Merge branch 'git-branch-exists' of https://github.com/scorphus/thefuck into scorphus-git-branch-exists

README.md

@@ -157,6 +157,7 @@ using the matched rule and runs it. Rules enabled by default are as follows:
 * `fix_file` – opens a file with an error in your `$EDITOR`;
 * `git_add` – fixes *"pathspec 'foo' did not match any file(s) known to git."*;
 * `git_branch_delete` – changes `git branch -d` to `git branch -D`;
+* `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_checkout` – fixes branch name or creates new branch;
 * `git_diff_staged` – adds `--staged` to previous `git diff` with unexpected output;

tests/rules/test_git_branch_exists.py

@@ -0,0 +1,33 @@
+import pytest
+from thefuck.rules.git_branch_exists import match, get_new_command
+from tests.utils import Command
+
+
+@pytest.fixture
+def stderr(branch_name):
+    return "fatal: A branch named '{}' already exists.".format(branch_name)
+
+
+@pytest.fixture
+def new_command(branch_name):
+    return [cmd.format(branch_name) for cmd in [
+        'git branch -d {0} && git branch {0}',
+        'git branch -D {0} && git branch {0}', 'git checkout {0}']]
+
+
+@pytest.mark.parametrize('script, branch_name', [
+    ('git branch foo', 'foo'),
+    ('git branch bar', 'bar')])
+def test_match(stderr, script, branch_name):
+    assert match(Command(script=script, stderr=stderr))
+
+
+@pytest.mark.parametrize('script', ['git branch foo', 'git branch bar'])
+def test_not_match(script):
+    assert not match(Command(script=script, stderr=''))
+
+
+@pytest.mark.parametrize('script, branch_name, ', [
+    ('git branch foo', 'foo'), ('git branch bar', 'bar')])
+def test_get_new_command(stderr, new_command, script, branch_name):
+    assert get_new_command(Command(script=script, stderr=stderr)) == new_command

thefuck/rules/git_branch_exists.py

@@ -0,0 +1,21 @@
+import re
+from thefuck.shells import shell
+from thefuck.specific.git import git_support
+
+
+@git_support
+def match(command):
+    return ('branch' in command.script
+            and "fatal: A branch named '" in command.stderr
+            and " already exists." in command.stderr)
+
+
+@git_support
+def get_new_command(command):
+    branch_name = re.findall(
+        r"fatal: A branch named '([^']*)' already exists.", command.stderr)[0]
+    return_ = [shell.and_(*cmd_list).format(branch_name) for cmd_list in [
+        ['git branch -d {0}', 'git branch {0}'],
+        ['git branch -D {0}', 'git branch {0}'],
+        ['git checkout {0}']]]
+    return return_