How can I change the text of an EnvDTE.Document?

Question

I assign new json text to a document using the following code:

    public virtual async Task SetDocumentText(FileInfo fileInfo, string contents)
    {
        if (fileInfo == null)
            throw new ArgumentNullException(nameof(fileInfo));
        var projectItem = FindDTEProjectItem(fileInfo.FullName);
        if (null == projectItem?.Document)
            await Task.Run(() => fileInfo.WriteAllText(contents));
        else
        {
            var textSelection = (TextSelection)projectItem.Document.Selection;
            textSelection.SelectAll();
            textSelection.Text = contents;
            projectItem.Document.Save();
        }
    }

But I have three problems with the current solution:

1. The json text is corrupted.
2. Assigning the new text is very slow.
3. All the text in the document is selected.

Is there a better way to assign the new text to the EnvDTE.Document?

This is what the corrupted text looks like:

But this is what I assigned:

  ...
  ...
  },
  "client": {
    "title": "Mr"
  }
}

The json text that I assigned is valid and well-formed, and even if it wasn't, I wouldn't expect such a drastic corruption of the json text.

If I write the text directly to the file, then Visual Studio will ask the user whether he wants to reload, and I am trying to avoid that popup too.

Any help would be appreciated. I was unsuccessful in using roslyn and the TextDocument because I am unable to load the AdditionalDocument. Only code files are included in the roslyn Project Documents collection.

Answer 1

Instead of textSelection.Text = contents; you can use textSelection.Insert(contents);. It is faster and prevents Visual Studio from changing the original contents.