"""Unit tests for image_utils.py — local only."""
import io
import pytest
from PIL import Image
from jlab_mcp.image_utils import _calculate_resize_dimensions, resize_image_if_needed
def _make_png(width: int, height: int) -> bytes:
"""Create a PNG image of given dimensions."""
img = Image.new("RGB", (width, height), color="red")
buf = io.BytesIO()
img.save(buf, format="PNG")
return buf.getvalue()
class TestCalculateResizeDimensions:
def test_small_image_unchanged(self):
assert _calculate_resize_dimensions(100, 100) == (100, 100)
def test_square_at_limit(self):
assert _calculate_resize_dimensions(512, 512) == (512, 512)
def test_wide_image(self):
w, h = _calculate_resize_dimensions(1024, 512)
assert w == 512
assert h == 256
def test_tall_image(self):
w, h = _calculate_resize_dimensions(512, 1024)
assert w == 256
assert h == 512
def test_very_large(self):
w, h = _calculate_resize_dimensions(4000, 3000)
assert w == 512
assert h == 384
def test_maintains_aspect_ratio(self):
w, h = _calculate_resize_dimensions(1000, 500, max_dim=200)
assert w == 200
assert h == 100
def test_custom_max_dim(self):
w, h = _calculate_resize_dimensions(1000, 1000, max_dim=256)
assert w == 256
assert h == 256
class TestResizeImageIfNeeded:
def test_small_image_passthrough(self):
original = _make_png(100, 100)
result = resize_image_if_needed(original)
assert result == original
def test_at_limit_passthrough(self):
original = _make_png(512, 512)
result = resize_image_if_needed(original)
assert result == original
def test_large_image_resized(self):
original = _make_png(1024, 768)
result = resize_image_if_needed(original)
assert result != original
img = Image.open(io.BytesIO(result))
assert img.width <= 512
assert img.height <= 512
def test_maintains_aspect_ratio(self):
original = _make_png(2000, 1000)
result = resize_image_if_needed(original)
img = Image.open(io.BytesIO(result))
assert img.width == 512
assert img.height == 256
def test_invalid_data_returns_original(self):
bad_data = b"not an image"
result = resize_image_if_needed(bad_data)
assert result == bad_data
def test_custom_max_dim(self):
original = _make_png(1000, 1000)
result = resize_image_if_needed(original, max_dim=256)
img = Image.open(io.BytesIO(result))
assert img.width == 256
assert img.height == 256
