If you're reading this section, you're probably interested in contributing to JupyterLab. Welcome and thanks for your interest in contributing!
Please take a look at the Contributor documentation, familiarize yourself with using JupyterLab, and introduce yourself on the mailing list and share what area of the project you are interested in working on. Please see also the Jupyter Community Guides.
We have labeled some issues as good first issue or help wanted that we believe are good examples of small, self-contained changes. We encourage those that are new to the code base to implement and/or ask questions about these issues.
Users without the commit rights to the jupyterlab repository can also tag the issues with labels. For example: To apply the label foo
and bar baz
to an issue, comment @meeseeksdev tag foo "bar baz"
on the issue.
For general documentation about contributing to Jupyter projects, see the Project Jupyter Contributor Documentation and Code of Conduct.
All source code is written in TypeScript. See the Style Guide.
All source code is formatted using prettier. When code is modified and committed, all staged files will be automatically formatted using pre-commit git hooks (with help from the lint-staged and husky libraries). The benefit of using a code formatter like prettier is that it removes the topic of code style from the conversation when reviewing pull requests, thereby speeding up the review process.
You may also use the prettier npm script (e.g. npm run prettier
or yarn prettier
or jlpm prettier
) to format the entire code base. We recommend
installing a prettier
extension for your code editor and configuring it to format your code with
a keyboard shortcut or automatically on save.
You can launch a binder with the latest JupyterLab master to test something (this may take a few minutes to load):
Building JupyterLab from its GitHub source code requires Node.js.
If you use conda
, you can get it with:
conda install -c conda-forge 'nodejs'
If you use Homebrew on Mac OS X:
brew install node
You can also use the installer from the Node.js website.
JupyterLab requires Jupyter Notebook version 4.3 or later.
If you use conda
, you can install notebook using:
conda install -c conda-forge notebook
You may also want to install nb_conda_kernels
to have a kernel option for different conda environments
conda install -c conda-forge nb_conda_kernels
If you use pip
, you can install notebook using:
pip install notebook
Fork the JupyterLab repository.
Once you have installed the dependencies mentioned above, use the following steps:
git clone https://github.com/<your-github-username>/jupyterlab.git
cd jupyterlab
pip install -e .
jlpm install
jlpm run build # Build the dev mode assets (optional)
jlpm run build:core # Build the core mode assets (optional)
jupyter lab build # Build the app dir assets (optional)
Notes:
-
A few of the scripts will run "python". If your target python is called something else (such as "python3") then parts of the build will fail. You may wish to build in a conda environment, or make an alias.
-
The
jlpm
command is a JupyterLab-provided, locked version of the yarn package manager. If you haveyarn
installed already, you can use theyarn
command when developing, and it will use the local version ofyarn
injupyterlab/yarn.js
when run in the repository or a built application directory. -
At times, it may be necessary to clean your local repo with the command
npm run clean:slate
. This will clean the repository, and re-install and rebuild. -
If
pip
gives aVersionConflict
error, it usually means that the installed version ofjupyterlab_server
is out of date. Runpip install --upgrade jupyterlab_server
to get the latest version. -
To install JupyterLab in isolation for a single conda/virtual environment, you can add the
--sys-prefix
flag to the extension activation above; this will tie the installation to thesys.prefix
location of your environment, without writing anything in your user-wide settings area (which are visible to all your envs): -
You can run
jlpm run build:dev:prod
to build more accurate sourcemaps that show the original Typescript code when debugging. However, it takes a bit longer to build the sources, so is used only to build for production by default.
If you are using a version of Jupyter Notebook earlier than 5.3, then you must also run the following command to enable the JupyterLab server extension:
jupyter serverextension enable --py --sys-prefix jupyterlab
For installation instructions to write documentation, please see Writing Documentation
Start JupyterLab in development mode:
jupyter lab --dev-mode
Development mode ensures that you are running the JavaScript assets that are built in the dev-installed Python package. When running in dev mode, a red stripe will appear at the top of the page; this is to indicate running an unreleased version.
jlpm run build:test
jlpm test
You can run tests for an individual package by changing to the appropriate folder in tests:
cd tests/test-notebook
jlpm test
Note: We are in the process of changing our test suite over to use jest
. For folders
that have a jest.conf.js
file, please see the jest
specific instructions below.
You can also select specific test file(s) to run using a pattern:
cd tests/test-notebook
jlpm test --pattern=src/*.spec.ts
jlpm test --pattern=src/history.spec.ts
You can run jlpm watch
from a test folder, and it will re-run the tests
when the source file(s) change. Note that you have to launch the browser
of your choice after it says No captured browser
. You can put a debugger
statement on a line and open the browser debugger to debug specific tests.
jlpm watch
also accepts the --pattern
argument.
Note that there are some helper functions in testutils
(which is a public npm package called @jupyterlab/testutils
) that are used by many of the tests.
We use karma
to run our tests in a browser, mocha
as the test framework, and chai
for test assertions. We use async/await for asynchronous tests. We have
a helper function in @jupyterlab/testutils
called testEmission
to help with
writing tests that use Phosphor
signals, as well as a framePromise
function
to get a Promise
for a requestAnimationFrame
. We sometimes have to set
a sentinel value inside a Promise
and then check that the sentinel was set if
we need a promise to run without blocking.
