Registry / devops / rollup-plugin-ifdef

rollup-plugin-ifdef

library1.1.1jsnpmunverified

A conditional compilation plugin for Rollup and Vite, allowing you to include or exclude code blocks based on build-time flags or environment variables. Supports JavaScript, TypeScript, CSS, SCSS, Vue, and React files. v1.1.1 is the current stable version, released in 2023 and last updated in 2023. It uses a comment-based syntax (e.g., @ifdef and @ifndef) similar to C preprocessor directives, making it easy to toggle debug code, platform-specific features, or feature flags without modifying the source. Unlike alternatives that rely on environment variable replacement or dead-code elimination, this plugin performs actual code removal at build time, ensuring zero runtime overhead.

devops

npm install rollup-plugin-ifdef

package ↗

INSTALL

IMPORT

SIG · ROLLUP-PLUGIN-IFDE

rollup-plugin-ifdef

devopsjavascriptv1.1.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–223 runs

build_error

glibc

node 18–223 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import ifdef from 'rollup-plugin-ifdef'

✗ const ifdef = require('rollup-plugin-ifdef')

Package is ESM-only; CommonJS require() will fail with Rollup/Vite. Use import.

ifdef

✓ import ifdef from 'rollup-plugin-ifdef'

✗ import { ifdef } from 'rollup-plugin-ifdef'

The plugin is exported as default, not a named export. Named import will be undefined.

ifdef (Vite)

✓ import ifdef from 'rollup-plugin-ifdef' // in vite.config.js

✗ import ifdef from 'rollup-plugin-ifdef/vite'

No separate Vite plugin; use the same module in vite.config.js under plugins array.

Shows Vite setup with environment variable DEBUG; conditionally compile code blocks based on NODE_ENV.

// vite.config.js import { defineConfig } from 'vite'; import ifdef from 'rollup-plugin-ifdef'; export default defineConfig({ plugins: [ ifdef({ DEBUG: process.env.NODE_ENV === 'development' ? 'true' : 'false', }), ], }); // src/main.js // @ifdef DEBUG console.log('Debug mode'); // @endif // @ifndef DEBUG console.log('Production mode'); // @endif

Debug

Known issues

gotchaConditions are string comparisons; boolean values from process.env are strings, so flags must be set as strings 'true'/'false' not boolean true/false.

fix

Always wrap boolean flags in quotes: 'true' vs 'false' (or use 'defined' check).

affects: >=1.0.0

gotchaThe plugin uses comment-based syntax; it will not work with dynamic expressions or template literals. Code inside conditionals must be statically analyzable.

fix

Place conditional code inside /* @ifdef */ comments, not inside JavaScript strings or expressions.

affects: >=1.0.0

deprecatedVersion 1.x uses a different syntax than 0.x; @ifdef/@ifndef instead of //#ifdef. Existing code from 0.x will not be recognized.

fix

Update comments from //#ifdef to /* @ifdef */ or use the new syntax. Refer to migration guide.

affects: >=1.0.0

gotchaNested conditionals are not supported; having @ifdef inside another @ifdef block may lead to incorrect compilation.

fix

Avoid nesting; use logical operators in the condition if needed (e.g., DEBUG && FEATURE_X).

affects: >=1.0.0

Errors

Common errors & fixes

Cannot find module 'rollup-plugin-ifdef'

Package not installed or not in node_modules.

fix

Run npm install rollup-plugin-ifdef --save-dev

'ifdef' is not a function

Named import instead of default import: import { ifdef } from 'rollup-plugin-ifdef'

fix

Use default import: import ifdef from 'rollup-plugin-ifdef'

Potential infinite recursion: found plugin 'ifdef' for file '...'

Plugin is applied multiple times or incorrectly configured to process its own output.

fix

Ensure plugin is only included once in plugins array. If using with other plugins, set 'order' or 'enforce' to 'pre'.

Error: @ifdef expected a valid condition

Syntax error in comment: missing condition or invalid characters (e.g., using == instead of plain string).

fix

Use correct syntax: /* @ifdef FLAG_NAME */ or /* @ifndef FLAG_NAME */

Upgrade

Version history

1.1.1latest on npm

Audit

Dependencies

rolluprequiredCore peer dependency; plugin is designed to work as a Rollup plugin.

@rollup/pluginutilsrequiredUsed for filtering files by pattern; automatically required at runtime.

magic-stringrequiredUsed for source map manipulation during code transformation.

Agent activity

8 hits · last 30 days

node

Resources

packagehttps://www.npmjs.com/package/rollup-plugin-ifdef ↗