From 15e13d7c1a3b5733c84139e89b09d105bb70de93 Mon Sep 17 00:00:00 2001
From: Pablo Santiago Blum de Aguiar <scorphus@gmail.com>
Date: Fri, 29 May 2015 18:38:01 -0300
Subject: [PATCH] add(rule): add the new git_diff_staged rule

---
 README.md                           |  1 +
 tests/rules/test_git_diff_staged.py | 27 +++++++++++++++++++++++++++
 thefuck/rules/git_diff_staged.py    |  6 ++++++
 3 files changed, 34 insertions(+)
 create mode 100644 tests/rules/test_git_diff_staged.py
 create mode 100644 thefuck/rules/git_diff_staged.py

diff --git a/README.md b/README.md
index 742ae9cf..06d8f18b 100644
--- a/README.md
+++ b/README.md
@@ -159,6 +159,7 @@ using the matched rule and runs it. Rules enabled by default are as follows:
 * `java` &ndash; removes `.java` extension when running Java programs;
 * `git_add` &ndash; fix *"Did you forget to 'git add'?"*;
 * `git_checkout` &ndash; creates the branch before checking-out;
+* `git_diff_staged` &ndash; adds `--staged` to previous `git diff` with unexpected output;
 * `git_no_command` &ndash; fixes wrong git commands like `git brnch`;
 * `git_pull` &ndash; sets upstream before executing previous `git pull`;
 * `git_push` &ndash; adds `--set-upstream origin $branch` to previous failed `git push`;
diff --git a/tests/rules/test_git_diff_staged.py b/tests/rules/test_git_diff_staged.py
new file mode 100644
index 00000000..93fe2536
--- /dev/null
+++ b/tests/rules/test_git_diff_staged.py
@@ -0,0 +1,27 @@
+import pytest
+from thefuck.rules.git_diff_staged import match, get_new_command
+from tests.utils import Command
+
+
+@pytest.mark.parametrize('command', [
+    Command(script='git diff'),
+    Command(script='git df'),
+    Command(script='git ds')])
+def test_match(command):
+    assert match(command, None)
+
+
+@pytest.mark.parametrize('command', [
+    Command(script='git tag'),
+    Command(script='git branch'),
+    Command(script='git log')])
+def test_not_match(command):
+    assert not match(command, None)
+
+
+@pytest.mark.parametrize('command, new_command', [
+    (Command('git diff'), 'git diff --staged'),
+    (Command('git df'), 'git df --staged'),
+    (Command('git ds'), 'git ds --staged')])
+def test_get_new_command(command, new_command):
+    assert get_new_command(command, None) == new_command
diff --git a/thefuck/rules/git_diff_staged.py b/thefuck/rules/git_diff_staged.py
new file mode 100644
index 00000000..32e5dcbb
--- /dev/null
+++ b/thefuck/rules/git_diff_staged.py
@@ -0,0 +1,6 @@
+def match(command, settings):
+    return command.script.startswith('git d')
+
+
+def get_new_command(command, settings):
+    return '{} --staged'.format(command.script)