What is @types/hast?
The @types/hast package provides TypeScript type definitions for HAST (Hypertext Abstract Syntax Tree) format, which is a virtual DOM format for HTML and XML. This allows developers to work with HAST trees in TypeScript projects with type safety, enabling better development experience, auto-completion, and error checking.
What are @types/hast's main functionalities?
Creating a HAST node
This code sample demonstrates how to create a simple HAST node representing a paragraph element containing the text 'Hello, world!'. The node is typed, ensuring that only valid properties and child nodes are used.
{"type": "element", "tagName": "p", "properties": {}, "children": [{"type": "text", "value": "Hello, world!"}]}
Type-checking a HAST tree
This code sample shows how to type-check a HAST tree to safely access properties. It specifically checks if a node is an anchor ('a') element and logs its 'href' property if available.
import {Element} from 'hast';
function processNode(node: Element): void {
if (node.tagName === 'a' && node.properties) {
console.log(node.properties.href);
}
}
Other packages similar to @types/hast
rehype
Rehype is a processor powered by plugins to work with HTML. It uses HAST under the hood, allowing manipulation of HTML documents. Compared to @types/hast, rehype offers higher-level operations like parsing, serializing, and transforming HTML content, whereas @types/hast focuses on providing type definitions.
unified
Unified is an interface for processing text using syntax trees, including HAST for HTML. It's more general-purpose than @types/hast, offering a framework to parse, transform, and serialize text through a unified ecosystem of plugins, whereas @types/hast specifically provides TypeScript types for HAST nodes.
remark
Remark is part of the unified ecosystem, focusing on Markdown processing using MDAST (Markdown Abstract Syntax Tree). While it serves a different syntax (Markdown vs. HTML/XML in HAST), it offers a similar concept of providing a structured tree format for content. Remark and @types/hast both enable developers to work with content trees, but they target different types of content.