@thi.ng/hdiff

[!NOTE] This is one of 210 standalone projects, maintained as part of the @thi.ng/umbrella monorepo and anti-framework.

🚀 Please help me to work full-time on these projects by sponsoring me on GitHub. Thank you! ❤️

• About
• Status
• Installation
  • CLI installation & usage
• Dependencies
• Usage examples
• API
  • computeDiff()
  • generateHtml()
  • compileTheme()
• Authors
• License

About

String diffing w/ hiccup output for further processing, e.g. with @thi.ng/hdom, @thi.ng/hiccup. Includes CLI util to generate HTML, with theme support and code folding.

Live example

Status

ALPHA - bleeding edge / work-in-progress

Search or submit any issues for this package

Installation

yarn add @thi.ng/hdiff

ESM import:

import * as hdiff from "@thi.ng/hdiff";

Browser ESM import:

<script type="module" src="https://esm.run/@thi.ng/hdiff"></script>

JSDelivr documentation

For Node.js REPL:

const hdiff = await import("@thi.ng/hdiff");

Package sizes (brotli'd, pre-treeshake): ESM: 1.42 KB

CLI installation & usage

Current limitations:

• output always written to stdout only
• only single theme available for now (easy to add new ones, PRs welcome!)

npx @thi.ng/hdiff

# any text files
npx hdiff file-a.txt file-b.txt > diff.html

# git revisions for given file (in local repo)
# rev can be any commit-ish ID understood by git (sha1, tag, etc.)
npx hdiff rel-file-path rev1 rev2 > diff.html

# example
npx hdiff packages/webgl/src/shader.ts develop~500 HEAD > diff.html

Dependencies

• @thi.ng/api
• @thi.ng/diff
• @thi.ng/hiccup
• @thi.ng/hiccup-css
• @thi.ng/strings

Note: @thi.ng/api is in most cases a type-only import (not used at runtime)

Usage examples

One project in this repo's /examples directory is using this package:

Screenshot	Description	Live demo	Source
	Applying thi.ng/hdiff to generate static HTML diff output	Demo	Source

API

Generated API docs

computeDiff()

Signature: computeDiff(a: string, b: string) => any[]

Takes two strings and performs line-based diff, then formats result as tree of HTML elements in @thi.ng/hiccup format.

The generated format only uses the following data attributes:

• data-diff: diff status for each code line ("+", "-" or " ")
• data-lnum: formatted line number for each code line
• data-fold: indicates folded pre-block
• data-fold-range: line number range string

generateHtml()

Signature: generateHtml(header: any[], body: any[], theme: Theme) => string

Takes two hiccup trees for header and body and an optional theme. Compiles theme into CSS, serializes hiccup trees and returns complete HTML document as string.

compileTheme()

Signature: compileTheme(theme: Theme) => string

Compiles a theme config into a complete CSS stylesheet string (using @thi.ng/hiccup-css).

Authors

• Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

@misc{thing-hdiff,
  title = "@thi.ng/hdiff",
  author = "Karsten Schmidt",
  note = "https://thi.ng/hdiff",
  year = 2018
}

License

© 2018 - 2025 Karsten Schmidt // Apache License 2.0