New config: More powerful :config- commands: remove

- `:config-remove-list` command to remove items from a list.
- `:config-remove-dict` command to remove items from a dict.
- Test coverage.

Continues #2794

qutebrowser/config/configcommands.py

@@ -300,6 +300,59 @@ class ConfigCommands:
             option_value[key] = value
             self._config.update_mutables(save_yaml=not temp)
 
+    @cmdutils.register(instance='config-commands')
+    @cmdutils.argument('option', completion=configmodel.list_option)
+    def config_remove_list(self, option, value, temp=False):
+        """Remove a value from a list.
+
+        Args:
+            option: The name of the option.
+            value: The value to remove from the list.
+            temp: Set value temporarily until qutebrowser is closed.
+        """
+        opt = self._config.get_opt(option)
+        valid_list_types = (configtypes.List, configtypes.ListOrValue)
+        if not isinstance(opt.typ, valid_list_types):
+            raise cmdexc.CommandError(":config-remove-list can only be used "
+                                      "for lists")
+
+        with self._handle_config_error():
+            option_value = self._config.get_mutable_obj(option)
+
+            if value not in option_value:
+                raise cmdexc.CommandError("{} is not in {}!".format(value,
+                                                                    option))
+
+            option_value.remove(value)
+
+            self._config.update_mutables(save_yaml=not temp)
+
+    @cmdutils.register(instance='config-commands')
+    @cmdutils.argument('option', completion=configmodel.dict_option)
+    def config_remove_dict(self, option, key, temp=False):
+        """Remove a key from a dict.
+
+        Args:
+            option: The name of the option.
+            key: The key to remove from the dict.
+            temp: Set value temporarily until qutebrowser is closed.
+        """
+        opt = self._config.get_opt(option)
+        if not isinstance(opt.typ, configtypes.Dict):
+            raise cmdexc.CommandError(":config-remove-dict can only be used "
+                                      "for dicts")
+
+        with self._handle_config_error():
+            option_value = self._config.get_mutable_obj(option)
+
+            if key not in option_value:
+                raise cmdexc.CommandError("{} is not in {}!".format(key,
+                                                                    option))
+
+            del option_value[key]
+
+            self._config.update_mutables(save_yaml=not temp)
+
     @cmdutils.register(instance='config-commands')
     def config_clear(self, save=False):
         """Set all settings back to their default.

tests/unit/config/test_configcommands.py

@@ -355,6 +355,61 @@ class TestAdd:
             commands.config_add_dict('aliases', 'missingkey', value)
 
 
+class TestRemove:
+
+    """Test :config-add-list and :config-add-dict."""
+
+    @pytest.mark.parametrize('value', ['25%', '50%'])
+    @pytest.mark.parametrize('temp', [True, False])
+    def test_remove_list(self, commands, config_stub, yaml_value, value, temp):
+        name = 'zoom.levels'
+        commands.config_remove_list(name, value, temp=temp)
+
+        assert value not in config_stub.get(name)
+        if temp:
+            assert yaml_value(name) == configutils.UNSET
+        else:
+            assert value not in yaml_value(name)
+
+    def test_remove_list_non_list(self, commands):
+        with pytest.raises(
+                cmdexc.CommandError,
+                match=":config-remove-list can only be used for lists"):
+            commands.config_remove_list('content.javascript.enabled',
+                                        'never')
+
+    def test_remove_list_no_value(self, commands):
+        with pytest.raises(
+                cmdexc.CommandError,
+                match="never is not in colors.completion.fg!"):
+            commands.config_remove_list('colors.completion.fg', 'never')
+
+    @pytest.mark.parametrize('key', ['w', 'q'])
+    @pytest.mark.parametrize('temp', [True, False])
+    def test_remove_dict(self, commands, config_stub, yaml_value, key, temp):
+        name = 'aliases'
+        commands.config_remove_dict(name, key, temp=temp)
+
+        assert key not in config_stub.get(name)
+        if temp:
+            assert yaml_value(name) == configutils.UNSET
+        else:
+            assert key not in yaml_value(name)
+
+    def test_remove_dict_non_dict(self, commands):
+        with pytest.raises(
+                cmdexc.CommandError,
+                match=":config-remove-dict can only be used for dicts"):
+            commands.config_remove_dict('content.javascript.enabled',
+                                        'never')
+
+    def test_remove_dict_no_value(self, commands):
+        with pytest.raises(
+                cmdexc.CommandError,
+                match="never is not in aliases!"):
+            commands.config_remove_dict('aliases', 'never')
+
+
 class TestUnsetAndClear:
 
     """Test :config-unset and :config-clear."""