Just: let an empty argument be an argument

Both entry points dropped empty arguments before looking at them, to absorb a
caller interpolating a variable that was never set. No justfile here can produce
one: a root that contributes nothing contributes no list element, so the case
the filtering existed for cannot arise, and dropping arguments silently is a bad
way to find out otherwise.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: redsun82

misc/just/codeql_test_run.py

@@ -117,8 +117,6 @@ def resolve_codeql(args: argparse.Namespace) -> Path:
 
 
 def main():
-    # An empty argument can come from a caller interpolating an unset variable.
-    sys.argv = [a for a in sys.argv if a]
     args = parse_arguments()
 
     if args.all:

misc/just/language_tests.py

@@ -17,10 +17,7 @@
 
 
 def main():
-    # Blank arguments are dropped before the count is taken: one comes of a caller
-    # interpolating a variable that was never set, and a list of nothing but those is no
-    # arguments at all rather than a root to find a justfile above.
-    argv = [arg for arg in sys.argv[1:] if arg]
+    argv = sys.argv[1:]
     if not argv:
         print("Usage: language_tests.py ROOT [ARG...]", file=sys.stderr)
         return 1

misc/just/test_codeql_test_run.py

@@ -129,23 +129,6 @@ def test_sorts_a_whole_command_line_at_once(self):
         self.assertTrue(args.all)
 
 
-class TestEmptyArguments(unittest.TestCase):
-    """Dropped by `main` before parsing, which is earlier than it looks.
-
-    Filtering these inside the sorting loop instead would leave them in front of
-    `argparse`, and an empty argument ahead of a `--` stops the separator being
-    recognised, so the `--` would reach `codeql test run` as an argument of its own.
-    """
-
-    def test_an_empty_argument_is_ignored(self):
-        # One of these comes of a caller interpolating a variable that was never set.
-        self.assertEqual(paths("", "some/test"), ["some/test"])
-
-    def test_an_empty_argument_does_not_disturb_a_separator(self):
-        self.assertEqual(flags("", "--", "--check-databases")[-1], "--check-databases")
-        self.assertNotIn("--", flags("", "--", "--check-databases"))
-
-
 class TestOfferedChecks(unittest.TestCase):
     """What a root offers and what `--all-checks` enables are separate things.
 

misc/just/test_language_tests.py

@@ -109,13 +109,6 @@ def test_needs_a_root(self):
         self.assertEqual(status, 1)
         run.assert_not_called()
 
-    def test_nothing_but_blank_arguments_is_no_arguments(self):
-        # An unset variable interpolated by a caller arrives as one of these. Counting
-        # it as an argument and then dropping it left nothing to take a root from.
-        status, run, _ = self.run_main("", "")
-        self.assertEqual(status, 1)
-        run.assert_not_called()
-
     def test_reports_a_root_with_no_justfile_above_it(self):
         orphan = self.semmle_code / "elsewhere"
         orphan.mkdir()