From 3eb12e1e75947dadb0823884a397bcfae75e37d3 Mon Sep 17 00:00:00 2001
From: himanshumahajan138 <himanshumahajan138@gmail.com>
Date: Sun, 8 Dec 2024 19:54:47 +0530
Subject: [PATCH 1/4] Web Examples

---
 .gitignore                                    |   4 +-
 example/package.mill                          |   1 +
 .../pythonlib/web/1-hello-flask/build.mill    |  32 +++++
 .../web/1-hello-flask/foo/src/foo.py          |  10 ++
 .../web/1-hello-flask/foo/test/src/test.py    |  17 +++
 .../pythonlib/web/3-hello-django/build.mill   |  31 +++++
 .../3-hello-django/foo/src/app/__init__.py    |   0
 .../web/3-hello-django/foo/src/app/asgi.py    |  16 +++
 .../3-hello-django/foo/src/app/settings.py    | 124 ++++++++++++++++++
 .../web/3-hello-django/foo/src/app/urls.py    |  24 ++++
 .../web/3-hello-django/foo/src/app/wsgi.py    |  16 +++
 .../3-hello-django/foo/src/main/__init__.py   |   0
 .../web/3-hello-django/foo/src/main/admin.py  |   3 +
 .../web/3-hello-django/foo/src/main/apps.py   |   6 +
 .../foo/src/main/migrations/__init__.py       |   0
 .../web/3-hello-django/foo/src/main/models.py |   3 +
 .../web/3-hello-django/foo/src/main/tests.py  |  12 ++
 .../web/3-hello-django/foo/src/main/views.py  |   5 +
 .../web/3-hello-django/foo/src/manage.py      |  22 ++++
 pythonlib/package.mill                        |   1 +
 .../src/mill/pythonlib/PythonModule.scala     |  76 +++++++++--
 .../MillBackgroundWrapper.java                |  30 ++++-
 scalalib/src/mill/scalalib/RunModule.scala    |  12 +-
 23 files changed, 424 insertions(+), 21 deletions(-)
 create mode 100644 example/pythonlib/web/1-hello-flask/build.mill
 create mode 100644 example/pythonlib/web/1-hello-flask/foo/src/foo.py
 create mode 100644 example/pythonlib/web/1-hello-flask/foo/test/src/test.py
 create mode 100644 example/pythonlib/web/3-hello-django/build.mill
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/app/__init__.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/app/asgi.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/app/settings.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/app/urls.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/app/wsgi.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/__init__.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/admin.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/apps.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/migrations/__init__.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/models.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/tests.py
 create mode 100644 example/pythonlib/web/3-hello-django/foo/src/main/views.py
 create mode 100755 example/pythonlib/web/3-hello-django/foo/src/manage.py

diff --git a/.gitignore b/.gitignore
index 70b9505b86a..e98cf1c7b51 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,4 +16,6 @@ lowered.hnir
 node_modules/
 dist/
 build/
-*.bak
\ No newline at end of file
+*.bak
+db.sqlite3
+__pycache__
\ No newline at end of file
diff --git a/example/package.mill b/example/package.mill
index 1f214fe09b2..f6437bf8534 100644
--- a/example/package.mill
+++ b/example/package.mill
@@ -68,6 +68,7 @@ object `package` extends RootModule with Module {
     object basic extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "basic"))
     object dependencies extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "dependencies"))
     object publishing extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "publishing"))
+    object web extends Cross[ExampleCrossModule](build.listIn(millSourcePath / "web"))
   }
 
