From 990bbe32c14a367955ccc4264c2ac237b6a9adff Mon Sep 17 00:00:00 2001
From: Ruslan Kuprieiev <ruslan@iterative.ai>
Date: Tue, 2 Oct 2018 21:09:47 +0300
Subject: [PATCH] gc: add a comfirmation prompt

Signed-off-by: Ruslan Kuprieiev <ruslan@iterative.ai>
---
 dvc/cli.py        |  6 ++++++
 dvc/command/gc.py | 16 ++++++++++++++++
 tests/test_gc.py  |  3 ++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/dvc/cli.py b/dvc/cli.py
index bc29bc7ba..79320c743 100644
--- a/dvc/cli.py
+++ b/dvc/cli.py
@@ -541,6 +541,12 @@ def parse_args(argv=None):
                         '-r',
                         '--remote',
                         help='Remote repository to collect garbage in.')
+    gc_parser.add_argument(
+                        '-f',
+                        '--force',
+                        action='store_true',
+                        default=False,
+                        help='Force garbage collection.')
     gc_parser.set_defaults(func=CmdGC)
 
     # Config
diff --git a/dvc/command/gc.py b/dvc/command/gc.py
index a43a05bb9..fa05faf86 100644
--- a/dvc/command/gc.py
+++ b/dvc/command/gc.py
@@ -3,6 +3,22 @@ from dvc.command.base import CmdBase
 
 class CmdGC(CmdBase):
     def run(self):
+        msg = 'This will remove all cache except the cache that is used in '
+        if not self.args.all_branches and not self.args.all_tags:
+            msg += 'the current git branch.'
+        elif self.args.all_branches and not self.args.all_tags:
+            msg += 'all git branches.'
+        elif not self.args.all_branches and self.args.all_tags:
+            msg += 'all git tags.'
+        else:
+            msg += 'all git branches and all git tags.'
+
+        self.project.logger.warn(msg)
+
+        msg = 'Are you sure you want to proceed?'
+        if not self.args.force and not self.project.prompt.prompt(msg):
+            return 1
+
         self.project.gc(all_branches=self.args.all_branches,
                         all_tags=self.args.all_tags,
                         cloud=self.args.cloud,
diff --git a/tests/test_gc.py b/tests/test_gc.py
index b2276ea5e..52da378be 100644
--- a/tests/test_gc.py
+++ b/tests/test_gc.py
@@ -29,7 +29,8 @@ class TestGC(TestDvc):
         self._test_gc()
 
     def test_cli(self):
-        ret = main(['gc'])
+        ret = main(['gc', '-f'])
+        self.assertEqual(ret, 0)
         self._test_gc()
 
     def _test_gc(self):