perspective-dev--perspective/packages/jupyterlab/DEVELOPMENT.md

Build

As of March 2025, the build process is a little different from the jupyterlab extension cookiecutter template. The build works as follows:

labextension

1. esbuild produces a bundle in dist/esm with src/index.js as its entrypoint
2. jupyter labextension build packages that bundle, which is read from the main field in package.json, into dist/cjs
3. the dist/cjs output is copied to the perspective-python package's .data directory.

This means running jupyter labextension build or watch out-of-band from the build script won't rebuild the labextension on its own; the labextension step runs on the output of the esbuild step.