Implement tests for non-default params in image_edit

Add unit tests to verify forwarding of non-default parameters in image_edit fallback handler.

tests/image_gen_tests/test_image_edit_non_default_params.py

@@ -0,0 +1,141 @@
+"""
+Unit tests for PR #30814: forward non_default_params in image_edit fallback handler.
+
+Before the fix, provider-specific kwargs (e.g. image_config) were silently
+dropped in the fallback branch of litellm.image_edit().  The bedrock, stability,
+and black_forest_labs branches already called
+    image_edit_request_params.update(non_default_params)
+but the else/fallback branch did not.
+
+These tests verify that any kwarg not in litellm's standard param list is
+forwarded to base_llm_http_handler.image_edit_handler via
+image_edit_optional_request_params.
+"""
+import sys
+import os
+
+sys.path.insert(0, os.path.abspath("../.."))
+
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+import litellm
+from litellm.images.main import image_edit
+from litellm.types.utils import ImageResponse, ImageObject
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+def _fake_image_response() -> ImageResponse:
+    return ImageResponse(
+        created=1700000000,
+        data=[ImageObject(url="https://example.com/edited.png")],
+    )
+
+
+def _make_logging_mock() -> MagicMock:
+    """Minimal stand-in for the LiteLLMLoggingObj passed via kwargs."""
+    m = MagicMock()
+    m.update_from_kwargs.return_value = None
+    return m
+
+
+def _make_provider_config_mock() -> MagicMock:
+    """Stand-in for BaseImageEditConfig."""
+    cfg = MagicMock()
+    cfg.get_supported_openai_params.return_value = []
+    return cfg
+
+
+def _make_request_utils_mock() -> MagicMock:
+    utils = MagicMock()
+    utils.get_requested_image_edit_optional_param.return_value = MagicMock()
+    # Base params dict -- non_default_params are merged on top of this.
+    utils.get_optional_params_image_edit.return_value = {}
+    return utils
+
+
+# ---------------------------------------------------------------------------
+# Tests
+# ---------------------------------------------------------------------------
+
+class TestFallbackHandlerForwardsNonDefaultParams:
+    """
+    The fallback branch (anything that is not bedrock / stability /
+    black_forest_labs) must call
+        image_edit_request_params.update(non_default_params)
+    before delegating to base_llm_http_handler.image_edit_handler.
+    """
+
+    def _run(self, **extra_kwargs):
+        """
+        Call image_edit() with all external dependencies mocked, returning the
+        captured call-kwargs of base_llm_http_handler.image_edit_handler.
+        """
+        mock_handler = MagicMock(return_value=_fake_image_response())
+
+        with (
+            patch(
+                "litellm.images.main.base_llm_http_handler.image_edit_handler",
+                mock_handler,
+            ),
+            patch(
+                "litellm.images.main.ProviderConfigManager.get_provider_image_edit_config",
+                return_value=_make_provider_config_mock(),
+            ),
+            patch(
+                "litellm.images.main._get_ImageEditRequestUtils",
+                return_value=_make_request_utils_mock(),
+            ),
+        ):
+            image_edit(
+                model="gpt-image-1",
+                image=b"fake-image-bytes",
+                prompt="add a sunset background",
+                litellm_logging_obj=_make_logging_mock(),
+                **extra_kwargs,
+            )
+
+        assert mock_handler.called, "image_edit_handler was never invoked"
+        return mock_handler.call_args.kwargs
+
+    # ------------------------------------------------------------------
+
+    def test_image_config_forwarded(self):
+        """image_config (a non-default param) must reach the handler."""
+        call_kw = self._run(image_config={"quality": "high", "background": "transparent"})
+        optional = call_kw.get("image_edit_optional_request_params", {})
+
+        assert "image_config" in optional, (
+            f"image_config was dropped. image_edit_optional_request_params={optional}"
+        )
+        assert optional["image_config"] == {"quality": "high", "background": "transparent"}
+
+    def test_multiple_non_default_params_forwarded(self):
+        """All non-default params are forwarded, not just image_config."""
+        call_kw = self._run(
+            image_config={"quality": "hd"},
+            custom_vendor_param="foo",
+        )
+        optional = call_kw.get("image_edit_optional_request_params", {})
+
+        assert "image_config" in optional, f"image_config missing: {optional}"
+        assert "custom_vendor_param" in optional, f"custom_vendor_param missing: {optional}"
+
+    def test_standard_params_not_in_non_default(self):
+        """
+        Standard openai/litellm params (e.g. n, size) are not in non_default_params
+        and must not be re-injected by the update() call.
+        """
+        call_kw = self._run(image_config={"quality": "standard"})
+        optional = call_kw.get("image_edit_optional_request_params", {})
+        # image_config is the non-default param -- it must be present.
+        assert "image_config" in optional
+
+    def test_no_non_default_params_still_calls_handler(self):
+        """Sanity check: the fallback path works with no extra kwargs too."""
+        call_kw = self._run()
+        assert "image_edit_optional_request_params" in call_kw