fix: watch with no query raises RuntimeError under PEP 479

CHANGELOG.md

@@ -3,6 +3,7 @@
 ### Bug Fixes
 
 - Expand `~` in configured log file paths before opening the log.
+- Print the usage message instead of raising `RuntimeError` when `watch` is run without a query.
 
 ### Internal
 

litecli/packages/special/iocommands.py

@@ -467,7 +467,7 @@ def watch_query(arg: str, **kwargs: Any) -> Generator[tuple, None, None]:
 """
     if not arg:
         yield (None, None, None, usage)
-        raise StopIteration
+        return
     seconds: float = 5.0
     clear_screen = False
     statement = None
@@ -476,7 +476,7 @@ def watch_query(arg: str, **kwargs: Any) -> Generator[tuple, None, None]:
         if not arg:
             # Oops, we parsed all the arguments without finding a statement
             yield (None, None, None, usage)
-            raise StopIteration
+            return
         (current_arg, _, arg) = arg.partition(" ")
         try:
             seconds = float(current_arg)
@@ -490,7 +490,7 @@ def watch_query(arg: str, **kwargs: Any) -> Generator[tuple, None, None]:
     destructive_prompt = confirm_destructive_query(statement)
     if destructive_prompt is False:
         click.secho("Wise choice!")
-        raise StopIteration
+        return
     elif destructive_prompt is True:
         click.secho("Your call!")
     cur = kwargs["cur"]
@@ -515,6 +515,6 @@ def watch_query(arg: str, **kwargs: Any) -> Generator[tuple, None, None]:
             # This prints the Ctrl-C character in its own line, which prevents
             # to print a line with the cursor positioned behind the prompt
             click.secho("", nl=True)
-            raise StopIteration
+            return
         finally:
             set_pager_enabled(old_pager_enabled)

tests/test_special_iocommands.py

@@ -87,3 +87,10 @@ def test_parse_special_command_edge_cases():
     sql = r"\llm+- Question"
     # '+' in command sets verbosity; strip('+-') removes both suffixes
     assert parse_special_command(sql) == ("\\llm", Verbosity.VERBOSE, "Question")
+
+
+@pytest.mark.parametrize("command", ["watch", "watch -c", "watch 3"])
+def test_watch_without_a_query_prints_usage(command):
+    results = list(litecli.packages.special.execute(None, command))
+    assert len(results) == 1
+    assert results[0][3].startswith("Syntax: watch")