Package Exports

api-check

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Readme

apiCheck.js

<-- if that build is ever red or that number is ever less than 100% then I want you to flame me on twitter (@kentcdodds) and be sure to mention how disappointed @josepheames would be in me

It's like ReactJS propTypes without React. Actually, it's very heavily inspired by this concept. It's purpose is for normal JavaScript functions rather than just React Components.

Demo Screenshot

Installation

$ npm i -S api-check or $bower i -S api-check

apiCheck.js utilizes UMD, so you can:

var apiCheck = require('api-check'); (also available as AMD module or global)

Example

Note, there are a bunch of tests. Those should be instructive as well.

// given we have a function like this:
function foo(bar, foobar) {
  // we can define our api as the first argument to apiCheck.warn
  apiCheck.warn([apiCheck.number, apiCheck.arrayOf(apiCheck.string)], arguments);
  // do stuff
}
// the function above can be called like so:
foo(3, ['a','b','c']);

// if it were called like so, a descriptive warning would be logged to the console
foo('whatever', false);


// the function below can be called in the following ways:
doSomething(person, options, callback);
doSomething(person, callback);

// if it is called differently, or if the shape of person is wrong, then a descriptive error is thrown.

function doSomething(person, options, callback) {
  apiCheck.throw([
    apiCheck.shape({
      name: apiCheck.shape({
        first: apiCheck.string,
        last: apiCheck.string
      }),
      age: apiCheck.number,
      isOld: apiCheck.bool,
      walk: apiCheck.func,
      childrenNames: apiCheck.arrayOf(apiCheck.string).optional
    }),
    apiCheck.any.optional,
    apiCheck.func
  ], arguments);

  // do stuff
}

// an example object that would pass the first apiCheck.shape is here:
var obj = {
  name: {
    first: 'Matt',
    last: 'Meese'
  },
  age: 27,
  isOld: false,
  walk: function() {}
};

// if you only wish to check the first argument to a function, you don't need to supply an array.
function bar(a) {
  var errorMessage = apiCheck(apiCheck.string, arguments);
  if (errorMessage === null) {
    // success
  } else if (typeof errorMessage === 'string') {
    // there was a problem and errorMessage would like to tell you about it
  } else {
    // this should never happen... if it does, log a bug :-)
  }
}

Differences from React's propTypes

Differences in Supported Types noted below with a *

All types are required by default, to set something as optional, append .optional
checkApi.js does not support element and node types
checkApi.js supports a few additional types
object fails on null. Use object.nullOk if you don't want that

Similarities to React's propTypes

This project was totally written from scratch, but it (should) support the same api as React's propTypes (with the noted difference above). If you notice something that functions differently, please file an issue.

apiCheck(), apiCheck.warn(), and apiCheck.throw()

These functions do the same thing, with minor differences. In both the warn and throw case, a message is generated based on the arguments that the function was received and the api that was defined to describe what was wrong with the invocation.

In the case of apiCheck(), an array is returned. Each element in the array is a boolean corresponding to whether the argument (at that position) was valid or not. For example:

var result = apiCheck([apiCheck.string, apiCheck.number], [3, 4]);
console.log(result); // <-- logs [false, true]

Also note that if you only have one argument, then the first argument to the apiCheck function can simply be the checker function. For example:

apiCheck(apiCheck.bool, [false]);

(Note, the primary use case for apiCheck is for checking arguments, hence the second argument should always be an array-like thing (like arguments).

Supported types

array

apiCheck.array([]); // <-- pass
apiCheck.array(23); // <-- fail

bool

apiCheck.bool(false); // <-- pass
apiCheck.bool('me bool too?'); // <-- fail

func

apiCheck.func(function() {}); // <-- pass
apiCheck.func(new RegExp()); // <-- fail

number

apiCheck.number(423.32); // <-- pass
apiCheck.number({}); // <-- fail

object *

null fails, use object.nullOk to allow null to pass

apiCheck.object({}); // <-- pass
apiCheck.object([]); // <-- fail
apiCheck.object(null); // <-- fail

object.nullOk *

Not available in React's propTypes

apiCheck.object.nullOk({}); // <-- pass
apiCheck.object.nullOk([]); // <--- false
apiCheck.object.nullOk(null); // <-- pass