   object cli extends Module{
diff --git a/example/pythonlib/web/1-hello-flask/build.mill b/example/pythonlib/web/1-hello-flask/build.mill
new file mode 100644
index 00000000000..1405b60501b
--- /dev/null
+++ b/example/pythonlib/web/1-hello-flask/build.mill
@@ -0,0 +1,32 @@
+package build
+import mill._, pythonlib._
+
+object foo extends PythonModule {
+
+  def mainScript = Task.Source { millSourcePath / "src" / "foo.py" }
+
+  def pythonDeps = Seq("flask==3.1.0")
+
+  object test extends PythonTests with TestModule.Unittest
+
+}
+
+/** Usage
+
+> ./mill foo.test
+...
+test_hello_flask (test.TestScript...)
+Test the '/' endpoint. ... ok
+...
+Ran 1 test...
+OK
+...
+
+> ./mill foo.runBackground
+
+> curl http://localhost:5000
+...<h1>Hello, Mill!</h1>...
+
+> ./mill clean foo.runBackgrouund
+
+*/
diff --git a/example/pythonlib/web/1-hello-flask/foo/src/foo.py b/example/pythonlib/web/1-hello-flask/foo/src/foo.py
new file mode 100644
index 00000000000..ca92ec70e52
--- /dev/null
+++ b/example/pythonlib/web/1-hello-flask/foo/src/foo.py
@@ -0,0 +1,10 @@
+from flask import Flask
+
+app = Flask(__name__)
+
+@app.route("/")
+def hello_world():
+    return "<h1>Hello, Mill!</h1>"
+
+if __name__ == '__main__':
+    app.run(debug=True)
\ No newline at end of file
diff --git a/example/pythonlib/web/1-hello-flask/foo/test/src/test.py b/example/pythonlib/web/1-hello-flask/foo/test/src/test.py
new file mode 100644
index 00000000000..982e222e474
--- /dev/null
+++ b/example/pythonlib/web/1-hello-flask/foo/test/src/test.py
@@ -0,0 +1,17 @@
+import unittest
+from foo import app  # type: ignore
+
+class TestScript(unittest.TestCase):
+    def setUp(self):
+        """Set up the test client before each test."""
+        self.app = app.test_client()  # Initialize the test client
+        self.app.testing = True       # Enable testing mode for better error handling
+
+    def test_hello_flask(self):
+        """Test the '/' endpoint."""
+        response = self.app.get('/')  # Simulate a GET request to the root endpoint
+        self.assertEqual(response.status_code, 200)  # Check the HTTP status code
+        self.assertIn(b"Hello, Mill!", response.data)  # Check if the response contains the expected text
+
+if __name__ == '__main__':
+    unittest.main()
diff --git a/example/pythonlib/web/3-hello-django/build.mill b/example/pythonlib/web/3-hello-django/build.mill
new file mode 100644
index 00000000000..205dda49b0d
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/build.mill
@@ -0,0 +1,31 @@
+package build
+import mill._, pythonlib._
+
+object foo extends PythonModule {
+
+  def mainScript = Task.Source { millSourcePath / "src" / "manage.py" }
+
+  def pythonDeps = Seq("django==5.1.4")
+
+}
+
+/** Usage
+
+> ./mill foo.run test main -v 2 # using inbuilt `django test`, `main` is the app name, `-v 2` is verbosity level 2
+...
+System check identified no issues (0 silenced).
+test_index_view (main.tests.TestScript...)
+Test that the index view returns a 200 status code ... ok
+...
+Ran 1 test...
+OK
+...
+
+> ./mill foo.runBackground runserver
+
+> curl http://localhost:8000
+...<h1>Hello, Mill!</h1>...
+
+> ./mill clean foo.runBackgrouund
+
+*/
diff --git a/example/pythonlib/web/3-hello-django/foo/src/app/__init__.py b/example/pythonlib/web/3-hello-django/foo/src/app/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/example/pythonlib/web/3-hello-django/foo/src/app/asgi.py b/example/pythonlib/web/3-hello-django/foo/src/app/asgi.py
new file mode 100644
index 00000000000..df7e978063c
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/app/asgi.py
@@ -0,0 +1,16 @@
+"""
+ASGI config for app project.
+
+It exposes the ASGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/5.1/howto/deployment/asgi/
+"""
+
+import os
+
+from django.core.asgi import get_asgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')
+
+application = get_asgi_application()
diff --git a/example/pythonlib/web/3-hello-django/foo/src/app/settings.py b/example/pythonlib/web/3-hello-django/foo/src/app/settings.py
new file mode 100644
index 00000000000..3c40a0f9649
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/app/settings.py
@@ -0,0 +1,124 @@
+"""
+Django settings for app project.
+
+Generated by 'django-admin startproject' using Django 5.1.4.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/5.1/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/5.1/ref/settings/
+"""
+
+from pathlib import Path
+
+# Build paths inside the project like this: BASE_DIR / 'subdir'.
+BASE_DIR = Path(__file__).resolve().parent.parent
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/5.1/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = 'django-insecure-7@1hg!(c00%z)t82=^_mu02sxa$nlex_xc!7j++18z5w4dc(iu'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+    'main',
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'app.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'app.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/5.1/ref/settings/#databases
+
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': BASE_DIR / 'db.sqlite3',
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/5.1/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/5.1/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/5.1/howto/static-files/
+
+STATIC_URL = 'static/'
+
+# Default primary key field type
