api-check

If that build is ever red or the coverage 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.

Installation

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

api-check utilizes UMD, so you can:

var apiCheck = require('api-check')(/* your custom options, checkers*/);

Also available as an AMD module or as apiCheck on global

Example

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

1var myApiCheck = require('api-check')({
2  /* config options */
3  output: {
4    prefix: 'app/lib Name',
5    suffix: 'Good luck!',
6    docsBaseUrl: 'http://www.example.com/error-docs#'
7  },
8  verbose: false
9}, {
10  /* custom checkers if you wanna */
11});
12
13// given we have a function like this:
14function foo(bar, foobar) {
15  // we can define our api as the first argument to myApiCheck.warn
16  myApiCheck.warn([myApiCheck.number, myApiCheck.arrayOf(myApiCheck.string)], arguments);
17  // do stuff
18}
19// the function above can be called like so:
20foo(3, ['a','b','c']);
21
22// if it were called like so, a descriptive warning would be logged to the console
23foo('whatever', false);
24
25
26// here's something a little more complex (this is what's in the screenshot and [the demo](http://jsbin.com/hibocu/edit?js,console,output))
27var myCheck = require('api-check')({
28  output: {
29    prefix: 'myApp',
30    suffix: 'see docs -->',
31    docsBaseUrl: 'http://example.com/error-descriptions#'
32  }
33});
34function doSomething(person, options, callback) {
35  myCheck.warn([ // you can also do myCheck.throw to throw an exception
36    myCheck.shape({
37      name: myCheck.shape({
38        first: myCheck.string,
39        last: myCheck.string
40      }),
41      age: myCheck.number,
42      isOld: myCheck.bool,
43      walk: myCheck.func,
44      ipAddress: function(val, name, location) {
45        if (!/(\d{1,3}\.){3}\d{1,3}/.test(val)) {
46          return myCheck.utils.getError(name, location, 'ipAddress');
47        }
48      },
49      childrenNames: myCheck.arrayOf(myCheck.string).optional
50    }),
51    myCheck.any.optional,
52    myCheck.func
53  ], arguments, {
54    prefix: 'doSomething',
55    suffix: 'Good luck!',
56    urlSuffix: 'dosomething-api-check-failure'
57  });
58
59  // do stuff
60}
61
62var person = {
63  name: {
64    first: 'Matt',
65    last: 'Meese'
66  },
67  age: 27,
68  isOld: false,
69  ipAddress: '127.0.0.1',
70  walk: function() {}
71};
72function callback() {}
73var options = 'whatever I want because it is an "any" type';
74
75console.log('Successful call');
76doSomething(person, options, callback);
77
78console.log('Successful call (without options)');
79doSomething(person, callback); // <-- options is optional
80
81console.log('Failed call (without person)');
82doSomething(callback); // <-- this would fail because person is not optional
83
84person.ipAddress = 'Invalid IP Address!!!';
85
86console.log('Failed call (invalid ip address)');
87doSomething(person, options, callback); // <-- this would fail because the ipAddress checker would fail
88
89// if you only wish to check the first argument to a function, you don't need to supply an array.
90
91var libCheck = apiCheck(); // you don't HAVE to pass anything if you don't want to.
92function bar(a) {
93  var errorMessage = libCheck(apiCheck.string, arguments);
94  if (!errorMessage) {
95    // success
96  } else if (typeof errorMessage === 'string') {
97    // there was a problem and errorMessage would like to tell you about it
98  }
99}
100bar('hello!'); // <-- success!

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 all cases, an object is returned with the following properties:

argTypes (arrayOf[Object])

This is an array of objects representing the types of the arguments passed.

apiTypes (arrayOf[Object])

This is an object representing the types of the api. It's a whole language of its own that you'll hopefully get after looking at it for a while.

failed (boolean)

Will be false when the check passes, and true when it fails

passed (boolean)

Will be true when the check passes, and false when it fails

message (string)

If the check failed, this will be a useful message for display to the user. If it passed, this will be an empty string

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:

1apiCheck(apiCheck.bool, arguments);

The second argument can either be an arguments-like object or an array.

Supported types

array

1apiCheck.array([]); // <-- pass
2apiCheck.array(23); // <-- fail

bool

1apiCheck.bool(false); // <-- pass
2apiCheck.bool('me bool too?'); // <-- fail

func

1apiCheck.func(function() {}); // <-- pass
2apiCheck.func(new RegExp()); // <-- fail

func.withProperties *

Not available in React's propTypes

1var checker = apiCheck.func.withProperties({
2  type: apiCheck.oneOfType([apiCheck.object, apiCheck.string]),
3  help: apiCheck.string.optional
4});
5function winning(){}
6winning.type = 'awesomeness';
7checker(winning); // <--pass
8
9function losing(){}
10checker(losing); // <-- fail

