🗒️ (No) configuration

(The meaning of ~ in this section is described in Module Resolution.)

¶ Targets

When Parcel runs, it can build your files in multiple different ways simultaneously. These are called targets.

For example, you could have a "modern" target that targets newer browsers and a "legacy" target for older browsers.

Every entrypoint will be processed (and output) once per target.

¶ Specifying Entrypoints

These are the files that contain the source code to your app before being compiled by Parcel and are picked up by:

1. $ parcel <entries>
2. $ parcel <folder(s)> uses <folder>/package.json#source (respectively)
3. ./src/index.*
4. ./index.*

From there, everything those assets depend on will be considered a "source" in Parcel.

¶ Setting the output path

The path where the output bundles should be placed can be specified (in that order) using a top-level field in package.json (see common targets and custom targets), using targets.*.distDir or the --dist-dir CLI parameter.

Default values for the output folder

• for the common targets is path.dirname(package.json#${targetName})
• for custom targets is path.dirname(package.json#${targetName}) or ~/dist/${targetName}/.

The implicit default target has the output folder ~/dist/.

With multiple entrypoints, you should use an explicit distDir as oppsed to the top-levle target fields because Parcel wouldn't know which bundle should have the specified name:

{
  "targets": {
    "app": {
      "distDir": "./www"
    }
  }
}

¶ Environments

Environments tell Parcel how to transform and bundle each asset. They tell Parcel if an asset is going to be run in a browser or in Node/Electron.

They also tell Parcel's plugins what their output should be by specifying which browsers (-versions) your build is targeting (e.g. Babel or Autoprefixer).

You can configure environments through targets#context and targets#engines and engines / browserslist.

¶ Configuring Parcel

When you do need to configure Parcel, it will be in one of 3 places.

• If you need to configure the CLI, it will be a CLI flag
• If you need to configure your package, it will be in the package.json
• If you need to configure something with your files or the Parcel asset pipeline, it will be in .parcelrc