+# https://docs.djangoproject.com/en/5.1/ref/settings/#default-auto-field
+
+DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'
diff --git a/example/pythonlib/web/3-hello-django/foo/src/app/urls.py b/example/pythonlib/web/3-hello-django/foo/src/app/urls.py
new file mode 100644
index 00000000000..879e54d05df
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/app/urls.py
@@ -0,0 +1,24 @@
+"""
+URL configuration for app project.
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/5.1/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  path('', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
+Including another URLconf
+    1. Import the include() function: from django.urls import include, path
+    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
+"""
+from django.contrib import admin
+from django.urls import path
+from main import views
+
+urlpatterns = [
+    path('admin/', admin.site.urls),
+    path('', views.index, name="homepage")
+]
diff --git a/example/pythonlib/web/3-hello-django/foo/src/app/wsgi.py b/example/pythonlib/web/3-hello-django/foo/src/app/wsgi.py
new file mode 100644
index 00000000000..829fcc707bb
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/app/wsgi.py
@@ -0,0 +1,16 @@
+"""
+WSGI config for app project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/5.1/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')
+
+application = get_wsgi_application()
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/__init__.py b/example/pythonlib/web/3-hello-django/foo/src/main/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/admin.py b/example/pythonlib/web/3-hello-django/foo/src/main/admin.py
new file mode 100644
index 00000000000..8c38f3f3dad
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/main/admin.py
@@ -0,0 +1,3 @@
+from django.contrib import admin
+
+# Register your models here.
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/apps.py b/example/pythonlib/web/3-hello-django/foo/src/main/apps.py
new file mode 100644
index 00000000000..167f04426e4
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/main/apps.py
@@ -0,0 +1,6 @@
+from django.apps import AppConfig
+
+
+class MainConfig(AppConfig):
+    default_auto_field = 'django.db.models.BigAutoField'
+    name = 'main'
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/migrations/__init__.py b/example/pythonlib/web/3-hello-django/foo/src/main/migrations/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/models.py b/example/pythonlib/web/3-hello-django/foo/src/main/models.py
new file mode 100644
index 00000000000..71a83623907
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/main/models.py
@@ -0,0 +1,3 @@
+from django.db import models
+
+# Create your models here.
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/tests.py b/example/pythonlib/web/3-hello-django/foo/src/main/tests.py
new file mode 100644
index 00000000000..aa6ec79bd6a
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/main/tests.py
@@ -0,0 +1,12 @@
+from django.test import TestCase
+from django.urls import reverse
+
+class TestScript(TestCase):
+    def test_index_view(self):
+        """
+        Test that the index view returns a 200 status code
+        and the expected HTML content.
+        """
+        response = self.client.get(reverse('homepage'))
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, '<h1>Hello, Mill!</h1>')
diff --git a/example/pythonlib/web/3-hello-django/foo/src/main/views.py b/example/pythonlib/web/3-hello-django/foo/src/main/views.py
new file mode 100644
index 00000000000..05b8dc7a8f6
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/main/views.py
@@ -0,0 +1,5 @@
+from django.shortcuts import render
+from django.http import HttpResponse
+
+def index(request):
+    return HttpResponse('<h1>Hello, Mill!</h1>')
\ No newline at end of file
diff --git a/example/pythonlib/web/3-hello-django/foo/src/manage.py b/example/pythonlib/web/3-hello-django/foo/src/manage.py
new file mode 100755
index 00000000000..49313893cbd
--- /dev/null
+++ b/example/pythonlib/web/3-hello-django/foo/src/manage.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+import os
+import sys
+
+
+def main():
+    """Run administrative tasks."""
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'app.settings')
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) from exc
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/pythonlib/package.mill b/pythonlib/package.mill
index cbc3a6a73f2..8e9f58da976 100644
--- a/pythonlib/package.mill
+++ b/pythonlib/package.mill
@@ -9,4 +9,5 @@ object `package` extends RootModule with build.MillPublishScalaModule {
   // we depend on scalalib for re-using some common infrastructure (e.g. License
   // management of projects), NOT for reusing build logic
   def moduleDeps = Seq(build.main, build.scalalib)
+  def testTransitiveDeps = super.testTransitiveDeps() ++ Seq(build.scalalib.backgroundwrapper.testDep())
 }
diff --git a/pythonlib/src/mill/pythonlib/PythonModule.scala b/pythonlib/src/mill/pythonlib/PythonModule.scala
index 219673a3254..3de68c7dfb9 100644
--- a/pythonlib/src/mill/pythonlib/PythonModule.scala
+++ b/pythonlib/src/mill/pythonlib/PythonModule.scala
@@ -75,6 +75,13 @@ trait PythonModule extends PipModule with TaskModule { outer =>
    */
   def unmanagedPythonPath: T[Seq[PathRef]] = Task { Seq.empty[PathRef] }
 
