plotly scraper demo

run_demo.sh

#!/usr/bin/env bash
# Before/after demo for plotly/plotly.py#5701 (sphinx-gallery scraper rewrite).
# Creates ./sgdemo and ./sgdemo-venv, builds the same one-example gallery with
# released plotly and with the PR branch, and prints what to compare.
set -euo pipefail

mkdir -p sgdemo/examples
# a rerun must not reuse sphinx-gallery's cache of executed examples
rm -rf sgdemo/auto_examples sgdemo/_build_before sgdemo/_build_after

cat > sgdemo/conf.py <<'EOF'
project = "plotly-scraper-demo"
extensions = ["sphinx_gallery.gen_gallery"]
sphinx_gallery_conf = {
    "examples_dirs": "examples",
    "gallery_dirs": "auto_examples",
    # spelled out so the same conf works before and after the PR;
    # with the new plotly this can be just "plotly"
    "image_scrapers": ("plotly.io._sg_scraper.plotly_sg_scraper",),
}
EOF
printf 'demo\n====\n.. toctree::\n\n   auto_examples/index\n' > sgdemo/index.rst
printf 'Examples\n========\n' > sgdemo/examples/GALLERY_HEADER.rst
cat > sgdemo/examples/plot_demo.py <<'EOF'
"""
Plotly demo
===========
"""
import plotly.graph_objects as go

fig = go.Figure(go.Bar(x=["a", "b", "c"], y=[1, 3, 2]))
fig.show()
EOF

python3 -m venv sgdemo-venv
PIP=sgdemo-venv/bin/pip
PY=sgdemo-venv/bin/python
$PIP install --quiet sphinx sphinx-gallery matplotlib pillow kaleido

# pip can consider either plotly satisfied by the other (same version
# number), so uninstall before each leg
echo "=== BEFORE: released plotly ==="
$PIP uninstall --quiet -y plotly 2>/dev/null || true
$PIP install --quiet plotly
$PY -m sphinx -b html sgdemo sgdemo/_build_before

echo "=== AFTER: plotly from the PR branch ==="
$PIP uninstall --quiet -y plotly
$PIP install --quiet "plotly @ git+https://github.com/larsoner/plotly.py@sgthumb"
rm -rf sgdemo/auto_examples  # sphinx-gallery caches executed examples
$PY -m sphinx -b html sgdemo sgdemo/_build_after

cat <<'EOF'

Compare the gallery thumbnail and the figure on the example page:
  before: sgdemo/_build_before/auto_examples/index.html
          (placeholder thumbnail; the figure is missing from the page)
  after:  sgdemo/_build_after/auto_examples/index.html
          (real figure thumbnail; interactive figure on the page)

The "after" build exports static images
EOF