From 7b43d0e4096b811ade3c40280a7438fa2554236e Mon Sep 17 00:00:00 2001
From: sayakpaul <spsayakpaul@gmail.com>
Date: Tue, 20 Jan 2026 09:29:32 +0530
Subject: [PATCH] add tests

---
 .../test_modular_pipelines_common.py          | 61 ++++++++++++++++++-
 1 file changed, 60 insertions(+), 1 deletion(-)

diff --git a/tests/modular_pipelines/test_modular_pipelines_common.py b/tests/modular_pipelines/test_modular_pipelines_common.py
index 661fcc2537..35855d39b6 100644
--- a/tests/modular_pipelines/test_modular_pipelines_common.py
+++ b/tests/modular_pipelines/test_modular_pipelines_common.py
@@ -1,4 +1,6 @@
 import gc
+import json
+import os
 import tempfile
 from typing import Callable, Union
 
@@ -8,9 +10,16 @@ import torch
 import diffusers
 from diffusers import ComponentsManager, ModularPipeline, ModularPipelineBlocks
 from diffusers.guiders import ClassifierFreeGuidance
+from diffusers.modular_pipelines import SequentialPipelineBlocks
 from diffusers.utils import logging
 
-from ..testing_utils import backend_empty_cache, numpy_cosine_similarity_distance, require_accelerator, torch_device
+from ..testing_utils import (
+    CaptureLogger,
+    backend_empty_cache,
+    numpy_cosine_similarity_distance,
+    require_accelerator,
+    torch_device,
+)
 
 
 class ModularPipelineTesterMixin:
@@ -335,3 +344,53 @@ class ModularGuiderTesterMixin:
         assert out_cfg.shape == out_no_cfg.shape
         max_diff = torch.abs(out_cfg - out_no_cfg).max()
         assert max_diff > expected_max_diff, "Output with CFG must be different from normal inference"
+
+
+class TestCustomBlockRequirements:
+    def get_dummy_block_pipe(self):
+        class DummyBlockOne:
+            # keep two arbitrary deps so that we can test warnings.
+            _requirements = {"xyz": ">=0.8.0", "abc": ">=10.0.0"}
+
+        class DummyBlockTwo:
+            # keep two dependencies that will be available during testing.
+            _requirements = {"transformers": ">=4.44.0", "diffusers": ">=0.2.0"}
+
+        pipe = SequentialPipelineBlocks.from_blocks_dict(
+            {"dummy_block_one": DummyBlockOne, "dummy_block_two": DummyBlockTwo}
+        )
+        return pipe
+
+    def test_custom_requirements_save_load(self):
+        pipe = self.get_dummy_block_pipe()
+        with tempfile.TemporaryDirectory() as tmpdir:
+            pipe.save_pretrained(tmpdir)
+            config_path = os.path.join(tmpdir, "modular_config.json")
+            with open(config_path, "r") as f:
+                config = json.load(f)
+
+        assert "requirements" in config
+        requirements = config["requirements"]
+
+        expected_requirements = {
+            "xyz": ">=0.8.0",
+            "abc": ">=10.0.0",
+            "transformers": ">=4.44.0",
+            "diffusers": ">=0.2.0",
+        }
+        assert expected_requirements == requirements
+
+    def test_warnings(self):
+        pipe = self.get_dummy_block_pipe()
+        with tempfile.TemporaryDirectory() as tmpdir:
+            logger = logging.get_logger("diffusers.modular_pipelines.modular_pipeline_utils")
+            logger.setLevel(30)
+
+            with CaptureLogger(logger) as cap_logger:
+                pipe.save_pretrained(tmpdir)
+
+            template = "{req} was specified in the requirements but wasn't found in the current environment"
+            msg_xyz = template.format(req="xyz")
+            msg_abc = template.format(req="abc")
+            assert msg_xyz in str(cap_logger.out)
+            assert msg_abc in str(cap_logger.out)