+  /**
+   * Folders containing source files that are generated rather than
+   * handwritten; these files can be generated in this target itself,
+   * or can refer to files generated from other targets
+   */
+  def generatedSources: T[Seq[PathRef]] = Task { Seq.empty[PathRef] }
+
   /**
    * The directories used to construct the PYTHONPATH for this module, used for
    * execution, excluding upstream modules.
@@ -83,7 +90,7 @@ trait PythonModule extends PipModule with TaskModule { outer =>
    * directories.
    */
   def localPythonPath: T[Seq[PathRef]] = Task {
-    sources() ++ resources() ++ unmanagedPythonPath()
+    sources() ++ resources() ++ generatedSources() ++ unmanagedPythonPath()
   }
 
   /**
@@ -95,21 +102,41 @@ trait PythonModule extends PipModule with TaskModule { outer =>
     localPythonPath() ++ upstream
   }
 
+  /**
+   * Any environment variables you want to pass to the forked Env
+   */
+  def forkEnv: T[Map[String, String]] = Task { Map.empty[String, String] }
+
+  /**
+   * Command-line options to pass to the Python Interpreter defined by the user.
+   */
+  def pythonOptions: T[Seq[String]] = Task { Seq.empty[String] }
+
+  /**
+   * Command-line options to pass as bundle configuration defined by the user.
+   */
+  def bundleOptions: T[Seq[String]] = Task { Seq.empty[String] }
+
   // TODO: right now, any task that calls this helper will have its own python
   // cache. This is slow. Look into sharing the cache between tasks.
   def runner: Task[PythonModule.Runner] = Task.Anon {
     new PythonModule.RunnerImpl(
       command0 = pythonExe().path.toString,
-      env0 = Map(
-        "PYTHONPATH" -> transitivePythonPath().map(_.path).mkString(java.io.File.pathSeparator),
-        "PYTHONPYCACHEPREFIX" -> (T.dest / "cache").toString,
-        if (Task.log.colored) { "FORCE_COLOR" -> "1" }
-        else { "NO_COLOR" -> "1" }
-      ),
+      options = pythonOptions(),
+      env0 = runnerEnvTask() ++ forkEnv(),
       workingDir0 = Task.workspace
     )
   }
 
+  private def runnerEnvTask = Task.Anon {
+    Map(
+      "PYTHONPATH" -> transitivePythonPath().map(_.path).mkString(java.io.File.pathSeparator),
+      "PYTHONPYCACHEPREFIX" -> (T.dest / "cache").toString,
+      if (Task.log.colored) { "FORCE_COLOR" -> "1" }
+      else { "NO_COLOR" -> "1" }
+    )
+  }
+
   /**
    * Run a typechecker on this module.
    */
@@ -169,6 +196,7 @@ trait PythonModule extends PipModule with TaskModule { outer =>
         "--exe", mainScript().path,
         "-o", pexFile,
         "--scie", "eager",
+        bundleOptions()
         // format: on
       ),
       workingDir = T.dest
@@ -176,6 +204,37 @@ trait PythonModule extends PipModule with TaskModule { outer =>
     PathRef(pexFile)
   }
 
+  /**
+   * Run the main python script of this module.
+   *
+   * @see [[mainScript]]
+   */
+  def runBackground(args: mill.define.Args) = Task.Command {
+    val (procUuidPath, procLockfile, procUuid) = mill.scalalib.RunModule.backgroundSetup(T.dest)
+
+    Jvm.runSubprocess(
+      mainClass = "mill.scalalib.backgroundwrapper.MillBackgroundWrapper",
+      classPath = mill.scalalib.ZincWorkerModule.backgroundWrapperClasspath().map(_.path).toSeq,
+      jvmArgs = Nil,
+      envArgs = runnerEnvTask(),
+      mainArgs = Seq(
+        procUuidPath.toString,
+        procLockfile.toString,
+        procUuid,
+        "500",
+        "<subprocess>",
+        pythonExe().path.toString,
+        mainScript().path.toString
+      ) ++ args.value,
+      workingDir = T.workspace,
+      background = true,
+      useCpPassingJar = false,
+      runBackgroundLogToConsole = true,
+      javaHome = mill.scalalib.ZincWorkerModule.javaHome().map(_.path)
+    )
+    ()
+  }
+
   trait PythonTests extends PythonModule {
     override def moduleDeps: Seq[PythonModule] = Seq(outer)
   }
@@ -194,6 +253,7 @@ object PythonModule {
 
   private class RunnerImpl(
       command0: String,
+      options: Seq[String],
       env0: Map[String, String],
       workingDir0: os.Path
   ) extends Runner {
@@ -204,7 +264,7 @@ object PythonModule {
         workingDir: os.Path = null
     )(implicit ctx: Ctx): Unit =
       Jvm.runSubprocess(
-        commandArgs = Seq(Option(command).getOrElse(command0)) ++ args.value,
+        commandArgs = Seq(Option(command).getOrElse(command0)) ++ options ++ args.value,
         envArgs = Option(env).getOrElse(env0),
         workingDir = Option(workingDir).getOrElse(workingDir0)
       )
diff --git a/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java b/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
index ebdd96f84d9..59b134eb1c9 100644
--- a/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
+++ b/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
@@ -2,10 +2,7 @@
 
 import java.io.RandomAccessFile;
 import java.nio.channels.FileChannel;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.Paths;
-import java.nio.file.StandardOpenOption;
+import java.nio.file.*;
 
