The entry object is where webpack looks to start building the bundle. The context is an absolute string to the directory that contains the entry files.
context
string
The base directory, an absolute path, for resolving entry points and loaders from configuration.
const path = require('path');
module.exports = {
//...
context: path.resolve(__dirname, 'app')
};
By default the current directory is used, but it's recommended to pass a value in your configuration. This makes your configuration independent from CWD (current working directory).
entry
string
[string]
object = { <key> string | [string] | object = { import string | [string], dependOn string | [string], filename string }}
(function() => string | [string] | object = { <key> string | [string] } | object = { import string | [string], dependOn string | [string], filename string })
The point or points where to start the application bundling process. If an array is passed then all items will be processed.
A dynamically loaded module is not an entry point.
Simple rule: one entry point per HTML page. SPA: one entry point, MPA: multiple entry points.
module.exports = {
//...
entry: {
home: './home.js',
about: './about.js',
contact: './contact.js'
}
};
If a string or array of strings is passed, the chunk is named main
. If an object is passed, each key is the name of a chunk, and the value describes the entry point for the chunk.
If an object is passed the value might be a string, array of strings or a descriptor:
module.exports = {
//...
entry: {
home: './home.js',
shared: ['react', 'react-dom', 'redux', 'react-redux'],
catalog: {
import: './catalog.js',
filename: 'pages/catalog.js',
dependOn:'shared'
},
personal: {
import: './personal.js',
filename: 'pages/personal.js',
dependOn:'shared'
}
}
};
Descriptor syntax might be used to pass additional options to an entry point.
By default, the output filename for the entry chunk is extracted from output.filename
but you can specify a custom output filename for a specific entry:
module.exports = {
//...
entry: {
app: './app.js',
home: { import: './contact.js', filename: 'pages/[name][ext]' },
about: { import: './about.js', filename: 'pages/[name][ext]' }
}
};
Descriptor syntax was used here to pass filename
-option to the specific entry points.
By default, every entry chunk stores all the modules that it uses. With dependOn
-option you can share the modules from one entry chunk to another:
module.exports = {
//...
entry: {
app: { import: './app.js', dependOn: 'react-vendors' },
'react-vendors': ['react', 'react-dom', 'prop-types']
}
};
The app
chunk will not contain the modules that react-vendors
has.
If a function is passed then it will be invoked on every make event.
Note that the make event triggers when webpack starts and for every invalidation when watching for file changes.
module.exports = {
//...
entry: () => './demo'
};
or
module.exports = {
//...
entry: () => new Promise((resolve) => resolve(['./demo', './demo2']))
};
For example: you can use dynamic entries to get the actual entries from an external source (remote server, file system content or database):
webpack.config.js
module.exports = {
entry() {
return fetchPathsFromSomeExternalSource(); // returns a promise that will be resolved with something like ['src/main-layout.js', 'src/admin-layout.js']
}
};
When combining with the output.library
option: If an array is passed only the last item is exported.