✅ Add tests for vendored _split_opt, for coverage

tests/test_others.py

@@ -10,6 +10,7 @@
 import shellingham
 import typer
 import typer.completion
+from typer.core import _split_opt
 from typer.main import solve_typer_info_defaults, solve_typer_info_help
 from typer.models import ParameterInfo, TyperInfo
 from typer.testing import CliRunner
@@ -243,3 +244,21 @@ def main(name: str):
 
     result = runner.invoke(app, ["main", "-h"])
     assert "Show this message and exit." in result.stdout
+
+
+def test_split_opt():
+    prefix, opt = _split_opt("--verbose")
+    assert prefix == "--"
+    assert opt == "verbose"
+
+    prefix, opt = _split_opt("//verbose")
+    assert prefix == "//"
+    assert opt == "verbose"
+
+    prefix, opt = _split_opt("-verbose")
+    assert prefix == "-"
+    assert opt == "verbose"
+
+    prefix, opt = _split_opt("verbose")
+    assert prefix == ""
+    assert opt == "verbose"