feat(pmpm): write our own minimum copy of npm in Python to remove the requirement for Node.js npm

Author: Xmader

README.md

@@ -68,7 +68,6 @@ Read this if you want to build a local version.
     - rust
     - python3.8 or later with header files (python3-dev)
     - spidermonkey 102.2.0 or later
-    - npm (nodejs)
     - [Poetry](https://python-poetry.org/docs/#installation)
     - [poetry-dynamic-versioning](https://github.com/mtkennerly/poetry-dynamic-versioning)
 

python/pminit/pmpm.py

@@ -0,0 +1,72 @@
+# @file     pmpm.py
+#           A minimum copy of npm written in pure Python.
+#           Currently, this can only install dependencies specified by package-lock.json into node_modules.
+# @author   Tom Tang <[email protected]>
+# @date     July 2023
+
+import json
+import io
+import os, shutil
+import tempfile
+import tarfile
+from dataclasses import dataclass
+import urllib.request
+from typing import List, Union
+
+WORK_DIR = os.path.join(
+    os.path.realpath(os.path.dirname(__file__)),
+    "pythonmonkey"
+)
+
+@dataclass
+class PackageItem:
+    installation_path: str
+    tarball_url: str
+    has_install_script: bool
+
+def parse_package_lock_json(json_data: Union[str, bytes]) -> List[PackageItem]:
+    # See https://docs.npmjs.com/cli/v9/configuring-npm/package-lock-json#packages
+    packages: dict = json.loads(json_data)["packages"]
+    items: List[PackageItem] = []
+    for key, entry in packages.items():
+        if key == "":
+            # Skip the root project (listed with a key of "")
+            continue
+        items.append(
+            PackageItem(
+                installation_path=key, # relative path from the root project folder
+                                       # The path is flattened for nested node_modules, e.g., "node_modules/create-ecdh/node_modules/bn.js"
+                tarball_url=entry["resolved"], # TODO: handle git dependencies
+                has_install_script=entry.get("hasInstallScript", False) # the package has a preinstall, install, or postinstall script
+            )
+        )
+    return items
+
+def download_package(tarball_url: str) -> bytes:
+    with urllib.request.urlopen(tarball_url) as response:
+        tarball_data: bytes = response.read()
+        return tarball_data
+
+def unpack_package(installation_path: str, tarball_data: bytes):
+    installation_path = os.path.join(WORK_DIR, installation_path)
+    shutil.rmtree(installation_path, ignore_errors=True)
+
+    with tempfile.TemporaryDirectory(prefix="pmpm_cache-") as tmpdir:
+        with io.BytesIO(tarball_data) as tar_file:
+            with tarfile.open(fileobj=tar_file) as tar:
+                tar.extractall(tmpdir)
+        shutil.move(
+            os.path.join(tmpdir, "package"), # Strip the root folder
+            installation_path
+        )
+
+def main():
+    with open(os.path.join(WORK_DIR, "package-lock.json"), encoding="utf-8") as f:
+        items = parse_package_lock_json(f.read())
+        for i in items:
+            print("Installing " + i.installation_path)
+            tarball_data = download_package(i.tarball_url)
+            unpack_package(i.installation_path, tarball_data)
+
+if __name__ == "__main__":
+    main()

python/pminit/post-install-hook.py

@@ -1,20 +1,7 @@
-import subprocess
-import sys
-
-def execute(cmd: str):
-    popen = subprocess.Popen(cmd, stdout = subprocess.PIPE, stderr = subprocess.STDOUT,
-        shell = True, text = True )
-    for stdout_line in iter(popen.stdout.readline, ""):
-        sys.stdout.write(stdout_line)
-        sys.stdout.flush()
-
-    popen.stdout.close()
-    return_code = popen.wait()
-    if return_code:
-        raise subprocess.CalledProcessError(return_code, cmd)
+import pmpm
 
 def main():
-    execute("cd pythonmonkey && npm i --no-package-lock") # do not update package-lock.json
+    pmpm.main() # cd pythonmonkey && npm i
 
 if __name__ == "__main__":
     main()