check if backup build is newer than runtime build

Author: rmorshea

setup.py

@@ -29,7 +29,6 @@ def list2cmdline(cmd_list):
 root_dir = Path(__file__).parent
 src_dir = root_dir / "src"
 package_dir = src_dir / name
-js_runtime_build = package_dir / "client" / "build"
 
 
 # -----------------------------------------------------------------------------
@@ -143,8 +142,6 @@ def run(self):
                 log.error(traceback.format_exc())
                 raise
             else:
-                if js_runtime_build.exists():
-                    shutil.rmtree(js_runtime_build)
                 log.info("Successfully installed Javascript")
             super().run()
 

src/idom/client/_private.py

@@ -1,6 +1,7 @@
 import json
 import re
 import shutil
+from os.path import getmtime
 from pathlib import Path
 from typing import Dict, Set, Tuple, cast
 
@@ -15,6 +16,15 @@
 IDOM_CLIENT_IMPORT_SOURCE_URL_INFIX = "/_snowpack/pkg"
 
 
+if getmtime(BACKUP_BUILD_DIR) > getmtime(IDOM_CLIENT_BUILD_DIR.current):
+    # delete the runtime build if the backup build is newer (i.e. IDOM was re-installed)
+    shutil.rmtree(IDOM_CLIENT_BUILD_DIR.current)
+
+if not IDOM_CLIENT_BUILD_DIR.current.exists():
+    # populate the runtime build directory if it doesn't exist
+    shutil.copytree(BACKUP_BUILD_DIR, IDOM_CLIENT_BUILD_DIR.current, symlinks=True)
+
+
 def get_user_packages_file(app_dir: Path) -> Path:
     return app_dir / "packages" / "idom-app-react" / "src" / "user-packages.js"
 
@@ -25,10 +35,6 @@ def web_modules_dir() -> Path:
     )
 
 
-if not IDOM_CLIENT_BUILD_DIR.current.exists():  # pragma: no cover
-    shutil.copytree(BACKUP_BUILD_DIR, IDOM_CLIENT_BUILD_DIR.current, symlinks=True)
-
-
 def restore_build_dir_from_backup() -> None:
     target = IDOM_CLIENT_BUILD_DIR.current
     if target.exists():