diff --git a/tests/test_bucket_table.py b/tests/test_bucket_table.py
new file mode 100644
index 00000000..cfcbebf9
--- /dev/null
+++ b/tests/test_bucket_table.py
@@ -0,0 +1,14 @@
+# tests/test_bucket_table.py
+from diffusers_helper.bucket_tools import bucket_options
+
+
+def test_bucket_options_nonempty():
+    """bucket_options should have integer keys and non-empty lists of (h, w) tuples."""
+    assert isinstance(bucket_options, dict)
+    assert all(isinstance(k, int) for k in bucket_options)
+    assert any(bucket_options.values())  # at least one non-empty list
+    for key, lst in bucket_options.items():
+        for h, w in lst:
+            assert isinstance(h, int)
+            assert isinstance(w, int)
+            assert h > 0 and w > 0
diff --git a/tests/test_bucket_tools.py b/tests/test_bucket_tools.py
new file mode 100644
index 00000000..7f4ec5f1
--- /dev/null
+++ b/tests/test_bucket_tools.py
@@ -0,0 +1,15 @@
+from diffusers_helper.bucket_tools import find_nearest_bucket, bucket_options
+
+
+def test_returns_known_bucket_and_shape():
+    """If input matches one of the bucket options exactly, it should return it."""
+    h, w = 480, 832
+    bh, bw = find_nearest_bucket(h, w, resolution=640)
+    assert (bh, bw) in bucket_options[640]
+    assert (bh, bw) == (480, 832)
+
+
+def test_picks_minimum_area_difference():
+    """If input does not match exactly, pick the closest area bucket."""
+    bh, bw = find_nearest_bucket(500, 800, resolution=640)
+    assert (bh, bw) == (512, 768)
diff --git a/tests/test_clip_vision.py b/tests/test_clip_vision.py
new file mode 100644
index 00000000..c2303665
--- /dev/null
+++ b/tests/test_clip_vision.py
@@ -0,0 +1,31 @@
+import numpy as np
+from diffusers_helper.clip_vision import hf_clip_vision_encode
+
+
+class _DummyBatch(dict):
+    def to(self, **kwargs):
+        return self
+
+
+class _DummyExtractor:
+    def preprocess(self, images, return_tensors="pt"):
+        assert return_tensors == "pt"
+        assert isinstance(images, np.ndarray)
+        return _DummyBatch({"pixel_values": "ok"})
+
+
+class _DummyEncoder:
+    device = "cpu"
+    dtype = "float32"
+
+    def __call__(self, **kwargs):
+        # Return a dummy output to simulate a successful encode
+        return {"last_hidden_state": "dummy"}
+
+
+def test_hf_clip_vision_encode_smoke():
+    """Smoke test: hf_clip_vision_encode should call extractor and encoder successfully."""
+    img = np.zeros((8, 8, 3), dtype=np.uint8)
+    out = hf_clip_vision_encode(img, _DummyExtractor(), _DummyEncoder())
+    assert isinstance(out, dict)
+    assert "last_hidden_state" in out
diff --git a/tests/test_hf_login.py b/tests/test_hf_login.py
new file mode 100644
index 00000000..b3e338b1
--- /dev/null
+++ b/tests/test_hf_login.py
@@ -0,0 +1,40 @@
+# tests/test_hf_login.py
+import importlib
+import types
+
+
+def test_login_retries_then_succeeds(monkeypatch, capsys):
+    """login() should retry on failure and eventually succeed (no autologin on import)."""