 public class MillBackgroundWrapper {
   public static void main(String[] args) throws Exception {
@@ -55,6 +52,27 @@ public static void main(String[] args) throws Exception {
     // Actually start the Java main method we wanted to run in the background
     String realMain = args[4];
     String[] realArgs = java.util.Arrays.copyOfRange(args, 5, args.length);
-    Class.forName(realMain).getMethod("main", String[].class).invoke(null, (Object) realArgs);
+    if (!realMain.equals("<subprocess>")) {
+      Class.forName(realMain).getMethod("main", String[].class).invoke(null, (Object) realArgs);
+    } else {
+      Process subprocess = new ProcessBuilder().command(realArgs).inheritIO().start();
+
+      Runtime.getRuntime().addShutdownHook(new Thread(() -> {
+        subprocess.destroy();
+
+        long now = System.currentTimeMillis();
+
+        while (subprocess.isAlive() && System.currentTimeMillis() - now < 100) {
+          try {
+            Thread.sleep(1);
+          } catch (InterruptedException e) {
+          }
+          if (subprocess.isAlive()) {
+            subprocess.destroyForcibly();
+          }
+        }
+      }));
+      System.exit(subprocess.waitFor());
+    }
   }
-}
+}
\ No newline at end of file
diff --git a/scalalib/src/mill/scalalib/RunModule.scala b/scalalib/src/mill/scalalib/RunModule.scala
index a371830e1e7..04cd5f41505 100644
--- a/scalalib/src/mill/scalalib/RunModule.scala
+++ b/scalalib/src/mill/scalalib/RunModule.scala
@@ -166,7 +166,7 @@ trait RunModule extends WithZincWorker {
 
   def runBackgroundTask(mainClass: Task[String], args: Task[Args] = Task.Anon(Args())): Task[Unit] =
     Task.Anon {
-      val (procUuidPath, procLockfile, procUuid) = backgroundSetup(T.dest)
+      val (procUuidPath, procLockfile, procUuid) = RunModule.backgroundSetup(T.dest)
       runner().run(
         args = Seq(
           procUuidPath.toString,
@@ -207,7 +207,7 @@ trait RunModule extends WithZincWorker {
       runUseArgsFile: Boolean,
       backgroundOutputs: Option[Tuple2[ProcessOutput, ProcessOutput]]
   )(args: String*): Ctx => Result[Unit] = ctx => {
-    val (procUuidPath, procLockfile, procUuid) = backgroundSetup(taskDest)
+    val (procUuidPath, procLockfile, procUuid) = RunModule.backgroundSetup(taskDest)
     try Result.Success(
         Jvm.runSubprocessWithBackgroundOutputs(
           "mill.scalalib.backgroundwrapper.MillBackgroundWrapper",
@@ -231,16 +231,16 @@ trait RunModule extends WithZincWorker {
         Result.Failure("subprocess failed")
     }
   }
+}
+
+object RunModule {
 
-  private[this] def backgroundSetup(dest: os.Path): (Path, Path, String) = {
+  private[mill] def backgroundSetup(dest: os.Path): (Path, Path, String) = {
     val procUuid = java.util.UUID.randomUUID().toString
     val procUuidPath = dest / ".mill-background-process-uuid"
     val procLockfile = dest / ".mill-background-process-lock"
     (procUuidPath, procLockfile, procUuid)
   }
-}
-
-object RunModule {
   trait Runner {
     def run(
         args: os.Shellable,

From 042c4274151ddcd1d5401f8e0df1a774ddacd72c Mon Sep 17 00:00:00 2001
From: himanshumahajan138 <himanshumahajan138@gmail.com>
Date: Sun, 8 Dec 2024 20:14:49 +0530
Subject: [PATCH 2/4] Fix Typos

---
 example/pythonlib/web/1-hello-flask/build.mill                  | 2 +-
 example/pythonlib/web/3-hello-django/build.mill                 | 2 +-
 .../mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/example/pythonlib/web/1-hello-flask/build.mill b/example/pythonlib/web/1-hello-flask/build.mill
index 1405b60501b..2fc70becb84 100644
--- a/example/pythonlib/web/1-hello-flask/build.mill
+++ b/example/pythonlib/web/1-hello-flask/build.mill
@@ -27,6 +27,6 @@ OK
 > curl http://localhost:5000
 ...<h1>Hello, Mill!</h1>...
 
-> ./mill clean foo.runBackgrouund
+> ./mill clean foo.runBackground
 
 */
diff --git a/example/pythonlib/web/3-hello-django/build.mill b/example/pythonlib/web/3-hello-django/build.mill
index 205dda49b0d..fb5158d0f70 100644
--- a/example/pythonlib/web/3-hello-django/build.mill
+++ b/example/pythonlib/web/3-hello-django/build.mill
@@ -26,6 +26,6 @@ OK
 > curl http://localhost:8000
 ...<h1>Hello, Mill!</h1>...
 
