Extracted watchdog into separate dependency group

.github/workflows/test.yml

@@ -41,9 +41,9 @@ jobs:
           python -m pip install --upgrade pip setuptools wheel
           pip install -e ./packages/python-ta-z3
           if [ "${{ matrix.dependency }}" == "z3-solver" ]; then
-            pip install -e ./packages/python-ta[dev,cfg,z3]
+            pip install -e ./packages/python-ta[dev,cfg,watchdog,z3]
           else
-            pip install -e ./packages/python-ta[dev,cfg]
+            pip install -e ./packages/python-ta[dev,cfg,watchdog]
           fi
       - name: Run python-ta tests
         run: |
@@ -123,7 +123,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip setuptools wheel
-          pip install -e ./packages/python-ta-z3 ./packages/python-ta[dev,cfg,z3]
+          pip install -e ./packages/python-ta-z3 ./packages/python-ta[dev,cfg,z3,watchdog]
       - name: Generate docs
         run: sphinx-build -b html -W docs docs/_build
         working-directory: packages/python-ta

README.md

@@ -8,7 +8,7 @@ For more information about the library, check out our [documentation website](ht
 If you're developing PyTA:
 
 1. First, clone this repository.
-2. Open a terminal in this repo, and run `pip install -e "./packages/python-ta-z3" "./packages/python-ta[dev, cfg, z3]"` to install the dependencies.
+2. Open a terminal in this repo, and run `pip install -e "./packages/python-ta-z3" "./packages/python-ta[dev, cfg, z3, watchdog]"` to install the dependencies.
 3. Then run `pre-commit install` to install the pre-commit hooks (for automatically formatting and checking your code on each commit).
 
 While not strictly necessary for debugging, some debugging tools require [graphviz](https://www.graphviz.org/download/) to be installed on your system.

packages/python-ta/CHANGELOG.md

@@ -13,6 +13,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - Extended `RecursionTable` to handle mutual recursion by taking in a list of function names to trace. Updated table output format correspondingly to include a "function" key column.
 - Extended `unnecessary_f_string_checker.py` to present an alternate message when the input is already a string.
 - Extended `snapshot_to_json` behaviour to handle `type` instances and display the `repr` of the type.
+- Make `watchdog` an optional dependency; users can opt in with `pip install python-ta[watchdog]`. This affects runs of `python_ta.check_all` with the `watch` config option set to `True`.
 
 ### 💫 New checkers
 

packages/python-ta/docs/usage/configuration.md

@@ -153,6 +153,12 @@ For the **HTMLReporter**, this enables a persistent server that serves the PyTA
 
 When `false` (default), PythonTA performs a one-time analysis and exits after generating the report.
 
+> **Note:** This option requires the optional `watchdog` extra. Install it with:
+>
+> ```bash
+> pip install python-ta[watchdog]
+> ```
+
 ### `server-port` (default: `0`)
 
 The server-port option specifies the port number to use when serving the PyTA HTML report. When set to 0 (the default),

packages/python-ta/pyproject.toml

@@ -24,7 +24,6 @@ dependencies = [
     "tabulate ~= 0.9.0",
     "toml ~= 0.10.2",
     "typeguard >= 4.1.0, < 5",
-    "watchdog ~= 6.0.0",
     "wrapt >= 1.15.0, < 3"
 ]
 requires-python = ">=3.10"
@@ -47,6 +46,9 @@ dev = [
 cfg = [
     "graphviz",
 ]
+watchdog = [
+    "watchdog ~= 6.0.0",
+]
 z3 = [
     "python-ta-z3 == 2.13.0.dev",
     "z3-solver",

packages/python-ta/src/python_ta/__init__.py

@@ -43,7 +43,6 @@
     upload_linter_results,
     verify_pre_check,
 )
-from .check.watch import watch_files
 
 if TYPE_CHECKING:
     from .reporters.core import PythonTaReporter
@@ -182,6 +181,9 @@ def _check(
         if is_any_file_checked:
             linter.generate_reports()
             if linter.config.watch:
+                # import only when needed to avoid dragging in watchdog
+                from .check.watch import watch_files
+
                 watch_files(
                     file_paths=linted_files,
                     level=level,

packages/python-ta/src/python_ta/check/watch.py

@@ -6,8 +6,15 @@
 from typing import Any, Optional, Union
 
 from pylint.lint import PyLinter
-from watchdog.events import FileSystemEventHandler
-from watchdog.observers import Observer
+
+# ``watchdog`` is an optional extra. If someone imports this module without
+# installing the extra, we print an error message before raising the error.
+try:
+    from watchdog.events import FileSystemEventHandler
+    from watchdog.observers import Observer
+except ImportError:  # pragma: no cover - impossible to trigger in CI since extra is installed
+    print("ERROR: watch mode requires python-ta[watchdog] to be installed.")
+    raise
 
 from .helpers import check_file, upload_linter_results
 

packages/python-ta/src/python_ta/config/.pylintrc

@@ -30,6 +30,14 @@ allow-pylint-comments = no
 # Set whether the default error messages by pylint should be overwritten by PythonTA's custom messages
 use-pyta-error-messages = yes
 
+# Watch mode automatically re-runs checks when your files change.
+# To use watch mode install PythonTA with the `watchdog` extra:
+#
+#     pip install python-ta[watchdog]
+#
+# The default is `no` (disabled).
+watch = no
+
 [REPORTS]
 # The type of reporter to use to display results. Available PyTA options are
 # pyta-plain, pyta-color, pyta-html, pyta-json.