[s2s] adjust finetune + test to work with fsmt (#7263)

examples/seq2seq/test_seq2seq_examples.py

@@ -103,6 +103,7 @@ T5_TINY = "patrickvonplaten/t5-tiny-random"
 BART_TINY = "sshleifer/bart-tiny-random"
 MBART_TINY = "sshleifer/tiny-mbart"
 MARIAN_TINY = "sshleifer/tiny-marian-en-de"
+FSMT_TINY = "stas/tiny-wmt19-en-de"
 
 
 stream_handler = logging.StreamHandler(sys.stdout)
@@ -374,11 +375,11 @@ def test_run_eval_search(model):
 
 @pytest.mark.parametrize(
     "model",
-    [T5_TINY, BART_TINY, MBART_TINY, MARIAN_TINY],
+    [T5_TINY, BART_TINY, MBART_TINY, MARIAN_TINY, FSMT_TINY],
 )
 def test_finetune(model):
     args_d: dict = CHEAP_ARGS.copy()
-    task = "translation" if model in [MBART_TINY, MARIAN_TINY] else "summarization"
+    task = "translation" if model in [MBART_TINY, MARIAN_TINY, FSMT_TINY] else "summarization"
     args_d["label_smoothing"] = 0.1 if task == "translation" else 0
 
     tmp_dir = make_test_data_dir()
@@ -407,7 +408,13 @@ def test_finetune(model):
         lm_head = module.model.lm_head
         assert not lm_head.weight.requires_grad
         assert (lm_head.weight == input_embeds.weight).all().item()
-
+    elif model == FSMT_TINY:
+        fsmt = module.model.model
+        embed_pos = fsmt.decoder.embed_positions
+        assert not embed_pos.weight.requires_grad
+        assert not fsmt.decoder.embed_tokens.weight.requires_grad
+        # check that embeds are not the same
+        assert fsmt.decoder.embed_tokens != fsmt.encoder.embed_tokens
     else:
         bart = module.model.model
         embed_pos = bart.decoder.embed_positions