-> ./mill clean foo.runBackgrouund
+> ./mill clean foo.runBackground
 
 */
diff --git a/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java b/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
index 59b134eb1c9..c7d9947c884 100644
--- a/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
+++ b/scalalib/backgroundwrapper/src/mill/scalalib/backgroundwrapper/MillBackgroundWrapper.java
@@ -75,4 +75,4 @@ public static void main(String[] args) throws Exception {
       System.exit(subprocess.waitFor());
     }
   }
-}
\ No newline at end of file
+}

From b9f93088db9e567e172748c446ddb003cf2e6714 Mon Sep 17 00:00:00 2001
From: himanshumahajan138 <himanshumahajan138@gmail.com>
Date: Mon, 9 Dec 2024 18:01:25 +0530
Subject: [PATCH 3/4] todo-flask[wip]

---
 .gitignore                                    |  4 +-
 example/pythonlib/web/2-todo-flask/build.mill | 24 ++++++
 .../web/2-todo-flask/todo/src/app.py          | 74 +++++++++++++++++++
 .../web/2-todo-flask/todo/src/forms.py        | 10 +++
 .../web/2-todo-flask/todo/src/models.py       | 14 ++++
 .../web/2-todo-flask/todo/static/style.css    | 21 ++++++
 .../web/2-todo-flask/todo/templates/base.html | 31 ++++++++
 .../2-todo-flask/todo/templates/index.html    | 30 ++++++++
 .../web/2-todo-flask/todo/templates/task.html | 24 ++++++
 .../web/2-todo-flask/todo/test/src/test.py    |  1 +
 10 files changed, 230 insertions(+), 3 deletions(-)
 create mode 100644 example/pythonlib/web/2-todo-flask/build.mill
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/src/app.py
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/src/forms.py
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/src/models.py
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/static/style.css
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/templates/base.html
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/templates/index.html
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/templates/task.html
 create mode 100644 example/pythonlib/web/2-todo-flask/todo/test/src/test.py

