Question

Copies individual files or entire directories to the build directory.

Install

npm install --save-dev copy-webpack-plugin

Usage

new CopyWebpackPlugin([patterns], options)

A pattern looks like: { from: 'source', to: 'dest' }

Or, in the simple case of just a from with the default destination, you can use a string primitive instead of an object: 'source'

#

Name	Required	Default	Details
from	Y		examples: 'relative/file.txt' '/absolute/file.txt' 'relative/dir' '/absolute/dir' '**/*' {glob:'**/*', dot: true} Globs accept minimatch options
to	N	output root if from is file or dir resolved glob path if from is glob	examples: 'relative/file.txt' '/absolute/file.txt' 'relative/dir' '/absolute/dir' 'relative/[name].[ext]' '/absolute/[name].[ext]' Templates are file-loader patterns
toType	N	'file' if to has extension or from is file 'dir' if from is directory, to has no extension or ends in '/' 'template' if to contains a template pattern
context	N	options.context \	\	compiler.options.context	A path that determines how to interpret the from path
flatten	N	false	Removes all directory references and only copies file names If files have the same name, the result is non-deterministic
ignore	N	[]	Additional globs to ignore for this pattern
transform	N	function(content, path) {   return content; }	Function that modifies file contents before writing to webpack
force	N	false	Overwrites files already in compilation.assets (usually added by other plugins)

Available options:

Name	Default	Details
context	compiler.options.context	A path that determines how to interpret the from path, shared for all patterns
ignore	[]	Array of globs to ignore (applied to from)
copyUnmodified	false	Copies files, regardless of modification when using watch or webpack-dev-server. All files are copied on first build, regardless of this option.
debug	'warning'	options: 'warning' - only warnings 'info' or true - file location and read info 'debug' - very detailed debugging info

Examples

const CopyWebpackPlugin = require('copy-webpack-plugin');
const path = require('path');

module.exports = {
    context: path.join(__dirname, 'app'),
    devServer: {
        // This is required for older versions of webpack-dev-server
        // if you use absolute 'to' paths. The path should be an
        // absolute path to your build destination.
        outputPath: path.join(__dirname, 'build')
    },
    plugins: [
        new CopyWebpackPlugin([
            // {output}/file.txt
            { from: 'from/file.txt' },

            // equivalent
            'from/file.txt',

            // {output}/to/file.txt
            { from: 'from/file.txt', to: 'to/file.txt' },

            // {output}/to/directory/file.txt
            { from: 'from/file.txt', to: 'to/directory' },

            // Copy directory contents to {output}/
            { from: 'from/directory' },

            // Copy directory contents to {output}/to/directory/
            { from: 'from/directory', to: 'to/directory' },

            // Copy glob results to /absolute/path/
            { from: 'from/directory/**/*', to: '/absolute/path' },

            // Copy glob results (with dot files) to /absolute/path/
            {
                from: {
                    glob:'from/directory/**/*',
                    dot: true
                },
                to: '/absolute/path'
            },

            // Copy glob results, relative to context
            {
                context: 'from/directory',
                from: '**/*',
                to: '/absolute/path'
            },

            // {output}/file/without/extension
            {
                from: 'path/to/file.txt',
                to: 'file/without/extension',
                toType: 'file'
            },

            // {output}/directory/with/extension.ext/file.txt
            {
                from: 'path/to/file.txt',
                to: 'directory/with/extension.ext',
                toType: 'dir'
            }
        ], {
            ignore: [
                // Doesn't copy any files with a txt extension    
                '*.txt',

                // Doesn't copy any file, even if they start with a dot
                '**/*',

                // Doesn't copy any file, except if they start with a dot
                { glob: '**/*', dot: false }
            ],

            // By default, we only copy modified files during
            // a watch or webpack-dev-server build. Setting this
            // to `true` copies all files.
            copyUnmodified: true
        })
    ]
};

FAQ

"EMFILE: too many open files" or "ENFILE: file table overflow"

Globally patch fs with graceful-fs

npm install graceful-fs --save-dev

At the top of your webpack config, insert this

const fs = require('fs');
const gracefulFs = require('graceful-fs');
gracefulFs.gracefulify(fs);

See this issue for more details

This doesn't copy my files with webpack-dev-server

Starting in version 3.0.0, we stopped using fs to copy files to the filesystem and started depending on webpack's in-memory filesystem:

... webpack-dev-server will serve the static files in your build folder. It’ll watch your source files for changes and when changes are made the bundle will be recompiled. This modified bundle is served from memory at the relative path specified in publicPath (see API). It will not be written to your configured output directory.

If you must have webpack-dev-server write to your output directory, you can force it with the write-file-webpack-plugin.