errors when rubbish arguments are provided to schema methods, instead of failing silently

Running the tests

yarn build && yarn lint && yarn test

Examples

Examples can be found in the docs, in the source code and in the tests.

Documentation