[tests] starting to write testing for LSL

tests/losses/test_lifted_structure_loss.py

@@ -1,16 +1,42 @@
 import tensorflow as tf
 from absl.testing import parameterized
-from tensorflow.keras.losses import Reduction
 from tensorflow.python.framework import combinations
+from tensorflow.keras.losses import Reduction
 from tensorflow_similarity import losses
 from . import utils
 
 @combinations.generate(combinations.combine(mode=["graph", "eager"]))
-class LiftedStructureLossTest(tf.test.TestCase, parameterized.TestCase):
+class TestLiftedStructLoss(tf.test.TestCase, parameterized.TestCase):
     def test_config(self):
-        lsl_obj = losses.LiftedStructLoss( name="lifted_struct_loss", distance="cosine"
+        lifted_obj = losses.LiftedStructLoss(
+            reduction=Reduction.SUM,
+            name="lifted_loss",
+            distance="cosine",
+        )
+        self.assertEqual(lifted_obj.distance.name, "cosine")
+        self.assertEqual(lifted_obj.name, "lifted_loss")
+        self.assertEqual(lifted_obj.reduction, Reduction.SUM)
+
+    @parameterized.named_parameters(
+        {
+            "testcase_name": "_soft_margin",
+            "margin": None,
+            "expected_loss": 0.31326169,
+        },
+        {
+            "testcase_name": "_fixed_margin",
+            "margin": 1.1,
+            "expected_loss": 0.1,
+        },
+    )
+    def test_all_correct_unweighted(self, margin, expected_loss):
+        lifted_obj = losses.LiftedStructLoss(
+            reduction=Reduction.SUM_OVER_BATCH_SIZE,
+            margin=margin,
         )
-        self.assertEqual(lsl_obj.distance.name, "cosine")
-        self.assertEqual(lsl_obj.name, "lifted_struct_loss")
+        y_true, y_preds = utils.generate_perfect_test_batch(batch_size=4)
+        loss = lifted_obj(y_true, y_preds)
+        self.assertAlmostEqual(self.evaluate(loss), expected_loss, 3)
+
+
 
-    # TODO calculate results by hand before