feat: Make sync-pnpm watch mode optional

Watch mode is selected by passing the `--watch` argument.

We now explicitly pass this argument when we want to watch
(e.g. when we have `start`ed) and we don't when we just need
to sync once (e.g. when linting or running tests on CI)

docs-app/package.json

@@ -21,7 +21,7 @@
     "lint:hbs:fix": "ember-template-lint . --fix --no-error-on-unmatched-pattern",
     "lint:js:fix": "eslint . --fix",
     "lint:types": "glint",
-    "start": "concurrently 'ember serve' 'npm:_syncPnpm' --names 'docs-app serve,docs-app sync built package'",
+    "start": "concurrently 'ember serve' 'pnpm sync-pnpm --watch' --names 'docs-app serve,docs-app sync built package'",
     "test:ember": "ember test",
     "_syncPnpm": "pnpm sync-pnpm"
   },

internal/sync-pnpm/bin/sync-pnpm.js

@@ -1,3 +1,5 @@
 import syncPnpm from '../index.js';
 
-await syncPnpm();
+let watchMode = process.argv.find((arg) => arg === '--watch') !== undefined;
+
+await syncPnpm({ watchMode });

internal/sync-pnpm/index.js

@@ -17,7 +17,7 @@ const syncDir = './dist';
 
 const DEBOUNCE_INTERVAL = 50;
 
-export default async function syncPnpm(dir = process.cwd()) {
+export default async function syncPnpm({ dir = process.cwd(), watchMode = false }) {
   const root = await findRoot(dir);
   const ownPackageJson = await readJson(join(dir, 'package.json'));
   const ownDependencies = [
@@ -48,6 +48,14 @@ export default async function syncPnpm(dir = process.cwd()) {
     }
   }
 
+  if (!watchMode) {
+    for (const [syncFrom, syncTo] of Object.entries(paths)) {
+      syncDependency(syncFrom, syncTo);
+    }
+
+    return;
+  }
+
   let fromPaths = Object.keys(paths);
   let watcher = new Watcher(fromPaths);
 
@@ -74,6 +82,7 @@ export default async function syncPnpm(dir = process.cwd()) {
         await syncDependency(foundFromPath, paths[foundFromPath]);
       }
     }
+
     setTimeout(handleDirtyPaths, DEBOUNCE_INTERVAL);
   }
 

test-app/package.json

@@ -21,7 +21,7 @@
     "lint:types": "glint",
     "lint:prettier": "prettier -c .",
     "lint:prettier:fix": "prettier -w .",
-    "start": "concurrently 'ember serve' 'npm:_syncPnpm' --names 'test-app serve,test-app sync built package'",
+    "start": "concurrently 'ember serve' 'sync-pnpm --watch' --names 'test-app serve,test-app sync built package'",
     "test": "ember test",
     "test:ember": "ember test",
     "typecheck": "pnpm tsc -v; pnpm glint --version; pnpm lint:types",