Metals TreeViewProtocol Neotree Integration

Additional neo-tree source that allows you to explore data from the tree-view protocol.

Motivation

Most of the time filesystem tree is enough for me. But there are cases where I want to explore 3rd party library by walking through its packages. This is not possible using filesystem tree because of how metals handles such files internally.

But nvim-metals already supports treeViewProtocol!

That is correct, however I really care about consistent feel & behavior in my neovim hence I want all tree-like sources to be managed by neotree.

Current state

treeViewProtocol is still experimental, so everything might break without prior notice.

Supported features:

• navigation around the tree and fetching of not-yet loaded nodes
• reveal in tree
• follow_cursor

Other neotree benefits:

• extensive ability to customize rendering

Known issues:

• Modules have to be compiled first otherwise you will get no results. Toggling a non-compiled module triggers the compilation, but results are not reported. Once the module was compiled, toggling it once again should work. This does not work on metals 1.2.0. See #6023 for details.

Demo.webm

Getting started

neotree configuration:

require("neo-tree").setup({
        sources = { "filesystem", "git_status", "buffers", "metals_tvp" },
        source_selector = {
            sources = {
              { source = "filesystem" },
              { source = "buffers" },
              { source = "git_status" },
              { source = "metals_tvp" },
        },
        metals_tvp = {
            follow_cursor = true,
            renderers = {
                root = {
                    { "indent" },
                    { "icon",  default = "C" },
                    { "name",  zindex = 10 },
                },
                symbol = {
                    { "indent",    with_expanders = true },
                    { "kind_icon", default = "?" },
                    {
                        "container",
                        content = {
                            { "name",      zindex = 10 },
                            { "kind_name", zindex = 20, align = "right" },
                        }
                    }
                },
            },
            window = {
                mappings = {
                    ["<cr>"] = "toggle_node",
                    ["<s-cr>"] = "execute_node_command",
                },
            }
        },
    })

metals configuration:

metals_config.handlers = {
        ["metals/treeViewDidChange"] = function(_, result)
            require("metals_tvp.api").tree_view_did_change(result)
        end
    }

Developer notes

What to test:

• open source before it is loaded
• open source once loaded -> libraries -> expand/collapse nodes
• jumping between metals-tvp and another buffer (make sure that we don't request any new data)
• follow_cursor both library and project
• make sure that non-compiled modules can be loaded eventually
• open a file from library and call reveal without having the tvp opened before