Fix :bind completion with invalid commands

Now that Command doesn't validate things anymore, we can't rely on parsing to
work.

qutebrowser/completion/models/configmodel.py

@@ -21,7 +21,7 @@
 
 from qutebrowser.config import configdata, configexc
 from qutebrowser.completion.models import completionmodel, listcategory, util
-from qutebrowser.commands import runners
+from qutebrowser.commands import runners, cmdexc
 
 
 def option(*, info):
@@ -72,7 +72,11 @@ def bind(key, *, info):
 
     if cmd_text:
         parser = runners.CommandParser()
+        try:
             cmd = parser.parse(cmd_text).cmd
+        except cmdexc.NoSuchCommandError:
+            data = [(cmd_text, 'Invalid command!', key)]
+        else:
             data = [(cmd_text, cmd.desc, key)]
         model.add_category(listcategory.ListCategory("Current", data))
 

tests/unit/completion/test_models.py

@@ -119,6 +119,7 @@ def configdata_stub(monkeypatch, configdata_init):
                 'normal': collections.OrderedDict([
                     ('<ctrl+q>', 'quit'),
                     ('ZQ', 'quit'),
+                    ('I', 'invalid'),
                 ])
             },
             backends=[],
@@ -538,7 +539,8 @@ def test_setting_option_completion(qtmodeltester, config_stub,
         "Options": [
             ('aliases', 'Aliases for commands.', '{"q": "quit"}'),
             ('bindings.commands', 'Default keybindings',
-                '{"normal": {"<ctrl+q>": "quit", "ZQ": "quit"}}'),
+                '{"normal": {"<ctrl+q>": "quit", "ZQ": "quit", '
+                '"I": "invalid"}}'),
             ('bindings.default', 'Default keybindings',
                 '{"normal": {"<ctrl+q>": "quit"}}'),
         ]
@@ -573,6 +575,25 @@ def test_bind_completion(qtmodeltester, cmdutils_stub, config_stub,
     })
 
 
+def test_bind_completion_invalid(cmdutils_stub, config_stub, key_config_stub,
+                                 configdata_stub, info):
+    """Test command completion with an invalid command bound."""
+    model = configmodel.bind('I', info=info)
+    model.set_pattern('')
+
+    _check_completions(model, {
+        "Current": [
+            ('invalid', 'Invalid command!', 'I'),
+        ],
+        "Commands": [
+            ('open', 'open a url', ''),
+            ('q', "Alias for 'quit'", ''),
+            ('quit', 'quit qutebrowser', 'ZQ, <ctrl+q>'),
+            ('scroll', 'Scroll the current tab in the given direction.', '')
+        ],
+    })
+
+
 def test_bind_completion_no_current(qtmodeltester, cmdutils_stub, config_stub,
                                     key_config_stub, configdata_stub, info):
     """Test keybinding completion with no current binding."""