"""Tests for agent/image_routing.py — the per-turn image input mode decision.""" from __future__ import annotations import base64 from pathlib import Path from unittest.mock import patch import pytest from agent.image_routing import ( _coerce_mode, _explicit_aux_vision_override, build_native_content_parts, decide_image_input_mode, ) # ─── _coerce_mode ──────────────────────────────────────────────────────────── class TestCoerceMode: def test_valid_modes_pass_through(self): assert _coerce_mode("auto") == "auto" assert _coerce_mode("native") == "native" assert _coerce_mode("text") == "text" def test_case_insensitive(self): assert _coerce_mode("NATIVE") == "native" assert _coerce_mode("Auto") == "auto" def test_invalid_falls_back_to_auto(self): assert _coerce_mode("nonsense") == "auto" assert _coerce_mode("") == "auto" assert _coerce_mode(None) == "auto" assert _coerce_mode(42) == "auto" def test_strips_whitespace(self): assert _coerce_mode(" native ") == "native" # ─── _explicit_aux_vision_override ─────────────────────────────────────────── class TestExplicitAuxVisionOverride: def test_none_config(self): assert _explicit_aux_vision_override(None) is False def test_empty_config(self): assert _explicit_aux_vision_override({}) is False def test_default_auto_is_not_explicit(self): cfg = {"auxiliary": {"vision": {"provider": "auto", "model": "", "base_url": ""}}} assert _explicit_aux_vision_override(cfg) is False def test_provider_set_is_explicit(self): cfg = {"auxiliary": {"vision": {"provider": "openrouter", "model": ""}}} assert _explicit_aux_vision_override(cfg) is True def test_model_set_is_explicit(self): cfg = {"auxiliary": {"vision": {"provider": "auto", "model": "google/gemini-2.5-flash"}}} assert _explicit_aux_vision_override(cfg) is True def test_base_url_set_is_explicit(self): cfg = {"auxiliary": {"vision": {"provider": "auto", "base_url": "http://localhost:11434"}}} assert _explicit_aux_vision_override(cfg) is True # ─── decide_image_input_mode ───────────────────────────────────────────────── class TestDecideImageInputMode: def test_explicit_native_overrides_everything(self): cfg = {"agent": {"image_input_mode": "native"}} # Non-vision model, aux-vision explicitly configured: native still wins. cfg["auxiliary"] = {"vision": {"provider": "openrouter", "model": "foo"}} with patch("agent.image_routing._lookup_supports_vision", return_value=False): assert decide_image_input_mode("openrouter", "some-non-vision-model", cfg) == "native" def test_explicit_text_overrides_everything(self): cfg = {"agent": {"image_input_mode": "text"}} with patch("agent.image_routing._lookup_supports_vision", return_value=True): assert decide_image_input_mode("anthropic", "claude-sonnet-4", cfg) == "text" def test_auto_with_vision_capable_model(self): with patch("agent.image_routing._lookup_supports_vision", return_value=True): assert decide_image_input_mode("anthropic", "claude-sonnet-4", {}) == "native" def test_auto_with_non_vision_model(self): with patch("agent.image_routing._lookup_supports_vision", return_value=False): assert decide_image_input_mode("openrouter", "qwen/qwen3-235b", {}) == "text" def test_auto_with_unknown_model(self): with patch("agent.image_routing._lookup_supports_vision", return_value=None): assert decide_image_input_mode("openrouter", "brand-new-slug", {}) == "text" def test_auto_respects_aux_vision_override_even_for_vision_model(self): """If the user configured a dedicated vision backend, don't bypass it.""" cfg = {"auxiliary": {"vision": {"provider": "openrouter", "model": "google/gemini-2.5-flash"}}} with patch("agent.image_routing._lookup_supports_vision", return_value=True): assert decide_image_input_mode("anthropic", "claude-sonnet-4", cfg) == "text" def test_none_config_is_auto(self): with patch("agent.image_routing._lookup_supports_vision", return_value=True): assert decide_image_input_mode("anthropic", "claude-sonnet-4", None) == "native" def test_invalid_mode_coerces_to_auto(self): cfg = {"agent": {"image_input_mode": "weird-value"}} with patch("agent.image_routing._lookup_supports_vision", return_value=True): assert decide_image_input_mode("anthropic", "claude-sonnet-4", cfg) == "native" def test_auto_uses_text_for_text_only_modalities_even_with_attachment_flag(self): registry = { "xiaomi": { "models": { "mimo-v2.5-pro": { "attachment": True, "modalities": {"input": ["text"]}, "tool_call": True, }, }, }, } with patch("agent.models_dev.fetch_models_dev", return_value=registry): assert decide_image_input_mode("xiaomi", "mimo-v2.5-pro", {}) == "text" # ─── build_native_content_parts ────────────────────────────────────────────── def _png_bytes() -> bytes: """Return a tiny valid 1x1 transparent PNG.""" return base64.b64decode( "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR4nGNgYGBgAAAABQABpfZFQAAAAABJRU5ErkJggg==" ) class TestBuildNativeContentParts: def test_text_then_image(self, tmp_path: Path): img = tmp_path / "cat.png" img.write_bytes(_png_bytes()) parts, skipped = build_native_content_parts("hello", [str(img)]) assert skipped == [] assert len(parts) == 2 assert parts[0]["type"] == "text" # User caption is preserved and a per-image path hint is appended so # the model can use the local path as a string argument for tools # that take ``image_url: str`` (issue #18960). assert parts[0]["text"] == f"hello\n\n[Image attached at: {img}]" assert parts[1]["type"] == "image_url" assert parts[1]["image_url"]["url"].startswith("data:image/png;base64,") def test_empty_text_inserts_default_prompt(self, tmp_path: Path): img = tmp_path / "cat.jpg" img.write_bytes(_png_bytes()) parts, skipped = build_native_content_parts("", [str(img)]) assert skipped == [] # Even with empty user text, we insert a neutral prompt so the turn # isn't just pixels, and the path hint is appended after. assert parts[0]["type"] == "text" assert parts[0]["text"] == ( f"What do you see in this image?