# azu/promises-book

JavaScript Promiseの本

Repository: https://github.com/azu/promises-book
Canonical: https://ross.abutalabs.com/products/promises-book
Homepage: https://azu.github.io/promises-book/
Language: HTML
License: MIT
License Family: permissive
Topics: javascript-promise, javascript, promise, book, free, ebook, pdf
Last push: 2025-06-23T14:43:16+00:00

## Health v2 (maintenance only)
Score: 35/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 28, release rhythm 8, longevity 100
- inputs: {"age_days": 4568, "days_push": 436, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1382, forks 568 (observed 2026-08-28T04:04:34.391233+00:00)

## What it is
A free, open-source ebook (in Japanese, with Chinese and Korean translations) teaching JavaScript Promises and async functions, written in AsciiDoc and published as HTML and PDF. The repository contains the book source, build tooling, and runnable example code.

## Use cases
- learn how JavaScript Promises work
- understand Promise.all, Promise.race, then/catch patterns
- learn async/await and how it relates to Promises
- find examples of testing Promise-based code with Mocha
- download a free PDF reference on JavaScript async programming
- contribute to or translate an open-source programming book

## When to choose
- you want a concise, free introduction to JavaScript Promises and async functions
- you prefer learning from a book with runnable, tested example code
- you need a reference you can read offline as PDF or on mobile via the web version

## When to avoid
- you need comprehensive coverage of all JavaScript topics rather than just Promises
- you require an English-language edition
- you want an interactive course or video tutorials instead of a text book

## Facets
- artifact type: learning-resource
- maturity: stable
- function: documentation, developer-tools
- domain: tutorials, web-development
- platform: cli
- tags: ebook, javascript-promises, async, free-book, asciidoctor, pdf, open-source-book, javascript, asynchronous-programming, web

## Member repositories
- azu/promises-book (main) score 35

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:34.391233+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:40:06.393644+00:00, confidence not recorded.
  - readme: https://github.com/azu/promises-book (fetched 2026-08-28T04:04:34.391233+00:00, sha b9e22fd7d37f)
  - homepage: https://azu.github.io/promises-book/ (fetched 2026-08-29T11:55:55.272913+00:00, sha 60ac87c99529)
- Data as of 2026-08-30T08:39:29.467469+00:00.