I didn’t have syntax highlighting and I found that the .heex extension wasn’t associated with “Html (Embedded Elixir)” despite ElixirLS lists support for such files in its capabilities.
I corrected the configuration by clicking on the file-type at the bottom right of the editor, then clicked “Configure File Association for ‘.heex’…” and selected Html (Embedded Elixir). See screenshot and note it’s been taken after the correction, I had Plain Text as file type before.
I get the syntax highlighting and some auto-completion now but my auto-completion is not perfect. For example, it doesn’t complete the get_flash function which is one I found in an autogenerated Phoenix template so I’m assuming it exists but it’s not being found. Thanks in advance to anyone confirming if get_flash should get auto-completed in this or other IDEs.
However I get hints at least for Kernel functions.
I’m not sure if it can be any better: this is my first Phoenix application and I’m guessing the dynamic nature of this code may make some auto-completion impossible/very-hard.