chore: Update owlbot.py to only format changed files (#10310)

Author: holtskinner

owlbot.py

@@ -12,30 +12,91 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from logging import Logger
+from pathlib import Path
+import re
+import subprocess
+
 import synthtool as s
 import synthtool.gcp as gcp
+from synthtool.log import logger
+
+logger: Logger = logger
+
+_EXCLUDED_DIRS = [r"^\."]
+
+
+def walk_through_owlbot_dirs(dir: Path, search_for_changed_files: bool) -> list[str]:
+    """
+    Walks through all sample directories
+    Returns:
+    A list of directories
+    """
+    owlbot_dirs: list[str] = []
+    packages_to_exclude = _EXCLUDED_DIRS
+    if search_for_changed_files:
+        try:
+            # Need to run this step first in the post processor since we only clone
+            # the branch the PR is on in the Docker container
+            output = subprocess.run(
+                ["git", "fetch", "origin", "main:main", "--deepen=200"], check=False
+            )
+            output.check_returncode()
+        except subprocess.CalledProcessError as error:
+            if error.returncode == 128:
+                logger.info(f"Error: ${error.output}; skipping fetching main")
+            else:
+                raise error
+    for path_object in dir.glob("**/requirements.txt"):
+        object_dir = str(Path(path_object).parents[0])
+        if (
+            path_object.is_file()
+            and object_dir != str(dir)
+            and not re.search(
+                "(?:% s)" % "|".join(packages_to_exclude), str(Path(path_object))
+            )
+        ):
+            if search_for_changed_files:
+                if (
+                    subprocess.run(
+                        ["git", "diff", "--quiet", "main...", object_dir], check=False
+                    ).returncode
+                    == 1
+                ):
+                    owlbot_dirs.append(object_dir)
+            else:
+                owlbot_dirs.append(object_dir)
+    for path_object in dir.glob("owl-bot-staging/*"):
+        owlbot_dirs.append(
+            f"{Path(path_object).parents[1]}/packages/{Path(path_object).name}"
+        )
+    return owlbot_dirs
+
 
 templated_files = gcp.CommonTemplates().py_library()
 
 # Copy the standard noxfile from templated_files
 s.move(templated_files / "noxfile.py")
 
-# Update BLACK_PATHS in order to run black on all files
-s.replace(
-    "noxfile.py",
-    r"""LINT_PATHS = \["docs", "google", "tests", "noxfile.py", "setup.py"\]""",
-    r"""LINT_PATHS = ["."]""",
-)
-
-# TODO: Remove once https://github.com/googleapis/synthtool/pull/1811 is merged.
-s.replace(
-    "noxfile.py",
-    r"""BLACK_VERSION = "black==22.3.0"\nISORT_VERSION = "isort==5.10.1""",
-    r"""BLACK_VERSION = "black[jupyter]==23.3.0"\nISORT_VERSION = "isort==5.11.0""",
-)
-
-# ----------------------------------------------------------------------------
-# Run blacken session
-# ----------------------------------------------------------------------------
-
-s.shell.run(["nox", "-s", "blacken"], hide_output=False)
+dirs: list[str] = walk_through_owlbot_dirs(Path.cwd(), search_for_changed_files=True)
+if dirs:
+    lint_paths = ", ".join(f'"{d}"' for d in dirs)
+    # Update LINT_PATHS in order to run black on changed files
+    s.replace(
+        "noxfile.py",
+        r"""LINT_PATHS = \["docs", "google", "tests", "noxfile.py", "setup.py"\]""",
+        f"""LINT_PATHS = [{lint_paths}]""",
+    )
+
+    # TODO: Remove once https://github.com/googleapis/synthtool/pull/1811 is merged.
+    s.replace(
+        "noxfile.py",
+        r"""BLACK_VERSION = "black==22.3.0"\nISORT_VERSION = "isort==5.10.1""",
+        r"""BLACK_VERSION = "black[jupyter]==23.3.0"\nISORT_VERSION = "isort==5.11.0""",
+    )
+
+    # ----------------------------------------------------------------------------
+    # Run blacken session
+    # ----------------------------------------------------------------------------
+
+    s.shell.run(["nox", "-s", "blacken"], hide_output=False)