anser

anser parses strings containing ANSI escape codes — the foreground/background colors, bold/italic/underline styling, and cursor-control sequences terminal programs emit — and turns them into either structured token objects (content plus resolved style) or ready-to-render HTML with inline styles or CSS classes applied. It supports the standard 16/256-color ANSI palettes as well as 24-bit true-color escape sequences.

Because it has no DOM or Node-specific dependency, anser is used both server-side (formatting captured CLI output for a web dashboard or log viewer) and in the browser (rendering colored terminal output inside a web-based console), and is a common dependency behind tools that need to display raw terminal/CI output as readable, styled HTML.

What You Get

• ansiToJson() - parses ANSI-coded text into an array of structured token objects (content, fg/bg color, style flags)
• ansiToHtml() - converts ANSI-coded text directly into HTML with inline styles or CSS classes
• ansiToText() - strips ANSI codes to produce plain text
• Support for standard 16-color, 256-color, and 24-bit true-color ANSI sequences
• TypeScript type definitions (lib/index.d.ts) for all exported functions

Common Use Cases

• Rendering colored CI/build-log output inside a web-based dashboard or log viewer
• Displaying captured terminal output (from a PTY or child_process) as styled HTML in an Electron or browser-based app
• Converting stored ANSI-coded log text into plain text for search indexing or plain-text export
• Building custom terminal-emulator-adjacent tooling that needs a dependency-light ANSI parser rather than a full terminal emulator

Under The Hood

Architecture - The entire implementation lives in a single lib/index.js module exporting an Anser class with static ansiToJson/ansiToHtml/ansiToText methods; internally it tokenizes the input string by scanning for the ESC (\x1b[) sequence prefix, accumulates styling state (foreground/background color, bold/italic/underline flags) across sequences, and emits one token per contiguous run of identically-styled text.

Tech Stack - Plain, dependency-free JavaScript (CommonJS, lib/index.js as both the source and published entry point) with hand-written TypeScript declarations; no build step is required since the published package is the source itself.

Code Quality - The single test/ansi_up-test.js suite (named for the project it was originally derived from) exercises color/style parsing via Mocha, and jshint/jslint provide static linting; the codebase is compact (~630 lines) which keeps its ANSI-parsing edge cases relatively easy to review, though recent commit activity has slowed.

API Design - The three top-level static methods (ansiToJson, ansiToHtml, ansiToText) cover the common conversion needs with a single function call each and an options object for things like class-name-based vs inline-style HTML output, making integration straightforward for both server- and browser-side consumers.