Setup

• Clone microsoft/vscode

• Run npm i at /, this will install

  • Dependencies for /extension/html-language-features/

  • Dependencies for /extension/html-language-features/server/

  • devDependencies such as gulp

• Open /extensions/html-language-features/ as the workspace in VS Code

• In /extensions/html-language-features/ run npm run compile(or npm run watch) to build the client and server

• Run the Launch Extension debug target in the Debug View. This will:

  • Launch a new VS Code instance with the html-language-features extension loaded

• Open a .html file to activate the extension. The extension will start the HTML language server process.

• Add "html.trace.server": "verbose" to the settings to observe the communication between client and server in the HTML Language Server output.

• Debug the extension and the language server client by setting breakpoints inhtml-language-features/client/

• Debug the language server process by using Attach to Node Process command in the VS Code window opened on html-language-features.

  • Pick the process that contains htmlServerMain in the command line. Hover over code-insiders resp code processes to see the full process command line.

  • Set breakpoints in html-language-features/server/

• Run Reload Window command in the launched instance to reload the extension

Contribute to vscode-html-languageservice

microsoft/vscode-html-languageservice contains the language smarts for html. This extension wraps the html language service into a Language Server for VS Code. If you want to fix html issues or make improvements, you should make changes at microsoft/vscode-html-languageservice.

However, within this extension, you can run a development version of vscode-html-languageservice to debug code or test language features interactively:

Linking vscode-html-languageservice in html-language-features/server/

• Clone microsoft/vscode-html-languageservice

• Run npm i in vscode-html-languageservice

• Run npm link in vscode-html-languageservice. This will compile and link vscode-html-languageservice

• In html-language-features/server/, run npm link vscode-html-languageservice

Testing the development version of vscode-html-languageservice

• Open both vscode-html-languageservice and this extension in two windows or with a single window with themulti-root workspace feature

• Run npm run watch at html-languagefeatures/server/ to recompile this extension with the linked version of vscode-html-languageservice

• Make some changes in vscode-html-languageservice

• Now when you run Launch Extension debug target, the launched instance will use your development version of vscode-html-languageservice. You can interactively test the language features.