rollup-plugin-typescript2

What is rollup-plugin-typescript2?

rollup-plugin-typescript2 is a Rollup plugin that integrates TypeScript compilation into the Rollup bundling process. It provides advanced TypeScript features, incremental compilation, and better error reporting compared to other TypeScript plugins for Rollup.

What are rollup-plugin-typescript2's main functionalities?

TypeScript Compilation

This feature allows you to compile TypeScript files into JavaScript as part of the Rollup bundling process. The plugin reads the tsconfig.json file for TypeScript configuration.

const typescript = require('rollup-plugin-typescript2');

module.exports = {
  input: 'src/main.ts',
  output: {
    file: 'bundle.js',
    format: 'cjs'
  },
  plugins: [
    typescript({
      tsconfig: 'tsconfig.json'
    })
  ]
};

Incremental Compilation

This feature enables incremental compilation, which speeds up the build process by only recompiling files that have changed since the last build.

const typescript = require('rollup-plugin-typescript2');

module.exports = {
  input: 'src/main.ts',
  output: {
    file: 'bundle.js',
    format: 'cjs'
  },
  plugins: [
    typescript({
      tsconfig: 'tsconfig.json',
      useTsconfigDeclarationDir: true
    })
  ]
};

Error Reporting

This feature provides enhanced error reporting, making it easier to debug TypeScript compilation issues. The 'clean' option ensures that the cache is cleared before each build, which can help in identifying persistent errors.

const typescript = require('rollup-plugin-typescript2');

module.exports = {
  input: 'src/main.ts',
  output: {
    file: 'bundle.js',
    format: 'cjs'
  },
  plugins: [
    typescript({
      tsconfig: 'tsconfig.json',
      clean: true
    })
  ]
};

Other packages similar to rollup-plugin-typescript2

rollup-plugin-typescript

rollup-plugin-typescript is another Rollup plugin for integrating TypeScript compilation. It is simpler and has fewer features compared to rollup-plugin-typescript2, lacking incremental compilation and advanced error reporting.

rollup-plugin-sucrase

rollup-plugin-sucrase is a Rollup plugin that uses Sucrase to compile TypeScript and other modern JavaScript syntax. It is faster than rollup-plugin-typescript2 but does not support type checking.

rollup-plugin-babel

rollup-plugin-babel is a Rollup plugin that uses Babel to transpile JavaScript, including TypeScript. It offers a wide range of plugins and presets but requires additional configuration for TypeScript support.

README

rollup-plugin-typescript2

Rollup plugin for typescript with compiler errors.

This is a rewrite of original rollup-plugin-typescript, starting and borrowing from this fork.

This version is somewhat slower than original, but it will print out typescript syntactic and semantic diagnostic messages (the main reason for using typescript after all).

Installation

# with npm
npm install rollup-plugin-typescript2 typescript --save-dev
# with yarn
yarn add rollup-plugin-typescript2 typescript --dev

Usage

// rollup.config.js
import typescript from 'rollup-plugin-typescript2';

export default {
	input: './main.ts',

	plugins: [
		typescript(/*{ plugin options }*/)
	]
}

The plugin inherits all compiler options and file lists from your tsconfig.json file. If your tsconfig has another name or another relative path from the root directory, see tsconfigDefaults, tsconfig and tsconfigOverride options below. This also allows for passing in different tsconfig files depending on your build target.

Some compiler options are forced

• noEmitHelpers: false
• importHelpers: true
• noResolve: false
• noEmit: false
• inlineSourceMap: false (see #71)
• outDir: ./placeholder in cache root, see 83 and Microsoft/TypeScript/issues/24715
• declarationDir: process.cwd() (only if useTsconfigDeclarationDir is false in the plugin options)
• moduleResolution: node (classic is deprecated. It also breaks this plugin, see #12 and #14)
• allowNonTsExtensions: true to let other plugins on the chain generate typescript, update plugin's include filter to pick them up (see #111)

Some compiler options have more than one compatible value.

• module: defaults to ES2015, other valid value is ESNext (required for dynamic imports, see #54).

Some options need additional configuration on plugin side

• allowJs: lets typescript process js files as well, if you use it, modify plugin's include option to add "*.js+(|x)", "**/*.js+(|x)" (might want to exclude node_modules, it will slow down the build significantly).

Compatibility

rollup-plugin-node-resolve

Must be before rollup-plugin-typescript2 in the plugin list, especially when browser: true option is used, see #66

rollup-plugin-commonjs

See explanation for rollupCommonJSResolveHack option below.

plugins using async/await

See objectHashIgnoreUnknownHack below.

rollup-plugin-babel

This plugin transpiles code, but doesn't change file extension. Babel plugin, even though it claims it processes all files, only looks at code with those extensions by default: .js,.jsx,.es6,.es,.mjs. To workaround add ts and tsx to the list of babel extensions.

...
import { DEFAULT_EXTENSIONS } from '@babel/core';
...
	babel({
		extensions: [
			...DEFAULT_EXTENSIONS,
			'.ts',
			'.tsx'
		]
	}),
...

See #108

Plugin options

• cwd: string

  The current work directory, default process.cwd().

• tsconfigDefaults: {}

  The object passed as tsconfigDefaults will be merged with loaded tsconfig.json. Final config passed to typescript will be the result of values in tsconfigDefaults replaced by values in loaded tsconfig.json, replaced by values in tsconfigOverride and then replaced by hard compilerOptions overrides on top of that (see above).

