add 'info' command to cli

src/setuptools_scm/__main__.py

@@ -3,4 +3,4 @@
 from ._cli import main
 
 if __name__ == "__main__":
-    main()
+    raise SystemExit(main())

src/setuptools_scm/_cli.py

@@ -1,16 +1,19 @@
 from __future__ import annotations
 
 import argparse
+import json
 import os
 import sys
 
+from typing import Any
+
 from setuptools_scm import Configuration
 from setuptools_scm._file_finders import find_files
 from setuptools_scm._get_version_impl import _get_version
 from setuptools_scm.discover import walk_potential_roots
 
 
-def main(args: list[str] | None = None) -> None:
+def main(args: list[str] | None = None) -> int:
     opts = _get_cli_opts(args)
     inferred_root: str = opts.root or "."
 
@@ -38,11 +41,8 @@ def main(args: list[str] | None = None) -> None:
         raise SystemExit("ERROR: no version found for", opts)
     if opts.strip_dev:
         version = version.partition(".dev")[0]
-    print(version)
 
-    if opts.command == "ls":
-        for fname in find_files(config.root):
-            print(fname)
+    return command(opts, version, config)
 
 
 def _get_cli_opts(args: list[str] | None) -> argparse.Namespace:
@@ -69,6 +69,30 @@ def _get_cli_opts(args: list[str] | None) -> argparse.Namespace:
         action="store_true",
         help="remove the dev/local parts of the version before printing the version",
     )
+    parser.add_argument(
+        "-N",
+        "--no-version",
+        action="store_true",
+        help="do not include package version in the output",
+    )
+    output_formats = ["json", "plain", "key-value"]
+    parser.add_argument(
+        "-f",
+        "--format",
+        type=str.casefold,
+        default="plain",
+        help="specify output format",
+        choices=output_formats,
+    )
+    parser.add_argument(
+        "-q",
+        "--query",
+        type=str.casefold,
+        nargs="*",
+        help="display setuptools_scm settings according to query, "
+        "e.g. dist_name, do not supply an argument in order to "
+        "print a list of valid queries.",
+    )
     parser.add_argument(
         "--force-write-version-files",
         action="store_true",
@@ -77,11 +101,80 @@ def _get_cli_opts(args: list[str] | None) -> argparse.Namespace:
     )
     sub = parser.add_subparsers(title="extra commands", dest="command", metavar="")
     # We avoid `metavar` to prevent printing repetitive information
-    desc = "List files managed by the SCM"
+    desc = "List information about the package, e.g. included files"
     sub.add_parser("ls", help=desc[0].lower() + desc[1:], description=desc)
     return parser.parse_args(args)
 
 
+# flake8: noqa: C901
+def command(opts: argparse.Namespace, version: str, config: Configuration) -> int:
+    data: dict[str, Any] = {}
+
+    if opts.command == "ls":
+        opts.query = ["files"]
+
+    if opts.query == []:
+        opts.no_version = True
+        sys.stderr.write("Available queries:\n\n")
+        opts.query = ["queries"]
+        data["queries"] = ["files"] + list(config.__dataclass_fields__.keys())
+
+    if opts.query is None:
+        opts.query = []
+
+    if not opts.no_version:
+        data["version"] = version
+
+    if "files" in opts.query:
+        data["files"] = find_files(config.root)
+
+    for q in opts.query:
+        if q in ["files", "queries", "version"]:
+            continue
+
+        try:
+            if q.startswith("_"):
+                raise AttributeError()
+            data[q] = getattr(config, q)
+        except AttributeError:
+            sys.stderr.write(f"Error: unknown query: '{q}'\n")
+            return 1
+
+    if opts.format == "json":
+        print(json.dumps(data, indent=2))
+
+    if opts.format == "plain":
+        _print_plain(data)
+
+    if opts.format == "key-value":
+        _print_key_value(data)
+
+    return 0
+
+
+def _print_plain(data: dict[str, Any]) -> None:
+    version = data.pop("version", None)
+    if version:
+        print(version)
+    files = data.pop("files", [])
+    for file_ in files:
+        print(file_)
+    queries = data.pop("queries", [])
+    for query in queries:
+        print(query)
+    if data:
+        print("\n".join(data.values()))
+
+
+def _print_key_value(data: dict[str, Any]) -> None:
+    for key, value in data.items():
+        if isinstance(value, str):
+            print(f"{key} = {value}")
+        else:
+            str_value = "\n  ".join(value)
+            print(f"{key} = {str_value}")
+
+
 def _find_pyproject(parent: str) -> str:
     for directory in walk_potential_roots(os.path.abspath(parent)):
         pyproject = os.path.join(directory, "pyproject.toml")