Fix fish shell aliasing (#753)

* Handle user defined fish aliases

* Add more aliases to test

* Revert unecessary Popen mock changes

* Add test for fish aliasing

Fixes #727

tests/shells/test_fish.py

@@ -13,9 +13,10 @@ class TestFish(object):
     @pytest.fixture(autouse=True)
     def Popen(self, mocker):
         mock = mocker.patch('thefuck.shells.fish.Popen')
-        mock.return_value.stdout.read.return_value = (
+        mock.return_value.stdout.read.side_effect = [(
             b'cd\nfish_config\nfuck\nfunced\nfuncsave\ngrep\nhistory\nll\nls\n'
-            b'man\nmath\npopd\npushd\nruby')
+            b'man\nmath\npopd\npushd\nruby'),
+            b'alias fish_key_reader /usr/bin/fish_key_reader\nalias g git']
         return mock
 
     @pytest.mark.parametrize('key, value', [
@@ -42,7 +43,8 @@ class TestFish(object):
         ('open', 'open'),
         ('vim', 'vim'),
         ('ll', 'fish -ic "ll"'),
-        ('ls', 'ls')])  # Fish has no aliases but functions
+        ('ls', 'ls'),
+        ('g', 'git')])
     def test_from_shell(self, before, after, shell):
         assert shell.from_shell(before) == after
 
@@ -65,7 +67,9 @@ class TestFish(object):
                                        'math': 'math',
                                        'popd': 'popd',
                                        'pushd': 'pushd',
-                                       'ruby': 'ruby'}
+                                       'ruby': 'ruby',
+                                       'g': 'git',
+                                       'fish_key_reader': '/usr/bin/fish_key_reader'}
 
     def test_app_alias(self, shell):
         assert 'function fuck' in shell.app_alias('fuck')

thefuck/shells/fish.py

@@ -10,12 +10,24 @@ from .generic import Generic
 
 
 @cache('~/.config/fish/config.fish', '~/.config/fish/functions')
-def _get_aliases(overridden):
+def _get_functions(overridden):
     proc = Popen(['fish', '-ic', 'functions'], stdout=PIPE, stderr=DEVNULL)
     functions = proc.stdout.read().decode('utf-8').strip().split('\n')
     return {func: func for func in functions if func not in overridden}
 
 
+@cache('~/.config/fish/config.fish')
+def _get_aliases(overridden):
+    aliases = {}
+    proc = Popen(['fish', '-ic', 'alias'], stdout=PIPE, stderr=DEVNULL)
+    alias_out = proc.stdout.read().decode('utf-8').strip().split('\n')
+    for alias in alias_out:
+        name, value = alias.replace('alias ', '', 1).split(' ', 1)
+        if name not in overridden:
+            aliases[name] = value
+    return aliases
+
+
 class Fish(Generic):
     def _get_overridden_aliases(self):
         overridden = os.environ.get('THEFUCK_OVERRIDDEN_ALIASES',
@@ -44,12 +56,17 @@ class Fish(Generic):
 
     def get_aliases(self):
         overridden = self._get_overridden_aliases()
-        return _get_aliases(overridden)
+        functions = _get_functions(overridden)
+        raw_aliases = _get_aliases(overridden)
+        functions.update(raw_aliases)
+        return functions
 
     def _expand_aliases(self, command_script):
         aliases = self.get_aliases()
         binary = command_script.split(' ')[0]
-        if binary in aliases:
+        if binary in aliases and aliases[binary] != binary:
+            return command_script.replace(binary, aliases[binary], 1)
+        elif binary in aliases:
             return u'fish -ic "{}"'.format(command_script.replace('"', r'\"'))
         else:
             return command_script