Registry / sticky-module

sticky-module

library0.1.1jsnpmunverified

sticky-module is a specialized JavaScript utility designed to guarantee that a given module is instantiated and evaluated only once, even across multiple imports or different bundling contexts within an application. It achieves this by storing and retrieving module instances using a unique, Symbol-based key, effectively creating an application-wide singleton for that module. This mechanism is particularly useful for libraries or components that require strict single-instance behavior to maintain consistent state or prevent redundant setup in complex module graphs, micro-frontends, or scenarios with multiple bundler outputs. The current stable version is 0.1.1. Its release cadence is likely slow, focusing on stability given its niche purpose. A key differentiator is its Symbol-based internal storage, which offers a robust and collision-resistant approach to global module caching compared to string-based keys.

npm install sticky-module

github ↗package ↗

INSTALL

IMPORT

SIG · STICKY-MODULE

sticky-module

javascriptv0.1.1

Install

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Import

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Disk

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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.

stickyModule

✓ import stickyModule from 'sticky-module';

✗ const stickyModule = require('sticky-module');

sticky-module is an ESM-first package and exposes a default export. CommonJS require() will likely fail or return an unexpected object.

Module interface

✓ let [{ config }, known] = stickyModule('my-config', { config: {} });

✗ let { config, known } = stickyModule('my-config', { config: {} });

The function returns a two-element array: the stored module object and a boolean indicating if it was already known. Destructure accordingly.

Demonstrates how sticky-module ensures a module is initialized only once, returning the original instance on subsequent calls.

import stickyModule from 'sticky-module'; console.log('--- First attempt to get module ---'); let [{a, b}, known] = stickyModule('@custom/my-singleton', { a: Math.random(), b: 'initial value' }); console.log(`Was module known? ${known}`); // Expected: false console.log(`Module values: a=${a}, b='${b}'`); // Shows initial random 'a' and 'b' // Simulate a delay or another part of the application importing it later setTimeout(() => { console.log('\n--- Second attempt to get module (after delay) ---'); let [{a: a2, b: b2}, known2] = stickyModule('@custom/my-singleton', { a: Math.random(), // This value will be ignored as module is already stored b: 'new value, ignored' // This value will also be ignored }); console.log(`Was module known? ${known2}`); // Expected: true console.log(`Module values: a=${a2}, b='${b2}'`); // Shows the *same* initial random 'a' and 'b' // Verify they are the same instance/values console.log(`Are 'a' and 'a2' the same? ${a === a2}`); // Expected: true console.log(`Are 'b' and 'b2' the same? ${b === b2}`); // Expected: true }, 100);

Debug

Known issues

gotchaThe package description explicitly calls itself a 'leaky utility'. This implies that once a module is stored, it will persist in memory for the lifetime of the JavaScript realm and is not automatically garbage collected unless the application explicitly manages its removal (which sticky-module itself does not provide an API for). This is intentional for its singleton purpose but can be a concern for long-running applications or if modules store large objects.

fix

Be mindful of what data you store in 'sticky' modules. Ensure large objects are managed appropriately or consider if this pattern is suitable for your use case if memory pressure is a concern.

affects: >=0.1.0

gotchaThe module uses a Symbol-based key for internal storage, which makes it effective for singleton enforcement within a single JavaScript realm (e.g., a single browser window, a Node.js process). However, this mechanism does not extend across different realms like iframes, Web Workers (without SharedWorker), or separate Node.js child processes, where each would have its own independent module storage.

fix

Do not assume global singleton behavior across distinct JavaScript realms. If cross-realm singletons are required, an alternative inter-realm communication or shared memory solution is needed.

affects: >=0.1.0

breakingGiven the current version is 0.1.1, any future major release (e.g., 1.0.0) is very likely to introduce breaking changes without a deprecation cycle. APIs might change significantly, or internal mechanisms could be altered.

fix

Pin to exact versions or use care when upgrading, especially when a 1.0.0 release is made available. Review release notes thoroughly for any breaking changes.

affects: <1.0.0

Errors

Common errors & fixes

TypeError: stickyModule is not a function

This typically occurs when attempting to import 'sticky-module' using CommonJS `require()` syntax in a project that expects ESM, or if transpilation is misconfigured, leading to the default export not being correctly resolved.

fix

Ensure you are using `import stickyModule from 'sticky-module';` in an ESM context. If using CommonJS, check your build tools for proper ESM-to-CJS interop or consider using dynamic import `import('sticky-module').then(m => m.default)`.

Module 'sticky-module' has no default export.

This error can occur if you're trying to destructure a named export when `sticky-module` only provides a default export, or if your TypeScript configuration (e.g., `esModuleInterop`) is not correctly set up for handling default ESM imports.

fix

Use the correct default import syntax: `import stickyModule from 'sticky-module';`. If in TypeScript, ensure `"esModuleInterop": true` and `"allowSyntheticDefaultImports": true` are set in your `tsconfig.json`.

Upgrade

Version history

0.1.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

7 hits · last 30 days

node

Resources

githubhttps://github.com/WebReflection/sticky-module ↗

packagehttps://www.npmjs.com/package/sticky-module ↗