Registry / serialization / iso-constants

iso-constants

library0.1.2jsnpmunverified

The `iso-constants` package provides Node.js's `process.constants` values in a way that is usable across both Node.js and browser environments. It aims to offer a consistent set of system-level constants, such as `RTLD_LAZY` or `UV_THREADPOOL_SIZE`, regardless of the execution context. Currently at version `0.1.2`, the library maintains a generally low release cadence, primarily issuing patch fixes, indicating a stable and focused scope rather than rapid feature development. A key differentiator is its automatic constant update mechanism, which runs during `npm install` to ensure the most current constants are available. This approach enables developers to write isomorphic code that relies on these specific constants without needing conditional logic for different runtimes, simplifying cross-environment development.

serialization observability

npm install iso-constants

github ↗package ↗

INSTALL

IMPORT

SIG · ISO-CONSTANTS

iso-constants

serializationjavascriptv0.1.2

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 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

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

constants

✓ const constants = require('iso-constants');

Primary CommonJS import for the entire constants object.

constants

✓ import constants from 'iso-constants';

✗ import { constants } from 'iso-constants';

Correct ESM import for the default constants object. The package exports a single object, not named properties at the top level.

RTLD_LAZY

✓ import constants from 'iso-constants'; console.log(constants.RTLD_LAZY);

✗ import { RTLD_LAZY } from 'iso-constants';

Individual constants are properties of the main 'constants' object and are not directly exported as named imports from the package root.

Demonstrates how to import and access various Node.js `process.constants`, such as `RTLD_LAZY` and `UV_THREADPOOL_SIZE`, using `iso-constants` in an isomorphic way.

import constants from 'iso-constants'; console.log('--- Node.js System Constants ---'); console.log('RTLD_LAZY:', constants.RTLD_LAZY); console.log('RTLD_NOW:', constants.RTLD_NOW); console.log('UV_THREADPOOL_SIZE:', constants.UV_THREADPOOL_SIZE); // This library ensures these Node.js process.constants are available // in both Node.js and browser environments, providing consistent values. // Example of a constant that might be platform-specific (e.g., Linux only) if (constants.hasOwnProperty('O_DIRECT')) { console.log('O_DIRECT constant is available:', constants.O_DIRECT); } else { console.log('O_DIRECT constant is not available (e.g., non-Linux platform).'); } // Accessing another common constant console.log('F_OK (File exists flag):', constants.F_OK);

Debug

Known issues

gotchaThe package uses a `postinstall` script to fetch and update constants, which can lead to non-deterministic builds if the remote source changes between installs of the same package version. This also requires network access during `npm install`.

fix

Pin exact package versions in your `package.json` and use `npm ci` or `yarn install --frozen-lockfile` to ensure reproducible builds from lock files.

affects: >=0.1.0

breakingAs a `0.1.x` version, the API is not yet considered stable and breaking changes may occur in minor or even patch releases, contrary to semver conventions for `1.0.0`+ versions.

fix

Review changelogs carefully for each update and test thoroughly, especially when upgrading between minor versions.

affects: <1.0.0

Errors

Common errors & fixes

ReferenceError: require is not defined

Attempting to use CommonJS `require` syntax in an ESM module context (e.g., in a `.mjs` file or a file within a package with `"type": "module"` in `package.json`).

fix

Change the import statement to `import constants from 'iso-constants';` in ESM files, or ensure your file is treated as CommonJS (e.g., by using `.cjs` extension or configuring `"type": "commonjs"` in your `package.json`).

TypeError: Cannot read properties of undefined (reading 'RTLD_LAZY') or similar 'constants' is undefined

The `constants` object was not successfully imported or initialized. This can happen if the `postinstall` script, which fetches the actual constant values, failed during `npm install`.

fix

Verify `iso-constants` is correctly installed by running `npm reinstall iso-constants` to re-execute the `postinstall` script. Check for any network errors or permission issues during the installation process.

Upgrade

Version history

0.1.2latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

12 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/hugomrdias/iso-constants ↗

packagehttps://www.npmjs.com/package/iso-constants ↗