notes/node_modules/browserslist/README.md

332 lines
8.7 KiB
Markdown
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Browserslist
Library to share supported browsers list between different front-end tools.
It is used in [Autoprefixer], [Stylelint], [eslint-plugin-compat]
and [babel-env-preset].
All tools that rely on Browserslist will find its config automatically,
when you add the following to `package.json`:
```json
{
"browserslist": [
"> 1%",
"last 2 versions"
]
}
```
Or in `browserslist` config:
```yaml
# Browsers that we support
> 1%
Last 2 versions
IE 10 # sorry
```
Developers set browsers list in queries like `last 2 version`
to be free from updating browser versions manually.
Browserslist will use [Can i Use] data for this queries.
Browserslist will take browsers queries from tool option,
`browserslist` config, `browserslist` section in `package.json`
or environment variables.
You can test Browserslist queries in [online demo].
<a href="https://evilmartians.com/?utm_source=browserslist">
<img src="https://evilmartians.com/badges/sponsored-by-evil-martians.svg"
alt="Sponsored by Evil Martians"
width="236"
height="54"
\>
</a>
[eslint-plugin-compat]: https://github.com/amilajack/eslint-plugin-compat
[babel-env-preset]: https://github.com/babel/babel-preset-env
[Autoprefixer]: https://github.com/postcss/autoprefixer
[online demo]: http://browserl.ist/
[Stylelint]: http://stylelint.io/
[Can I Use]: http://caniuse.com/
## Queries
Browserslist will use browsers query from one of this sources:
1. Tool options. For example `browsers` option in Autoprefixer.
2. `BROWSERSLIST` environment variable.
3. `browserslist` config file in current or parent directories.
4. `browserslist` key in `package.json` file in current or parent directories.
5. If the above methods did not produce a valid result
Browserslist will use defaults: `> 1%, last 2 versions, Firefox ESR`.
We recommends to write queries in `browserslist` config or `package.json`.
You can specify the versions by queries (case insensitive):
* `last 2 versions`: the last 2 versions for each major browser.
* `last 2 Chrome versions`: the last 2 versions of Chrome browser.
* `> 5%`: versions selected by global usage statistics.
* `> 5% in US`: uses USA usage statistics. It accepts [two-letter country code].
* `> 5% in my stats`: uses [custom usage data].
* `ie 6-8`: selects an inclusive range of versions.
* `Firefox > 20`: versions of Firefox newer than 20.
* `Firefox >= 20`: versions of Firefox newer than or equal to 20.
* `Firefox < 20`: versions of Firefox less than 20.
* `Firefox <= 20`: versions of Firefox less than or equal to 20.
* `Firefox ESR`: the latest [Firefox ESR] version.
* `iOS 7`: the iOS browser version 7 directly.
* `not ie <= 8`: exclude browsers selected before by previous queries.
You can add `not ` to any query.
Browserslist works with separated versions of browsers.
You should avoid queries like `Firefox > 0`.
Multiple criteria are combined as a boolean `OR`. A browser version must match
at least one of the criteria to be selected.
All queries are based on the [Can I Use] support table,
e.g. `last 3 iOS versions` might select `8.4, 9.2, 9.3` (mixed major and minor),
whereas `last 3 Chrome versions` might select `50, 49, 48` (major only).
[two-letter country code]: http://en.wikipedia.org/wiki/ISO_3166-1_alpha-2#Officially_assigned_code_elements
[custom usage data]: #custom-usage-data
[Can I Use]: http://caniuse.com/
## Browsers
Names are case insensitive:
### Major Browsers
* `Chrome` for Google Chrome.
* `Firefox` or `ff` for Mozilla Firefox.
* `Explorer` or `ie` for Internet Explorer.
* `Edge` for Microsoft Edge.
* `iOS` or `ios_saf` for iOS Safari.
* `Opera` for Opera.
* `Safari` for desktop Safari.
* `ExplorerMobile` or `ie_mob` for Internet Explorer Mobile.
### Others
* `Android` for Android WebView.
* `BlackBerry` or `bb` for Blackberry browser.
* `ChromeAndroid` or `and_chr` for Chrome for Android
(in Other section, because mostly same as common `Chrome`).
* `FirefoxAndroid` or `and_ff` for Firefox for Android.
* `OperaMobile` or `op_mob` for Opera Mobile.
* `OperaMini` or `op_mini` for Opera Mini.
* `Samsung` for Samsung Internet.
* `UCAndroid` or `and_uc` for UC Browser for Android.
