| 1 | /** |
| 2 | * changelog-lib.mjs — parse the repository CHANGELOG.md into the compact, |
| 3 | * deterministic shape the website renders (`lib/changelog.generated.ts`). |
| 4 | * |
| 5 | * Keep a Changelog format: `## [version] - date` (or `## [Unreleased]`), |
| 6 | * `### Section` headings, and `- ` bullets that may continue on indented |
| 7 | * lines. Compare links live at the bottom as `[version]: url`. |
| 8 | * |
| 9 | * Pure and dependency-free so the derive script, the drift test, and any |
| 10 | * future check can share one parser. |
| 11 | */ |
| 12 | |
| 13 | const DEFAULT_LIMIT = 6; |
| 14 | // Most Keep-a-Changelog bullets in this repository run one to three |
| 15 | // sentences; 480 chars keeps the great majority readable in place, and the |
| 16 | // per-release "Full notes" link on /changelog carries the rest. |
| 17 | const DEFAULT_ITEMS_PER_SECTION = 12; |
| 18 | const DEFAULT_ITEM_CHARS = 480; |
| 19 | |
| 20 | /** Collapse Markdown emphasis and links to plain text for a one-line summary. */ |
| 21 | export function plainText(markdown) { |
| 22 | return markdown |
| 23 | .replace(/\[([^\]]+)\]\([^)]*\)/g, "$1") |
| 24 | .replace(/`([^`]*)`/g, "$1") |
| 25 | .replace(/\*\*([^*]+)\*\*/g, "$1") |
| 26 | .replace(/\s+/g, " ") |
| 27 | .trim(); |
| 28 | } |
| 29 | |
| 30 | /** Truncate at a word boundary; never mid-word, never past `max` chars. */ |
| 31 | export function clip(text, max = DEFAULT_ITEM_CHARS) { |
| 32 | if (text.length <= max) return text; |
| 33 | const cut = text.lastIndexOf(" ", max - 1); |
| 34 | return `${text.slice(0, cut > max / 2 ? cut : max - 1).trimEnd()}…`; |
| 35 | } |
| 36 | |
| 37 | /** |
| 38 | * Parse a CHANGELOG.md string. |
| 39 | * |
| 40 | * @returns {{ releases: Array<{version: string, date: string | null, unreleased: boolean, compareUrl: string | null, sections: Array<{heading: string, items: string[], itemCount: number}>}> }} |
| 41 | */ |
| 42 | export function parseChangelog(markdown, options = {}) { |
| 43 | const limit = options.limit ?? DEFAULT_LIMIT; |
| 44 | const itemsPerSection = options.itemsPerSection ?? DEFAULT_ITEMS_PER_SECTION; |
| 45 | const itemChars = options.itemChars ?? DEFAULT_ITEM_CHARS; |
| 46 | |
| 47 | const lines = markdown.split(/\r?\n/); |
| 48 | const links = new Map(); |
| 49 | for (const line of lines) { |
| 50 | const m = line.match(/^\[([^\]]+)\]:\s*(\S+)\s*$/); |
| 51 | if (m) links.set(m[1], m[2]); |
| 52 | } |
| 53 | |
| 54 | const releases = []; |
| 55 | let release = null; |
| 56 | let section = null; |
| 57 | let item = null; |
| 58 | |
| 59 | const flushItem = () => { |
| 60 | if (section && item !== null) { |
| 61 | section.raw.push(plainText(item)); |
| 62 | } |
| 63 | item = null; |
| 64 | }; |
| 65 | |
| 66 | for (const line of lines) { |
| 67 | const heading = line.match(/^## \[([^\]]+)\](?:\s*-\s*(.+))?\s*$/); |
| 68 | if (heading) { |
| 69 | flushItem(); |
| 70 | section = null; |
| 71 | const label = heading[1].trim(); |
| 72 | const unreleased = /^unreleased$/i.test(label); |
| 73 | const dateText = heading[2]?.trim() ?? null; |
| 74 | release = { |
| 75 | version: label, |
| 76 | date: dateText && /^\d{4}-\d{2}-\d{2}$/.test(dateText) ? dateText : null, |
| 77 | unreleased, |
| 78 | compareUrl: links.get(label) ?? null, |
| 79 | sections: [], |
| 80 | }; |
| 81 | releases.push(release); |
