rollup-plugin-deassert

1.3.0 verified Mon Apr 27 auth: no javascript

Rollup plugin to remove assert, invariant, and similar statements from production bundles. Current stable version: 1.3.2 (2024-08-23). Release cadence: active development with frequent updates. Key differentiator: supports both ESM and CJS, ships TypeScript definitions, and handles conditional expressions. Unlike alternatives, it integrates naturally with Rollup's plugin system and respects source maps. Peer dependencies: acorn ^8.12.1 and rollup ^4.20.0.

Common errors

error Error: Cannot find module 'rollup-plugin-deassert' ↓

cause Package not installed or named incorrectly.

fix

Run 'npm install -D rollup-plugin-deassert' or check package.json for correct name.

error TypeError: deassert is not a function ↓

cause Using default import incorrectly or wrong import path.

fix

Use 'import { rollupPlugin as deassert } from 'rollup-plugin-deassert'' instead of 'import deassert from ...'.

error Error: The plugin deassert does not exist or is not a function. ↓

cause Incorrect import or plugin not added to rollup config.

fix

Ensure the import is correct and the plugin is included in the plugins array: plugins: [deassert()].

error AssertionError [ERR_ASSERTION]: false == true ↓

cause The plugin didn't remove the assert statement (e.g., when include option is missing for TypeScript).

fix

Add 'include: ["**/*.ts"]' to deassert options if using TypeScript files.

Warnings

gotcha Default export may be removed in future versions; use named export 'rollupPlugin' for stability. ↓

fix Replace default import { deassert } from 'rollup-plugin-deassert' with named import { rollupPlugin as deassert } from 'rollup-plugin-deassert'.

breaking Version 1.3.0 introduced support for conditional expressions; previous versions would ignore assert inside ternary/if conditions. ↓

fix Upgrade to >=1.3.0 to handle conditional expressions.

gotcha If using TypeScript, you must explicitly set include: ['**/*.ts'] in options; otherwise the plugin only processes JavaScript files. ↓

fix Add include: ['**/*.ts'] or appropriate glob to deassert() options.

deprecated The package 'rollup-plugin-deassert' is deprecated in favor of the unified 'deassert' package that supports multiple bundlers. ↓

fix Consider migrating to the 'deassert' package for cross-bundler compatibility.

Install

npm install rollup-plugin-deassert

yarn add rollup-plugin-deassert

pnpm add rollup-plugin-deassert

Imports

deassert (rollupPlugin)
wrong
```
const deassert = require('rollup-plugin-deassert')
```
correct
```
import { rollupPlugin as deassert } from 'rollup-plugin-deassert'
```
Package exports ESM primarily; named export 'rollupPlugin' must be aliased per documentation. CJS require may not work in some environments.
deassert (default)
wrong
```
import { default as deassert } from 'rollup-plugin-deassert'
```
correct
```
import deassert from 'rollup-plugin-deassert'
```
The package also has a default export, but the README uses the named export pattern. Both are valid.
type DeassertOptions
wrong
```
import { DeassertOptions } from 'rollup-plugin-deassert'
```
correct
```
import type { DeassertOptions } from 'rollup-plugin-deassert'
```
TypeScript types are bundled; use 'import type' for compile-time only usage to avoid runtime errors.

Quickstart

Example of using rollup-plugin-deassert in a Rollup config to strip assert statements from TypeScript files.

// rollup.config.js
import { rollupPlugin as deassert } from 'rollup-plugin-deassert';

export default {
  input: 'src/index.ts',
  output: {
    file: 'dist/bundle.js',
    format: 'cjs'
  },
  plugins: [
    deassert({
      include: ['**/*.ts'],
      sourcemap: true
    })
  ]
};