predicate

is.js - Adding clarity and conciseness to your JS through predicates

is.js is a predicate library for JS. is doesn't have any dependencies which makes it easy to integrate into new and existing projects.

Docs

landau.github.io/is

install

npm install --save is-predicate

or

download the file from the dist directory

Usage

is.equal(1, 1); // true
is.not.pos(-1); // true
is.ternary(true, 'foo', 'bar'); // foo
is.fn(function () {}); // true
is.not.equal(1, 3); // true

Every/Some

Every and some are functions that allow you to chain predicate calls. The calls are not evaluated until .val() is executed on the chain.

// All evaluations must be true
is.every().equal(1, 1).contains([1, 2, 3], 2).val(); // true
is.all().equal(1, 5).contains([1, 2, 3], 2).val(); // false

// At least one eval must be true
is.some().equal(1, 1).contains([1, 2, 3], 2).val(); // true
is.any().equal(1, 5).contains([1, 2, 3], 2).val(); // true
is.some().equal(1, 5).contains([1, 2, 3], 5).val(); // false

Alternaively to .val you can execute valueOf

// All evaluations must be true
!!is.every().equal(1, 1).contains([1, 2, 3], 2); // true

Notice the alias of all/any if you prefer that flavor

NOTE: Chaining doesnt work with .not yet.

Author

Trevor Landau

contributing

• Suggestions welcome!
• Tests!
• Ping me on twitter if I take too long to respond! That probably means I missed the alert/email.

Tests

To run tests, install devDeps and type npm ts

Building

To build, type npm run build.

This will create a UMDified version of is in the dist directory along with a minified version.