Device agnostic trainer testing (#27131)

src/transformers/testing_utils.py

@@ -629,6 +629,20 @@ def require_torch_multi_gpu(test_case):
     return unittest.skipUnless(torch.cuda.device_count() > 1, "test requires multiple GPUs")(test_case)
 
 
+def require_torch_multi_accelerator(test_case):
+    """
+    Decorator marking a test that requires a multi-accelerator (in PyTorch). These tests are skipped on a machine
+    without multiple accelerators. To run *only* the multi_accelerator tests, assuming all test names contain
+    multi_accelerator: $ pytest -sv ./tests -k "multi_accelerator"
+    """
+    if not is_torch_available():
+        return unittest.skip("test requires PyTorch")(test_case)
+
+    return unittest.skipUnless(backend_device_count(torch_device) > 1, "test requires multiple accelerators")(
+        test_case
+    )
+
+
 def require_torch_non_multi_gpu(test_case):
     """
     Decorator marking a test that requires 0 or 1 GPU setup (in PyTorch).
@@ -641,6 +655,16 @@ def require_torch_non_multi_gpu(test_case):
     return unittest.skipUnless(torch.cuda.device_count() < 2, "test requires 0 or 1 GPU")(test_case)
 
 
+def require_torch_non_multi_accelerator(test_case):
+    """
+    Decorator marking a test that requires 0 or 1 accelerator setup (in PyTorch).
+    """
+    if not is_torch_available():
+        return unittest.skip("test requires PyTorch")(test_case)
+
+    return unittest.skipUnless(backend_device_count(torch_device) < 2, "test requires 0 or 1 accelerator")(test_case)
+
+
 def require_torch_up_to_2_gpus(test_case):
     """
     Decorator marking a test that requires 0 or 1 or 2 GPU setup (in PyTorch).
@@ -653,6 +677,17 @@ def require_torch_up_to_2_gpus(test_case):
     return unittest.skipUnless(torch.cuda.device_count() < 3, "test requires 0 or 1 or 2 GPUs")(test_case)
 
 
+def require_torch_up_to_2_accelerators(test_case):
+    """
+    Decorator marking a test that requires 0 or 1 or 2 accelerator setup (in PyTorch).
+    """
+    if not is_torch_available():
+        return unittest.skip("test requires PyTorch")(test_case)
+
+    return unittest.skipUnless(backend_device_count(torch_device) < 3, "test requires 0 or 1 or 2 accelerators")
+    (test_case)
+
+
 def require_torch_tpu(test_case):
     """
     Decorator marking a test that requires a TPU (in PyTorch).
@@ -774,7 +809,9 @@ def require_torch_gpu(test_case):
 
 def require_torch_accelerator(test_case):
     """Decorator marking a test that requires an accessible accelerator and PyTorch."""
-    return unittest.skipUnless(torch_device != "cpu", "test requires accelerator")(test_case)
+    return unittest.skipUnless(torch_device is not None and torch_device != "cpu", "test requires accelerator")(
+        test_case
+    )
 
 
 def require_torch_fp16(test_case):