From fef8ea4602f2112cbc3cd1a08c650cda143379e2 Mon Sep 17 00:00:00 2001
From: Ruslan Kuprieiev <kupruser@gmail.com>
Date: Sun, 15 Jul 2018 18:09:36 +0300
Subject: [PATCH] dvc: add confirmation for `dvc destroy`

Signed-off-by: Ruslan Kuprieiev <ruslan@iterative.ai>
---
 dvc/cli.py             |  5 +++++
 dvc/command/destroy.py | 13 ++++++++++++-
 dvc/prompt.py          | 18 ++++++++++++++++++
 tests/test_destroy.py  | 21 +++++++++++++++++++++
 4 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 dvc/prompt.py
 create mode 100644 tests/test_destroy.py

diff --git a/dvc/cli.py b/dvc/cli.py
index 3be482007..7836f4c84 100644
--- a/dvc/cli.py
+++ b/dvc/cli.py
@@ -94,6 +94,11 @@ def parse_args(argv=None):
                         'destroy',
                         parents=[parent_parser],
                         help='Destroy dvc')
+    destroy_parser.add_argument('-f',
+                        '--force',
+                        action='store_true',
+                        default=False,
+                        help='Force destruction')
     destroy_parser.set_defaults(func=CmdDestroy)
 
 
diff --git a/dvc/command/destroy.py b/dvc/command/destroy.py
index 8d2a719db..5308239bc 100644
--- a/dvc/command/destroy.py
+++ b/dvc/command/destroy.py
@@ -1,9 +1,20 @@
 from dvc.command.common.base import CmdBase
+from dvc.prompt import prompt
 
 
 class CmdDestroy(CmdBase):
-    def run(self):
+    def run_cmd(self):
         try:
+            msg = u'This will destroy all information about your pipelines as ' \
+                  u'well as cache in .dvc/cache.\n' \
+                  u'Are you sure you want to continue?'
+
+            if not self.args.force and not prompt(msg, False):
+                err = u'Cannot destroy without a confirmation from the user. ' \
+                      u'Use \'-f\' to force.'
+                self.project.logger.error(err)
+                return 1
+
             self.project.destroy()
         except Exception as exc:
             self.project.logger.error('Failed to destroy DVC', exc)
diff --git a/dvc/prompt.py b/dvc/prompt.py
new file mode 100644
index 000000000..f8befe411
--- /dev/null
+++ b/dvc/prompt.py
@@ -0,0 +1,18 @@
+import sys
+
+try:
+    # NOTE: in Python3 raw_input() was renamed to input()
+    input = raw_input
+except NameError:
+    pass
+
+
+def prompt(msg, default=False):
+    if not sys.stdout.isatty():
+        return default
+
+    answer = input(msg + u'\n').lower()
+    while answer not in ['yes', 'no', 'y', 'n']:
+        answer = input('Enter \'yes\' or \'no\'.\n').lower()
+
+    return answer[0] == "y"
diff --git a/tests/test_destroy.py b/tests/test_destroy.py
new file mode 100644
index 000000000..cd45e43f2
--- /dev/null
+++ b/tests/test_destroy.py
@@ -0,0 +1,21 @@
+import os
+
+from dvc.main import main
+
+from tests.test_repro import TestRepro
+
+
+class TestDestroyNoConfirmation(TestRepro):
+    def test(self):
+        ret = main(['destroy'])
+        self.assertNotEqual(ret, 0)
+
+
+class TestDestroyForce(TestRepro):
+    def test(self):
+        ret = main(['destroy', '-f'])
+        self.assertEqual(ret, 0)
+
+        self.assertFalse(os.path.exists(self.dvc.dvc_dir))
+        self.assertFalse(os.path.exists(self.file1_stage))
+        self.assertFalse(os.path.exists(self.file1))