copy-webpack-plugin

Copies individual files or entire directories, which already exist, to the build directory.

Getting Started

To begin, you'll need to install copy-webpack-plugin:

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

or

yarn add -D copy-webpack-plugin

or

pnpm add -D copy-webpack-plugin

Then add the plugin to your webpack config. For example:

webpack.config.js

const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        { from: "source", to: "dest" },
        { from: "other", to: "public" },
      ],
    }),
  ],
};

Note

copy-webpack-plugin is not designed to copy files generated from the build process; rather, it is to copy files that already exist in the source tree, as part of the build process.

Note

If you want webpack-dev-server to write files to the output directory during development, you can force it with the writeToDisk option or the write-file-webpack-plugin.

Note

You can get the original source filename from Asset Objects.

Options

• patterns
• options

The plugin's signature:

webpack.config.js

const CopyPlugin = require("copy-webpack-plugin");

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        { from: "source", to: "dest" },
        "path/to/source", // absolute or relative, files/directories/globs - see below for examples
      ],
      options: {
        concurrency: 100,
      },
    }),
  ],
};

Patterns

• from
• to
• context
• globOptions
• filter
• toType
• force
• priority
• transform
• transformAll
• noErrorOnMissing
• info

from

Type:

type from = string;

Default: undefined

Glob or path from where we copy files. Globs accept fast-glob pattern-syntax. Glob can only be a string.

Warning

Don't use directly \\ in from option if it is a glob (i.e path\to\file.ext) option because on UNIX the backslash is a valid character inside a path component, i.e., it's not a separator. On Windows, the forward slash and the backward slash are both separators. Instead please use /.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        "relative/path/to/file.ext",
        "relative/path/to/dir",
        path.resolve(__dirname, "src", "file.ext"),
        path.resolve(__dirname, "src", "dir"),
        "**/*",
        {
          from: "**/*",
        },
        // If absolute path is a `glob` we replace backslashes with forward slashes, because only forward slashes can be used in the `glob`
        path.posix.join(
          path.resolve(__dirname, "src").replace(/\\/g, "/"),
          "*.txt",
        ),
      ],
    }),
  ],
};

For windows

If you define from as absolute file path or absolute folder path on Windows, you can use windows path segment (\\)

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, "file.txt"),
        },
      ],
    }),
  ],
};

But you should always use forward-slashes in glob expressions See fast-glob manual.

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          // If absolute path is a `glob` we replace backslashes with forward slashes, because only forward slashes can be used in the `glob`
          from: path.posix.join(
            path.resolve(__dirname, "fixtures").replace(/\\/g, "/"),
            "*.txt",
          ),
        },
      ],
    }),
  ],
};

The context behaves differently depending on what the from is (glob, file or dir). More examples

to

Type:

type to =
  | string
  | ((pathData: { context: string; absoluteFilename?: string }) => string);

Default: compiler.options.output

string

Output path.

Warning

Don't use directly \\ in to (i.e path\to\dest) option because on UNIX the backslash is a valid character inside a path component, i.e., it's not a separator. On Windows, the forward slash and the backward slash are both separators. Instead please use / or path methods.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "**/*",
          to: "relative/path/to/dest/",
        },
        {
          from: "**/*",
          to: "/absolute/path/to/dest/",
        },
        {
          from: "**/*",
          to: "[path][name].[contenthash][ext]",
        },
      ],
    }),
  ],
};

function

Allows to modify the writing path.

Warning

Don't return directly \\ in to (i.e path\to\newFile) option because on UNIX the backslash is a valid character inside a path component, i.e., it's not a separator. On Windows, the forward slash and the backward slash are both separators. Instead please use / or path methods.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to({ context, absoluteFilename }) {
            return "dest/newPath/[name][ext]";
          },
        },
      ],
    }),
  ],
};

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to({ context, absoluteFilename }) {
            return Promise.resolve("dest/newPath/[name][ext]");
          },
        },
      ],
    }),
  ],
};

context

Type:

type context = string;

Default: options.context|compiler.options.context

A path to be (1) prepended to from and (2) removed from the start of the result path(s).

