test(rewrite): record the introspection gaps nothing fixes yet

Two expression types still show a value the rewriter never decomposes:
a list/dict/set literal, and a name that happens to hold a callable.
Neither has a fix in flight, so they stay strict xfails tagged with a
group name; the tests state the message we would want instead.

Kept out of the coverage matrix itself so that PR carries only tests
that pass, and off the fix branches so each of those lands its own
group green.

Author: RonnyPfannschmidt

testing/test_assertrewrite_coverage.py

@@ -7,6 +7,12 @@
 2. Semantic correctness: rewritten code has identical behavior to original
 3. Single evaluation: side-effecting expressions are not evaluated multiple times
 4. Evaluation order: operands see the values Python would give them
+
+Two known gaps remain, recorded as strict xfails whose reason starts with a
+group name, so that a change can state which group it closes::
+
+    introspect-container-literal  list/dict/set literals are not decomposed
+    introspect-callable-variable  a called variable shows <function ...>
 """
 
 from __future__ import annotations
@@ -486,6 +492,23 @@ def f(x):
             must_contain=["where 6 = ", "(3)"],
         )
 
+    @pytest.mark.xfail(
+        strict=True,
+        reason="introspect-callable-variable: a called name shows its <function ...> repr",
+    )
+    def test_simple_call_clean_name(self) -> None:
+        """Ideally the message should show 'f()' not '<function ... at 0x...>()'."""
+        assert_introspects(
+            """
+            def check():
+                def f():
+                    return 42
+                assert f() == 100
+            """,
+            must_contain=["where 42 = f()"],
+            must_not_contain=["<function"],
+        )
+
     def test_method_call_shows_result(self) -> None:
         assert_introspects(
             """
@@ -624,6 +647,21 @@ def check():
 class TestIntrospectionContainerLiteral:
     """Container literals ([...], {...}, {k:v})."""
 
+    @pytest.mark.xfail(
+        strict=True,
+        reason="introspect-container-literal: list/dict/set literals are not decomposed",
+    )
+    def test_list_literal_shows_elements(self) -> None:
+        assert_introspects(
+            """
+            def check():
+                def f():
+                    return 99
+                assert [f(), 2, 3] == [1, 2, 3]
+            """,
+            must_contain=["where 99 = f()"],
+        )
+
     def test_list_literal_semantics_preserved(self) -> None:
         assert_semantically_equivalent("""
             def check():
@@ -727,6 +765,24 @@ def factory():
             must_contain=["where 42 = ", "()"],
         )
 
+    @pytest.mark.xfail(
+        strict=True,
+        reason="introspect-callable-variable: a called name shows its <function ...> repr",
+    )
+    def test_callable_variable_clean_name(self) -> None:
+        """Ideally should show 'fn()' not '<function factory at 0x...>()'."""
+        assert_introspects(
+            """
+            def check():
+                def factory():
+                    return 42
+                fn = factory
+                assert fn() == 100
+            """,
+            must_contain=["where 42 = fn()"],
+            must_not_contain=["<function"],
+        )
+
 
 class TestIntrospectionWalrus:
     """Walrus operator (:=) — has dedicated visitor."""