Add tests, ensure that labels are set correctly

Author: tomaarsen

tests/test_trainer.py

@@ -472,6 +472,8 @@ def test_trainer_evaluate_with_strings(model: SetFitModel):
     # The only supported types are: float64, float32, float16, complex64, complex128, int64, int32, int16, int8, uint8, and bool."
     model.predict(["another positive sentence"])
 
+    assert set(model.labels) == {"positive", "negative"}
+
 
 def test_trainer_evaluate_multilabel_f1():
     dataset = Dataset.from_dict({"text_new": ["", "a", "b", "ab"], "label_new": [[0, 0], [1, 0], [0, 1], [1, 1]]})
@@ -606,6 +608,7 @@ def test_evaluate_with_strings(model: SetFitModel) -> None:
     trainer.train()
     metrics = trainer.evaluate()
     assert "accuracy" in metrics
+    assert set(model.labels) == {"positive", "negative"}
 
 
 def test_trainer_wrong_args(model: SetFitModel, tmp_path: Path) -> None: