Trainers: Add check name collision for losses

src/ashpy/trainers/classifier.py

@@ -134,6 +134,8 @@ def toy_dataset():
         self._loss = loss
         self._loss.reduction = tf.keras.losses.Reduction.NONE
 
+        super()._check_loss_name_collision([self._loss])
+
         self._avg_loss = ClassifierLoss(name="ashpy/avg_loss")
         if metrics:
             metrics = (*metrics, self._avg_loss)

src/ashpy/trainers/gan.py

@@ -192,6 +192,10 @@ def __init__(
         self._discriminator_loss = discriminator_loss
         self._discriminator_loss.reduction = tf.losses.Reduction.NONE
 
+        super()._check_loss_name_collision(
+            [self._generator_loss, self._discriminator_loss]
+        )
+
         losses_metrics = (
             DiscriminatorLoss(name="ashpy/d_loss", logdir=logdir),
             GeneratorLoss(name="ashpy/g_loss", logdir=logdir),
@@ -586,6 +590,10 @@ def __init__(
         self._encoder_loss = encoder_loss
         self._encoder_loss.reduction = tf.losses.Reduction.NONE
 
+        super()._check_loss_name_collision(
+            [self._generator_loss, self._discriminator_loss, self._encoder_loss]
+        )
+
         ckpt_dict = {
             self.ckpt_id_encoder: self._encoder,
             self.ckpt_id_optimizer_encoder: self._encoder_optimizer,

src/ashpy/trainers/trainer.py

@@ -173,6 +173,26 @@ def _check_name_collision(objects: List, obj_type: str):
                 raise ValueError(f"{obj_type} should have unique names.")
             buffer.append(obj.name)
 
+    @staticmethod
+    def _check_loss_name_collision(losses: List[ashpy.losses.Executor]):
+        """Check that all losses have unique names."""
+        names = []
+
+        for loss in losses:
+            if loss.name in names:
+                raise ValueError(f"Losses should have unique names.")
+            else:
+                names.append(loss.name)
+
+            if isinstance(loss, ashpy.losses.SumExecutor):
+                loss: ashpy.losses.SumExecutor
+                sublosses_names = [subloss.name for subloss in loss.sublosses]
+                for subloss_name in sublosses_names:
+                    if loss.name in names:
+                        raise ValueError(f"Losses should have unique names.")
+                    else:
+                        names.append(subloss_name)
+
     def _validate_metrics(self):
         """Check if every metric is an :py:class:`ashpy.metrics.Metric`."""
         validate_objects(self._metrics, Metric)