Warning

Don't use directly \\ in context (i.e path\to\context) option because on UNIX the backslash is a valid character inside a path component, i.e., it's not a separator. On Windows, the forward slash and the backward slash are both separators. Instead please use / or path methods.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.txt",
          to: "dest/",
          context: "app/",
        },
      ],
    }),
  ],
};

context can be an absolute path or a relative path. If it is a relative path, then it will be converted to an absolute path based on compiler.options.context.

context should be explicitly set only when from contains a glob. Otherwise, context is automatically set, based on whether from is a file or a directory:

If from is a file, then context is its directory. The result path will be the filename alone.

If from is a directory, then context equals from. The result paths will be the paths of the directory's contents (including nested contents), relative to the directory.

The use of context is illustrated by these examples.

globOptions

Type:

type globOptions = import("globby").Options;

Default: undefined

Allows to configure the glob pattern matching library used by the plugin. See the list of supported options To exclude files from the selection, you should use globOptions.ignore option

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "public/**/*",
          globOptions: {
            dot: true,
            gitignore: true,
            ignore: ["**/file.*", "**/ignored-directory/**"],
          },
        },
      ],
    }),
  ],
};

filter

Type:

type filter = (filepath: string) => boolean;

Default: undefined

Note

To ignore files by path please use the globOptions.ignore option.

webpack.config.js

const fs = require("fs").promise;

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "public/**/*",
          filter: async (resourcePath) => {
            const data = await fs.promises.readFile(resourcePath);
            const content = data.toString();

            if (content === "my-custom-content") {
              return false;
            }

            return true;
          },
        },
      ],
    }),
  ],
};

toType

Type:

type toType = "dir" | "file" | "template";

Default: undefined

Determinate what is to option - directory, file or template. Sometimes it is hard to say what is to, example path/to/dir-with.ext. If you want to copy files in directory you need use dir option. We try to automatically determine the type so you most likely do not need this option.

| Name | Type | Default | Description | | :---------------------------: | :------: | :---------: | :--------------------------------------------------------------------------------------------------- | | 'dir' | string | undefined | If to has no extension or ends on '/' | | 'file' | string | undefined | If to is not a directory and is not a template | | 'template' | string | undefined | If to contains a template pattern |

'dir'

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "path/to/file.txt",
          to: "directory/with/extension.ext",
          toType: "dir",
        },
      ],
    }),
  ],
};

'file'

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "path/to/file.txt",
          to: "file/without/extension",
          toType: "file",
        },
      ],
    }),
  ],
};

'template'

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/",
          to: "dest/[name].[contenthash][ext]",
          toType: "template",
        },
      ],
    }),
  ],
};

force

Type:

type force = boolean;

Default: false

Overwrites files already in compilation.assets (usually added by other plugins/loaders).

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/**/*",
          to: "dest/",
          force: true,
        },
      ],
    }),
  ],
};

priority

Type:

type priority = number;

Default: 0

Allows to specify the priority of copying files with the same destination name. Files for patterns with higher priority will be copied later. To overwrite files, the force option must be enabled.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        // Copied second and will overwrite "dir_2/file.txt"
        {
          from: "dir_1/file.txt",
          to: "newfile.txt",
          force: true,
          priority: 10,
        },
        // Copied first
        {
          from: "dir_2/file.txt",
          to: "newfile.txt",
          priority: 5,
        },
      ],
    }),
  ],
};

transform

Type:

type transform =
  | {
      transformer: (input: string, absoluteFilename: string) => string | Buffer;
      cache?: boolean | TransformerCacheObject | undefined;
    }
  | ((input: string, absoluteFilename: string) => string | Buffer);

Default: undefined

Allows to modify the file contents.

function

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          // The `content` argument is a [`Buffer`](https://nodejs.org/api/buffer.html) object, it could be converted to a `String` to be processed using `content.toString()`
          // The `absoluteFrom` argument is a `String`, it is absolute path from where the file is being copied
          transform(content, absoluteFrom) {
            return optimize(content);
          },
        },
      ],
    }),
  ],
};

object

| Name | Default | Description | | :-------------------------------: | :---------: | :--------------------------------------------------------------------------------------------------------------- | | transformer | undefined | Allows to modify the file contents. | | cache | false | Enable transform caching. You can use transform: { cache: { key: 'my-cache-key' } } to invalidate the cache. |

transformer

Type:

type transformer = (input: string, absoluteFilename: string) => string;

