Add JSON encoder (#6)

This command produces JSON output to be consumed by shell scripts via
the jq command.

README.md

@@ -17,6 +17,21 @@ The motivating use case for this project is
 [`pre-commit-hooks`](https://github.com/rapidsai/pre-commit-hooks), but other
 projects may certainly use it too.
 
+This package can also output the metadata in JSON form for consumption by
+external programs, such as shell scripts and `jq`. To get JSON output, run:
+
+```
+rapids-metadata-json
+```
+
+This will print the metadata for the RAPIDS version specified by the `VERSION`
+file in the current directory or above. If you wish to get metadata for all
+RAPIDS versions instead, run:
+
+```
+rapids-metadata-json --all-versions
+```
+
 ## Justification
 
 `pre-commit-hooks` has to know things about the structure of the RAPIDS project

pyproject.toml

@@ -27,6 +27,9 @@ classifiers = [
 ]
 requires-python = ">=3.9"
 
+[project.scripts]
+rapids-metadata-json = "rapids_metadata.json:main"
+
 [build-system]
 build-backend = "setuptools.build_meta"
 requires = [

src/rapids_metadata/__init__.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 from .metadata import (
-    PseudoRepository,
     RAPIDSMetadata,
     RAPIDSPackage,
     RAPIDSRepository,
@@ -28,7 +27,7 @@
 
 rapids_metadata.versions["24.08"] = RAPIDSVersion(
     repositories={
-        PseudoRepository.NVIDIA: RAPIDSRepository(
+        "_nvidia": RAPIDSRepository(
             packages={
                 "cubinlinker": RAPIDSPackage(),
             }

src/rapids_metadata/json.py

@@ -0,0 +1,64 @@
+# Copyright (c) 2024, NVIDIA CORPORATION.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import dataclasses
+import json
+import os
+import sys
+from typing import Any, Union
+
+from . import rapids_metadata
+from .metadata import (
+    RAPIDSMetadata,
+    RAPIDSPackage,
+    RAPIDSRepository,
+    RAPIDSVersion,
+)
+from .rapids_version import get_rapids_version
+
+
+__all__ = [
+    "main",
+]
+
+
+class _RAPIDSMetadataEncoder(json.JSONEncoder):
+    def default(
+        self, o: Union[RAPIDSMetadata, RAPIDSPackage, RAPIDSRepository, RAPIDSVersion]
+    ) -> dict[str, Any]:
+        return dataclasses.asdict(o)
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--all-versions", action="store_true")
+
+    parsed = parser.parse_args()
+    metadata = (
+        rapids_metadata
+        if parsed.all_versions
+        else RAPIDSMetadata(
+            versions={
+                get_rapids_version(os.getcwd()): rapids_metadata.get_current_version(
+                    os.getcwd()
+                )
+            }
+        )
+    )
+    json.dump(metadata, sys.stdout, cls=_RAPIDSMetadataEncoder)
+
+
+if __name__ == "__main__":
+    main()

src/rapids_metadata/metadata.py

@@ -13,29 +13,19 @@
 # limitations under the License.
 
 from dataclasses import dataclass, field
-from enum import Enum
 from os import PathLike
-from typing import Union
 
 from packaging.version import Version
 from .rapids_version import get_rapids_version
 
 __all__ = [
-    "PseudoRepository",
     "RAPIDSMetadata",
     "RAPIDSPackage",
     "RAPIDSRepository",
     "RAPIDSVersion",
 ]
 
 
-class PseudoRepository(Enum):
-    NVIDIA = "nvidia"
-
-    def __str__(self):
-        return f"_{self.value}"
-
-
 @dataclass
 class RAPIDSPackage:
     has_alpha_spec: bool = field(default=True)
@@ -49,9 +39,7 @@ class RAPIDSRepository:
 
 @dataclass
 class RAPIDSVersion:
-    repositories: dict[Union[str, PseudoRepository], RAPIDSRepository] = field(
-        default_factory=dict
-    )
+    repositories: dict[str, RAPIDSRepository] = field(default_factory=dict)
 
     @property
     def all_packages(self) -> set[str]: