This is a template repository to get you started on building a VS Code extension for your favorite python tool. It could be a linter, formatter, or code analysis, or all of those together. This template will give you the basic building blocks you need to build a VS Code extension for it.
The extension template has two parts, the extension part and language server part. The extension part is written in TypeScript, and language server part is written in Python over the pygls (Python language server) library.
For the most part you will be working on the python part of the code when using this template. You will be integrating your tool with the extension part using the Language Server Protocol. pygls currently works on the version 3.16 of LSP.
The TypeScript part handles working with VS Code and its UI. The extension template comes with few settings pre configured that can be used by your tool. If you need to add new settings to support your tool, you will have to work with a bit of TypeScript. The extension has examples for few settings that you can follow. You can also look at extensions developed by our team for some of the popular tools as reference.
- VS Code 1.64.0 or greater
- Python 3.7 or greater
- node >= 14.19.0
- npm >= 8.3.0 (
npm
is installed with node, check npm version, usenpm install -g npm@8.3.0
to update) - Python extension for VS Code
You should know to create and work with python virtual environments.
- Use this template to create your repo.
- Check-out your repo locally on your development machine.
- Create and activate a python virtual environment for this project in a terminal. Be sure to use the minimum version of python for your tool. This template was written to work with python 3.7 or greater.
- Install
nox
in the activated environment:python -m pip install nox
. - Add your favorite tool to
requirements.in
- Run
nox --session setup
. - Optional Install test dependencies
python -m pip install -r src/test/python_tests/requirements.txt
. You will have to install these to run tests from the Test Explorer. - Open
package.json
, look for and update the following things:- Find and replace
<pytool-module>
with module name for your tool. This will be used internally to create settings namespace, register commands, etc. Recommendation is to use lower case version of the name, no spaces,-
are ok. For example, replacing<pytool-module>
withpylint
will lead to settings looking likepylint.args
. Another example, replacing<pytool-module>
withblack-formatter
will make settings look likeblack-formatter.args
. - Find and replace
<pytool-display-name>
with display name for your tool. This is used as the title for the extension in market place, extensions view, output logs, etc. For example, for theblack
extension this isBlack Formatter
.
- Find and replace
- Install node packages using
npm install
.
After finishing the getting started part, this template would have added the following. Assume <pytool-module>
was replaced with mytool
, and <pytool-display-name>
withMy Tool
:
- A command
My Tool: Restart Server
(command Id:mytool.restart
). - Following setting:
mytool.logLevel
mytool.args
mytool.path
mytool.importStrategy
mytool.interpreter
mytool.showNotification
- Following triggers for extension activation:
- On Language
python
. - On File with
.py
extension found in the opened workspace. - On Command
mytool.restart
.
- On Language
- Output Channel for logging
Output
>My Tool
Open bundled/tool/server.py
, here is where you will do most of the changes. Look for TODO
comments there for more details.
Also look for TODO
in other locations in the entire template:
bundled/tool/runner.py
: You may need to update this in some special cases.src/test/python_tests/test_server.py
: This is where you will write tests. There are two incomplete examples provided there to get you started.- All the markdown files in this template have some
TODO
items, be sure to check them out as well. That includes updating the LICENSE file, even if you want to keep it MIT License.
References, to other extension created by our team using the template:
- Protocol reference: https://microsoft.github.io/language-server-protocol/specifications/specification-3-16/
- Implementation showing how to handle Linting on file
open
,save
, andclose
. Pylint - Implementation showing how to handle Formatting. Black Formatter
- Implementation showing how to handle Code Actions. isort
Run the Debug Extension and Python
configuration form VS Code. That should build and debug the extension in host window.
Note: if you just want to build you can run the build task in VS Code (ctrl
+shift
+B
)
To debug both TypeScript and Python code use Debug Extension and Python
debug config. This is the recommended way. Also, when stopping, be sure to stop both the Typescript, and Python debug sessions. Otherwise, it may not reconnect to the python session.
To debug only TypeScript code, use Debug Extension
debug config.
To debug a already running server or in production server, use Python Attach
, and select the process that is running server.py
.
You can add new settings by adding details for the settings in package.json
file. To pass this configuration to your python tool server (i.e, server.py
) update the settings.ts
as need. There are examples of different types of settings in that file that you can base your new settings on.
You can follow how restart
command is implemented in package.json
and extension.ts
for how to add commands. You cam also contribute commands from Python via the Language Server Protocol.
See src\test\python_tests\test_server.py
for starting point. See, other referred projects here for testing various aspects of running the tool over LSP.
If you have installed the test requirements you should be able to see the tests in the test explorer.
You can also run all tests using nox --session tests
command.
Run nox --session lint
to run linting on both Python and TypeScript code. Please update the nox file if you want to use a different linter and formatter.
- Update various fields in
package.json
. At minimum, check the following fields and update them accordingly. See extension manifest reference to add more fields:"publisher"
: Update this to your publisher id from https://marketplace.visualstudio.com/."version"
: See https://semver.org/ for details of requirements and limitations for this field."license"
: Update license as per your project. Defaults toMIT
."keywords"
: Update keywords for your project, these will be used when searching in the VS Code marketplace."categories"
: Update categories for your project, makes it easier to filter in the VS Code marketplace."homepage"
,"repository"
, and"bugs"
: Update URLs for these fields to point to your project.- Optional Add
"icon"
field with relative path to a image file to use as icon for this project.
- Make sure to check the following markdown files:
- REQUIRED First time only:
CODE_OF_CONDUCT.md
,LICENSE
,SUPPORT.md
,SECURITY.md
- Every Release:
CHANGELOG.md
- REQUIRED First time only:
- Build package using
nox --session build_package
. - Take the generated
.vsix
file and upload it to your extension management page https://marketplace.visualstudio.com/manage.
To do this from the command line see here https://code.visualstudio.com/api/working-with-extensions/publishing-extension
Dependabot yml is provided to make it easy to setup upgrading dependencies in this extension. Be sure to add the labels used in the dependabot to your repo.
To manually upgrade your local project:
- Create a new branch
- Run
npm update
to update node modules. - Run
nox --session setup
to upgrade python packages.
If you want to change the name of server.py
to something else, you can. Be sure to update constants.ts
and src\test\python_tests\lsp_test_client\session.py
.
Also make sure that the inserted paths in server.py
are pointing to the right folders to pick up the dependent packages.
This can occurs if bundled/libs
is empty. That is the folder where we put your tool and other dependencies. Be sure to follow the build steps need for creating and bundling the required libs.
Common one is pygls module not found.
Repo Owner Make sure you update this. As a repository owner you will need to update this file with specific instructions for your extension.