| 82 | continue; |
| 83 | } |
| 84 | if (!release) continue; |
| 85 | |
| 86 | const sub = line.match(/^### (.+?)\s*$/); |
| 87 | if (sub) { |
| 88 | flushItem(); |
| 89 | section = { heading: sub[1], raw: [] }; |
| 90 | release.sections.push(section); |
| 91 | continue; |
| 92 | } |
| 93 | if (!section) continue; |
| 94 | |
| 95 | const bullet = line.match(/^- (.*)$/); |
| 96 | if (bullet) { |
| 97 | flushItem(); |
| 98 | item = bullet[1]; |
| 99 | continue; |
| 100 | } |
| 101 | if (item !== null && /^\s{2,}\S/.test(line)) { |
| 102 | item += ` ${line.trim()}`; |
| 103 | continue; |
| 104 | } |
| 105 | if (item !== null && line.trim() === "") { |
| 106 | flushItem(); |
| 107 | } |
| 108 | } |
| 109 | flushItem(); |
| 110 | |
| 111 | return { |
| 112 | releases: releases.slice(0, limit).map((r) => ({ |
| 113 | version: r.version, |
| 114 | date: r.date, |
| 115 | unreleased: r.unreleased, |
| 116 | compareUrl: r.compareUrl, |
| 117 | sections: r.sections |
| 118 | .filter((s) => s.raw.length > 0) |
| 119 | .map((s) => ({ |
| 120 | heading: s.heading, |
| 121 | items: s.raw.slice(0, itemsPerSection).map((t) => clip(t, itemChars)), |
| 122 | itemCount: s.raw.length, |
| 123 | })), |
| 124 | })), |
| 125 | }; |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * The fragment GitHub's Markdown renderer assigns to a release heading such |
| 130 | * as `## [0.9.11] - 2026-08-22`: lower-cased, punctuation other than hyphens |
| 131 | * dropped, spaces turned to hyphens — so `0911---2026-08-22`. Lets the site |
| 132 | * deep-link a version's full notes instead of the top of a 470 KB file. |
| 133 | */ |
| 134 | export function changelogAnchor(release) { |
| 135 | const heading = release.unreleased |
| 136 | ? "Unreleased" |
| 137 | : release.date |
| 138 | ? `[${release.version}] - ${release.date}` |
| 139 | : `[${release.version}]`; |
| 140 | return heading |
| 141 | .toLowerCase() |
| 142 | .replace(/[^\p{L}\p{N} _-]/gu, "") |
| 143 | .replace(/ /g, "-"); |
| 144 | } |
| 145 | |
| 146 | /** Render the generated TypeScript module from a parse result. */ |
| 147 | export function renderChangelogModule(parsed, sourcePath = "CHANGELOG.md") { |
| 148 | return `// AUTO-GENERATED by web/scripts/derive-changelog.mjs at prebuild from ${sourcePath}. |
| 149 | // DO NOT EDIT — re-run \`npm run prebuild\` (or just \`npm run build\`) after changing the changelog. |
| 150 | // Deterministic: no timestamps, so a clean rebuild leaves the tracked file unchanged. |
| 151 | |
| 152 | export interface ChangelogSection { |
| 153 | heading: string; |
| 154 | /** Plain-text entries, clipped for the web; \`itemCount\` is the full count. */ |
| 155 | items: string[]; |
| 156 | itemCount: number; |
| 157 | } |
| 158 | |
| 159 | export interface ChangelogRelease { |
| 160 | /** "Unreleased" or a semantic version such as "0.9.11". */ |
| 161 | version: string; |
| 162 | /** ISO date from the heading, or null for the unreleased lane. */ |
| 163 | date: string | null; |
| 164 | unreleased: boolean; |
| 165 | /** The changelog's own compare link for this version, when it has one. */ |
| 166 | compareUrl: string | null; |
| 167 | sections: ChangelogSection[]; |
| 168 | } |
| 169 | |
| 170 | export const CHANGELOG: ChangelogRelease[] = ${JSON.stringify(parsed.releases, null, 2)}; |
| 171 | `; |
| 172 | } |
| 173 |