Add preview environments: CoW provisioner and preview tools

src/helpers/fast-copy.ts

@@ -0,0 +1,75 @@
+import { execFile } from 'child_process';
+import { promisify } from 'util';
+import * as fs from 'fs-extra';
+import * as path from 'path';
+
+const execFileAsync = promisify(execFile);
+
+interface CopyTreeOptions {
+	exclude?: string[];
+	intoExisting?: boolean;
+}
+
+export async function copyTree(
+	src: string,
+	dest: string,
+	opts: CopyTreeOptions = {},
+): Promise<{ method: 'clonefile' | 'copy' }> {
+	const exclude = new Set(['.DS_Store', ...(opts.exclude || [])]);
+
+	if (process.platform === 'darwin' && (!opts.exclude || opts.exclude.length === 0)) {
+		try {
+			const copySource = opts.intoExisting ? `${src}${path.sep}.` : src;
+			await execFileAsync('/bin/cp', ['-Rc', copySource, dest]);
+			return { method: 'clonefile' };
+		} catch {
+			// Fall through when clonefile is unavailable, including cross-volume copies.
+		}
+	}
+
+	await fs.copy(src, dest, {
+		filter: (source) => !exclude.has(path.basename(source)),
+	});
+
+	return { method: 'copy' };
+}
+
+/**
+ * Re-point absolute symlinks that still target the source tree a copy was made
+ * from (e.g. Query Monitor's wp-content/db.php) at the equivalent path inside
+ * the copy. Relative symlinks already resolve within the copy and are left alone.
+ */
+export async function retargetSymlinks(root: string, fromPrefix: string, toPrefix: string): Promise<number> {
+	const skip = new Set(['node_modules', '.git']);
+	let retargeted = 0;
+
+	async function walk(dir: string): Promise<void> {
+		let entries;
+		try {
+			entries = await fs.readdir(dir, { withFileTypes: true });
+		} catch {
+			return;
+		}
+		for (const entry of entries) {
+			const fullPath = path.join(dir, entry.name);
+			if (entry.isSymbolicLink()) {
+				try {
+					const target = await fs.readlink(fullPath);
+					if (target.startsWith(fromPrefix)) {
+						const newTarget = toPrefix + target.slice(fromPrefix.length);
+						await fs.remove(fullPath);
+						await fs.symlink(newTarget, fullPath);
+						retargeted += 1;
+					}
+				} catch {
+					// Leave unreadable/broken links alone
+				}
+			} else if (entry.isDirectory() && !skip.has(entry.name)) {
+				await walk(fullPath);
+			}
+		}
+	}
+
+	await walk(root);
+	return retargeted;
+}