From 878693383e823b2dfb200b99b3b7d7a14162ea68 Mon Sep 17 00:00:00 2001
From: LordBaryhobal <lordbaryhobal@gmail.com>
Date: Mon, 22 Jun 2026 14:14:05 +0200
Subject: [PATCH] feat(cli): add watch option to stubs command

---
 midas/cli/commands/stubs.py | 59 ++++++++++++++++++++++++++++++-------
 pyproject.toml              |  6 +++-
 2 files changed, 53 insertions(+), 12 deletions(-)

diff --git a/midas/cli/commands/stubs.py b/midas/cli/commands/stubs.py
index 98b3cd4..a5267c9 100644
--- a/midas/cli/commands/stubs.py
+++ b/midas/cli/commands/stubs.py
@@ -1,27 +1,64 @@
 import ast
+import time
 from pathlib import Path
 from typing import TextIO
 
+import black
 import click
+from watchdog.events import DirModifiedEvent, FileModifiedEvent, FileSystemEventHandler
+from watchdog.observers import Observer
 
 from midas.checker.checker import TypeChecker
 from midas.generator.stubs import StubsGenerator
 
 
-@click.command(help="Generate stubs from Midas definitions")
-@click.argument("file", type=click.File("r"))
-@click.option("-o", "--output", type=click.File("w"), default="-")
-def stubs(
-    file: TextIO,
-    output: TextIO,
-):
-    source_path: Path = Path(file.name).resolve()
-
+def generate_stubs(in_path: Path, out_path: Path):
     checker = TypeChecker()
-    checker.import_midas(source_path)
+    checker.import_midas(in_path)
 
     generator = StubsGenerator(checker.types)
     module: ast.Module = generator.generate_stubs()
     module = ast.fix_missing_locations(module)
 
-    output.write(ast.unparse(module))
+    output: str = ast.unparse(module)
+    output = black.format_str(output, mode=black.Mode(is_pyi=True))
+
+    out_path.write_text(output)
+
+
+class Handler(FileSystemEventHandler):
+    def __init__(self, in_path: Path, out_path: Path) -> None:
+        super().__init__()
+        self.in_path: Path = in_path
+        self.out_path: Path = out_path
+
+    def on_modified(self, event: DirModifiedEvent | FileModifiedEvent) -> None:
+        generate_stubs(self.in_path, self.out_path)
+
+
+@click.command(help="Generate stubs from Midas definitions")
+@click.argument("file", type=click.File("r"))
+@click.option("-o", "--output", type=click.File("w"), default="-")
+@click.option("-w", "--watch", is_flag=True)
+def stubs(
+    file: TextIO,
+    output: TextIO,
+    watch: bool,
+):
+    source_path: Path = Path(file.name).resolve()
+    out_path: Path = Path(output.name).resolve()
+    generate_stubs(source_path, out_path)
+
+    if watch:
+        print(f"Watching {source_path}...")
+        print("Press CTRL+C to stop")
+        handler = Handler(source_path, out_path)
+        observer = Observer()
+        observer.schedule(handler, str(source_path))
+        observer.start()
+        try:
+            while True:
+                time.sleep(1)
+        except KeyboardInterrupt:
+            observer.stop()
+        observer.join()
diff --git a/pyproject.toml b/pyproject.toml
index 69a9f7e..48f3b21 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -8,7 +8,11 @@ authors = [
     { name = "Louis Heredero", email = "louis.heredero@students.hevs.ch" },
 ]
 classifiers = ["Programming Language :: Python :: 3"]
-dependencies = ["click>=8.4.1"]
+dependencies = [
+    "black>=26.5.1",
+    "click>=8.4.1",
+    "watchdog>=6.0.0",
+]
 
 [project.urls]
 Homepage = "https://git.kbk28.ch/HEL/midas"