string

apiCheck.string('I am a string!'); // <-- pass
apiCheck.string([]); // <-- fail

instanceOf

apiCheck.instanceOf(RegExp)(new RegExp); // <-- pass
apiCheck.instanceOf(Date)('wanna go on a date?'); // <-- fail

oneOf

apiCheck.oneOf(['Treek', ' Wicket Wystri Warrick'])('Treek'); // <-- pass
apiCheck.oneOf(['Chewbacca', 'Snoova'])('Snoova'); // <-- fail

oneOfType

apiCheck.oneOfType([apiCheck.string, apiCheck.object])({}); // <-- pass
apiCheck.oneOfType([apiCheck.array, apiCheck.bool])('Kess'); // <-- fail

arrayOf

apiCheck.arrayOf(apiCheck.string)(['Huraga', 'Japar', 'Kahless']); // <-- pass
apiCheck.arrayOf(
  apiCheck.arrayOf(
    apiCheck.arrayOf(
      apiCheck.number
    )
  )
)([[[1,2,3], [4,5,6], [7,8,9]], [[1,2,3], [4,5,6], [7,8,9]]]); // <-- pass (for realz)
apiCheck.arrayOf(apiCheck.bool)(['a', 'b', 'c']); // <-- fail

typeOrArrayOfType *

Not available in React's propTypes

Convenience checker that combines oneOfType with arrayOf and whatever you specify. So you could take this:

apiCheck.oneOfType([
  apiCheck.string, apiCheck.arrayOf(apiCheck.string)
]);

with

apiCheck.typeOrArrayOfType(apiCheck.string);

which is a common enough use case to justify the checker.

apiCheck.typeOrArrayOfType(apiCheck.string)('string'); // <-- pass
apiCheck.typeOrArrayOfType(apiCheck.string)(['array', 'of strings']); // <-- pass
apiCheck.typeOrArrayOfType(apiCheck.bool)(['array', false]); // <-- fail
apiCheck.typeOrArrayOfType(apiCheck.object)(32); // <-- fail

objectOf

apiCheck.objectOf(apiCheck.arrayOf(apiCheck.bool))({a: [true, false], b: [false, true]}); // <-- pass
apiCheck.objectOf(apiCheck.number)({a: 'not a number?', b: 'yeah, me neither (◞‸◟；)'}); // <-- fail

shape *

Note: React propTypes does support shape, however it does not support the strict option

If you add strict = true to the shape, then it will enforce that the given object does not have any extra properties outside those specified in the shape. See below for an example...

apiCheck.shape({
  name: checkers.shape({
    first: checkers.string,
    last: checkers.string
  }),
  age: checkers.number,
  isOld: checkers.bool,
  walk: checkers.func,
  childrenNames: checkers.arrayOf(checkers.string)
})({
  name: {
    first: 'Matt',
    last: 'Meese'
  },
  age: 27,
  isOld: false,
  walk: function() {},
  childrenNames: []
}); // <-- pass
apiCheck.shape({
  mint: checkers.bool,
  chocolate: checkers.bool
})({mint: true}); // <-- fail

Example of strict

var strictShape = apiCheck.shape({
  cookies: apiCheck.bool,
  milk: apiCheck.bool,
  popcorn: apiCheck.bool.optional
});

strictShape.strict = true; // <-- that!

strictShape({
  cookies: true,
  milk: true,
  popcorn: true,
  candy: true
}); // <-- fail because the extra `candy` property

strictShape({
  cookies: true,
  milk: true
}); // <-- pass because it has no extra properties and `popcorn` is optional

shape.onlyIf *

Not available in React's propTypes

This can only be used in combination with shape

apiCheck.shape({
  cookies: apiCheck.shape.onlyIf(['mint', 'chips'], apiCheck.bool)
})({cookies: true, mint: true, chips: true}); // <-- pass

apiCheck.shape({
  cookies: apiCheck.shape.onlyIf(['mint', 'chips'], apiCheck.bool)
})({chips: true}); // <-- pass (cookies not specified)

