#942: Add new git_branch_0v_to_dash_v rule

* fix fuckup `branch 0v` by...

...deleting branch `0v` and running `git branch -v` as the user intended

* use quotes consistently

* provide new  solution implementation based on feedback on PR

* rename files to more accurately reflect their more generic contents

* update import statement to match new file name

* update command name in README.md

* separate out matching tests so the pattern is clear for those who add matches in the future

README.md

@@ -231,6 +231,7 @@ following rules are enabled by default:
 * `git_branch_delete_checked_out` – changes `git branch -d` to `git checkout master && git branch -D` when trying to delete a checked out branch;
 * `git_branch_exists` – offers `git branch -d foo`, `git branch -D foo` or `git checkout foo` when creating a branch that already exists;
 * `git_branch_list` – catches `git branch list` in place of `git branch` and removes created branch;
+* `git_branch_flag_0_to_flag_dash_v` – undoes `git branch 0v` and runs `git branch -v` in its place;
 * `git_checkout` – fixes branch name or creates new branch;
 * `git_clone_git_clone` – replaces `git clone git clone ...` with `git clone ...`
 * `git_commit_amend` – offers `git commit --amend` after previous commit;

tests/rules/test_git_branch_flag_0_to_flag_dash_v.py

@@ -0,0 +1,22 @@
+import pytest
+from thefuck.rules.git_branch_flag_0_to_flag_dash_v import match, get_new_command
+from thefuck.types import Command
+
+
+@pytest.fixture
+def output():
+    return ""
+
+
+def test_match_git_branch_0v(output):
+    assert match(Command('git branch 0v', output))
+
+
+def test_matches_no__git_branch_0_anything(output):
+    assert not match(Command('git branch -v', ''))
+    assert not match(Command('ls', output))
+
+
+def test_get_new_command(output):
+    assert get_new_command(Command('git branch 0v', output))\
+        == 'git branch -D 0v && git branch -v'

thefuck/rules/git_branch_flag_0_to_flag_dash_v.py

@@ -0,0 +1,36 @@
+from thefuck.shells import shell
+from thefuck.specific.git import git_support
+from thefuck.utils import memoize
+
+'''
+keys are fatfingered entry, values are two-element tuples
+where the first element is "the fix" and the second element
+is "what you meant to do
+ '''
+# clunky when there's only one key, but as others get added, I _think_
+# this will be cleaner
+flags_and_their_fixes = dict()
+flags_and_their_fixes["v"] = ('git branch -D 0v', 'git branch -v')
+
+
+@memoize
+def _supported_flag_fix(command):
+    flag = command.script_parts[2:][0]
+
+    if len(flag) == 2 and flag.startswith("0"):
+        return flags_and_their_fixes[flag[1]]
+    else:
+        return None
+
+
+@git_support
+def match(command):
+    return (command.script_parts
+            and command.script_parts[1] == 'branch'
+            and _supported_flag_fix(command) is not None)
+
+
+@git_support
+def get_new_command(command):
+    fix_parts = _supported_flag_fix(command)
+    return shell.and_(fix_parts[0], fix_parts[1])