Add --reload-dir command line argument

CHANGELOG.md

@@ -10,6 +10,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### New features
 
+* `shiny run` now takes a `--reload-dir <DIR>` argument that indicates a directory `--reload` should (recursively) monitor for changes, in addition to the app's parent directory. Can be used more than once. (#353)
+
 ### Bug fixes
 
 ### Other changes

shiny/_main.py

@@ -3,6 +3,7 @@
 import copy
 import importlib
 import importlib.util
+import inspect
 import os
 import platform
 import re
@@ -77,6 +78,14 @@ def main() -> None:
     default=False,
     help="Enable auto-reload, when these types of files change: .py .css .js .html",
 )
+@click.option(
+    "--reload-dir",
+    "reload_dirs",
+    multiple=True,
+    help="Indicate a directory `--reload` should (recursively) monitor for changes, in "
+    "addition to the app's parent directory. Can be used more than once.",
+    type=click.Path(exists=True),
+)
 @click.option(
     "--ws-max-size",
     type=int,
@@ -121,6 +130,7 @@ def run(
     port: int,
     autoreload_port: int,
     reload: bool,
+    reload_dirs: tuple[str, ...],
     ws_max_size: int,
     log_level: str,
     app_dir: str,
@@ -133,6 +143,7 @@ def run(
         port=port,
         autoreload_port=autoreload_port,
         reload=reload,
+        reload_dirs=list(reload_dirs),
         ws_max_size=ws_max_size,
         log_level=log_level,
         app_dir=app_dir,
@@ -147,6 +158,7 @@ def run_app(
     port: int = 8000,
     autoreload_port: int = 0,
     reload: bool = False,
+    reload_dirs: Optional[list[str]] = None,
     ws_max_size: int = 16777216,
     log_level: Optional[str] = None,
     app_dir: Optional[str] = ".",
@@ -227,7 +239,18 @@ def run_app(
 
     log_config: dict[str, Any] = copy.deepcopy(uvicorn.config.LOGGING_CONFIG)
 
+    if reload_dirs is None:
+        reload_dirs = []
+
     if reload:
+        # Always watch the app_dir
+        if app_dir:
+            reload_dirs.append(app_dir)
+        # For developers of Shiny itself; autoreload the app when Shiny package changes
+        if os.getenv("SHINY_PKG_AUTORELOAD"):
+            shinypath = Path(inspect.getfile(shiny)).parent
+            reload_dirs.append(str(shinypath))
+
         if autoreload_port == 0:
             autoreload_port = _utils.random_port(host=host)
 
@@ -249,7 +272,7 @@ def run_app(
             "reload": reload,
             # Adding `reload_includes` param while `reload=False` produces an warning
             # https://github.com/encode/uvicorn/blob/d43afed1cfa018a85c83094da8a2dd29f656d676/uvicorn/config.py#L298-L304
-            "reload_includes": ["*.py", "*.css", "*.js", "*.html"],
+            "reload_includes": ["*.py", "*.css", "*.js", "*.htm", "*.html", "*.png"],
             "reload_dirs": reload_dirs,
         }