# Bare Modules

Bare modules provide a robust system for managing code dependencies within Bare applications. This section delves into the details of Bare's module system.

```
npm i bare-module
```

## Usage

```js
const Module = require('bare-module')
````

## External Modules for Bare
Supported Modules |
:--- |
<https://github.com/holepunchto/bare-abort>
<https://github.com/holepunchto/bare-assert>
<https://github.com/holepunchto/bare-atomics>
<https://github.com/holepunchto/bare-buffer>
<https://github.com/holepunchto/bare-bundle>
<https://github.com/holepunchto/bare-channel>
<https://github.com/holepunchto/bare-console>
<https://github.com/holepunchto/bare-env>
<https://github.com/holepunchto/bare-events>
<https://github.com/holepunchto/bare-fs>
<https://github.com/holepunchto/bare-hrtime>
<https://github.com/holepunchto/bare-http1>
<https://github.com/holepunchto/bare-inspect>
<https://github.com/holepunchto/bare-module>
<https://github.com/holepunchto/bare-os>
<https://github.com/holepunchto/bare-path>
<https://github.com/holepunchto/bare-pipe>
<https://github.com/holepunchto/bare-process>
<https://github.com/holepunchto/bare-readline>
<https://github.com/holepunchto/bare-repl>
<https://github.com/holepunchto/bare-signals>
<https://github.com/holepunchto/bare-subprocess>
<https://github.com/holepunchto/bare-timers>
<https://github.com/holepunchto/bare-tty>
<https://github.com/holepunchto/bare-url>

## Packages

A package is directory with a `package.json` file.

### Fields

#### `"name"`

```json
{
  "name": "my-package"
}
```

The name of the package. This is used for [addon resolution](https://github.com/holepunchto/bare-addon-resolve#algorithm), [self-referencing](#self-referencing), and importing packages by name.

#### `"version"`

```json
{
  "version": "1.2.3"
}
```

The current version of the package. This is used for [addon resolution](https://github.com/holepunchto/bare-addon-resolve#algorithm).

#### `"type"`

```json
{
  "type": "module"
}
```

The module format used for `.js` files. If not defined, `.js` files are interpreted as CommonJS. If set to `"module"` the `.js` files are instead interpreted as ES modules.

#### `"exports"`

```json
{
  "exports": {
    ".": "./index.js"
  }
}
```

The entry points of the package. If defined, only the modules explicitly exported by the package may be imported when importing the package by name.

##### Subpath exports

A package may define more than one entry point by declaring several subpaths with the main export being `"."`:

```json
{
  "exports": {
    ".": "./index.js",
    "./submodule": "./lib/submodule.js"
  }
}
```

When importing the package by name, `require('my-package')` will resolve to `<modules>/my-package/index.js` whereas `require('my-package/submodule')` will resolve to `<modules>/my-package/lib/submodule.js`.

##### Conditional exports

Conditional exports allow packages to provide different exports for different conditions, such as the module format of the importing module:

```json
{
  "exports": {
    ".": {
      "import": "./index.mjs",
      "require": "./index.cjs"
    }
  }
}
```

When importing the package by name, `require('my-package')` will resolve to `<modules>/my-package/index.cjs` whereas `import 'my-package'` will resolve to `<modules>/my-package/index.mjs`.

Similarly, conditional exports can be used to provide different entry points for different runtimes:

```json
{
  "exports": {
    ".": {
      "bare": "./bare.js",
      "node": "./node.js"
    }
  }
}
```

To provide a fallback for when no other conditions match, the `"default"` condition can be declared:

```json
{
  "exports": {
    ".": {
      "bare": "./bare.js",
      "node": "./node.js",
      "default": "./fallback.js"
    }
  }
}
```

The following conditions are supported, listed in order from most specific to least specific as conditions should be defined:

Condition | Description
:-- | :--
`"bare"` | This applies when the module is being imported from another Bare module. 
`"node"` | This applies when the module is being imported within a Node.js environment.
`"import"` | This applies when the module is being imported using an ES module import statement.
`"require"` | This applies when the module is being imported using the CommonJS require() function.
`"default"` | This serves as a fallback export if none of the more specific conditions (bare, node, import, require) are met.

##### Self-referencing

Within a package, exports defined in the `"exports"` field can be referenced by importing the package by name. For example, given the following `package.json`...

```json
{
  "name": "my-package",
  "exports": {
    ".": "./index.js",
    "./submodule": "./lib/submodule.js"
  }
}
```

...any module within `my-package` may reference these entry points using either `require('my-package')` or `require('my-package/submodule')`.

##### Exports sugar

If a package defines only a single export, `"."`, it may leave out the subpath entirely:

```json
{
  "exports": "./index.js"
}
```