https://github.com/inokawa/babel-plugin-evaluate-modules

A babel plugin to evaluate modules at build-time.
https://github.com/inokawa/babel-plugin-evaluate-modules

babel babel-plugin

Last synced: 26 days ago
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A babel plugin to evaluate modules at build-time.

• Host: GitHub
• URL: https://github.com/inokawa/babel-plugin-evaluate-modules
• Owner: inokawa
• License: mit
• Created: 2022-05-15T03:42:42.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2023-12-15T08:25:32.000Z (11 months ago)
• Last Synced: 2024-02-15T11:50:35.361Z (9 months ago)
• Topics: babel, babel-plugin
• Language: TypeScript
• Homepage: https://www.npmjs.com/package/babel-plugin-evaluate-modules
• Size: 162 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# babel-plugin-evaluate-modules

![npm](https://img.shields.io/npm/v/babel-plugin-evaluate-modules) ![check](https://github.com/inokawa/babel-plugin-evaluate-modules/workflows/check/badge.svg)

A babel plugin to evaluate modules at build-time.

## Why?

I wanted to evaluate some functions and calculations in build process that didn't need to run at runtime, to remove the modules themselves from the bundle to reduce its size.

- [babel-plugin-preval](https://github.com/kentcdodds/babel-plugin-preval) and [babel-plugin-codegen](https://github.com/kentcdodds/babel-plugin-codegen) only supports CommonJS not ES Modules, and the evaluation does not run in a sandbox.

- [babel-plugin-polished](https://github.com/styled-components/babel-plugin-polished) only supports [polished](https://github.com/styled-components/polished) and only handles simple syntaxes.

- [babel-plugin-inline-constants](https://github.com/wooorm/babel-plugin-inline-constants) only handles constants inlining.

## Setup

```sh

npm install babel-plugin-evaluate-modules

```

## Usage

### Evaluate modules in node_modules

```ts

// babel.config.js

module.exports = {

  plugins: [["babel-plugin-evaluate-modules", { name: "polished" }]],

};

// App.js

import { rgba } from "polished";

const val = "blue";

const obj = {

  color: "#123456",

  red: "red",

};

const a = rgba(val, 0.5); // const a = "rgba(0,0,255,0.5)";

const b = rgba(obj["color"], 0.5); // const b = "rgba(18,52,86,0.5)";

const c = rgba(obj.red, 0.5); // const c = "rgba(255,0,0,0.5)";

```

### Evaluate local modules

```ts

// babel.config.js

module.exports = {

  plugins: [["babel-plugin-evaluate-modules", { name: /\/constants\// }]],

};

// constants/foo.js

export const foo = 2 * 7;

export const bar = "bar" + "baz";

// App.js

import { foo, bar } from "./constants/foo.js";

const fooVal = foo; // const fooVal = 14;

const barVal = bar; // const barVal = "barbaz";

```

## Contribute

All contributions are welcome.

If you find a problem, feel free to create an [issue](https://github.com/inokawa/babel-plugin-evaluate-modules/issues) or a [PR](https://github.com/inokawa/babel-plugin-evaluate-modules/pulls).

### Making a Pull Request

1. Fork this repo.

2. Run `npm install`.

3. Commit your fix.

4. Add tests to cover your fix.

5. Make a PR and confirm all the CI checks passed.