Display close matches for invalid settings

4 files changed, 35 insertions, 10 deletions

diff --git a/qutebrowser/config/config.py b/qutebrowser/config/config.py
index 834709ae6..918c9b894 100644
--- a/qutebrowser/config/config.py
+++ b/qutebrowser/config/config.py
@@ -373,7 +373,11 @@ class Config(QObject):
             deleted = name in configdata.MIGRATIONS.deleted
             renamed = configdata.MIGRATIONS.renamed.get(name)
             exception = configexc.NoOptionError(
-                name, deleted=deleted, renamed=renamed)
+                name,
+                deleted=deleted,
+                renamed=renamed,
+                all_names=list(configdata.DATA),
+            )
             raise exception from None
 
     def ensure_has_opt(self, name: str) -> None:
diff --git a/qutebrowser/config/configexc.py b/qutebrowser/config/configexc.py
index 27a1001b5..58e5ad67a 100644
--- a/qutebrowser/config/configexc.py
+++ b/qutebrowser/config/configexc.py
@@ -19,8 +19,9 @@
 
 """Exceptions related to config parsing."""
 
+import difflib
 import dataclasses
-from typing import Any, Mapping, Optional, Sequence, Union
+from typing import Any, Mapping, Optional, Sequence, Union, List
 
 from qutebrowser.utils import usertypes, log
 
@@ -91,6 +92,7 @@ class NoOptionError(Error):
     """Raised when an option was not found."""
 
     def __init__(self, option: str, *,
+                 all_names: List[str] = None,
                  deleted: bool = False,
                  renamed: str = None) -> None:
         if deleted:
@@ -98,6 +100,12 @@ class NoOptionError(Error):
             suffix = ' (this option was removed from qutebrowser)'
         elif renamed is not None:
             suffix = ' (this option was renamed to {!r})'.format(renamed)
+        elif all_names:
+            matches = difflib.get_close_matches(option, all_names, n=1)
+            if matches:
+                suffix = f' (did you mean {matches[0]!r}?)'
+            else:
+                suffix = ''
         else:
             suffix = ''
 
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index b88bc2f8d..ab1fba789 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -782,7 +782,7 @@ class TestContainer:
         assert len(configapi.errors) == 1
         error = configapi.errors[0]
         assert error.text == "While getting 'tabs.foobar'"
-        assert str(error.exception) == "No option 'tabs.foobar'"
+        assert str(error.exception).startswith("No option 'tabs.foobar'")
 
     def test_confapi_missing_prefix(self, container):
         configapi = types.SimpleNamespace(errors=[])
@@ -793,7 +793,7 @@ class TestContainer:
 
         error1 = configapi.errors[0]
         assert error1.text == "While getting 'content.host_blocking'"
-        assert str(error1.exception) == "No option 'content.host_blocking'"
+        assert str(error1.exception).startswith("No option 'content.host_blocking'")
 
         error2 = configapi.errors[1]
         assert error2.text == "While setting 'content.host_blocking.lists'"
diff --git a/tests/unit/config/test_configexc.py b/tests/unit/config/test_configexc.py
index a236494f9..0c64cf8c6 100644
--- a/tests/unit/config/test_configexc.py
+++ b/tests/unit/config/test_configexc.py
@@ -32,13 +32,26 @@ def test_validation_error():
     assert str(e) == "Invalid value 'val' - msg"
 
 
-@pytest.mark.parametrize('deleted, renamed, expected', [
-    (False, None, "No option 'opt'"),
-    (True, None, "No option 'opt' (this option was removed from qutebrowser)"),
-    (False, 'new', "No option 'opt' (this option was renamed to 'new')"),
+@pytest.mark.parametrize('deleted, renamed, all_names, expected', [
+    (False, None, [], "No option 'opt'"),
+    (True, None, [], "No option 'opt' (this option was removed from qutebrowser)"),
+    (False, 'new', [], "No option 'opt' (this option was renamed to 'new')"),
+    (False, None, ["opto"], "No option 'opt' (did you mean 'opto'?)"),
+    (
+        True,
+        None,
+        ["opto"],
+        "No option 'opt' (this option was removed from qutebrowser)",
+    ),
+    (False, 'new', ["opto"], "No option 'opt' (this option was renamed to 'new')"),
 ])
-def test_no_option_error(deleted, renamed, expected):
-    e = configexc.NoOptionError('opt', deleted=deleted, renamed=renamed)
+def test_no_option_error(deleted, renamed, all_names, expected):
+    e = configexc.NoOptionError(
+        'opt',
+        deleted=deleted,
+        renamed=renamed,
+        all_names=all_names,
+    )
     assert e.option == 'opt'
     assert str(e) == expected