Registry / web-framework / hast-util-is-conditional-comment

hast-util-is-conditional-comment

library3.0.1jsnpmunverified

This package, `hast-util-is-conditional-comment`, is a specialized utility within the unified (specifically rehype) ecosystem designed to determine if a given `hast` (Hypertext Abstract Syntax Tree) node represents an HTML conditional comment. Conditional comments are a legacy feature primarily used by older versions of Internet Explorer (discontinued after IE 9) and are generally recommended for removal in modern web development. The current stable version is 3.0.1. As part of the `unified` collective, it adheres to a release cadence tied to major `unified` ecosystem updates, ensuring compatibility with other `hast` and `unist` utilities. Key differentiators include its tight integration with the `hast` AST format, its ESM-only distribution, and its strict compatibility with maintained Node.js versions (currently Node.js 16+). It does not perform transformations but provides a focused predicate function for identifying this specific, non-standard HTML comment type.

web-framework serialization

npm install hast-util-is-conditional-comment

github ↗package ↗

INSTALL

IMPORT

SIG · HAST-UTIL-IS-CONDI

hast-util-is-conditional-comment

web-frameworkjavascriptv3.0.1

Install

—

Import

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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.

isConditionalComment

✓ import { isConditionalComment } from 'hast-util-is-conditional-comment'

✗ const isConditionalComment = require('hast-util-is-conditional-comment')

This package is ESM-only since v3 and exports `isConditionalComment` as a named export. CommonJS `require` is not supported.

Node

✓ import type { Node } from 'hast'

✗ import { Node } from 'hast'

For TypeScript users, import `Node` as a type from `hast` to ensure correct type checking for AST nodes.

✓ import { u } from 'unist-builder'

✗ import u from 'unist-builder'

`u` from `unist-builder` is often used for creating `unist` (and by extension `hast`) nodes in examples. It is a named export, not a default export.

Demonstrates how to import and use `isConditionalComment` to programmatically check various `hast` comment nodes for Internet Explorer conditional comment syntax.

import { isConditionalComment } from 'hast-util-is-conditional-comment'; import { u } from 'unist-builder'; // u for creating unist/hast nodes // A valid IE conditional comment const ieConditionalComment = u({ type: 'comment', value: '[if IE]>...<![endif]' }); // An IE conditional end comment const ieConditionalEndComment = u({ type: 'comment', value: '<![endif]' }); // A regular HTML comment const regularComment = u({ type: 'comment', value: 'This is a regular comment' }); console.log('Is IE Conditional Comment (full):', isConditionalComment(ieConditionalComment)); // => true console.log('Is IE Conditional Comment (end):', isConditionalComment(ieConditionalEndComment)); // => true console.log('Is Regular Comment:', isConditionalComment(regularComment)); // => false

Debug

Known issues

breakingVersion 3.x of `hast-util-is-conditional-comment` is ESM-only and requires Node.js 16 or later. Attempting to use it in a CommonJS environment or older Node.js versions will result in import errors or runtime failures.

fix

Ensure your project is configured for ESM (e.g., `"type": "module"` in `package.json` or `.mjs` files) and upgrade Node.js to version 16 or newer. Replace `require()` calls with `import` statements.

affects: >=3.0.0

gotchaWhile this utility itself only checks node types and does not modify the AST, working with `hast` trees in general (especially with other `rehype` plugins) can expose applications to Cross-Site Scripting (XSS) vulnerabilities if not handled carefully.

fix

Always use `rehype-sanitize` when processing untrusted HTML to prevent potential XSS attacks, especially if other plugins are transforming the tree.

affects: >=1.0.0

gotchaThis package specifically identifies legacy Internet Explorer conditional comments. It will not identify other types of special comments or directives, only the specific patterns recognized as IE conditional comments.

fix

If you need to identify other specific comment patterns, you will need to implement custom logic or use other `hast` utilities designed for broader comment analysis.

affects: >=1.0.0

Errors

Common errors & fixes

ERR_REQUIRE_ESM

Attempting to use `require()` to import `hast-util-is-conditional-comment` in a CommonJS module.

fix

Change your import statement to `import { isConditionalComment } from 'hast-util-is-conditional-comment';` and ensure your environment supports ESM.

TypeError: isConditionalComment is not a function

Incorrectly importing `isConditionalComment` as a default import, or attempting to destructure from a module that has no named export.

fix

The package has no default export. Always use named import syntax: `import { isConditionalComment } from 'hast-util-is-conditional-comment';`.

Upgrade

Version history

3.0.1latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/rehypejs/rehype-minify.git#main ↗

packagehttps://www.npmjs.com/package/hast-util-is-conditional-comment ↗