Default: undefined

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          // The `content` argument is a [`Buffer`](https://nodejs.org/api/buffer.html) object, it could be converted to a `String` to be processed using `content.toString()`
          // The `absoluteFrom` argument is a `String`, it is absolute path from where the file is being copied
          transform: {
            transformer(content, absoluteFrom) {
              return optimize(content);
            },
          },
        },
      ],
    }),
  ],
};

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          transform: {
            transformer(content, path) {
              return Promise.resolve(optimize(content));
            },
          },
        },
      ],
    }),
  ],
};

cache

Type:

type cache =
  | boolean
  | {
      keys: {
        [key: string]: any;
      };
    }
  | {
      keys: (
        defaultCacheKeys: {
          [key: string]: any;
        },
        absoluteFilename: string,
      ) => Promise<{
        [key: string]: any;
      }>;
    }
  | undefined;

Default: false

webpack.config.js

Enable/disable and configure caching. Default path to cache directory: node_modules/.cache/copy-webpack-plugin.

boolean

Enables/Disable transform caching.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          transform: {
            transformer(content, path) {
              return optimize(content);
            },
            cache: true,
          },
        },
      ],
    }),
  ],
};

object

Enables transform caching and setup invalidation keys.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          transform: {
            transformer(content, path) {
              return optimize(content);
            },
            cache: {
              keys: {
                // May be useful for invalidating cache based on external values
                // For example, you can invalid cache based on `process.version` - { node: process.version }
                key: "value",
              },
            },
          },
        },
      ],
    }),
  ],
};

You can setup invalidation keys using a function.

Simple function:

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          transform: {
            transformer(content, path) {
              return optimize(content);
            },
            cache: {
              keys: (defaultCacheKeys, absoluteFrom) => {
                const keys = getCustomCacheInvalidationKeysSync();

                return {
                  ...defaultCacheKeys,
                  keys,
                };
              },
            },
          },
        },
      ],
    }),
  ],
};

Async function:

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/*.png",
          to: "dest/",
          transform: {
            transformer(content, path) {
              return optimize(content);
            },
            cache: {
              keys: async (defaultCacheKeys, absoluteFrom) => {
                const keys = await getCustomCacheInvalidationKeysAsync();

                return {
                  ...defaultCacheKeys,
                  keys,
                };
              },
            },
          },
        },
      ],
    }),
  ],
};

transformAll

Type:

type transformAll = (
  data: {
    data: Buffer;
    sourceFilename: string;
    absoluteFilename: string;
  }[],
) => any;

Default: undefined

Allows you to modify the contents of multiple files and save the result to one file.

Note

The to option must be specified and point to a file. It is allowed to use only [contenthash] and [fullhash] template strings.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/**/*.txt",
          to: "dest/file.txt",
          // The `assets` argument is an assets array for the pattern.from ("src/**/*.txt")
          transformAll(assets) {
            const result = assets.reduce((accumulator, asset) => {
              // The asset content can be obtained from `asset.source` using `source` method.
              // The asset content is a [`Buffer`](https://nodejs.org/api/buffer.html) object, it could be converted to a `String` to be processed using `content.toString()`
              const content = asset.data;

              accumulator = `${accumulator}${content}\n`;
              return accumulator;
            }, "");

            return result;
          },
        },
      ],
    }),
  ],
};

noErrorOnMissing

Type:

type noErrorOnMissing = boolean;

Default: false

Doesn't generate an error on missing file(s).