diff --git a/.gitignore b/.gitignore
index e98cf1c7b51..70b9505b86a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,6 +16,4 @@ lowered.hnir
 node_modules/
 dist/
 build/
-*.bak
-db.sqlite3
-__pycache__
\ No newline at end of file
+*.bak
\ No newline at end of file
diff --git a/example/pythonlib/web/2-todo-flask/build.mill b/example/pythonlib/web/2-todo-flask/build.mill
new file mode 100644
index 00000000000..c3523519099
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/build.mill
@@ -0,0 +1,24 @@
+package build
+import mill._, pythonlib._
+
+object todo extends PythonModule {
+
+  def mainScript = Task.Source { millSourcePath / "src" / "app.py" }
+
+  def pythonDeps = Seq("flask==3.1.0", "Flask-SQLAlchemy==3.1.1", "Flask-WTF==1.2.2")
+
+  object test extends PythonTests with TestModule.Unittest
+
+}
+
+// TODO: Testing will be added soon...
+
+/** Usage
+
+> ./mill todo.runBackground
+
+> curl http://localhost:5001
+
+> ./mill clean todo.runBackground
+
+*/
diff --git a/example/pythonlib/web/2-todo-flask/todo/src/app.py b/example/pythonlib/web/2-todo-flask/todo/src/app.py
new file mode 100644
index 00000000000..0cebf1afb94
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/src/app.py
@@ -0,0 +1,74 @@
+from flask import Flask, render_template, redirect, url_for, flash, request
+from flask_sqlalchemy import SQLAlchemy
+from flask_wtf import FlaskForm
+from wtforms import StringField, TextAreaField, SelectField, DateField, SubmitField
+from wtforms.validators import DataRequired, Length
+
+# Initialize Flask App and Database
+app = Flask(__name__, static_folder="../static", template_folder="../templates")
+app.config["SQLALCHEMY_DATABASE_URI"] = "sqlite:///todo.db"
+app.config["SQLALCHEMY_TRACK_MODIFICATIONS"] = False
+app.config["SECRET_KEY"] = "your_secret_key"
+
+# Import models
+from models import Task, db
+
+# Import forms
+from forms import TaskForm
+
+db.init_app(app)
+
+
+# Routes
+@app.route("/")
+def index():
+    tasks = Task.query.all()
+    return render_template("index.html", tasks=tasks)
+
+
+@app.route("/add", methods=["GET", "POST"])
+def add_task():
+    form = TaskForm()
+    if form.validate_on_submit():
+        new_task = Task(
+            title=form.title.data,
+            description=form.description.data,
+            status=form.status.data,
+            deadline=form.deadline.data,
+        )
+        db.session.add(new_task)
+        db.session.commit()
+        flash("Task added successfully!", "success")
+        return redirect(url_for("index"))
+    return render_template("task.html", form=form, title="Add Task")
+
+
+@app.route("/edit/<int:task_id>", methods=["GET", "POST"])
+def edit_task(task_id):
+    task = Task.query.get_or_404(task_id)
+    form = TaskForm(obj=task)
+    if form.validate_on_submit():
+        task.title = form.title.data
+        task.description = form.description.data
+        task.status = form.status.data
+        task.deadline = form.deadline.data
+        db.session.commit()
+        flash("Task updated successfully!", "success")
+        return redirect(url_for("index"))
+    return render_template("task.html", form=form, title="Edit Task")
+
+
+@app.route("/delete/<int:task_id>")
+def delete_task(task_id):
+    task = Task.query.get_or_404(task_id)
+    db.session.delete(task)
+    db.session.commit()
+    flash("Task deleted successfully!", "success")
+    return redirect(url_for("index"))
+
+
+# Create database tables and run the app
+if __name__ == "__main__":
+    with app.app_context():
+        db.create_all()
+    app.run(debug=True, port=5001)
diff --git a/example/pythonlib/web/2-todo-flask/todo/src/forms.py b/example/pythonlib/web/2-todo-flask/todo/src/forms.py
new file mode 100644
index 00000000000..be10adcff0f
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/src/forms.py
@@ -0,0 +1,10 @@
+from flask_wtf import FlaskForm
+from wtforms import StringField, TextAreaField, SelectField, DateField, SubmitField
+from wtforms.validators import DataRequired, Length
+
+class TaskForm(FlaskForm):
+    title = StringField('Title', validators=[DataRequired(), Length(max=100)])
+    description = TextAreaField('Description')
+    status = SelectField('Status', choices=[('Pending', 'Pending'), ('Completed', 'Completed')])
+    deadline = DateField('Deadline', format='%Y-%m-%d', validators=[DataRequired()])
+    submit = SubmitField('Save')
diff --git a/example/pythonlib/web/2-todo-flask/todo/src/models.py b/example/pythonlib/web/2-todo-flask/todo/src/models.py
new file mode 100644
index 00000000000..93bd7c82bf4
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/src/models.py
@@ -0,0 +1,14 @@
+from flask_sqlalchemy import SQLAlchemy
+
+db = SQLAlchemy()
+
+class Task(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    title = db.Column(db.String(100), nullable=False)
+    description = db.Column(db.Text, nullable=True)
+    status = db.Column(db.String(20), default='Pending')  # Options: Pending, Completed
+    created_at = db.Column(db.DateTime, default=db.func.current_timestamp())
+    deadline = db.Column(db.Date)
+
+    def __repr__(self):
+        return f'<Task {self.title}>'
diff --git a/example/pythonlib/web/2-todo-flask/todo/static/style.css b/example/pythonlib/web/2-todo-flask/todo/static/style.css
new file mode 100644
index 00000000000..54f07a91f48
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/static/style.css
@@ -0,0 +1,21 @@
+body {
+    background-color: #f8f9fa;
+}
+
+.navbar-brand {
+    font-weight: bold;
+}
+
+.table th,
+.table td {
+    text-align: center;
+    vertical-align: middle;
+}
+
+.btn {
+    margin-right: 5px;
+}
+
+.container {
+    max-width: 900px;
+}
diff --git a/example/pythonlib/web/2-todo-flask/todo/templates/base.html b/example/pythonlib/web/2-todo-flask/todo/templates/base.html
new file mode 100644
index 00000000000..7beef670609
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/templates/base.html
@@ -0,0 +1,31 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Flask To-Do App</title>
+    <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css">
+    <link rel="stylesheet" href="{{ url_for('static', filename='styles.css') }}">
+</head>
+<body>
+    <nav class="navbar navbar-expand-lg navbar-dark bg-dark">
+        <div class="container">
+            <a class="navbar-brand" href="{{ url_for('index') }}">To-Do App Using Mill Build Tool</a>
+        </div>
+    </nav>
+    <div class="container mt-4">
+        {% with messages = get_flashed_messages(with_categories=True) %}
+            {% if messages %}
+                {% for category, message in messages %}
+                    <div class="alert alert-{{ category }} alert-dismissible fade show" role="alert">
+                        {{ message }}
+                        <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
+                    </div>
+                {% endfor %}
+            {% endif %}
+        {% endwith %}
+        {% block content %}{% endblock %}
+    </div>
+    <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/js/bootstrap.bundle.min.js"></script>
+</body>
+</html>
diff --git a/example/pythonlib/web/2-todo-flask/todo/templates/index.html b/example/pythonlib/web/2-todo-flask/todo/templates/index.html
new file mode 100644
index 00000000000..8d1619a4758
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/templates/index.html
@@ -0,0 +1,30 @@
+{% extends 'base.html' %}
+{% block content %}
+<h1 class="mb-4">Task List</h1>
+<a href="{{ url_for('add_task') }}" class="btn btn-primary mb-3">Add Task</a>
+<table class="table table-bordered">
+    <thead>
+        <tr>
+            <th>#</th>
+            <th>Title</th>
+            <th>Status</th>
+            <th>Deadline</th>
+            <th>Actions</th>
+        </tr>
+    </thead>
+    <tbody>
+        {% for task in tasks %}
+        <tr>
+            <td>{{ loop.index }}</td>
+            <td>{{ task.title }}</td>
+            <td>{{ task.status }}</td>
+            <td>{{ task.deadline }}</td>
+            <td>
+                <a href="{{ url_for('edit_task', task_id=task.id) }}" class="btn btn-sm btn-warning">Edit</a>
+                <a href="{{ url_for('delete_task', task_id=task.id) }}" class="btn btn-sm btn-danger">Delete</a>
+            </td>
+        </tr>
+        {% endfor %}
+    </tbody>
+</table>
+{% endblock %}
diff --git a/example/pythonlib/web/2-todo-flask/todo/templates/task.html b/example/pythonlib/web/2-todo-flask/todo/templates/task.html
new file mode 100644
index 00000000000..672696454a9
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/templates/task.html
@@ -0,0 +1,24 @@
+{% extends 'base.html' %}
+{% block content %}
+<h1 class="mb-4">{{ title }}</h1>
+<form method="POST">
+    {{ form.hidden_tag() }}
+    <div class="mb-3">
+        {{ form.title.label }}<br>
+        {{ form.title(class="form-control") }}
+    </div>
+    <div class="mb-3">
+        {{ form.description.label }}<br>
+        {{ form.description(class="form-control") }}
+    </div>
+    <div class="mb-3">
+        {{ form.status.label }}<br>
+        {{ form.status(class="form-control") }}
+    </div>
+    <div class="mb-3">
+        {{ form.deadline.label }}<br>
+        {{ form.deadline(class="form-control") }}
+    </div>
+    <button type="submit" class="btn btn-success">{{ form.submit.label }}</button>
+</form>
+{% endblock %}
diff --git a/example/pythonlib/web/2-todo-flask/todo/test/src/test.py b/example/pythonlib/web/2-todo-flask/todo/test/src/test.py
new file mode 100644
index 00000000000..ab5258cae2a
--- /dev/null
+++ b/example/pythonlib/web/2-todo-flask/todo/test/src/test.py
@@ -0,0 +1 @@
+# Work in Progress...
\ No newline at end of file

