def test_imager(enable_bitmap, tmpdir):
with tmpdir.as_cwd():
tex = TeX()
tex.ownerDocument.config['images']["imager"] = "none"
tex.ownerDocument.config['images']["vector-imager"] = "pdf2svg"
tex.input(r'''
\documentclass{article}
\begin{document}
$a + b = x$
\end{document}
''')
doc = tex.parse()
renderer = Renderer()
renderer.imager = NullImager(doc)
renderer.vectorBitmap = enable_bitmap
renderer['math'] = lambda node: node.vectorImage.url
if enable_bitmap:
with pytest.raises(ValueError):
renderer.render(doc)
else:
renderer.render(doc)
