Merge lab into refactor/split-style-css

tests/helpers/stylesheets.mjs

@@ -0,0 +1,67 @@
+import { readFile } from 'node:fs/promises';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const HERE = dirname(fileURLToPath(import.meta.url));
+const STATIC = join(HERE, '..', '..', 'static');
+const INDEX = join(STATIC, 'index.html');
+
+const LINK = /<link\b[^>]*\brel\s*=\s*["']stylesheet["'][^>]*\bhref\s*=\s*["']\/static\/([^"'?]+)([^"']*)["']/gi;
+
+async function entries() {
+  const html = await readFile(INDEX, 'utf8');
+  const out = [];
+
+  for (const match of html.matchAll(LINK)) {
+    const rel = match[1];
+    const query = match[2];
+
+    if (rel.startsWith('lib/')) continue;
+
+    out.push({
+      path: join(STATIC, rel),
+      url: `/static/${rel}${query}`,
+    });
+  }
+
+  if (!out.length) {
+    throw new Error(`no app stylesheet <link> tags found in ${INDEX}`);
+  }
+
+  for (const entry of out) {
+    try {
+      await readFile(entry.path);
+    } catch {
+      throw new Error(
+        `index.html links a stylesheet that does not exist: ${entry.path}`,
+      );
+    }
+  }
+
+  return out;
+}
+
+export async function stylesheetPaths() {
+  return (await entries()).map(entry => entry.path);
+}
+
+export async function stylesheetUrls() {
+  return (await entries()).map(entry => entry.url);
+}
+
+export async function stylesheetLinkTags() {
+  return (await stylesheetUrls())
+    .map(url => `<link rel="stylesheet" href="${url}">`)
+    .join('');
+}
+
+export async function appCss() {
+  const paths = await stylesheetPaths();
+  const parts = [];
+
+  for (const path of paths) {
+    parts.push(await readFile(path, 'utf8'));
+  }
+
+  return parts.join('\n');
+}