Add support for SnippetString in TextEdit and WorkspaceEdit

[jrieken]

The TextEdit and WorkspaceEdit APIs are used to apply refactorings. Those will benefit from being able to place the cursor and add placeholders, like add a placeholder for the suggested name of an extracted vairable

[jrieken]

For April I have enabled this (for editor dnd) and for May we can make this more prominent. Questions

• how to handle N snippet edits
• where to allow snippets edits
• how do snippet edits fit into workspace edits

[jrieken]

The actual refactoring is staged but it allow for cool things like such an enhanced extract const flow

Screen.Recording.2022-07-07.at.11.58.17.mov

[zardoy]

Hey! Thank you so much for planning this feature! I'd use it in my extension to replace some typed text into snippet.
Currently, in order to achieve that I need to a hack with onDidChangeTextDocument to track deletion before inserting snippet.

I checked it in insiders and IMO the current implementation is just ideal as it works with multiple different snippets!
Is there a plan to finally release in it August update?

[jrieken]

Plan to finalize this API for September

[jrieken]

This is now done via SnippetTextEdit and WorkspaceEdit.set(Uri, SnippetTextEdit[])

[jrieken]

fyi @matklad

[zardoy]

@jrieken as I understand, CompletionItem.additionalTextEdits won't receive snippets support, right?

Inserting/replacing content with snippets would require additional command execution for these cases. I can imagine cases, where it could be handly to replace a few lines with some snippet on completion accepted.

[jrieken]

@jrieken as I understand, CompletionItem.additionalTextEdits won't receive snippets support, right?

As for this issue no and it needs thinking if it can be done, esp since they can come late and since the main edit can already be a snippet

[zardoy]

@jrieken I also want to ask you about white space normalization. It'd much easier to describe the issue with the following code:

const insertString = '1\n\t1\n1'
const snippetString = new vscode.SnippetString(insertString)
const editor = vscode.window.activeTextEditor!
const insertPos = editor.selection.active
// 1
const edit = new vscode.WorkspaceEdit()
edit.set(editor.document.uri, [vscode.SnippetTextEdit.insert(insertPos, snippetString)])
void vscode.workspace.applyEdit(edit)
// 2
void editor.insertSnippet(snippetString, insertPos)

For me, these approaches to insert snippet seemed equal, but they actually insert different text (vscode.SnippetTextEdit.insert doesn't do space adjusting like editor.insertSnippet).

Is that also by design?

[jrieken]

Is that also by design?

Fair question and something I didn't consider yet. Don't know yet what the design should be but looking at the sources they should behave the same: both should default to adjusting whitespace. I will investigate

[zardoy]

Fair question and something I didn't consider yet. I will investigate

If I lived in ideal world I'd see an option to also disable this behavior :) IMO these two cases I described above should be aligned with what accepting completion does. e.g. ok if it does space adjusting by default, but there also should be away to disable that, like we can disable it with keepWhitespace=false for suggestions. Hope you will consider that 🙏

I will investigate

Thank you so much, I really appreciate the work you're doing here! Let me know how it goes!