Files with .es6 suffix are treated as TypeScript files

[jbutz]

• VSCode Version: 0.10.11
• OS Version: OS X El Capitan v 10.11.4

Steps to Reproduce:

1. Create a new file with the extension .es6 and the following code

   class Testing {
      constructor() {
          this.myValue = "Hello World";
      }
   
      test() {
          return this.myValue;
      }
   }

2. The Language Mode is automatically set to "JavaScript", but on this.myValue you get Property 'myValue' does not exist on type 'Testing' errors.

3. Close the file and rename it to use a .js extension

4. Open the file and notice that the errors are gone

[egamma]

What is happening is that VS Code registers .es6 files as JavaScript files and Code sends them over to the tsserver. Inside the tsserver .es6are not treated as JavaScript files but as TypeScript files. For this reason you get the additional errors.

One work around is to disable the error diagnostics from the tsserver for js files in the settings: "javascript.validate.enable": false. When you do so you should really setup eslint to get javascript diagnostics https://github.com/Microsoft/vscode-docs/blob/vnext/release-notes/vFebruary.md#linters.

Moving to TypeScript, there should be a way to configure that .es6 files need to be treated as JavaScript files. If VS Code doesn't send .es6 to the tsserver then the user doesn't get Intellisense and only coloring.

[egamma]

This issue was moved to microsoft/TypeScript#7926