tests

Author: willmcgugan

src/textual/_slug.py

@@ -128,16 +128,17 @@ def slug_for_tcss_id(text: str) -> str:
     Returns:
         A slugified version of text suitable for use as a TCSS id.
     """
+
     slug = "".join(
         (
             character
             if character in VALID_ID_CHARACTERS
             else ord(character).__format__("x")
         )
-        for character in text
+        for character in text.casefold().replace(" ", "-")
     )
     if not slug:
-        return "-"
+        return "_"
     if slug[0].isdecimal():
-        return f"-{slug}"
+        return f"_{slug}"
     return slug

tests/test_slug.py

@@ -1,6 +1,7 @@
 import pytest
 
-from textual._slug import TrackedSlugs, slug_for_tcss_id
+from textual._slug import TrackedSlugs, slug, slug_for_tcss_id
+from textual.dom import check_identifiers
 
 
 @pytest.mark.xdist_group("group1")
@@ -31,7 +32,7 @@
 )
 def test_simple_slug(text: str, expected: str) -> None:
     """The simple slug function should produce the expected slug."""
-    assert slug_for_tcss_id(text) == expected
+    assert slug(text) == expected
 
 
 @pytest.fixture(scope="module")
@@ -64,3 +65,24 @@ def tracker() -> TrackedSlugs:
 def test_tracked_slugs(tracker: TrackedSlugs, text: str, expected: str) -> None:
     """The tracked slugging class should produce the expected slugs."""
     assert tracker.slug(text) == expected
+
+
+@pytest.mark.parametrize(
+    "text, expected",
+    [
+        ("", "_"),
+        (" ", "-"),
+        ("5", "_5"),
+        ("a", "a"),
+        ("hello world", "hello-world"),
+        ("🙂", "_1f642"),
+        ("🙂🙂", "_1f6421f642"),
+        ("Foo🙂", "foo1f642"),
+        ("ß", "ss"),
+    ],
+)
+def test_slug_for_tcss_id(text: str, expected: str) -> None:
+    """Test the slug_for_tcss_id"""
+    slug = slug_for_tcss_id(text)
+    assert slug == expected
+    check_identifiers(slug)