FetchThrow.js
FetchThrow.js is a mixin for the Fetch API for browsers and Node.js that rejects the returned promise with a FetchError.js instance should the network request fail or the response have a status of at least 400 and less than 600 (as defined for error responses in the HTTP specs).
Installing
npm install fetch-throw
FetchThrow.js follows semantic versioning, so feel free to depend on its major version with something like >= 1.0.0 < 2
(a.k.a ^1.0.0
).
If you'd like more convenient access to the thrown FetchError
instance (e.g. for instanceof
checks), also install fetch-error
and ensure there's only one installed:
npm install fetch-errornpm dedupe fetch-error
Using
Wrap the native fetch
function with the one from FetchThrow.js:
var fetch = globalfetch
Then call the returned function as you would with the regular Fetch API:
var res =
Should /models
respond with 404, res
will be rejected with an instance of FetchError
. The FetchError
property on FetchThrow
is identical to doing require("fetch-error")
.
var FetchError = FetchError res
In case of unexpected errors (such as network name lookup failures) thrown by fetch
before a request is made, res
will also be rejected with an instance of FetchError
. This allows you to identify failed requests for logging, for example, as shown above.
For a description of properties on the error, see below.
Browser
Browsers have the Fetch API available at window.fetch
:
var fetch = windowfetch
Node.js
Node.js doesn't have a built-in implementation of the Fetch API, but you can use any library with a compatible interface, such as my Fetch/Off.js or node-fetch:
var fetch =
Properties on an instance of FetchError
Property | Description |
---|---|
code | Response's statusCode or 0 in case of network error. |
message | Response's statusText or "Network Error." . |
request | A new Fetch API Request object to help identify the request. |
response | The Fetch API Response of the failed request. |
error | In case of non-response errors, it's set to the original error. |
License
FetchThrow.js is released under a Lesser GNU Affero General Public License, which in summary means:
- You can use this program for no cost.
- You can use this program for both personal and commercial reasons.
- You do not have to share your own program's code which uses this program.
- You have to share modifications (e.g. bug-fixes) you've made to this program.
For more convoluted language, see the LICENSE
file.
About
Andri Möll typed this and the code.
Monday Calendar supported the engineering work.
If you find FetchThrow.js needs improving, please don't hesitate to type to me now at andri@dot.ee or create an issue online.