apiCheck.shape({
  cookies: apiCheck.shape.onlyIf('mint', apiCheck.bool)
})({cookies: true}); // <-- fail

shape.ifNot *

Not available in React's propTypes

This can only be used in combination with shape

apiCheck.shape({
  cookies: apiCheck.shape.ifNot('mint', apiCheck.bool)
})({cookies: true}); // <-- pass

apiCheck.shape({
  cookies: apiCheck.shape.ifNot(['mint', 'chips'], apiCheck.bool)
})({cookies: true, chips: true}); // <-- fail

args *

Not available in React's propTypes

This will check if the given item is an arguments-like object (non-array object that has a length property)

function foo(bar) {
  apiCheck.args(arguments); // <-- pass
}
apiCheck.args([]); // <-- fail
apiCheck.args({}); // <-- fail
apiCheck.args({length: 3}); // <-- pass
apiCheck.args({length: 'not-number'}); // <-- fail

any

apiCheck.any({}); // <-- pass
apiCheck.any([]); // <-- pass
apiCheck.any(true); // <-- pass
apiCheck.any(false); // <-- pass
apiCheck.any(/* seriously, anything, except undefined */); // <-- fail
apiCheck.any.optional(/* unless you specify optional :-) */); // <-- pass
apiCheck.any(3); // <-- pass
apiCheck.any(3.1); // <-- pass
apiCheck.any(3.14); // <-- pass
apiCheck.any(3.141); // <-- pass
apiCheck.any(3.1415); // <-- pass
apiCheck.any(3.14159); // <-- pass
apiCheck.any(3.141592); // <-- pass
apiCheck.any(3.1415926); // <-- pass
apiCheck.any(3.14159265); // <-- pass
apiCheck.any(3.141592653); // <-- pass
apiCheck.any(3.1415926535); // <-- pass
apiCheck.any(3.14159265359); // <-- pass
apiCheck.any(jfio,.jgo); // <-- Syntax error.... ಠ_ಠ

Custom Types

You can specify your own type. You do so like so:

function foo(string, ipAddress) {
  apiCheck.warn([
    apiCheck.string,
    ipAddressChecker
  ], arguments);

  function ipAddressChecker(val, name, location) {
    if (!/(\d{1,3}\.){3}\d{1,3}/.test(val)) {
      return apiCheck.utils.getError(name, location, ipAddressChecker.type);
    }
  };
  ipAddressChecker.type = 'ipAddressString';
}

Then, if you invoked that function like this:

foo('hello', 'not-an-ip-address');

It would result in a warning like this:

apiCheck failed! Argument 1 passed, value at Argument 2 must be ipAddressString

You passed: String, String

The API calls for: String, ipAddressString

Customization

Note, obviously, these things are specific to apiCheck and not part of React propTypes

config.output

You can specify some extra options for the output of the message.

apiCheck.config.output = {
  prefix: 'Global prefix',
  suffix: 'global suffix',
  docsBaseUrl: 'https://example.com/errors-and-warnings#'
};

You can also specify an output object to each apiCheck(), apiCheck.throw(), and apiCheck.warn() request:

apiCheck(apiCheck.bool, arguments, {
  prefix: 'instance prefix:',
  suffix: 'instance suffix',
  url: 'example-error-additional-info'
});

A failure with the above configuration would yield something like this:

Global prefix instance prefix {{error message}} instance suffix global suffix https://example.com/errors-and-warnings#example-error-additional-info

getErrorMessage

This is the method that apiCheck uses to get the message it throws or console.warns. If you don't like it, feel free to make a better one by simply: apiCheck.getErrorMessage = function(api, args, output) {/* return message */}

handleErrorMessage

This is the method that apiCheck uses to throw or warn the message. If you prefer to do your own thing, that's cool. Simply apiCheck.handleErrorMessage = function(message, shouldThrow) { /* throw or warn */ }

Disable apiCheck

It's a good idea to disable the apiCheck in production. To do this, simply invoke disable()

apiCheck.disable();

// to re-enable it
apiCheck.enable();

Credits

This library was written by Kent C. Dodds. Again, big credits go to the team working on React for thinking up the api. This library was written from scratch, but I'd be lying if I didn't say that I referenced their functions a time or two.