@stdlib/assert/is-email-address/README.md

Standard assertion utilities.

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# isEmail

> Test if a value is an email address.

<section class="intro">

</section>

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<section class="usage">

## Usage

```javascript
var isEmail = require( '@stdlib/assert/is-email-address' );
```

#### isEmail( value )

Tests if a `value` is an [email address][validate-email-address].

```javascript
var bool = isEmail( 'beep@boop.com' );
// returns true
```

</section>

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<section class="notes">

## Notes

-   Validation is **not** rigorous, nor [should it be][validate-email-address]. **9** RFCs relate to email addresses, and accounting for all of them is a fool's errand. This module performs the simplest validation; i.e., requiring **at least** one `@` symbol.
-   For rigorous validation, send a confirmation email. If the email bounces, consider the email invalid.

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<section class="examples">

## Examples

<!-- eslint no-undef: "error" -->

```javascript
var isEmail = require( '@stdlib/assert/is-email-address' );

var bool;

bool = isEmail( 'beep@boop.com' );
// returns true

bool = isEmail( 'beep' );
// returns false

bool = isEmail( 'beep.com' );
// returns false

bool = isEmail( null );
// returns false
```

</section>

<!-- /.examples -->

* * *

<section class="cli">

## CLI

<section class="usage">

### Usage

```text
Usage: is-email-address [options] [<string>]

Options:

  -h,    --help                Print this message.
  -V,    --version             Print the package version.
         --split sep           Delimiter for stdin data. Default: '/\\r?\\n/'.
```

</section>

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<section class="notes">

### Notes

-   If the split separator is a [regular expression][mdn-regexp], ensure that the `split` option is either properly escaped or enclosed in quotes.

    ```bash
    # Not escaped...
    $ echo -n $'foo@bar.com\nboop' | is-email --split /\r?\n/

    # Escaped...
    $ echo -n $'foo@bar.com\nboop' | is-email --split /\\r?\\n/
    ```

-   The implementation ignores trailing delimiters.

</section>

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<section class="examples">

### Examples

```bash
$ is-email-address beep@boop.com
true
```

To use as a [standard stream][standard-streams],

```bash
$ echo -n 'beep@boop.com' | is-email
true
```

By default, when used as a [standard stream][standard-streams], the implementation assumes newline-delimited data. To specify an alternative delimiter, set the `split` option.

```bash
$ echo -n 'foo@bar.com\tbeep' | is-email --split '\t'
true
false
```

</section>

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</section>

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<section class="related">

</section>

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<section class="links">

[validate-email-address]: http://davidcel.is/posts/stop-validating-email-addresses-with-regex/

[standard-streams]: https://en.wikipedia.org/wiki/Standard_streams

[mdn-regexp]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions

</section>

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