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, "missing-file.txt"),
          noErrorOnMissing: true,
        },
      ],
    }),
  ],
};

info

Type:

type info =
  | Record<string, any>
  | ((item: {
      absoluteFilename: string;
      sourceFilename: string;
      filename: string;
      toType: ToType;
    }) => Record<string, any>);

Default: undefined

Allows to add assets info.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        "relative/path/to/file.ext",
        {
          from: "**/*",
          // Terser skip this file for minimization
          info: { minimized: true },
        },
      ],
    }),
  ],
};

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        "relative/path/to/file.ext",
        {
          from: "**/*",
          // Terser skip this file for minimization
          info: (file) => ({ minimized: true }),
        },
      ],
    }),
  ],
};

Options

• concurrency

concurrency

type:

type concurrency = number;

default: 100

limits the number of simultaneous requests to fs

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [...patterns],
      options: { concurrency: 50 },
    }),
  ],
};

Examples

Different variants of from (glob, file or dir).

Take for example the following file structure:

src/directory-nested/deep-nested/deepnested-file.txt
src/directory-nested/nested-file.txt

From is a Glob

Everything that you specify in from will be included in the result:

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/directory-nested/**/*",
        },
      ],
    }),
  ],
};

Result:

src/directory-nested/deep-nested/deepnested-file.txt,
src/directory-nested/nested-file.txt

If you don't want the result paths to start with src/directory-nested/, then you should move src/directory-nested/ to context, such that only the glob pattern **/* remains in from:

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "**/*",
          context: path.resolve(__dirname, "src", "directory-nested"),
        },
      ],
    }),
  ],
};

Result:

deep-nested/deepnested-file.txt,
nested-file.txt

From is a Dir

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(__dirname, "src", "directory-nested"),
        },
      ],
    }),
  ],
};

Result:

deep-nested/deepnested-file.txt,
nested-file.txt

Technically, this is **/* with a predefined context equal to the specified directory.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "**/*",
          context: path.resolve(__dirname, "src", "directory-nested"),
        },
      ],
    }),
  ],
};

Result:

deep-nested/deepnested-file.txt,
nested-file.txt

From is a File

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.resolve(
            __dirname,
            "src",
            "directory-nested",
            "nested-file.txt",
          ),
        },
      ],
    }),
  ],
};

Result:

nested-file.txt

Technically, this is a filename with a predefined context equal to path.dirname(pathToFile).

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "nested-file.txt",
          context: path.resolve(__dirname, "src", "directory-nested"),
        },
      ],
    }),
  ],
};

Result:

nested-file.txt

Ignoring files

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: path.posix.join(
            path.resolve(__dirname, "src").replace(/\\/g, "/"),
            "**/*",
          ),
          globOptions: {
            ignore: [
              // Ignore all `txt` files
              "**/*.txt",
              // Ignore all files in all subdirectories
              "**/subdir/**",
            ],
          },
        },
      ],
    }),
  ],
};

Flatten copy

Removes all directory references and only copies file names.

Warning

If files have the same name, the result is non-deterministic.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: "src/**/*",
          to: "[name][ext]",
        },
      ],
    }),
  ],
};

Result:

file-1.txt
file-2.txt
nested-file.txt

Copy in new directory

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          // When copying files starting with a dot, must specify the toType option
          // toType: "file",
          to({ context, absoluteFilename }) {
            return `newdirectory/${path.relative(context, absoluteFilename)}`;
          },
          from: "directory",
        },
      ],
    }),
  ],
};

Result:

"newdirectory/file-1.txt",
"newdirectory/nestedfile.txt",
"newdirectory/nested/deep-nested/deepnested.txt",
"newdirectory/nested/nestedfile.txt",

Skip running JavaScript files through a minimizer

Useful if you need to simply copy *.js files to destination "as is" without evaluating and minimizing them using Terser.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        "relative/path/to/file.ext",
        {
          from: "**/*",
          // Terser skip this file for minimization
          info: { minimized: true },
        },
      ],
    }),
  ],
};

yarn workspaces and monorepos

When using yarn workspaces or monorepos, relative copy paths from node_modules can be broken due to the way packages are hoisting. To avoid this, should explicitly specify where to copy the files from using require.resolve.

webpack.config.js

module.exports = {
  plugins: [
    new CopyPlugin({
      patterns: [
        {
          from: `${path.dirname(
            require.resolve(`${moduleName}/package.json`),
          )}/target`,
          to: "target",
        },
      ],
    }),
  ],
};

Contributing

Please take a moment to read our contributing guidelines if you haven't yet done so.

CONTRIBUTING

License

MIT