Extend existing tests to spancat_exclusive

In this commit, I extended the existing tests for spancat to include
spancat_exclusive. I parametrized the test functions with 'name'
(similar var name with textcat and textcat_multilabel) for each
applicable test.

TODO: Add overfitting tests for spancat_exclusive

spacy/tests/pipeline/test_spancat.py

@@ -41,38 +41,42 @@ def make_examples(nlp, data=TRAIN_DATA):
     return train_examples
 
 
-def test_no_label():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_no_label(name):
     nlp = Language()
-    nlp.add_pipe("spancat", config={"spans_key": SPAN_KEY})
+    nlp.add_pipe(name, config={"spans_key": SPAN_KEY})
     with pytest.raises(ValueError):
         nlp.initialize()
 
 
-def test_no_resize():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_no_resize(name):
     nlp = Language()
-    spancat = nlp.add_pipe("spancat", config={"spans_key": SPAN_KEY})
+    spancat = nlp.add_pipe(name, config={"spans_key": SPAN_KEY})
     spancat.add_label("Thing")
     spancat.add_label("Phrase")
     assert spancat.labels == ("Thing", "Phrase")
     nlp.initialize()
-    assert spancat.model.get_dim("nO") == 2
+    assert spancat.model.get_dim("nO") == spancat._n_labels
     # this throws an error because the spancat can't be resized after initialization
     with pytest.raises(ValueError):
         spancat.add_label("Stuff")
 
 
-def test_implicit_labels():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_implicit_labels(name):
     nlp = Language()
-    spancat = nlp.add_pipe("spancat", config={"spans_key": SPAN_KEY})
+    spancat = nlp.add_pipe(name, config={"spans_key": SPAN_KEY})
     assert len(spancat.labels) == 0
     train_examples = make_examples(nlp)
     nlp.initialize(get_examples=lambda: train_examples)
     assert spancat.labels == ("PERSON", "LOC")
 
 
-def test_explicit_labels():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_explicit_labels(name):
     nlp = Language()
-    spancat = nlp.add_pipe("spancat", config={"spans_key": SPAN_KEY})
+    spancat = nlp.add_pipe(name, config={"spans_key": SPAN_KEY})
     assert len(spancat.labels) == 0
     spancat.add_label("PERSON")
     spancat.add_label("LOC")
@@ -371,7 +375,8 @@ def test_overfitting_IO_overlapping():
         assert set([span.label_ for span in spans2]) == {"LOC", "DOUBLE_LOC"}
 
 
-def test_zero_suggestions():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_zero_suggestions(name):
     # Test with a suggester that returns 0 suggestions
 
     @registry.misc("test_zero_suggester")
@@ -388,20 +393,21 @@ def test_zero_suggestions():
     fix_random_seed(0)
     nlp = English()
     spancat = nlp.add_pipe(
-        "spancat",
+        name,
         config={"suggester": {"@misc": "test_zero_suggester"}, "spans_key": SPAN_KEY},
     )
     train_examples = make_examples(nlp)
     optimizer = nlp.initialize(get_examples=lambda: train_examples)
-    assert spancat.model.get_dim("nO") == 2
+    assert spancat.model.get_dim("nO") == spancat._n_labels
     assert set(spancat.labels) == {"LOC", "PERSON"}
 
     nlp.update(train_examples, sgd=optimizer)
 
 
-def test_set_candidates():
+@pytest.mark.parametrize("name", ["spancat", "spancat_exclusive"])
+def test_set_candidates(name):
     nlp = Language()
-    spancat = nlp.add_pipe("spancat", config={"spans_key": SPAN_KEY})
+    spancat = nlp.add_pipe(name, config={"spans_key": SPAN_KEY})
     train_examples = make_examples(nlp)
     nlp.initialize(get_examples=lambda: train_examples)
     texts = [