rollup-plugin-inline-ts

⚡ A Rollup plugin to process TypeScript code inside <script lang="ts"> tags.

Supports compilation using one of four engines: oxc, swc, esbuild, or typescript.
Only transpile, without type checking and diagnostics.

Requirements

This plugin requires Node.js v14.16.1+ (LTS recommended).

Install

npm install rollup-plugin-inline-ts --save-dev

Optional: Install one of the transpiler engines as needed

oxc

npm install oxc-transform --save-dev

swc

npm install @swc/core --save-dev

esbuild

npm install esbuild --save-dev

typescript

npm install typescript --save-dev

Usage

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

import inlineTs from 'rollup-plugin-inline-ts';

export default {
  // ...
  plugins: [
    // ...
    inlineTs(),
  ],
};

Example with all available options:

import inlineTs from 'rollup-plugin-inline-ts';

export default {
  // ...
  plugins: [
    // ...
    inlineTs({
      extensions: ['.html', '.xht'], // Files to process
      engine: 'swc', // Transpiler engine
      options: { jsc: { parser: { syntax: 'typescript' } } }, // Engine specific options
      tsScriptAttr: 'lang="ts"', // Match attribute
      jsScriptAttr: '', // Replacement attribute
      logPrefix: '[inline-ts]', // Log prefix
      debug: false, // Debug logging
    }),
  ],
};

Options

extensions

Type: Array<string>
Default: ['.html']

File extensions for <script lang="ts"> blocks processing.

engine

Type: 'oxc' | 'swc' | 'esbuild' | 'typescript'
Default: 'oxc'

Transpilation engine to use.

options

Type: object (depends on specified engine)
Default: engine-specific
Passed directly to the underlying transpiler.

Engine	Type	Package	Default
oxc	TransformOptions	oxc-transform	{}
swc	Config	@swc/core	{ jsc: { parser: { syntax: 'typescript' } } }
esbuild	TransformOptions	esbuild	{ loader: 'ts' }
typescript	CompilerOptions	typescript	{ target: ts.ScriptTarget.ESNext }

tsScriptAttr

Type: string
Default: 'lang="ts"'

Attribute used to detect TypeScript <script> tags.

jsScriptAttr

Type: string
Default: ''

Attribute to replace tsScriptAttr with after transpilation.

keepComponentImports

Type: boolean
Default: true

If set to true, the plugin will preserve import statements for files with extensions listed in the extensions option.
These imports will not be removed as unused during the transformation.

logPrefix

Type: string
Default: '[inline-ts]'

Prefix for plugin logs.

debug

Type: boolean
Default: false

Enable debug logging.

How it works

1. Scans input files with configured extensions (e.g., .html).
2. Detects <script lang="ts"> blocks.
3. Transpiles TypeScript code using the specified engine.
4. Replaces the script content and removes or updates the tag’s lang attribute.
5. Preserves imports with extensions from extensions option to avoid them being removed as unused.

Meta

LICENSE (MIT)