number

1apiCheck.number(423.32); // <-- pass
2apiCheck.number({}); // <-- fail

object *

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

1apiCheck.object({}); // <-- pass
2apiCheck.object([]); // <-- fail
3apiCheck.object(null); // <-- fail

object.nullOk *

Not available in React's propTypes

1apiCheck.object.nullOk({}); // <-- pass
2apiCheck.object.nullOk([]); // <--- false
3apiCheck.object.nullOk(null); // <-- pass

string

1apiCheck.string('I am a string!'); // <-- pass
2apiCheck.string([]); // <-- fail

range

1apiCheck.range(0, 10)(4); // <-- pass
2apiCheck.rang(-100, 100)(500); // <-- fail

greaterThan

1apiCheck.greaterThan(100)(200); // <-- pass
2apiCheck.greaterThan(-10)(-20); // <-- fail
3apiCheck.greaterThan(50)('Frogs!'); // <-- fail

lessThan

1apiCheck.lessThan(100)(50); // <-- pass
2apiCheck.lessThan(-10)(0); // <-- fail
3apiCheck.lessThan(50)('Frogs!'); // <-- fail

instanceOf

1apiCheck.instanceOf(RegExp)(new RegExp); // <-- pass
2apiCheck.instanceOf(Date)('wanna go on a date?'); // <-- fail

oneOf

1apiCheck.oneOf(['Treek', ' Wicket Wystri Warrick'])('Treek'); // <-- pass
2apiCheck.oneOf(['Chewbacca', 'Snoova'])('Snoova'); // <-- fail

oneOfType

1apiCheck.oneOfType([apiCheck.string, apiCheck.object])({}); // <-- pass
2apiCheck.oneOfType([apiCheck.array, apiCheck.bool])('Kess'); // <-- fail

arrayOf

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

typeOrArrayOf *

Not available in React's propTypes

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

1apiCheck.oneOfType([
2  apiCheck.string, apiCheck.arrayOf(apiCheck.string)
3]);

with

1apiCheck.typeOrArrayOf(apiCheck.string);

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

1apiCheck.typeOrArrayOf(apiCheck.string)('string'); // <-- pass
2apiCheck.typeOrArrayOf(apiCheck.string)(['array', 'of strings']); // <-- pass
3apiCheck.typeOrArrayOf(apiCheck.bool)(['array', false]); // <-- fail
4apiCheck.typeOrArrayOf(apiCheck.object)(32); // <-- fail

objectOf

1apiCheck.objectOf(apiCheck.arrayOf(apiCheck.bool))({a: [true, false], b: [false, true]}); // <-- pass
2apiCheck.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 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...

1apiCheck.shape({
2  name: checkers.shape({
3    first: checkers.string,
4    last: checkers.string
5  }),
6  age: checkers.number,
7  isOld: checkers.bool,
8  walk: checkers.func,
9  childrenNames: checkers.arrayOf(checkers.string)
10})({
11  name: {
12    first: 'Matt',
13    last: 'Meese'
14  },
15  age: 27,
16  isOld: false,
17  walk: function() {},
18  childrenNames: []
19}); // <-- pass
20apiCheck.shape({
21  mint: checkers.bool,
22  chocolate: checkers.bool
23})({mint: true}); // <-- fail

Example of strict

1var strictShape = apiCheck.shape({
2  cookies: apiCheck.bool,
3  milk: apiCheck.bool,
4  popcorn: apiCheck.bool.optional
5}).strict; // <-- that!
6
7strictShape({
8  cookies: true,
9  milk: true,
10  popcorn: true,
11  candy: true
12}); // <-- fail because the extra `candy` property
13
14strictShape({
15  cookies: true,
16  milk: true
17}); // <-- pass because it has no extra properties and `popcorn` is optional

Note, you can also append .optional to the .strict (as in: apiCheck.shape({}).strict.optional)

shape.onlyIf *

Not available in React's propTypes

This can only be used in combination with shape

1apiCheck.shape({
2  cookies: apiCheck.shape.onlyIf(['mint', 'chips'], apiCheck.bool)
3})({cookies: true, mint: true, chips: true}); // <-- pass
4
5apiCheck.shape({
6  cookies: apiCheck.shape.onlyIf(['mint', 'chips'], apiCheck.bool)
7})({chips: true}); // <-- pass (cookies not specified)
8
9apiCheck.shape({
10  cookies: apiCheck.shape.onlyIf('mint', apiCheck.bool)
11})({cookies: true}); // <-- fail

shape.ifNot *

Not available in React's propTypes

This can only be used in combination with shape

1apiCheck.shape({
2  cookies: apiCheck.shape.ifNot('mint', apiCheck.bool)
3})({cookies: true}); // <-- pass
4
5apiCheck.shape({
6  cookies: apiCheck.shape.ifNot(['mint', 'chips'], apiCheck.bool)
7})({cookies: true, chips: true}); // <-- fail

