apply: add --no-force deprecation message

dvc/commands/experiments/apply.py

@@ -4,12 +4,20 @@ import logging
 from dvc.cli import completion
 from dvc.cli.command import CmdBase
 from dvc.cli.utils import append_doc_link
+from dvc.ui import ui
 
 logger = logging.getLogger(__name__)
 
 
 class CmdExperimentsApply(CmdBase):
     def run(self):
+        if not self.args.force:
+            ui.write(
+                "The --no-force option is deprecated and will be removed in a future"
+                " DVC release. To revert the result of 'exp apply', run:\n"
+                "\n\tgit reset --hard\n"
+                "\tgit stash apply refs/exps/apply/stash\n"
+            )
         self.repo.experiments.apply(self.args.experiment)
 
         return 0
@@ -24,6 +32,12 @@ def add_parser(experiments_subparsers, parent_parser):
         help=EXPERIMENTS_APPLY_HELP,
         formatter_class=argparse.RawDescriptionHelpFormatter,
     )
+    experiments_apply_parser.add_argument(
+        "--no-force",
+        action="store_false",
+        dest="force",
+        help="Fail if this command would overwrite conflicting changes.",
+    )
     experiments_apply_parser.add_argument(
         "experiment", help="Experiment to be applied."
     ).complete = completion.EXPERIMENT

tests/unit/command/test_experiments.py

@@ -27,7 +27,7 @@ from .test_repro import common_arguments as repro_arguments
 
 
 def test_experiments_apply(dvc, scm, mocker):
-    cli_args = parse_args(["experiments", "apply", "--no-force", "exp_rev"])
+    cli_args = parse_args(["experiments", "apply", "exp_rev"])
     assert cli_args.func == CmdExperimentsApply
 
     cmd = cli_args.func(cli_args)
@@ -35,7 +35,7 @@ def test_experiments_apply(dvc, scm, mocker):
 
     assert cmd.run() == 0
 
-    m.assert_called_once_with(cmd.repo, "exp_rev", force=False)
+    m.assert_called_once_with(cmd.repo, "exp_rev")
 
 
 def test_experiments_diff(dvc, scm, mocker):