* `Electron` for Electron framework. It will be converted to Chrome version.
### Electron
[`electron-to-chromium`](https://www.npmjs.com/package/electron-to-chromium)
could return a compatible Browserslist query
for your (major) Electron version:
```js
const e2c = require('electron-to-chromium')
autoprefixer({
browsers: e2c.electronToBrowserList('1.4') //=> "Chrome >= 53"
})
```
## Config File
Browserslist config should be named `browserslist` and have browsers queries
split by a new line. Comments starts with `#` symbol:
```yaml
# Browsers that we support
> 1%
Last 2 versions
IE 8 # sorry
```
Browserslist will check config in every directory in `path`.
So, if tool process `app/styles/main.css`, you can put config to root,
`app/` or `app/styles`.
You can specify direct path in `BROWSERSLIST_CONFIG` environment variables.
## `package.json`
If you want to reduce config files in project root, you can specify
browsers in `package.json` with `browserslist` key:
```js
{
"private": true,
"dependencies": {
"autoprefixer": "^6.5.4"
},
"browserslist": [
"> 1%",
"last 2 versions"
]
}
```
## Environments
You can also specify different browser queries for various environments.
Browserslist will choose query according to `BROWSERSLIST_ENV` or `NODE_ENV`
variables. If none of them is declared, Browserslist will firstly look
for `development` queries and then use defaults.
In `package.json`:
```js
{
"browserslist": {
"production": [
"last 2 version",
"ie 9"
],
"development": [
"last 1 version"
]
}
}
```
In `browserslist` config:
```ini
[production]
last 2 version
ie 9
[development]
last 1 version
```
## Environment Variables
If some tool use Browserslist inside, you can change browsers settings
by [environment variables]:
* `BROWSERSLIST` with browsers queries.
```sh
BROWSERSLIST="> 5%" gulp css
```
* `BROWSERSLIST_CONFIG` with path to config file.
```sh
BROWSERSLIST_CONFIG=./config/browserslist gulp css
```
* `BROWSERSLIST_ENV` with environments string.
```sh
BROWSERSLIST_ENV="development" gulp css
```
* `BROWSERSLIST_STATS` with path to the custom usage data
for `> 1% in my stats` query.
```sh
BROWSERSLIST_STATS=./config/usage_data.json gulp css
```
[environment variables]: https://en.wikipedia.org/wiki/Environment_variable
## Custom Usage Data
If you have a website, you can query against the usage statistics of your site:
1. Import your Google Analytics data into [Can I Use].
Press `Import…` button in Settings page.
2. Open browser DevTools on [Can I Use] and paste this snippet
into the browser console:
```js
var e=document.createElement('a');e.setAttribute('href', 'data:text/plain;charset=utf-8,'+encodeURIComponent(JSON.stringify(JSON.parse(localStorage['usage-data-by-id'])[localStorage['config-primary_usage']])));e.setAttribute('download','stats.json');document.body.appendChild(e);e.click();document.body.removeChild(e);
```
3. Save the data to a `browserslist-stats.json` file in your project.
Of course, you can generate usage statistics file by any other method.
File format should be like:
```js
{
"ie": {
"6": 0.01,
"7": 0.4,
"8": 1.5
},
"chrome": {
},
}
```
Note that you can query against your custom usage data
while also querying against global or regional data.
For example, the query `> 1% in my stats, > 5% in US, 10%` is permitted.
[Can I Use]: http://caniuse.com/
## JS API
```js
var browserslist = require('browserslist');
// Your CSS/JS build tool code
var process = function (source, opts) {
var browsers = browserslist(opts.browsers, {
stats: opts.stats,
path: opts.file,
env: opts.env
});
// Your code to add features for selected browsers
}
```
Queries can be a string `"> 5%, last 1 version"`
or an array `['> 5%', 'last 1 version']`.
If a query is missing, Browserslist will look for a config file.
You can provide a `path` option (that can be a file) to find the config file
relatively to it.
For non-JS environment and debug purpose you can use CLI tool:
```sh
browserslist "> 1%, last 2 versions"
```
## Coverage
You can get total users coverage for selected browsers by JS API:
```js
browserslist.coverage(browserslist('> 1%')) //=> 81.4
```
```js
browserslist.coverage(browserslist('> 1% in US'), 'US') //=> 83.1
```
Or by CLI:
```sh
$ browserslist --coverage "> 1%"
These browsers account for 81.4% of all users globally
```
```sh
$ browserslist --coverage=US "> 1% in US"
These browsers account for 83.1% of all users in the US
```