get code cooverage to pass

python/cudf_polars/cudf_polars/dsl/translate.py

@@ -134,11 +134,7 @@ def translate_expr(self, *, n: int) -> expr.Expr:
             raise NotImplementedError(
                 "Could not retrieve the current expression"
             ) from e
-        try:
-            dtype = dtypes.from_polars(self.visitor.get_dtype(n))
-        except Exception as e:
-            self.errors.append(e)
-            raise NotImplementedError("Could not compute schema") from e
+        dtype = dtypes.from_polars(self.visitor.get_dtype(n))
         try:
             return _translate_expr(node, self, dtype)
         except Exception as e:

python/cudf_polars/tests/testing/test_asserts.py

@@ -7,14 +7,16 @@
 
 import polars as pl
 
+from cudf_polars.dsl.translate import Translator
 from cudf_polars.testing.asserts import (
+    IRTranslationFailed,
     assert_collect_raises,
     assert_gpu_result_equal,
     assert_ir_translation_raises,
 )
 
 
-def test_translation_assert_raises():
+def test_translation_assert_raises(monkeypatch):
     df = pl.LazyFrame({"a": [1, 2, 3]})
 
     # This should succeed
@@ -35,6 +37,14 @@ class E(Exception):
         # This should fail, because we can't translate this query, but it doesn't raise E.
         assert_ir_translation_raises(unsupported, E)
 
+    def raise_unimplemented(self):
+        raise NotImplementedError("foo")
+
+    monkeypatch.setattr(Translator, "translate_ir", raise_unimplemented)
+
+    with pytest.raises(IRTranslationFailed):
+        assert_ir_translation_raises(df, NotImplementedError)
+
 
 def test_collect_assert_raises():
     df = pl.LazyFrame({"a": [1, 2, 3], "b": ["a", "b", "c"]})