Merge branch 'dfadev-master'

README.md

@@ -259,6 +259,7 @@ using the matched rule and runs it. Rules enabled by default are as follows:
 * `workon_doesnt_exists` – fixes `virtualenvwrapper` env name os suggests to create new.
 * `yarn_alias` – fixes aliased `yarn` commands like `yarn ls`;
 * `yarn_command_not_found` – fixes misspelled `yarn` commands;
+* `yarn_command_replaced` – fixes replaced `yarn` commands;
 * `yarn_help` – makes it easier to open `yarn` documentation;
 
 Enabled by default only on specific platforms:

tests/rules/test_yarn_command_replaced.py

@@ -0,0 +1,32 @@
+import pytest
+from tests.utils import Command
+from thefuck.rules.yarn_command_replaced import match, get_new_command
+
+
+stderr = ('error `install` has been replaced with `add` to add new '
+          'dependencies. Run "yarn add {}" instead.').format
+
+
+@pytest.mark.parametrize('command', [
+    Command(script='yarn install redux', stderr=stderr('redux')),
+    Command(script='yarn install moment', stderr=stderr('moment')),
+    Command(script='yarn install lodash', stderr=stderr('lodash'))])
+def test_match(command):
+    assert match(command)
+
+
+@pytest.mark.parametrize('command', [
+    Command('yarn install')])
+def test_not_match(command):
+    assert not match(command)
+
+
+@pytest.mark.parametrize('command, new_command', [
+    (Command('yarn install redux', stderr=stderr('redux')),
+     'yarn add redux'),
+    (Command('yarn install moment', stderr=stderr('moment')),
+     'yarn add moment'),
+    (Command('yarn install lodash', stderr=stderr('lodash')),
+     'yarn add lodash')])
+def test_get_new_command(command, new_command):
+    assert get_new_command(command) == new_command

thefuck/rules/yarn_command_replaced.py

@@ -0,0 +1,13 @@
+import re
+from thefuck.utils import for_app
+
+regex = re.compile(r'Run "(.*)" instead')
+
+
+@for_app('yarn', at_least=1)
+def match(command):
+    return regex.findall(command.stderr)
+
+
+def get_new_command(command):
+    return regex.findall(command.stderr)[0]