kerf-engine/engine/tests/test_api.py

"""Integration tests for the /engine/trace endpoint."""

import json

import cv2
import numpy as np
import pytest
from fastapi.testclient import TestClient

from main import app

client = TestClient(app)


def _make_test_png(width: int = 100, height: int = 100) -> bytes:
    """Create a simple test PNG with a white rectangle on black background."""
    img = np.zeros((height, width, 3), dtype=np.uint8)
    cv2.rectangle(img, (20, 20), (80, 80), (255, 255, 255), -1)
    ok, buf = cv2.imencode(".png", img)
    assert ok
    return buf.tobytes()


@pytest.fixture
def test_png() -> bytes:
    return _make_test_png()


class TestTraceEndpointPotrace:
    """Tests for /engine/trace with mode=potrace."""

    def test_basic_trace(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace"},
        )
        assert resp.status_code == 200
        body = resp.json()
        assert body["format"] == "svg"
        assert "<svg" in body["output"]
        assert "metadata" in body

    def test_metadata_shape(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace"},
        )
        body = resp.json()
        meta = body["metadata"]
        assert "path_count" in meta
        assert "node_count_total" in meta
        assert "open_paths" in meta
        assert "warnings" in meta
        assert "processing_ms" in meta
        assert isinstance(meta["path_count"], int)
        assert isinstance(meta["processing_ms"], float)

    def test_svg_has_paths(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace"},
        )
        body = resp.json()
        assert body["metadata"]["path_count"] >= 1

    def test_custom_params(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={
                "mode": "potrace",
                "params": json.dumps({"turdsize": 5, "alphamax": 0.5}),
            },
        )
        assert resp.status_code == 200
        assert "<svg" in resp.json()["output"]


class TestTraceEndpointVtracer:
    """Tests for /engine/trace with mode=vtracer."""

    def test_basic_trace(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "vtracer"},
        )
        assert resp.status_code == 200
        body = resp.json()
        assert body["format"] == "svg"
        assert "<svg" in body["output"].lower() or "svg" in body["output"]

    def test_metadata_present(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "vtracer"},
        )
        body = resp.json()
        meta = body["metadata"]
        assert isinstance(meta["path_count"], int)
        assert isinstance(meta["processing_ms"], float)

    def test_custom_params(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={
                "mode": "vtracer",
                "params": json.dumps({"filter_speckle": 10, "corner_threshold": 90}),
            },
        )
        assert resp.status_code == 200


class TestTraceEndpointValidation:
    """Tests for input validation on /engine/trace."""

    def test_invalid_mode(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "invalid"},
        )
        assert resp.status_code == 422

    def test_unsupported_output_format(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace", "output_format": "pdf"},
        )
        assert resp.status_code == 422

    def test_invalid_params_json(self, test_png):
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace", "params": "not-json"},
        )
        assert resp.status_code == 422

    def test_empty_file(self):
        resp = client.post(
            "/engine/trace",
            files={"file": ("empty.png", b"", "image/png")},
            data={"mode": "potrace"},
        )
        assert resp.status_code == 422

    def test_corrupt_image(self):
        resp = client.post(
            "/engine/trace",
            files={"file": ("bad.png", b"not an image", "image/png")},
            data={"mode": "potrace"},
        )
        assert resp.status_code == 422

    def test_defaults_to_potrace(self, test_png):
        """Mode defaults to potrace when not specified."""
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
        )
        assert resp.status_code == 200
        assert "<svg" in resp.json()["output"]

    def test_preset_ignored(self, test_png):
        """Preset param is accepted but ignored for now."""
        resp = client.post(
            "/engine/trace",
            files={"file": ("test.png", test_png, "image/png")},
            data={"mode": "potrace", "preset": "logo"},
        )
        assert resp.status_code == 200