build: clean stale dist output and add worktree setup script

apps/api/package.json

@@ -7,6 +7,7 @@
   "scripts": {
     "start": "node --enable-source-maps .",
     "build": "swc src  --config-file ../../.swcrc --out-dir dist --strip-leading-paths",
+    "clean": "node ../../apps/scripts/src/clean-dist.ts",
     "typecheck": "tsc --noEmit",
     "lint": "oxlint",
     "lint:ci": "oxlint --format=github"

apps/discord-bot/package.json

@@ -7,6 +7,7 @@
   "scripts": {
     "start": "node --enable-source-maps .",
     "build": "swc src --out-dir dist --strip-leading-paths",
+    "clean": "node ../../apps/scripts/src/clean-dist.ts",
     "typecheck": "tsc --noEmit",
     "lint": "oxlint",
     "lint:ci": "oxlint --format=github"

apps/scripts/package.json

@@ -5,11 +5,13 @@
   "type": "module",
   "scripts": {
     "lint": "oxlint",
+    "typecheck": "tsc --noEmit",
     "lint:ci": "oxlint --format=github",
     "api-key": "node src/api-key.js",
     "delete-sessions": "node src/delete-sessions.js",
     "limit-redis": "node src/limit-redis.js",
     "purge": "node src/purge.js",
+    "setup-worktree": "node src/setup-worktree.ts",
     "rank-emojis": "node src/rank-emojis.js",
     "timestamp": "node --no-warnings src/timestamp.js",
     "validate-commands": "node --no-warnings src/validate-commands.js"

apps/scripts/src/clean-dist.ts

@@ -0,0 +1,83 @@
+/**
+ * Copyright (c) Statsify
+ *
+ * This source code is licensed under the GNU GPL v3 license found in the
+ * LICENSE file in the root directory of this source tree.
+ * https://github.com/Statsify/statsify/blob/main/LICENSE
+ */
+
+/**
+ * Removes files from `dist` whose source file in `src` no longer exists.
+ *
+ * Runs in a package directory as its turbo `clean` task, which `build` depends on, so it
+ * runs before both a real build and a cache restore. A cache restore writes outputs on
+ * top of `dist` without deleting anything, so this is what keeps deleted or renamed
+ * sources from leaving orphaned files behind.
+ *
+ * Only orphans are removed, so `dist` is never empty while `pnpm build:watch` rebuilds
+ * and running apps keep their files.
+ *
+ * Usage: node ../../apps/scripts/src/clean-dist.ts
+ */
+
+import { existsSync, readdirSync, rmSync, rmdirSync } from "node:fs";
+import { join } from "node:path";
+
+const DIST = "dist";
+const SRC = "src";
+
+// The source extensions swc compiles to each output extension, with the same base name.
+// .cjs isn't compiled, so --copy-files copies it as is
+const SOURCE_EXTENSIONS: Record<string, string[]> = {
+  ".js": [".ts", ".tsx", ".js", ".jsx", ".mjs", ".es6", ".es"],
+  ".mjs": [".mts"],
+  ".cjs": [".cts", ".cjs"],
+};
+
+/**
+ * @param file path relative to dist
+ */
+function hasSource(file: string): boolean {
+  const match = /^(.+?)(\.[cm]?js)(\.map)?$/.exec(file);
+
+  // Files that swc copies as is with --copy-files
+  if (!match) return existsSync(join(SRC, file));
+
+  const [, base, outputExtension] = match;
+
+  // swc doesn't compile declaration files, so a .d.js output is always an orphan
+  if (base.endsWith(".d")) return false;
+
+  return SOURCE_EXTENSIONS[outputExtension].some((extension) =>
+    existsSync(join(SRC, `${base}${extension}`)),
+  );
+}
+
+/**
+ * @param dir path relative to dist
+ * @returns the number of orphaned files removed
+ */
+function prune(dir: string): number {
+  let removed = 0;
+
+  for (const entry of readdirSync(join(DIST, dir), { withFileTypes: true })) {
+    const path = join(dir, entry.name);
+
+    if (entry.isDirectory()) {
+      removed += prune(path);
+    } else if (!hasSource(path)) {
+      rmSync(join(DIST, path), { force: true });
+      removed++;
+    }
+  }
+
+  if (dir && readdirSync(join(DIST, dir)).length === 0)
+    rmdirSync(join(DIST, dir));
+
+  return removed;
+}
+
+if (existsSync(DIST)) {
+  const removed = prune("");
+  if (removed > 0) console.log(`Removed ${removed} orphaned files from dist`);
+}