This folder contains all of the files necessary for your extension
package.json - this is the manifest file in which you declare your extension and command.
The sample plugin registers a command and defines its title and command name. With this information
VS Code can show the command in the command palette. It doesn’t yet need to load the plugin.
src/extension.ts - this is the main file where you will provide the implementation of your command.
The file exports one function, activate, which is called the very first time your extension is
activated (in this case by executing the command). Inside the activate function we call registerCommand.
We pass the function containing the implementation of the command as the second parameter to
registerCommand.
Get up and running straight away
press F5 to open a new window with your extension loaded
run your command from the command palette by pressing (Ctrl+Shift+P or Cmd+Shift+P on Mac) and typing Hello World
set breakpoints in your code inside src/extension.ts to debug your extension
find output from your extension in the debug console
Make changes
you can relaunch the extension from the debug toolbar after changing code in src/extension.ts
you can also reload (Ctrl+R or Cmd+R on Mac) the VS Code window with your extension to load your changes
Explore the API
you can open the full set of our API when you open the file node_modules/vscode/vscode.d.ts
Run tests
open the debug viewlet (Ctrl+Shift+D or Cmd+Shift+D on Mac) and from the launch configuration dropdown pick Launch Tests
press F5 to run the tests in a new window with your extension loaded
see the output of the test result in the debug console
make changes to test/extension.test.ts or create new test files inside the test folder
by convention, the test runner will only consider files matching the name pattern **.test.ts
you can create folders inside the test folder to structure your tests any way you want