80 lines
2.9 KiB
Python
80 lines
2.9 KiB
Python
"""
|
||
Test suite for pydyf.
|
||
|
||
This module adds a PNG export based on GhostScript, that is released under
|
||
AGPL. As "the end user has the ability to opt out of installing the AGPL
|
||
version of [Ghostscript] during the install process", and with explicit
|
||
aggreement from Artifex, it is OK to distribute this code under BSD.
|
||
|
||
See https://www.ghostscript.com/license.html.
|
||
|
||
"""
|
||
|
||
import io
|
||
import os
|
||
from pathlib import Path
|
||
from subprocess import PIPE, run
|
||
|
||
from PIL import Image
|
||
|
||
PIXELS_BY_CHAR = dict(
|
||
_=(255, 255, 255), # white
|
||
R=(255, 0, 0), # red
|
||
B=(0, 0, 255), # blue
|
||
G=(0, 255, 0), # lime green
|
||
K=(0, 0, 0), # black
|
||
z=None, # any color
|
||
)
|
||
|
||
|
||
def assert_pixels(document, reference_pixels):
|
||
"""Test that the rendered document matches the reference pixels."""
|
||
|
||
# Transform the PDF document into a list of RGB tuples
|
||
pdf = io.BytesIO()
|
||
document.write(pdf)
|
||
command = [
|
||
'gs', '-q', '-dNOPAUSE', '-dSAFER', '-sDEVICE=png16m',
|
||
'-r576', '-dDownScaleFactor=8', '-sOutputFile=-', '-']
|
||
png = run(command, input=pdf.getvalue(), stdout=PIPE).stdout
|
||
image = Image.open(io.BytesIO(png))
|
||
pixels = image.getdata()
|
||
|
||
# Transform reference drawings into a list of RGB tuples
|
||
lines = tuple(
|
||
line.strip() for line in reference_pixels.splitlines() if line.strip())
|
||
assert len({len(line) for line in lines}) == 1, (
|
||
'The lines of reference pixels don’t have the same length')
|
||
width, height = len(lines[0]), len(lines)
|
||
assert (width, height) == image.size, (
|
||
f'Reference size is {width}×{height}, '
|
||
f'output size is {image.width}×{image.height}')
|
||
reference_pixels = tuple(
|
||
PIXELS_BY_CHAR[char] for line in lines for char in line)
|
||
|
||
# Compare pixels
|
||
if pixels != reference_pixels: # pragma: no cover
|
||
for i, (value, reference) in enumerate(zip(pixels, reference_pixels)):
|
||
if reference is None:
|
||
continue
|
||
if any(value != reference
|
||
for value, reference in zip(value, reference)):
|
||
name = os.environ.get('PYTEST_CURRENT_TEST')
|
||
name = name.split(':')[-1].split(' ')[0]
|
||
write_png(f'{name}', pixels, width, height)
|
||
reference_pixels = [
|
||
pixel or (255, 255, 255) for pixel in reference_pixels]
|
||
write_png(f'{name}-reference', reference_pixels, width, height)
|
||
x, y = i % width, i // width
|
||
assert 0, (
|
||
f'Pixel ({x}, {y}) in {name}: '
|
||
f'reference rgba{reference}, got rgba{value}')
|
||
|
||
|
||
def write_png(name, pixels, width, height): # pragma: no cover
|
||
"""Take a pixel matrix and write a PNG file."""
|
||
directory = Path(__file__).parent / 'results'
|
||
directory.mkdir(exist_ok=True)
|
||
image = Image.new('RGB', (width, height))
|
||
image.putdata(pixels)
|
||
image.save(directory / f'{name}.png')
|