build: point llms.txt at the Solid 2.0 files

package.json

@@ -7,7 +7,8 @@
 	"scripts": {
 		"sync:orama": "pnpm build && node scripts/sync-orama.mjs",
 		"dev": "vite dev",
-		"build": "vite build",
+		"build": "vite build && pnpm build:llms",
+		"build:llms": "node scripts/build-llms.mjs",
 		"start": "vite start",
 		"e2e": "npx playwright test",
 		"format": "prettier . --write",

scripts/build-llms.mjs

@@ -0,0 +1,52 @@
+// Post-processes the llms files that solidbase writes into the build output.
+// The 1.x index is the canonical https://docs.solidjs.com/llms.txt; the first
+// line under its title points tools at the Solid 2.0 files, which live on
+// their own host until 2.0 is stable.
+import { readFile, writeFile } from "node:fs/promises";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const ROOT = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const OUTPUT_DIR = resolve(ROOT, process.argv[2] ?? "dist");
+const V2_ORIGIN = "https://v2.solidjs.com";
+const V2_POINTER = `> Solid 2.0 (release candidate) documentation for tools: ${V2_ORIGIN}/llms.txt and ${V2_ORIGIN}/llms-full.txt`;
+const FILES = ["llms.txt", "llms-full.txt"];
+
+async function readIfPresent(filePath) {
+	try {
+		return await readFile(filePath, "utf8");
+	} catch (error) {
+		if (error.code === "ENOENT") return undefined;
+		throw error;
+	}
+}
+
+// Inserts the pointer as a blockquote directly under the level-one heading,
+// where the llms.txt convention keeps its summary line.
+function addV2Pointer(fileName, content) {
+	if (content.includes(V2_POINTER)) return content;
+
+	const lines = content.split("\n");
+	if (!lines[0]?.startsWith("# ")) {
+		throw new Error(`${fileName} must start with a level-one heading`);
+	}
+
+	lines.splice(1, 0, "", V2_POINTER);
+	return lines.join("\n");
+}
+
+const updated = [];
+for (const fileName of FILES) {
+	const filePath = resolve(OUTPUT_DIR, fileName);
+	const content = await readIfPresent(filePath);
+	if (content === undefined) continue;
+
+	await writeFile(filePath, addV2Pointer(fileName, content), "utf8");
+	updated.push(fileName);
+}
+
+if (updated.length === 0) {
+	throw new Error(`No llms files found in ${OUTPUT_DIR}`);
+}
+
+console.log(`Added the Solid 2.0 pointer to ${updated.join(" and ")}.`);