https://github.com/stdlib-js/utils-async-try-catch
If a function does not return an error, invoke a callback with the function result; otherwise, invoke a callback with a value `y`.
https://github.com/stdlib-js/utils-async-try-catch
async asynchronous catch condition conditional control either-or flow javascript node node-js nodejs stdlib trap try try-catch util utilities utility utils
Last synced: 9 months ago
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If a function does not return an error, invoke a callback with the function result; otherwise, invoke a callback with a value `y`.
- Host: GitHub
- URL: https://github.com/stdlib-js/utils-async-try-catch
- Owner: stdlib-js
- License: apache-2.0
- Created: 2021-06-13T19:27:21.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2025-03-10T00:24:42.000Z (11 months ago)
- Last Synced: 2025-04-12T17:44:41.319Z (10 months ago)
- Topics: async, asynchronous, catch, condition, conditional, control, either-or, flow, javascript, node, node-js, nodejs, stdlib, trap, try, try-catch, util, utilities, utility, utils
- Language: JavaScript
- Homepage: https://github.com/stdlib-js/stdlib
- Size: 947 KB
- Stars: 2
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Citation: CITATION.cff
- Security: SECURITY.md
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README
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# trycatchAsync
[![NPM version][npm-image]][npm-url] [![Build Status][test-image]][test-url] [![Coverage Status][coverage-image]][coverage-url]
> If a function does not return an error, invoke a callback with the function result; otherwise, invoke a callback with a value `y`.
## Installation
```bash
npm install @stdlib/utils-async-try-catch
```
Alternatively,
- To load the package in a website via a `script` tag without installation and bundlers, use the [ES Module][es-module] available on the [`esm`][esm-url] branch (see [README][esm-readme]).
- If you are using Deno, visit the [`deno`][deno-url] branch (see [README][deno-readme] for usage intructions).
- For use in Observable, or in browser/node environments, use the [Universal Module Definition (UMD)][umd] build available on the [`umd`][umd-url] branch (see [README][umd-readme]).
The [branches.md][branches-url] file summarizes the available branches and displays a diagram illustrating their relationships.
To view installation and usage instructions specific to each branch build, be sure to explicitly navigate to the respective README files on each branch, as linked to above.
## Usage
```javascript
var trycatchAsync = require( '@stdlib/utils-async-try-catch' );
```
#### trycatchAsync( x, y, done )
If a function `x` does not return an error, invokes a `done` callback with the function result; otherwise, invokes a `done` callback with a value `y`.
```javascript
var randu = require( '@stdlib/random-base-randu' );
function x( clbk ) {
setTimeout( onTimeout, 0 );
function onTimeout() {
if ( randu() > 0.5 ) {
return clbk( null, 1.0 );
}
clbk( new Error( 'oops' ) );
}
}
function done( error, result ) {
if ( error ) {
console.log( error.message );
}
console.log( result );
}
trycatchAsync( x, -1.0, done );
```
The function `x` is provided a single argument:
- `clbk`: callback to invoke upon function completion.
The callback accepts two arguments:
- `error`: error object.
- `result`: function result.
The `done` callback is invoked upon function completion and is provided two arguments:
- `error`: error object.
- `result`: either the result of `x` or the provided value `y`.
If the function `x` does not return a truthy `error` argument, the `error` argument provided to the `done` callback is `null`. If `x` does return a truthy `error` argument, the `done` callback is invoked with both the `error` and the provided value `y`.
## Notes
- Execution is **not** guaranteed to be asynchronous. To guarantee asynchrony, wrap the `done` callback in a function which either executes at the end of the current stack (e.g., `nextTick`) or during a subsequent turn of the event loop (e.g., `setImmediate`, `setTimeout`).
## Examples
```javascript
var randu = require( '@stdlib/random-base-randu' );
var trycatchAsync = require( '@stdlib/utils-async-try-catch' );
var i;
function next() {
trycatchAsync( x, 'beep', done );
}
function x( clbk ) {
setTimeout( onTimeout, 0 );
function onTimeout() {
if ( randu() > 0.9 ) {
return clbk( null, 'BOOP' );
}
clbk( new Error( 'oops' ) );
}
}
function done( error, result ) {
if ( error ) {
console.log( error.message );
}
i += 1;
console.log( result );
if ( i < 100 ) {
return next();
}
}
i = 0;
next();
```
* * *
## See Also
- [`@stdlib/utils-try-catch`][@stdlib/utils/try-catch]: if a function does not throw, return the function return value; otherwise, return `y`.
- [`@stdlib/utils-async/try-then`][@stdlib/utils/async/try-then]: if a function does not return an error, invoke a callback with the function result; otherwise, invoke a second function.
* * *
## Notice
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
#### Community
[![Chat][chat-image]][chat-url]
---
## License
See [LICENSE][stdlib-license].
## Copyright
Copyright © 2016-2025. The Stdlib [Authors][stdlib-authors].
[npm-image]: http://img.shields.io/npm/v/@stdlib/utils-async-try-catch.svg
[npm-url]: https://npmjs.org/package/@stdlib/utils-async-try-catch
[test-image]: https://github.com/stdlib-js/utils-async-try-catch/actions/workflows/test.yml/badge.svg?branch=main
[test-url]: https://github.com/stdlib-js/utils-async-try-catch/actions/workflows/test.yml?query=branch:main
[coverage-image]: https://img.shields.io/codecov/c/github/stdlib-js/utils-async-try-catch/main.svg
[coverage-url]: https://codecov.io/github/stdlib-js/utils-async-try-catch?branch=main
[chat-image]: https://img.shields.io/gitter/room/stdlib-js/stdlib.svg
[chat-url]: https://app.gitter.im/#/room/#stdlib-js_stdlib:gitter.im
[stdlib]: https://github.com/stdlib-js/stdlib
[stdlib-authors]: https://github.com/stdlib-js/stdlib/graphs/contributors
[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/utils-async-try-catch/tree/deno
[deno-readme]: https://github.com/stdlib-js/utils-async-try-catch/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/utils-async-try-catch/tree/umd
[umd-readme]: https://github.com/stdlib-js/utils-async-try-catch/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/utils-async-try-catch/tree/esm
[esm-readme]: https://github.com/stdlib-js/utils-async-try-catch/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/utils-async-try-catch/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/utils-async-try-catch/main/LICENSE
[@stdlib/utils/try-catch]: https://github.com/stdlib-js/utils-try-catch
[@stdlib/utils/async/try-then]: https://github.com/stdlib-js/utils-async-try-then