requiredIfNot *

Not available in React's propTypes

This can only be used in combination with shape

1checker = checkers.shape({
2  foobar: checkers.shape.requiredIfNot(['foobaz', 'baz'], checkers.bool),
3  foobaz: checkers.object.optional,
4  baz: checkers.string.optional,
5  foo: checkers.string.optional
6});
7checker({
8  foo: [1, 2],
9  foobar: true
10}); // <-- passes
11
12checker({foo: 'bar'}); // <-- fails

all

Not available in React's propTypes

This can only be used in combination with shape.requiredIfNot

1checker = checkers.shape({
2  foobar: checkers.shape.requiredIfNot.all(['foobaz', 'baz'], checkers.bool),
3  foobaz: checkers.object.optional,
4  baz: checkers.string.optional,
5  foo: checkers.string.optional
6});
7checker({
8  foo: [1, 2]
9}); // <-- fails
10
11checker({
12  foo: [1, 2],
13  foobar: true
14}); // <-- passes
15
16checker({
17  foo: [1, 2],
18  baz: 'foo'
19}); // <-- passes

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)

1function foo(bar) {
2  apiCheck.args(arguments); // <-- pass
3}
4apiCheck.args([]); // <-- fail
5apiCheck.args({}); // <-- fail
6apiCheck.args({length: 3}); // <-- pass
7apiCheck.args({length: 'not-number'}); // <-- fail

any

1apiCheck.any({}); // <-- pass
2apiCheck.any([]); // <-- pass
3apiCheck.any(true); // <-- pass
4apiCheck.any(false); // <-- pass
5apiCheck.any(/* seriously, anything, except undefined */); // <-- fail
6apiCheck.any.optional(/* unless you specify optional :-) */); // <-- pass
7apiCheck.any(3); // <-- pass
8apiCheck.any(3.1); // <-- pass
9apiCheck.any(3.14); // <-- pass
10apiCheck.any(3.141); // <-- pass
11apiCheck.any(3.1415); // <-- pass
12apiCheck.any(3.14159); // <-- pass
13apiCheck.any(3.141592); // <-- pass
14apiCheck.any(3.1415926); // <-- pass
15apiCheck.any(3.14159265); // <-- pass
16apiCheck.any(3.141592653); // <-- pass
17apiCheck.any(3.1415926535); // <-- pass
18apiCheck.any(3.14159265359); // <-- pass
19apiCheck.any(jfio,.jgo); // <-- Syntax error.... ಠ_ಠ

Custom Types

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

1var myCheck = require('api-check')({
2  output: {prefix: 'myCheck'}
3});
4
5function ipAddressChecker(val, name, location) {
6  if (!/(\d{1,3}\.){3}\d{1,3}/.test(val)) {
7    return apiCheck.utils.getError(name, location, ipAddressChecker.type);
8  }
9};
10ipAddressChecker.type = 'ipAddressString';
11
12function foo(string, ipAddress) {
13  myCheck.warn([
14    myCheck.string,
15    ipAddressChecker
16  ], arguments);
17}

Then, if you invoked that function like this:

1foo('hello', 'not-an-ip-address');

It would result in a warning like this:

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

You passed:
[
  "hello",
  "not-an-ip-address"
]

With the types:
[
  "string",
  "string"
]

The API calls for:
[
  "String",
  "ipAddressString"
]

There's actually quite a bit of cool stuff you can do with custom types checkers. If you want to know what they are, look at the tests or file an issue for me to go document them. :-)

apiCheck.utils

When writing custom types, you may find the utils helpful. Please file an issue to ask me to improve documentation for what's available. For now, check out api-check-utils.test.js

Customization

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

When you create your instance of apiCheck, you can configure it with different options as part of the first argument.

config.output

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

1var myApiCheck = require('api-check')({
2  output: {
3    prefix: 'Global prefix',
4    suffix: 'global suffix',
5    docsBaseUrl: 'https://example.com/errors-and-warnings#'
6  },
7  verbose: false, // <-- defaults to false
8  disabled: false // <-- defaults to false, set this to true in production
9});

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

1myApiCheck(apiCheck.bool, arguments, {
2  prefix: 'instance prefix:',
3  suffix: 'instance suffix',
4  urlSuffix: 'example-error-additional-info'
5});

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

As an alternative to urlSuffix, you can also specify a url:

1myApiCheck(apiCheck.bool, arguments, {
2  url: 'https://example.com/some-direct-url-that-does-not-use-the-docsBaseUrl'
3});

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. You can disable your own instance of apiCheck as part of the options, but it's probably just better to disable apiCheck globally. I recommend you do this before you (or any of you dependencies) create an instance of apiCheck. Here's how you would do that:

1var apiCheck = require('api-check');
2apiCheck.globalConfig.disabled = true;

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.