Support setting encoding from extension

[TheCrether]

It is great that with 1.100 the encoding API is finalized. I wanted to use it for an extension I am developing but I could not find a "simple" way to set the encoding of an open editor.

For files that are on disk, I am able to just use window.openTextDocument with the same URI and change the encoding through this.

For untitled files this is not possible, since I can't "reopen" an untitled file with it's URI. Would it be possible to introduce a general way to set the encoding of an editor? (IMO this also makes more sense)

[bpasero]

This is actually a bug because the intention was that this should work:

const doc = await vscode.workspace.openTextDocument({ content: 'Hello World' });
assert.strictEqual(doc.encoding, 'utf8');

await vscode.workspace.openTextDocument(doc.uri, { encoding: 'windows1252' });
assert.strictEqual(doc.encoding, 'windows1252');

[vs-code-engineering]

This bug has been fixed in the latest release of VS Code Insiders!

@TheCrether, you can help us out by commenting /verified if things are now working as expected.

If things still don't seem right, please ensure you're on version e2a90e9 of Insiders (today's or later - you can use Help: About in the command palette to check), and leave a comment letting us know what isn't working as expected.

Happy Coding!