Thank you Jose and team! We are running 1.13.3 on prod now and all good on our end. We love Elixir, crazy I been using it since 2016 over a stranger on reddit just giving away a ticket to Orlando’s elixirconf. He radically changed my life and he probably doesn’t even know it.

Here it is feliperenan/heex_formatter: Formatter for Phoenix Live View templates. (github.com)

Thank you

I am using VS Code and for elixir support I am using elixir-lsp/vscode-elixir-ls: (github.com) and under the hood vscode-elixir-ls (github.com) is used.
So, the regular elixir code was getting formatted on save, if we set editor.formatOnSave=true in the VS Code settings. Even after the release of elixir 1.13, the sigils and the heex files are not getting formatted. I have asked in the vscode-elixir-ls repository How does this format the file? · Discussion #224 · elixir-lsp/vscode-elixir-ls (github.com) a question regarding this. @axelson has been very receptive and responded back. An issue Feature Request: Support mix format plugins · Issue #660 · elixir-lsp/elixir-ls (github.com) to this effect has been created as well. The main issue of contention has been elixir-ls does not use mix format but uses its own function.
However, with the release of elixir 1.13.3 suddenly, the formatting in the ~H sigil started working in all *.ex files.
I think the reason heex files are not getting formatted because they are not associated with elixir-ls extension. If they are, most likely, they also will be getting automatically formatted.
I do think not just vs-code, all the editors elixir-lsp/elixir-ls: (github.com) listed here should get the benefit of automatic formatting.

Oh! What a pleasure it is to watch the ugly HTML snippets written inside the ~H sigil to be formatted on save in VS Code. Thanks a lot @josevalim .
One question though. html.heex files are not getting formatted automatically. I am running mix format still. Is it file association the issue? Should I be adding heex files also to be elixir files now?