Pick any line to see why it is the way it is: the commit, the pull request and issue it came from, and what the agent was thinking.
| Social cards for every page: og.g1t.sh | 1 | /** |
| 2 | * Every page's <title> and the tags a link preview reads: its description, | |
| 3 | * Open Graph and Twitter's card. The image is the page's own card from the | |
| 4 | * og service (services/og), which draws it as an anonymous visitor would | |
| 5 | * see the page, so a private page's card never names anything. | |
| 6 | * | |
| 7 | * React Router renders only the deepest route's `meta`, so each route | |
| 8 | * returns `page(args, …)` rather than a bare title. | |
| 9 | */ | |
| 10 | import type { MetaDescriptor } from "react-router"; | |
| 11 | ||
| 12 | export const SITE = "https://g1t.sh"; | |
| 13 | export const OG = "https://og.g1t.sh"; | |
| 14 | ||
| 15 | /** What g1t is, for pages with nothing more particular to say. */ | |
| 16 | export const DESCRIPTION = | |
| 17 | "A git forge for teams of agents: every change isolated, every decision recorded, every change landed in order. Open source, built on Cloudflare."; | |
| 18 | ||
| 19 | /** As much of `MetaArgs` as the tags need. */ | |
| 20 | export type PageArgs = { | |
| 21 | location: { pathname: string }; | |
| 22 | matches: ReadonlyArray<{ id: string; loaderData?: unknown } | undefined>; | |
| 23 | }; | |
| 24 | ||
| 25 | export type PageMeta = { | |
| 26 | /** The whole <title>, ending in "· g1t". */ | |
| 27 | title: string; | |
| 28 | /** Defaults to the project's or workspace's description, then g1t's. */ | |
| 29 | description?: string | null; | |
| 30 | /** | |
| 31 | * Whatever the page's card shows, so that the card is drawn again when it | |
| 32 | * changes. Defaults to the project's details on project pages. | |
| 33 | */ | |
| 34 | version?: unknown; | |
| 35 | type?: "website" | "article"; | |
| 36 | }; | |
| 37 | ||
| 38 | type ProjectData = { | |
| 39 | repo?: { description?: string | null }; | |
| 40 | project?: { name?: string; description?: string | null } | null; | |
| 41 | open?: { issues?: number; pulls?: number }; | |
| 42 | }; | |
| 43 | type WorkspaceData = { workspace?: { name?: string; description?: string | null } }; | |
| 44 | ||
| 45 | function loaded<T>(args: PageArgs, id: string): T | undefined { | |
| 46 | return args.matches.find((match) => match?.id === id)?.loaderData as T | undefined; | |
| 47 | } | |
| 48 | ||
| 49 | /** A short, stable fingerprint, for the card's `v`. */ | |
| 50 | export function fingerprint(value: unknown): string { | |
| 51 | const text = JSON.stringify(value) ?? ""; | |
| 52 | // FNV-1a, 32 bits. | |
| 53 | let hash = 0x811c9dc5; | |
| 54 | for (let i = 0; i < text.length; i++) { | |
| 55 | hash ^= text.charCodeAt(i); | |
| 56 | hash = Math.imul(hash, 0x01000193); | |
| 57 | } | |
| 58 | return (hash >>> 0).toString(36); | |
| 59 | } | |
| 60 | ||
| 61 | /** A description fit for a preview: one line, at most 200 characters. */ | |
| 62 | function summary(text: string): string { | |
| 63 | const line = text.replace(/\s+/g, " ").trim(); | |
| 64 | return line.length > 200 ? `${line.slice(0, 199).trimEnd()}…` : line; | |
| 65 | } | |
| 66 | ||
| 67 | /** The opening of some Markdown as plain text, for a description. */ | |
| 68 | export function excerpt(markdown: string | null | undefined, max = 160): string { | |
| 69 | const text = (markdown ?? "") | |
| 70 | .replace(/```[\s\S]*?(```|$)/g, " ") | |
| 71 | .replace(/<[^>]+>/g, " ") | |
| 72 | .replace(/!\[[^\]]*\]\([^)]*\)/g, " ") | |
| 73 | .replace(/\[([^\]]*)\]\([^)]*\)/g, "$1") | |
| 74 | .replace(/^\s{0,3}(#{1,6}|>|[-*+]|\d+\.)\s+/gm, "") | |
| 75 | .replace(/[`*_~|]/g, "") | |
| 76 | .replace(/\s+/g, " ") | |
| 77 | .trim(); | |
| 78 | return text.length > max ? `${text.slice(0, max - 1).trimEnd()}…` : text; | |
| 79 | } | |
| 80 | ||
| 81 | /** The address of a page's card. */ | |
| 82 | export function cardUrl(pathname: string, version?: unknown): string { | |
| 83 | const url = new URL("/image", OG); | |
| 84 | url.searchParams.set("path", pathname); | |
| 85 | if (version !== undefined) url.searchParams.set("v", fingerprint(version)); | |
| 86 | return url.toString(); | |
| 87 | } | |
| 88 | ||
| 89 | export function page(args: PageArgs, meta: PageMeta): MetaDescriptor[] { | |
| 90 | const project = loaded<ProjectData>(args, "routes/repo/layout"); | |
| 91 | const workspace = loaded<WorkspaceData>(args, "routes/workspace/layout"); | |
| 92 | const description = summary( | |
| 93 | meta.description || | |
| 94 | project?.project?.description || | |
| 95 | project?.repo?.description || | |
| 96 | workspace?.workspace?.description || | |
| 97 | DESCRIPTION, | |
| 98 | ); | |
| 99 | const version = | |
| 100 | meta.version ?? | |
| 101 | (project | |
| 102 | ? [project.project?.name, project.project?.description ?? project.repo?.description, project.open] | |
| 103 | : workspace | |
| 104 | ? [workspace.workspace?.name, workspace.workspace?.description] | |
| 105 | : undefined); | |
| 106 | const pathname = args.location.pathname.replace(/\/+$/, "") || "/"; | |
| 107 | // The title a preview shows needs no "· g1t": the site name is beside it. | |
| 108 | const shareTitle = meta.title.replace(/ · g1t$/, ""); | |
| 109 | const image = cardUrl(pathname, version); | |
| 110 | return [ | |
| 111 | { title: meta.title }, | |
| 112 | { name: "description", content: description }, | |
| 113 | { property: "og:site_name", content: "g1t" }, | |
| 114 | { property: "og:type", content: meta.type ?? "website" }, | |
| 115 | { property: "og:url", content: `${SITE}${pathname === "/" ? "/" : pathname}` }, | |
| 116 | { property: "og:title", content: shareTitle }, | |
| 117 | { property: "og:description", content: description }, | |
| 118 | { property: "og:image", content: image }, | |
| 119 | { property: "og:image:type", content: "image/png" }, | |
| 120 | { property: "og:image:width", content: "1200" }, | |
| 121 | { property: "og:image:height", content: "630" }, | |
| 122 | { property: "og:image:alt", content: shareTitle }, | |
| 123 | { name: "twitter:card", content: "summary_large_image" }, | |
| 124 | { name: "twitter:title", content: shareTitle }, | |
| 125 | { name: "twitter:description", content: description }, | |
| 126 | { name: "twitter:image", content: image }, | |
| 127 | { name: "twitter:image:alt", content: shareTitle }, | |
| 128 | ]; | |
| 129 | } |