fix(cookbook): allow local Windows Diffusers serving (#4077)

tests/test_cookbook_cpu_only_serve.py

@@ -15,6 +15,7 @@ import re
 from pathlib import Path
 
 SRC = Path(__file__).resolve().parent.parent / "static/js/cookbook.js"
+SERVE_SRC = Path(__file__).resolve().parent.parent / "static/js/cookbookServe.js"
 
 
 def test_cpu_only_drops_gpu_only_flags():
@@ -28,3 +29,25 @@ def test_cpu_only_drops_gpu_only_flags():
     # The CUDA unified-memory env must be suppressed for CPU-only too.
     assert "f.unified_mem && !_cpuOnly" in text, \
         "GGML_CUDA_ENABLE_UNIFIED_MEMORY must be gated on !_cpuOnly"
+
+
+def test_diffusers_is_not_blocked_on_windows_dependencies_panel():
+    text = SRC.read_text(encoding="utf-8")
+
+    assert "const _winUnsupported = new Set(['hf_transfer', 'vllm', 'rembg', 'gfpgan']);" in text
+    assert "new Set(['diffusers'" not in text
+
+
+def test_diffusers_is_available_on_windows_serve_panel():
+    text = SERVE_SRC.read_text(encoding="utf-8")
+
+    assert "? ['llamacpp', 'diffusers']" in text
+    assert "? [['llamacpp','llama.cpp'],['diffusers','Diffusers']]" in text
+
+
+def test_windows_diffusers_uses_python_not_python3():
+    text = SRC.read_text(encoding="utf-8")
+
+    assert "const diffusersPy = _isWindows() ? 'python' : _py3Bin;" in text
+    assert "cmd += `${diffusersPy} scripts/diffusion_server.py" in text
+    assert "cmd += `python3 scripts/diffusion_server.py" not in text

tests/test_cookbook_package_detection.py

@@ -23,6 +23,7 @@ def test_llama_cpp_maps_to_llama_cpp_python_distribution():
 
 def test_extras_and_version_markers_are_stripped():
     assert _pip_dist_name({"name": "diffusers", "pip": "diffusers[torch]"}) == "diffusers"
+    assert _pip_dist_name({"name": "transformers", "pip": "transformers"}) == "transformers"
     assert _pip_dist_name({"name": "sglang", "pip": "sglang[all]"}) == "sglang"
     assert _pip_dist_name({"name": "rembg", "pip": "rembg[gpu]"}) == "rembg"
     assert _pip_dist_name({"name": "x", "pip": "foo>=1.2,<2"}) == "foo"
@@ -48,3 +49,11 @@ def test_route_uses_dist_name_helper_not_munged_import_name():
     src = (Path(__file__).resolve().parents[1] / "routes" / "shell_routes.py").read_text(encoding="utf-8")
     assert "importlib_metadata.version(_pip_dist_name(pkg))" in src
     assert 'importlib_metadata.version(pkg["name"].replace("_", "-"))' not in src
+
+
+def test_transformers_is_listed_as_image_dependency():
+    src = (Path(__file__).resolve().parents[1] / "routes" / "shell_routes.py").read_text(encoding="utf-8")
+
+    assert '"name": "transformers"' in src
+    assert '"pip": "transformers"' in src
+    assert '"transformers",' in src