To create a new test for a package in packages/
, use the following
command, where <package-directory-name>
is the name of the folder in
packages/
:
jlpm create:test <package-directory-name>
For those test folders that use jest
, they can be run as jlpm test
to run the files
directly. You can also use jlpm test --namePattern=<regex>
to specify specific test
suite names, and jlpm test --pathPattern=<regex>
to specify specific test module names. In order to watch the code, add a debugger
line in your code and run jlpm watch
. This will start a node V8 debugger, which can be debugged
in Chrome by browsing to chrome://inspect/
and launching the remote session.
To install and build the examples in the examples
directory:
jlpm run build:examples
To run a specific example, change to the examples directory (i.e.
examples/filebrowser
) and enter:
python main.py
All methods of building JupyterLab produce source maps. The source maps
should be available in the source files view of your browser's development
tools under the webpack://
header.
When running JupyterLab normally, expand the ~
header to see the source maps for individual packages.
When running in --dev-mode
, the core packages are available under
packages/
, while the third party libraries are available under ~
.
Note: it is recommended to use jupyter lab --watch --dev-mode
while
debugging.
When running a test, the packages will be available at the top level
(e.g. application/src
), and the current set of test files available under
/src
. Note: it is recommended to use jlpm run watch
in the test folder
while debugging test options. See above for more info.
The JupyterLab application is made up of two major parts:
- an npm package
- a Jupyter server extension (Python package)
Each part is named jupyterlab
. The developer tutorial documentation
provides additional architecture information.
The repository consists of many npm packages that are managed using the lerna
build tool. The npm package source files are in the packages/
subdirectory.
git clone https://github.com/jupyterlab/jupyterlab.git
cd jupyterlab
pip install -e .
jlpm
jlpm run build:packages
Rebuild
jlpm run clean
jlpm run build:packages
Documentation is written in Markdown and reStructuredText. In particular, the documentation on our Read the Docs page is written in reStructuredText. To ensure that the Read the Docs page builds, you'll need to install the documentation dependencies with conda
. These dependencies are located in docs/environment.yml
. You can install the dependencies for building the documentation by creating a new conda environment:
conda env create -f docs/environment.yml
Alternatively, you can install the documentation dependencies in an existing environment using the following command:
conda env update -n <ENVIRONMENT> -f docs/environment.yml
The Developer Documentation includes a guide to writing documentation including writing style, naming conventions, keyboard shortcuts, and screenshots.
To test the docs run:
py.test --check-links -k .md . || py.test --check-links -k .md --lf .
The Read the Docs pages can be built using make
:
cd docs
make html
Or with jlpm
:
jlpm run docs
The Jupyter server extension source files are in the jupyterlab/
subdirectory. To use this extension, make sure the Jupyter Notebook server
version 4.3 or later is installed.
When you make a change to JupyterLab npm package source files, run:
jlpm run build
to build the changes, and then refresh your browser to see the changes.
To have the system build after each source file change, run:
jupyter lab --dev-mode --watch
There is a range of build utilities for maintaining the repository.
To get a suggested version for a library use jlpm run get:dependency foo
.
To update the version of a library across the repo use jlpm run update:dependency foo ^latest
.
To remove an unwanted dependency use jlpm run remove:dependency foo
.
The key utility is jlpm run integrity
, which ensures the integrity of
the packages in the repo. It will:
- Ensure the core package version dependencies match everywhere.
- Ensure imported packages match dependencies.
- Ensure a consistent version of all packages.
- Manage the meta package.
The packages/metapackage
package is used to build all of the TypeScript
in the repository at once, instead of 50+ individual builds.
The integrity script also allows you to automatically add a dependency for
a package by importing from it in the TypeScript file, and then running:
jlpm run integrity
from the repo root.
We also have scripts for creating and removing packages in packages/
,
jlpm run create:package
and jlpm run remove:package
.
If you want to make changes to one of JupyterLab's external packages (for example, Phosphor) and test them out against your copy of JupyterLab, you can easily do so using the link
command:
- Make your changes and then build the external package
- Register a link to the modified external package
- navigate to the external package dir and run
jlpm link
- navigate to the external package dir and run
- Link JupyterLab to modded package
- navigate to top level of your JupyterLab repo, then run
jlpm link "<package-of-interest>"
- navigate to top level of your JupyterLab repo, then run
You can then (re)build JupyterLab (eg jlpm run build
) and your changes should be picked up by the build.
To restore JupyterLab to its original state, you use the unlink
command:
- Unlink JupyterLab and modded package
- navigate to top level of your JupyterLab repo, then run
jlpm unlink "<package-of-interest>"
- navigate to top level of your JupyterLab repo, then run
- Reinstall original version of the external package in JupyterLab
- run
jlpm install --check-files
- run
You can then (re)build JupyterLab and everything should be back to default.
If you're working on an external project with more than one package, you'll probably have to link in your copies of every package in the project, including those you made no changes to. Failing to do so may cause issues relating to duplication of shared state.
Specifically, when working with Phosphor, you'll probably have to link your copy of the "@phosphor/messaging"
package (in addition to whatever packages you actually made changes to). This is due to potential duplication of objects contained in the MessageLoop
namespace provided by the messaging
package.
-
By default, the application will load from the JupyterLab staging directory (default is
<sys-prefix>/share/jupyter/lab/build
. If you wish to run the core application in<git root>/jupyterlab/build
, runjupyter lab --core-mode
. This is the core application that will be shipped. -
If working with extensions, see the extension documentation on https://jupyterlab.readthedocs.io/en/latest/index.html.
-
The npm modules are fully compatible with Node/Babel/ES6/ES5. Simply omit the type declarations when using a language other than TypeScript.
-
For more information, read the documentation.