test

Author: willmcgugan

src/textual/css/parse.py

@@ -40,20 +40,20 @@
     "nested": (SelectorType.NESTED, (0, 0, 0)),
 }
 
-RE_IDENTIFIER = re.compile(r"\#" + IDENTIFIER)
+RE_ID_SELECTOR = re.compile(r"\#" + IDENTIFIER)
 
 
 @lru_cache(maxsize=128)
 def is_id_selector(selector: str) -> bool:
-    """Is the selector an ID selector, i.e. "#foo"?
+    """Is the selector an single ID selector, i.e. "#foo"?
 
     Args:
         selector: A CSS selector.
 
     Returns:
         `True` if the selector is a simple ID selector, otherwise `False`.
     """
-    return RE_IDENTIFIER.fullmatch(selector) is not None
+    return RE_ID_SELECTOR.fullmatch(selector) is not None
 
 
 def _add_specificity(

tests/css/test_parse.py

@@ -4,7 +4,7 @@
 
 from textual.color import Color
 from textual.css.errors import UnresolvedVariableError
-from textual.css.parse import substitute_references
+from textual.css.parse import is_id_selector, substitute_references
 from textual.css.scalar import Scalar, Unit
 from textual.css.stylesheet import Stylesheet, StylesheetParseError
 from textual.css.tokenize import tokenize
@@ -1272,3 +1272,25 @@ def test_parse_bad_pseudo_selector_with_suggestion():
         stylesheet.parse()
 
     assert error.value.start == (2, 7)
+
+
+@pytest.mark.parametrize(
+    "selector, expected",
+    [
+        # True cases
+        ("#foo", True),
+        ("#bar", True),
+        ("#f", True),
+        # False cases
+        ("#", False),
+        ("Foo", False),
+        (".foo", False),
+        ("#5foo", False),
+        ("#foo .bar", False),
+        ("#foo>.bar", False),
+        ("#foo.bar", False),
+    ],
+)
+def test_is_id_selector(selector: str, expected: bool):
+    """Test is_id_selector is working as expected"""
+    assert is_id_selector(selector) is expected