feat: Add option to delete preexisting files created by dfg each run …

…(#32)

This adds the ability to request that dfg erase any files it previously
created before generating new ones. This logic may be used to replace
cleanup logic already present in the tests as well as logic currently
embedded [in the GHA tool currently running
dfg](https://github.com/rapidsai/gha-tools/blob/37f3946294647eadf5b60d8229ac396a4d913b59/tools/rapids-dependency-file-checker#L9-L15).
Moving this logic directly into dfg will allow us to use its pre-commit
hook as the primary source of truth for how to run it, both locally and
in CI.

Contributes to
rapidsai/shared-workflows#46

---------

Co-authored-by: AJ Schmidt <ajschmidt8@users.noreply.github.com>

src/rapids_dependency_file_generator/cli.py

@@ -1,10 +1,14 @@
 import argparse
+import os
 
 import yaml
 
 from ._version import __version__ as version
 from .constants import OutputTypes, default_dependency_file_path
-from .rapids_dependency_file_generator import make_dependency_files
+from .rapids_dependency_file_generator import (
+    delete_existing_files,
+    make_dependency_files,
+)
 from .rapids_dependency_file_validator import validate_dependencies
 
 
@@ -17,6 +21,17 @@ def validate_args(argv):
         default=default_dependency_file_path,
         help="Path to YAML config file",
     )
+    parser.add_argument(
+        "--clean",
+        nargs="?",
+        default=None,
+        const="",
+        help=(
+            "Delete any files previously created by dfg before running. An optional "
+            "path to clean may be provided, otherwise the current working directory "
+            "is used as the root from which to clean."
+        ),
+    )
 
     codependent_args = parser.add_argument_group("optional, but codependent")
     codependent_args.add_argument(
@@ -45,6 +60,11 @@ def validate_args(argv):
             + "".join([f"\n  --{x}" for x in dependent_arg_keys])
         )
 
+    # If --clean was passed without arguments, default to cleaning from the root of the
+    # tree where the config file is.
+    if args.clean == "":
+        args.clean = os.path.dirname(os.path.abspath(args.config))
+
     return args
 
 
@@ -79,4 +99,6 @@ def main(argv=None):
             }
         }
 
+    if args.clean:
+        delete_existing_files(args.clean)
     make_dependency_files(parsed_config, args.config, to_stdout)

src/rapids_dependency_file_generator/rapids_dependency_file_generator.py

@@ -15,6 +15,27 @@
 
 OUTPUT_ENUM_VALUES = [str(x) for x in OutputTypes]
 NON_NONE_OUTPUT_ENUM_VALUES = [str(x) for x in OutputTypes if not x == OutputTypes.NONE]
+HEADER = f"# This file is generated by `{cli_name}`."
+
+
+def delete_existing_files(root="."):
+    """Delete any files generated by this generator.
+
+    This function can be used to clean up a directory tree before generating a new set
+    of files from scratch.
+
+    Parameters
+    ----------
+    root : str
+        The path to the root of the directory tree to search for files to delete.
+    """
+    for dirpath, _, filenames in os.walk(root):
+        for fn in filter(
+            lambda fn: fn.endswith(".txt") or fn.endswith(".yaml"), filenames
+        ):
+            with open(file_path := os.path.join(dirpath, fn)) as f:
+                if HEADER in f.read():
+                    os.remove(file_path)
 
 
 def dedupe(dependencies):
@@ -94,7 +115,7 @@ def make_dependency_file(
     relative_path_to_config_file = os.path.relpath(config_file, output_dir)
     file_contents = textwrap.dedent(
         f"""\
-        # This file is generated by `{cli_name}`.
+        {HEADER}
         # To make changes, edit {relative_path_to_config_file} and run `{cli_name}`.
         """
     )

tests/test_examples.py

@@ -1,7 +1,5 @@
 import glob
-import os
 import pathlib
-import shutil
 
 import jsonschema
 import pytest
@@ -20,13 +18,6 @@
 INVALID_EXAMPLE_FILES = list(CURRENT_DIR.glob("examples/invalid/*/dependencies.yaml"))
 
 
-@pytest.fixture(scope="session", autouse=True)
-def clean_actual_files():
-    for root, _, _ in os.walk("tests"):
-        if pathlib.Path(root).name == "actual":
-            shutil.rmtree(root)
-
-
 def make_file_set(file_dir):
     return {
         pathlib.Path(f).relative_to(file_dir)
@@ -56,7 +47,14 @@ def test_examples(example_dir):
     actual_dir = example_dir.joinpath("output", "actual")
     dep_file_path = example_dir.joinpath("dependencies.yaml")
 
-    main(["--config", str(dep_file_path)])
+    main(
+        [
+            "--config",
+            str(dep_file_path),
+            "--clean",
+            str(example_dir.joinpath("output", "actual")),
+        ]
+    )
 
     expected_file_set = make_file_set(expected_dir)
     actual_file_set = make_file_set(actual_dir)
@@ -75,7 +73,14 @@ def test_error_examples(test_name):
     dep_file_path = test_dir.joinpath("dependencies.yaml")
 
     with pytest.raises(ValueError):
-        main(["--config", str(dep_file_path)])
+        main(
+            [
+                "--config",
+                str(dep_file_path),
+                "--clean",
+                str(test_dir.joinpath("output", "actual")),
+            ]
+        )
 
 
 def test_examples_are_valid(schema, example_dir):