# Welcome to your first VS Code Extension
## What's in the folder
* 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