Adds utils/gen-commands-json.py (#9958)

Following #9656, this script generates a "commands.json" file from the output
of the new COMMAND. The output of this script is used in redis/redis-doc#1714
and by redis/redis-io#259. This also converts a couple of rogue dashes (in 
'key-specs' and 'multiple-token' flags) to underscores (continues #9959).

1 files changed, 114 insertions, 0 deletions

diff --git a/utils/generate-commands-json.py b/utils/generate-commands-json.py
new file mode 100755
index 000000000..8e6d915df
--- /dev/null
+++ b/utils/generate-commands-json.py
@@ -0,0 +1,114 @@
+#!/usr/bin/env python
+import argparse
+import json
+from collections import OrderedDict
+from sys import argv, stdin
+
+def convert_flags_to_boolean_dict(flags):
+    """Return a dict with a key set to `True` per element in the flags list."""
+    return {f: True for f in flags}
+
+
+def set_if_not_none_or_empty(dst, key, value):
+    """Set 'key' in 'dst' if 'value' is not `None` or an empty list."""
+    if value is not None and (type(value) is not list or len(value)):
+        dst[key] = value
+
+
+def convert_argument(arg):
+    """Transform an argument."""
+    arg.update(convert_flags_to_boolean_dict(arg.pop('flags', [])))
+    set_if_not_none_or_empty(arg, 'arguments', 
+                            [convert_argument(x) for x in arg.pop('arguments',[])])
+    return arg
+
+
+def convert_keyspec(spec):
+    """Transform a key spec."""
+    spec.update(convert_flags_to_boolean_dict(spec.pop('flags', [])))
+    return spec
+
+
+def convert_entry_to_objects_array(container, cmd):
+    """Transform the JSON output of `COMMAND` to a friendlier format.
+
+    `COMMAND`'s output per command is a fixed-size (8) list as follows:
+    1. Name (lower case, e.g. "lolwut")
+    2. Arity
+    3. Flags
+    4-6. First/last/step key specification (deprecated as of Redis v7.0)
+    7. ACL categories
+    8. A dict of meta information (as of Redis 7.0)
+
+    This returns a list with a dict for the command and per each of its
+    subcommands. Each dict contains one key, the command's full name, with a
+    value of a dict that's set with the command's properties and meta
+    information."""
+    assert len(cmd) >= 8
+    obj = {}
+    rep = [obj]
+    name = cmd[0].upper()
+    arity = cmd[1]
+    command_flags = cmd[2]
+    acl_categories   = cmd[6]
+    meta = cmd[7]
+    key = f'{container} {name}' if container else name
+
+    rep.extend([convert_entry_to_objects_array(name, x)[0] for x in meta.pop('subcommands', [])])
+
+    # The command's value is ordered so the interesting stuff that we care about
+    # is at the start. Optional `None` and empty list values are filtered out.
+    value = OrderedDict()
+    value['summary'] = meta.pop('summary')
+    value['since'] = meta.pop('since')
+    value['group'] = meta.pop('group')
+    set_if_not_none_or_empty(value, 'complexity', meta.pop('complexity', None))
+    set_if_not_none_or_empty(value, 'deprecated_since', meta.pop('deprecated_since', None))
+    set_if_not_none_or_empty(value, 'replaced_by', meta.pop('replaced_by', None))
+    set_if_not_none_or_empty(value, 'history', meta.pop('history', []))
+    set_if_not_none_or_empty(value, 'acl_categories', acl_categories)
+    value['arity'] = arity
+    set_if_not_none_or_empty(value, 'key_specs', 
+                            [convert_keyspec(x) for x in meta.pop('key_specs',[])])
+    set_if_not_none_or_empty(value, 'arguments',
+                            [convert_argument(x) for x in meta.pop('arguments', [])])
+    set_if_not_none_or_empty(value, 'command_flags', command_flags)
+    set_if_not_none_or_empty(value, 'doc_flags', meta.pop('doc_flags', []))
+    set_if_not_none_or_empty(value, 'hints', meta.pop('hints', []))
+
+    # All remaining meta key-value tuples, if any, are appended to the command
+    # to be future-proof.
+    while len(meta) > 0:
+        (k, v) = meta.popitem()
+        value[k] = v
+
+    obj[key] = value
+    return rep
+
+
+# MAIN
+if __name__ == '__main__':
+    opts = {
+        'description': 'Transform the output from `redis-cli --json COMMAND` to commands.json format.',
+        'epilog': f'Usage example: src/redis-cli --json COMMAND | {argv[0]}'
+    }
+    parser = argparse.ArgumentParser(**opts)
+    parser.add_argument('input', help='JSON-formatted input file (default: stdin)',
+                        nargs='?', type=argparse.FileType(), default=stdin)
+    args = parser.parse_args()
+
+    payload = OrderedDict()
+    commands = []
+    data = json.load(args.input)
+
+    for entry in data:
+        cmds = convert_entry_to_objects_array(None, entry)
+        commands.extend(cmds)
+
+    # The final output is a dict of all commands, ordered by name.
+    commands.sort(key=lambda x: list(x.keys())[0])
+    for cmd in commands:
+        name = list(cmd.keys())[0]
+        payload[name] = cmd[name]
+
+    print(json.dumps(payload, indent=4))