From 52b4b8fbb6a6b10d0f1714c0ac590a47b07cf042 Mon Sep 17 00:00:00 2001
From: Himanshu Mahajan <83700343+himanshumahajan138@users.noreply.github.com>
Date: Tue, 10 Dec 2024 21:54:25 +0530
Subject: [PATCH 4/4] Update PythonModule.scala

---
 .../src/mill/pythonlib/PythonModule.scala     | 35 ++-----------------
 1 file changed, 2 insertions(+), 33 deletions(-)

diff --git a/pythonlib/src/mill/pythonlib/PythonModule.scala b/pythonlib/src/mill/pythonlib/PythonModule.scala
index 75f453befa5..c5d247c66a7 100644
--- a/pythonlib/src/mill/pythonlib/PythonModule.scala
+++ b/pythonlib/src/mill/pythonlib/PythonModule.scala
@@ -168,37 +168,6 @@ trait PythonModule extends PipModule with TaskModule { outer =>
     )
   }
 
-  /**
-   * Run the main python script of this module.
-   *
-   * @see [[mainScript]]
-   */
-  def runBackground(args: mill.define.Args) = Task.Command {
-    val (procUuidPath, procLockfile, procUuid) = mill.scalalib.RunModule.backgroundSetup(T.dest)
-
-    Jvm.runSubprocess(
-      mainClass = "mill.scalalib.backgroundwrapper.MillBackgroundWrapper",
-      classPath = mill.scalalib.ZincWorkerModule.backgroundWrapperClasspath().map(_.path).toSeq,
-      jvmArgs = Nil,
-      envArgs = runnerEnvTask(),
-      mainArgs = Seq(
-        procUuidPath.toString,
-        procLockfile.toString,
-        procUuid,
-        "500",
-        "<subprocess>",
-        pythonExe().path.toString,
-        mainScript().path.toString
-      ) ++ args.value,
-      workingDir = T.workspace,
-      background = true,
-      useCpPassingJar = false,
-      runBackgroundLogToConsole = true,
-      javaHome = mill.scalalib.ZincWorkerModule.javaHome().map(_.path)
-    )
-    ()
-  }
-
   override def defaultCommandName(): String = "run"
 
   /**
@@ -241,7 +210,7 @@ trait PythonModule extends PipModule with TaskModule { outer =>
    * @see [[mainScript]]
    */
   def runBackground(args: mill.define.Args) = Task.Command {
-    val (procUuidPath, procLockfile, procUuid) = mill.scalalib.RunModule.backgroundSetup(T.dest)
+    val (procUuidPath, procLockfile, procUuid) = mill.scalalib.RunModule.backgroundSetup(Task.dest)
 
     Jvm.runSubprocess(
       mainClass = "mill.scalalib.backgroundwrapper.MillBackgroundWrapper",
@@ -257,7 +226,7 @@ trait PythonModule extends PipModule with TaskModule { outer =>
         pythonExe().path.toString,
         mainScript().path.toString
       ) ++ args.value,
-      workingDir = T.workspace,
+      workingDir = Task.workspace,
       background = true,
       useCpPassingJar = false,
       runBackgroundLogToConsole = true,