什么是app-root-path，Determine an app's root path from anywhere inside the app
App Root Path Module
Please Note: Due to the very limited scope of this module, I do not anticipate needing to make very many changes to it. Expect long stretches of zero updates—that does not mean that the module is outdated.
This simple module helps you access your application’s root path from anywhere in the application without resorting to relative paths like
$ npm i -S app-root-path
To simply access the app’s root path, use the module as though it were a string:
var appRoot = require('app-root-path'); var myModule = require(appRoot + '/lib/my-module.js');
Side note: the module actually returns an object, but that object implements the
toStringmethod, so you can use it as though it were a string. There are a few edge cases where this might not be the case (most notably
console.log), but they shouldn’t affect actual use of the module, where you’re almost always concatenating with an additional string.
A helper function is also provided:
var reqlib = require('app-root-path').require; var myModule = reqlib('/lib/my-module.js');
It’s a little hacky, but you can also put this method on your application’s
global object to use it everywhere in your project:
// In app.js global.reqlib = require('app-root-path').require; // In lib/module/component/subcomponent.js var myModule = reqlib('/lib/my-module.js');
Finally, you can also just resolve a module path:
var myModulePath = require('app-root-path').resolve('/lib/my-module.js');
You can explicitly set the path, using the environmental variable
APP_ROOT_PATH or by calling
How It Works (under the hood)
No need to read this unless your curious—or you run into a (very unlikely) case where the module does not work as expected.
This module uses two different methods to determine the app’s root path, depending on the circumstances.
If the module is located inside your project’s directory, somewhere within the
node_modules directory (whether directly, or inside a submodule), we effectively do (the actual code takes cross-platform path names/etc into consideration):
This will take a path like
/var/www/node_modules/submodule/node_modules/app-root-path and return
/var/www. In nearly all cases, this is just what you need.
Secondary Method (for edge cases)
The node module loader will also look in a few other places for modules (for example, ones that you install globally with
npm install -g). These can be in one of:
Or, anywhere in the
NODE_PATH environmental variable (see documentation).
In these cases, we fall back to an alternate trick:
When a file is run directly from Node,
require.main is set to that file’s
module. Each module has a
filename property that refers to the filename of that module, so by fetching the directory name for that file, we at least get the directory of file passed to
node. In some cases (process managers and test suites, for example) this doesn’t actually give the correct directory, though, so this method is only used as a fallback.
Edge-Case: Global CLIs
If your module is installed as a global CLI, for example in
require.main.filename will report
/usr/local/lib/node_modules/yourmodule/bin, which is probably not what you want.
app-root-path is aware of this edge-case and will strip the
- Minor tweaks to how electron-specific logic runs. Should help with packagers that try to resolve all
require()statements during packaging.
- Removed official support for node < 4.0
- Removed support for passing
appRootPath.require(which has been deprecated for a while)
- Implemented semantic-release from here on out
- Added browserify-compatible shim
- Updated electron to match changes in version 1.0 of that project
- Had to bump package version because 1.2.0 got published to npm as @beta
- Special logic to resolve correctly when in an electron renderer process
- Special logic to handle an edge case when used in a globally-installed CLI project
- Fixed a bug where
setPath()did not update
- Moved some logic outside of the
resolve()function so that it’s not called multiple times
- No changes. Just updated the version to signify a locked API (see semver).
- Added Windows support (and, theoretically, other operating systems that have a directory separator that’s not “/”)
- Completely rewrote the path resolution method to account for most possible scenarios. This shouldn’t cause and backwards compatibility issues, but always test your code.
- Removed the need to pass a modules’s
require()method to the
appRootPath.require()function. Which it’s true that each module has its own
require()method, in practice it doesn’t matter, and it’s much simpler this way.
- Added tests
When using semantic-release, the preferred method for commits is:
git add …
git cz(see commitizen)
This helps ensure that commits match the expected format. Commits to
master will cause releases.