+    calls = {"n": 0}
+
+    def fake_login(_token):
+        calls["n"] += 1
+        if calls["n"] < 3:
+            raise RuntimeError("temporary HF error")
+        # success on third attempt
+
+    # Ensure no autologin during import
+    monkeypatch.delenv("HF_TOKEN", raising=False)
+
+    # Make sure we import a fresh module
+    if "diffusers_helper.hf_login" in importlib.sys.modules:
+        del importlib.sys.modules["diffusers_helper.hf_login"]
+
+    # Provide fake huggingface_hub before import
+    monkeypatch.setitem(
+        importlib.import_module("sys").modules,
+        "huggingface_hub",
+        types.SimpleNamespace(login=fake_login),
+    )
+
+    # Avoid real sleeps
+    monkeypatch.setattr("time.sleep", lambda *_a, **_k: None)
+
+    # Import module (no autologin because HF_TOKEN is unset)
+    from diffusers_helper import hf_login
+
+    # Now call the function explicitly (this will do the retries)
+    hf_login.login("abc")
+    captured = capsys.readouterr().out
+    assert calls["n"] == 3
+    assert "HF login ok." in captured
diff --git a/tests/test_memory_dynamic_swap.py b/tests/test_memory_dynamic_swap.py
new file mode 100644
index 00000000..2211435e
--- /dev/null
+++ b/tests/test_memory_dynamic_swap.py
@@ -0,0 +1,95 @@
+import sys, types, importlib
+
+
+def _import_memory_with_fake_torch():
+    """Import diffusers_helper.memory with a minimal fake torch API."""
+    fake_torch = types.ModuleType("torch")
+
+    # torch.device -> echo string/device id
+    fake_torch.device = lambda x: str(x)
+
+    # Minimal Parameter
+    class Parameter:
+        def __init__(self, data=None, requires_grad=False):
+            self.data = data
+            self.requires_grad = requires_grad
+
+        def to(self, **kwargs):
+            return self.data
+
+    # Minimal Module
+    class Module:
+        def __init__(self):
+            self._parameters = {}
+
+        def modules(self):
+            return []
+
+    # torch.nn namespace
+    class NN:
+        pass
+
+    NN.Parameter = Parameter
+    NN.Module = Module
+    fake_torch.nn = NN()
+
+    # torch.cuda stub
+    class _CUDA:
+        @staticmethod
+        def current_device():
+            return 0
+
+        @staticmethod
+        def memory_stats(device):
+            return {"active_bytes.all.current": 0, "reserved_bytes.all.current": 0}
+
+        @staticmethod
+        def mem_get_info(device):
+            return (0, 0)
+
+        @staticmethod
+        def empty_cache():
+            return None
+
+    fake_torch.cuda = _CUDA()
+
+    sys.modules["torch"] = fake_torch
+
+    if "diffusers_helper.memory" in sys.modules:
+        del sys.modules["diffusers_helper.memory"]
+    return importlib.import_module("diffusers_helper.memory")
+
+
+def test_dynamic_swap_install_and_uninstall():
+    """Installing should wrap __getattr__ to cast parameters; uninstall should restore the class."""
+    memory = _import_memory_with_fake_torch()
+
+    # A tiny fake "module" with _parameters and a .to() method
+    class Layer:
+        def __init__(self):
+            self._parameters = {
+                "weight": memory.torch.nn.Parameter(data="W", requires_grad=True)
+            }
+
+        def to(self, **kwargs):
+            self.last_to = kwargs
+            return self
+
+        # modules() is used by DynamicSwapInstaller.install_model
+        def modules(self):
+            yield self
+
+    layer = Layer()
+    original_cls = layer.__class__
+
+    # Install swapper and access a parameter to trigger __getattr__
+    memory.DynamicSwapInstaller.install_model(layer, dtype="float16")
+    assert layer.__class__ is not original_cls  # class is replaced
+
+    wrapped = layer.weight  # __getattr__ should create a new Parameter with casted data
+    assert isinstance(wrapped, memory.torch.nn.Parameter)
+    assert wrapped.requires_grad is True
+    # After uninstall, class should be restored
+    memory.DynamicSwapInstaller.uninstall_model(layer)
+    assert layer.__class__ is original_cls
+    assert "forge_backup_original_class" not in layer.__dict__