  For simplicity and other tools' sake, try to minimize usage of defaults and overrides and keep everything in tsconfig.json file (tsconfigs can themselves be chained, so save some turtles).

  let defaults = { compilerOptions: { declaration: true } };
  let override = { compilerOptions: { declaration: false } };
  
  // ...
  plugins: [
  	typescript({
  		tsconfigDefaults: defaults,
  		tsconfig: "tsconfig.json",
  		tsconfigOverride: override
  	})
  ]
  

  This is a deep merge (objects are merged, arrays are concatenated, primitives are replaced, etc), increase verbosity to 3 and look for parsed tsconfig if you get something unexpected.

• tsconfig: undefined

  Path to tsconfig.json. Set this if your tsconfig has another name or relative location from the project directory. By default will try to load ./tsconfig.json, but will not fail if file is missing unless the value is set explicitly.

• tsconfigOverride: {}

  See tsconfigDefaults.

• check: true

  Set to false to avoid doing any diagnostic checks on the code.

• verbosity: 1

  • 0 -- Error
  • 1 -- Warning
  • 2 -- Info
  • 3 -- Debug

• clean: false

  Set to true for clean build (wipes out cache on every build).

• cacheRoot: node_modules/.cache/rollup-plugin-typescript2

  Path to cache. Defaults to a folder in node_modules.

• include: [ "*.ts+(|x)", "**/*.ts+(|x)" ]

  By default passes all .ts files through typescript compiler.

• exclude: [ "*.d.ts", "**/*.d.ts" ]

  But excludes type definitions.

• abortOnError: true

  Bail out on first syntactic or semantic error. In some cases setting this to false will result in exception in rollup itself (for example for unresolvable imports).

• rollupCommonJSResolveHack: false

  On windows typescript resolver favors POSIX path, while commonjs plugin (and maybe others?) uses native path as module id. This can result in namedExports being ignored if rollup happened to use typescript's resolution. Set to true to pass resolved module path through resolve() to match up with rollup-plugin-commonjs.

  rollup-plugin-commonjs fixed this in 10.1.0, so projects using this option who update to new version will be broken again.

  This also works around the similar bug affecting code splitting (see rollup/issues/3094).

• objectHashIgnoreUnknownHack: false

  The plugin uses rollup config as part of cache key. object-hash is used to generate a hash, but it can't hash certain elements at the moment. Setting this option to true will make object-hash ignore unknowns, at the cost of not invalidating the cache if ignored elements are changed. Only enable this if you need it (Error: Unknown object type "asyncfunction" for example) and make sure to run with clean: true once in a while and definitely before a release. (See #105)

• useTsconfigDeclarationDir: false

  If true, declaration files will be emitted in the directory given in the tsconfig. If false, the declaration files will be placed inside the destination directory given in the Rollup configuration.

  Set to false if any other rollup plugins need access to declaration files.

• typescript: typescript module installed with the plugin

  When typescript version installed by the plugin (latest 2.x) is unacceptable, you can import your own typescript module and pass it in as typescript: require("typescript"). Must be 2.0+, things might break if transpiler interfaces changed enough from what the plugin was built against.

• transformers: undefined

  experimental, typescript 2.4.1+

  Transformers will likely be available in tsconfig eventually, so this is not a stable interface, see Microsoft/TypeScript/issues/14419.

  For example, integrating kimamula/ts-transformer-keys:

  const keysTransformer = require('ts-transformer-keys/transformer').default;
  const transformer = (service) =>
  {
  	before: [ keysTransformer(service.getProgram()) ],
  	after: []
  };
  
  // ...
  plugins: [
  	typescript({ transformers: [transformer] })
  ]
  

Declarations

This plugin respects declaration: true in your tsconfig.json file. When set, it will emit *.d.ts files for your bundle. The resulting file(s) can then be used with the types property in your package.json file as described here. By default, the declaration files will be located in the same directory as the generated Rollup bundle. If you want to override this behavior and instead use the declarationDir set useTsconfigDeclarationDir to true in the plugin options.

Watch mode

The way typescript handles type-only imports and ambient types effectively hides them from rollup watch, because import statements are not generated and changing them doesn't trigger a rebuild.

Otherwise the plugin should work in watch mode. Make sure to run a normal build after watch session to catch any type errors.

Requirements

TypeScript 2.4+ Rollup 1.26.3+ Node 6.4.0+ (basic es6 support)

Reporting bugs

Report any bugs on github: https://github.com/ezolenko/rollup-plugin-typescript2/issues.

Attach your tsconfig.json, package.json (for versions of dependencies), rollup script and anything else that could influence module resolution, ambient types and typescript compilation.

Check if problem is reproducible after running npm prune to clear any rogue types from npm_modules (by default typescript grabs all ambient types).

Check if you get the same problem with clean option set to true (might indicate a bug in the cache).

If makes sense, check if running tsc directly produces similar results.

Attach plugin output with verbosity option set to 3 (this will list all files being transpiled and their imports).

Contributing

Use the normal github process of forking, making a branch and creating a PR when ready. Fix all linting problems (run npm lint), fix any failed checks that are run on the PR (basically lint right now). Use an editor that supports editorconfig, or match the settings from .editorconfig file manually.

Fastest way to test changes is to do a self build, the plugin is part of its own build system:

• make changes
• run npm build (uses build committed to master branch)
• check that you get expected changes in dist
• run npm build-self (uses fresh local build)
• check dist for the expected changes
• run npm build-self again to make sure plugin built by new version can still build itself

If build-self breaks at some point, fix the problem and restart from build step (a known good copy).

This repo badly needs unittests and integration tests with various scenarios and expected outcomes though.