# Coding Guidelines

## Introduction

These are VS Code coding guidelines. Please also review our [Source Code Organisation](https://github.com/microsoft/vscode/wiki/Source-Code-Organization) page.

## Indentation

We use tabs, not spaces.

## Naming Conventions

* Use PascalCase for `type` names
* Use PascalCase for `enum` values
* Use camelCase for `function` and `method` names
* Use camelCase for `property` names and `local variables`
* Use whole words in names when possible

## Types

* Do not export `types` or `functions` unless you need to share it across multiple components
* Do not introduce new `types` or `values` to the global namespace

## Comments

* When there are comments for `functions`, `interfaces`, `enums`, and `classes` use JSDoc style comments

## Strings

* Use "double quotes" for strings shown to the user that need to be externalized (localized)
* Use 'single quotes' otherwise
* All strings visible to the user need to be externalized

## Style

* Use arrow functions `=>` over anonymous function expressions
* Only surround arrow function parameters when necessary. For example, `(x) => x + x` is wrong but the following are correct:

```javascript
x => x + x
(x, y) => x + y
<T>(x: T, y: T) => x === y
```

* Always surround loop and conditional bodies with curly braces
* Open curly braces always go on the same line as whatever necessitates them
* Parenthesized constructs should have no surrounding whitespace. A single space follows commas, colons, and semicolons in those constructs. For example:

```javascript
for (let i = 0, n = str.length; i < 10; i++) {
    if (x < 10) {
        foo();
    }
}

function f(x: number, y: string): void { }
```