minecraft-dev.nvim

A Neovim plugin designed to streamline Minecraft mod development with Fabric Loom.

Features

• Fabric Loom DAP Adapter: Launch and attach to Minecraft dev instances directly from Neovim via ./gradlew.
• Launch Configurations: Load custom run configurations generated by Gradle (.nvim/launch.json).
• ASM & Bytecode Inspection: Easily inspect class bytecode or ASM API generation code.
• Bundled Syntax Highlighting: Includes syntax highlighting for OW2 ASM Textifier bytecode output (asm-java).
• Clean jdt:// URI Formatting: Automatically resolves raw jdt:// URIs into readable Java class names in your statusline and quickfix list.
• Isolated jdtls Workspaces: Automatically configures project-isolated workspace cache directories for jdtls.

---

Requirements

• Neovim v0.10+
• mfussenegger/nvim-jdtls
• mfussenegger/nvim-dap
• jdtls executable installed (e.g. via mason.nvim)
• java-debug-adapter (required for debugging support)

Optional

• JavaHello/java-deps.nvim – View project Java dependencies.
• tunaflsh/follow-md-links.nvim – Open jdt:// URIs when following links.

---

Gradle Configuration

To generate Neovim launch configurations (.nvim/launch.json) that minecraft-dev.nvim and nvim-dap can consume, add the neovim Gradle task to your build.gradle file:

import groovy.json.JsonOutput

tasks.register('neovim') {
    group = 'ide'
    description = 'Generates Neovim launch configurations.'

    doLast {
        def runsData = loom.runs.collect { run ->
            def taskName = "run${run.name.capitalize()}"
            [
                type: "fabric-loom",
                taskName: taskName,
                name: "${run.configName} (gradlew ${taskName})",
                request: "launch",
                console: "integratedTerminal"
            ]
        }
        def rootData = [
            version: "1.0.0",
            configurations: runsData
        ]
        def outputFile = file(".nvim/launch.json")
        outputFile.parentFile.mkdirs()
        outputFile.text = JsonOutput.prettyPrint(JsonOutput.toJson(rootData))
    }
}

Then generate your configurations by running:

./gradlew neovim

Sometimes jdtls gets your project name wrong. Put this at the top of your build.gradle:

plugins {
    id 'eclipse'
}

eclipse {
    project {
        name = rootProject.name
    }
}

---

Example Setup

Below is an example configuration using vim.pack.add, incorporating nvim-jdtls, nvim-dap, mason.nvim, and related Java utilities:

vim.pack.add({
  'https://github.com/tunaflsh/minecraft-dev.nvim',
  'https://codeberg.org/mfussenegger/nvim-jdtls',
  'https://codeberg.org/mfussenegger/nvim-dap',
  'https://github.com/JavaHello/java-deps.nvim',
  'https://mason-org/mason.nvim',
  {
    src = 'https://github.com/tunaflsh/follow-md-links.nvim',
    version = 'custom-handler',
  },
}, { load = true })

-- Enable opening jdt:// URIs in LSP hovers
require('follow-md-links').handler = function(link)
  if vim.startswith(link, 'jdt://') then
    vim.cmd.split(vim.fn.fnameescape(link))
    return true
  end
end

-- Preview Java dependencies
local javadeps = require('java-deps')
javadeps.setup({
  keymaps = { toggle_fold = '<cr>' },
  position = 'left',
})

local mcdev = require('minecraft-dev')
local mason_dir = require('mason.settings').current.install_root_dir
local jdtls = require('jdtls')

mcdev.setup({
  statusline = vim.o.statusline,
  -- See api-win_config
  win_config = { win = -1, split = 'right' }, -- split far right
  -- Envars for the Minecraft instance can be set here
  env = { -- E.g. to ensure Minecraft is running on a NVIDIA dGPU
    __NV_PRIME_RENDER_OFFLOAD = 1,
    __VK_LAYER_NV_optimus = 'NVIDIA_only',
    __GLX_VENDOR_LIBRARY_NAME = 'nvidia',
  },
  -- See nvim-jdtls
  jdtls_config = {
    init_options = {
      bundles = {
        vim.fn.glob( -- :MasonInstall java-debug-adapter
          mason_dir .. '/share/java-debug-adapter/com.microsoft.java.debug.plugin-*.jar',
          true
        ),
        vim.fn.glob( -- :MasonInstall vscode-java-dependencies
          mason_dir .. '/share/vscode-java-dependency/com.microsoft.jdtls.ext.core-*.jar',
          true
        ),
      },
    },
    on_attach = function(client, bufnr)
      local command = function(name, cmd, desc)
        vim.api.nvim_buf_create_user_command(bufnr, name, cmd, { desc = desc })
      end

      command('Asmify', mcdev.asmify, 'View ASM API calls')
      command('Bytecode', mcdev.bytecode, 'View ASM bytecode')
      command('Deps', javadeps.toggle_outline, 'View dependencies')

      local map = function(lhs, rhs)
        vim.keymap.set('', lhs, rhs, { buf = bufnr })
      end

      -- These are additional capabilities provided by jdtls
      -- For built-in LSP mappings, check `:help lsp-defaults`
      map('gro', jdtls.organize_imports)
      map('grv', jdtls.extract_variable_all)
      map('grc', jdtls.extract_constant)
      map('grm', jdtls.extract_method)
    end,
  },
})

---

Default Options

require('minecraft-dev').setup({
  -- Filetypes to which jdtls will attach
  filetypes = { 'java', 'groovy', 'kotlin', 'jproperties' },

  -- Format statusline occurrences of %f, %F, or %t resolving jdt:// URIs
  statusline = nil,

  -- Resolve jdt:// URIs in quickfix list to fully qualified class names
  quickfixtextfunc = true,

  -- Window configuration for opening ASM / Bytecode split windows
  win_config = nil,

  -- Environment variables passed when launching Minecraft
  env = {},

  -- Configuration passed directly to jdtls.start_or_attach()
  jdtls_config = {
    cmd = { 'jdtls' },
  },
})

---

Health Check

You can verify your setup at any time by running:

:checkhealth minecraft-dev

This checks for required plugins (nvim-jdtls, nvim-dap), external tools (jdtls), debug adapters (java-debug-adapter), and project configuration files (.nvim/launch.json).