@rollup/plugin-yaml

What is @rollup/plugin-yaml?

@rollup/plugin-yaml is a Rollup plugin that allows you to import YAML files as JavaScript modules. This can be particularly useful for configuration files, data files, or any other structured data that you want to include in your JavaScript project.

What are @rollup/plugin-yaml's main functionalities?

Import YAML files

This feature allows you to import YAML files directly into your JavaScript code. The YAML content is parsed and converted into a JavaScript object.

import data from './data.yaml';
console.log(data);

Custom YAML parsing

This feature allows you to customize the YAML parsing process using the `js-yaml` library. You can include or exclude specific files and transform the YAML content as needed.

import { createFilter } from '@rollup/pluginutils';
import yaml from 'js-yaml';

export default function yamlPlugin(options = {}) {
  const filter = createFilter(options.include, options.exclude);
  return {
    name: 'yaml',
    transform(code, id) {
      if (!filter(id)) return null;
      const parsed = yaml.load(code);
      return {
        code: `export default ${JSON.stringify(parsed)};`,
        map: { mappings: '' }
      };
    }
  };
}

Other packages similar to @rollup/plugin-yaml

yaml-loader

yaml-loader is a Webpack loader that allows you to import YAML files as JavaScript modules. It is similar to @rollup/plugin-yaml but is designed specifically for use with Webpack.

js-yaml

js-yaml is a standalone JavaScript library for parsing and dumping YAML. While it does not integrate directly with build tools like Rollup or Webpack, it can be used in conjunction with custom plugins or loaders to achieve similar functionality.

rollup-plugin-json

rollup-plugin-json is a Rollup plugin that allows you to import JSON files as JavaScript modules. While it is not specifically for YAML, it provides similar functionality for JSON files and can be used alongside @rollup/plugin-yaml for projects that use both JSON and YAML.

README

@rollup/plugin-yaml

🍣 A Rollup plugin which Converts YAML files to ES6 modules.

Requirements

This plugin requires an LTS Node version (v14.0.0+) and Rollup v1.20.0+.

Install

Using npm:

npm install @rollup/plugin-yaml --save-dev

Usage

Create a rollup.config.js configuration file and import the plugin:

import yaml from '@rollup/plugin-yaml';

export default {
  input: 'src/index.js',
  output: {
    dir: 'output',
    format: 'cjs'
  },
  plugins: [yaml()]
};

Then call rollup either via the CLI or the API.

With an accompanying file src/index.js, the local heroes.yaml file would now be importable as seen below:

// src/index.js
import { batman } from './heroes.yaml';

console.log(`na na na na ${batman}`);

Options

documentMode

Type: String
Default: single

If single, specifies that the target YAML documents contain only one document in the target file(s). If more than one document stream exists in the target YAML file(s), set documentMode: 'multi'.

exclude

Type: String | Array[...String]
Default: null

A picomatch pattern, or array of patterns, which specifies the files in the build the plugin should ignore. By default no files are ignored.

include

Type: String | Array[...String]
Default: null

A picomatch pattern, or array of patterns, which specifies the files in the build the plugin should operate on. By default all files are targeted.

safe

Type: Boolean
Default: true

If true, specifies that the data in the target YAML file(s) contain trusted data and should be loaded normally. If false, data is assumed to be untrusted and will be loaded using safety methods.

transform

Type: Function
Default: undefined

A function which can optionally mutate parsed YAML. The function should return the mutated object, or undefined which will make no changes to the parsed YAML.

yaml({
  transform(data, filePath) {
    if (Array.isArray(data) && filePath === './my-file.yml') {
      return data.filter((character) => !character.batman);
    }
  }
});

Meta

CONTRIBUTING

LICENSE (MIT)