completion: support completing config variables (#10864)

Author: skshetry

dvc/cli/completion.py

@@ -27,6 +27,10 @@
     local _dvc_remotes=($(dvc remote list | cut -d' ' -f1))
     compgen -W "${_dvc_remotes[*]}" -- $1
 }
+
+_dvc_compgen_config_vars() {
+    compgen -W "${_dvc_config_vars[*]}" -- $1
+}
 """
 
 ZSH_PREAMBLE = """
@@ -64,6 +68,10 @@
 _dvc_compadd_remotes() {
     _describe 'remotes' "($(dvc remote list | cut -d' ' -f1))"
 }
+
+_dvc_compadd_config_vars() {
+    _describe 'config_vars' _dvc_config_vars
+}
 """
 
 PREAMBLE = {
@@ -81,3 +89,21 @@
 }
 EXPERIMENT = {"bash": "_dvc_compgen_exps", "zsh": "_dvc_compadd_exps"}
 REMOTE = {"bash": "_dvc_compgen_remotes", "zsh": "_dvc_compadd_remotes"}
+CONFIG_VARS = {"bash": "_dvc_compgen_config_vars", "zsh": "_dvc_compadd_config_vars"}
+
+
+def get_preamble() -> dict[str, str]:
+    from dvc.config_schema import config_vars_for_completion
+
+    ret: dict[str, str] = {}
+    config_vars = list(config_vars_for_completion())
+
+    nl = "\n\t".expandtabs(4)
+    config_vars_arr = f"""
+_dvc_config_vars=(
+    {nl.join(config_vars)}
+)
+"""
+    for shell, preamble in PREAMBLE.items():
+        ret[shell] = config_vars_arr + preamble
+    return ret

dvc/commands/completion.py

@@ -1,6 +1,6 @@
 from dvc.cli import formatter
 from dvc.cli.command import CmdBaseNoRepo
-from dvc.cli.completion import PREAMBLE
+from dvc.cli.completion import get_preamble
 from dvc.cli.utils import append_doc_link
 from dvc.log import logger
 from dvc.ui import ui
@@ -17,7 +17,7 @@ def run(self):
 
         shell = self.args.shell
         parser = self.args.parser
-        script = shtab.complete(parser, shell=shell, preamble=PREAMBLE)
+        script = shtab.complete(parser, shell=shell, preamble=get_preamble())
         ui.write(script, force=True)
         return 0
 

dvc/commands/config.py

@@ -3,7 +3,7 @@
 
 from funcy import set_in
 
-from dvc.cli import formatter
+from dvc.cli import completion, formatter
 from dvc.cli.command import CmdBaseNoRepo
 from dvc.cli.utils import append_doc_link
 from dvc.log import logger
@@ -224,7 +224,7 @@ def add_parser(subparsers, parent_parser):
         nargs="?",
         type=_name_type,
         help="Option name (section.option or remote.name.option).",
-    )
+    ).complete = completion.CONFIG_VARS
     config_parser.add_argument("value", nargs="?", help="Option value.")
     config_parser.add_argument(
         "-l",