\n\n[Image attached at: {img}]" ) assert parts[1]["type"] == "image_url" def test_missing_file_is_skipped(self, tmp_path: Path): parts, skipped = build_native_content_parts("hi", [str(tmp_path / "missing.png")]) assert skipped == [str(tmp_path / "missing.png")] # Skipped paths are NOT advertised in the path hints — the model # would otherwise be told a non-existent file is attached. assert parts == [{"type": "text", "text": "hi"}] def test_path_hint_appended(self, tmp_path: Path): """The local path of each attached image is appended to the user text part so MCP/skill tools that take ``image_url: str`` can be invoked on the same image (issue #18960). Mirrors text-mode behaviour (`Runner._enrich_message_with_vision`). """ img = tmp_path / "scan.png" img.write_bytes(_png_bytes()) parts, _ = build_native_content_parts("attach this", [str(img)]) text_part = next(p for p in parts if p.get("type") == "text") assert "[Image attached at:" in text_part["text"] assert str(img) in text_part["text"] # User caption is preserved verbatim ahead of the hint. assert text_part["text"].startswith("attach this") def test_path_hint_one_per_attached_image(self, tmp_path: Path): """Each successfully attached image gets its own path hint line; skipped images do NOT appear in the hints. """ good = tmp_path / "good.png" good.write_bytes(_png_bytes()) missing = tmp_path / "missing.png" # never created parts, skipped = build_native_content_parts( "see attached", [str(good), str(missing)] ) assert skipped == [str(missing)] text_part = next(p for p in parts if p.get("type") == "text") assert text_part["text"].count("[Image attached at:") == 1 assert str(good) in text_part["text"] assert str(missing) not in text_part["text"] def test_multiple_images(self, tmp_path: Path): img1 = tmp_path / "a.png" img2 = tmp_path / "b.png" img1.write_bytes(_png_bytes()) img2.write_bytes(_png_bytes()) parts, skipped = build_native_content_parts("compare these", [str(img1), str(img2)]) assert skipped == [] image_parts = [p for p in parts if p.get("type") == "image_url"] assert len(image_parts) == 2 # Both paths surface in the text part, one per line. text_part = next(p for p in parts if p.get("type") == "text") assert text_part["text"].count("[Image attached at:") == 2 assert str(img1) in text_part["text"] assert str(img2) in text_part["text"] def test_mime_inference_jpg(self, tmp_path: Path): # Real JPEG bytes (SOI marker FF D8 FF): sniffing now wins over suffix. img = tmp_path / "photo.jpg" img.write_bytes(b"\xff\xd8\xff\xe0\x00\x10JFIF\x00\x01" + b"\x00" * 32) parts, _ = build_native_content_parts("x", [str(img)]) url = parts[1]["image_url"]["url"] assert url.startswith("data:image/jpeg;base64,") def test_mime_inference_webp(self, tmp_path: Path): # Real WEBP bytes (RIFF....WEBP): sniffing now wins over suffix. img = tmp_path / "pic.webp" img.write_bytes(b"RIFF\x24\x00\x00\x00WEBPVP8 " + b"\x00" * 32) parts, _ = build_native_content_parts("", [str(img)]) url = parts[1]["image_url"]["url"] assert url.startswith("data:image/webp;base64,") def test_mime_sniff_overrides_misleading_extension(self, tmp_path: Path): """Discord-style bug: file is named .webp but contains PNG bytes. Anthropic rejects on MIME mismatch (HTTP 400) so we MUST sniff. Regression guard for the user-reported Discord PNG-as-WEBP failure. """ img = tmp_path / "discord_cached.webp" img.write_bytes(_png_bytes()) # bytes are PNG, suffix lies parts, _ = build_native_content_parts("", [str(img)]) url = parts[1]["image_url"]["url"] assert url.startswith("data:image/png;base64,"), ( f"Expected MIME sniffing to detect PNG bytes regardless of .webp suffix, got: {url[:60]}" ) # ─── Oversize handling ─────────────────────────────────────────────────────── class TestLargeImageHandling: """Large images attach at native size; shrink is handled reactively at retry time in ``run_agent._try_shrink_image_parts_in_messages`` rather than proactively here. """ def test_large_image_passes_through_unchanged(self, tmp_path: Path): """A multi-MB image is attached as-is — no resize, no skip.""" from agent import image_routing as _ir img = tmp_path / "medium.png" # 200 KB of real bytes; not huge but enough to verify no size gate fires. img.write_bytes(b"\x89PNG\r\n\x1a\n" + b"X" * 200_000) url = _ir._file_to_data_url(img) assert url is not None assert url.startswith("data:image/png;base64,") # Base64 expansion means output is ~4/3 of input, plus header. assert len(url) > 200_000 def test_missing_file_returns_none(self, tmp_path: Path): from agent import image_routing as _ir missing = tmp_path / "does_not_exist.png" assert _ir._file_to_data_url(missing) is None def test_build_native_parts_no_provider_kwarg(self, tmp_path: Path): """build_native_content_parts takes text + paths, no provider kwarg.""" from agent import image_routing as _ir img = tmp_path / "cat.png" img.write_bytes(_png_bytes()) parts, skipped = _ir.build_native_content_parts("hi", [str(img)]) assert skipped == [] assert len(parts) == 2 assert parts[0]["type"] == "text" assert parts[1]["type"] == "image_url"