init POC version

Author: dm1try

.gitignore

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+/**/**/_build
+/cover
+/**/**/deps
+/tmp
+/spec/fixtures/xdg_home/nvim/plugin/*
+/spec/fixtures/xdg_home/nvim/rplugin/*
+erl_crash.dump
+*.ez
+

README.md

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+# Neovim Elixir host
+
+Implements support for Neovim remote plugins written in Elixir.
+
+
+## Installation
+
+Assume you are already dealing with a working Elixir install.
+
+Install the host archive, we will use it to build the host locally.
+
+```
+$ mix archive.install https://github.com/dm1try/neovim_host/raw/master/nvim.ez
+```
+
+Build and install the host by running `nvim.install` and providing the path to nvim config(`~/.config/nvim` by default on linux systems)
+
+```
+$ mix nvim.install /path/to/nvim/config
+```
+
+## Usage
+
+Currently, each time you somehow update remote plugins you should run `:UpdateElixirPlugins` nvim command(the wrapper for `:UpdateRemotePlugins`). See `:h remote-plugins-manifest` for the clarification why the manifest is needed(generally, it saves the neovim startup time if remote plugins are installed).
+
+# Plugin Development
+## Structure
+
+Host supports two types of plugins:
+1. Scripts (an elixir script that usually contains simple logic and does not depend on other libs/does not need the versioning/etc).
+
+2. Applications (an OTP application that is implemented as part of host umbrella project). You can find more information about umbrella projects [here](http://elixir-lang.org/getting-started/mix-otp/dependencies-and-umbrella-apps.html).
+
+Host with plugins lives in `rplugin/elixir` of neovim config directory.
+Typical files tree for such dir:
+```bash
+~/.config/nvim/rplugin/elixir
+
+├── scripts <~ scripts
+├── apps <~ applications AKA "precompiled plugins"
+└── mix.exs
+```
+
+### Plugin DSL
+#### Events
+`on_event`(better known as `autocmd` for vim users) defines the callback that triggered by editor when some event
+happened. Run `:h autocmd-events` for the list of events.
+
+```elixir
+on_event :vim_enter do
+  Logger.info("the editor is ready")
+end
+```
+#### Functions
+`function` defines the vim function
+```
+function wrong_sum(left, right) do
+  {:ok, left - right}
+end
+```
+use it in the editor `:echo WrongSum(1,2)`
+
+#### Commands
+`command` defines the command.
+
+```
+command just_echo do
+  NVim.Session.vim_command("echo from remote plugin")
+end
+```
+use it in the editor `:JustEcho`
+
+### Session
+In the latest example we used `vim_command` method which is part of Neovim remote API.
+In the examples below we asume that we import `NVim.Session` in context of plugin.
+
+### State
+Each plugin is [GenServer](http://elixir-lang.org/docs/stable/elixir/GenServer.html).
+So you can share the state between all actions while the plugin is running:
+```elixir
+on_event :cursor_moved do
+  state = %{state | {move_counts: state[:move_counts] + 1}
+end
+
+command :show_moves_count do
+  moves_info = "Current moves: #{state[:move_count]}"
+  vim_command("echo '#{moves_info}'")
+end
+```
+### Pre-evaluated values
+Any vim value can be pre-evaluated before the action will be triggered:
+```
+on_event :cursor_hold_i,
+  pre_evaluate: %{
+    "expand('cWORD')" => word_under_cursor
+  }
+do
+  if word_under_cursor == "Elixir" do
+    something()
+  end
+end
+```
+## Basic scripts
+This example demonstrates the highlighting of outdated packeges in your mix.exs
+```
+# ~/.config/nvim/rplugin/elixir/scripts/highlight_outdated_packages.exs

config/config.exs

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+use Mix.Config
+
+config :logger,
+  backends: [{LoggerFileBackend, :error_log}],
+  level: :error
+
+config :logger, :error_log,
+  path: Path.expand("#{__DIR__}/../tmp/neovim_elixir_host.log"),
+  level: :error

installer/lib/install.ex

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+defmodule Mix.Tasks.Nvim.Install do
+  use Mix.Task
+
+  import Mix.Generator
+  @shortdoc "Installs the host to provided nvim config path."
+
+  def run(argv) do
+    {_opts, argv} = OptionParser.parse!(argv)
+
+    case argv do
+      [] ->
+        Mix.raise "Expected NVIM_CONFIG_PATH to be given, please use \"mix nvim.install NVIM_CONFIG_PATH\""
+      [nvim_config_path | _] ->
+        create_file Path.join(nvim_config_path, "plugin/elixir_host.vim"), elixir_host_plugin_vim_text, force: true
+
+        remote_plugin_path = Path.join(nvim_config_path, "rplugin/elixir")
+
+        create_directory Path.join(remote_plugin_path, "scripts")
+        create_directory Path.join(remote_plugin_path, "apps")
+        create_file Path.join(remote_plugin_path, "mix.exs"), apps_mixfile_text, force: true
+        create_file Path.join([remote_plugin_path, "config", "config.exs"]), apps_config_text, force: true
+
+        host_path =  Path.join([remote_plugin_path, "apps","host"])
+
+        create_file Path.join(host_path, "mix.exs"), host_mixfile_text, force: true
+        create_file Path.join([host_path, "config", "config.exs"]), host_config_text, force: true
+
+        print_successful_info
+    end
+  end
+
+  defp print_successful_info do
+    Mix.shell.info [:green, """
+
+    Elixir host succesfully installed.
+    """]
+  end
+
+  embed_text :host_mixfile, ~s"""
+  defmodule Host.Mixfile do
+    use Mix.Project
+
+    def project do
+      [app: :host,
+       version: "#{Mix.Project.config[:version]}",
+       build_path: "../../_build",
+       config_path: "../../config/config.exs",
+       deps_path: "../../deps",
+       lockfile: "../../mix.lock",
+       elixir: "~> 1.3",
+       deps: deps,
+       aliases: aliases,
+       escript: escript]
+    end
+
+    def application do
+      [applications: [:logger, :nvim], env: [plugin_module: NVim.Host.Plugin]]
+    end
+
+    def escript do
+      [main_module: NVim.Host, emu_args: "-noinput"]
+    end
+
+    defp deps do
+      [{:nvim, "#{Mix.Project.config[:version]}"}]
+    end
+
+    defp aliases do
+      ["nvim.build_host": ["deps.get", "nvim.build_host"]]
+    end
+  end
+  """
+  embed_text :apps_mixfile, """
+  defmodule Elixir.Mixfile do
+    use Mix.Project
+
+    def project do
+      [apps_path: "apps",
+       deps: []]
+    end
+  end
+  """
+
+  embed_text :apps_config, """
+  use Mix.Config
+  import_config "../apps/*/config/config.exs"
+  """
+
+  embed_text :host_config, ~S"""
+  use Mix.Config
+
+  config :logger,
+    backends: [{LoggerFileBackend, :error_log}],
+    level: :error
+
+  config :logger, :error_log,
+    path: Path.expand("#{__DIR__}/../neovim_elixir_host.log"),
+    level: :error
+  """
+
+  embed_text :elixir_host_plugin_vim, """
+  let s:nvim_path = expand('<sfile>:p:h:h')
+  let s:xdg_home_path = expand('<sfile>:p:h:h:h')
+
+  function! s:RequireElixirHost(host)
+    try
+      let channel_id = rpcstart(s:nvim_path . '/rplugin/elixir/apps/host/host',[])
+      if rpcrequest(channel_id, 'poll') == 'ok'
+        return channel_id
+      endif
+    catch
+    endtry
+    throw 'Failed to load elixir host.' . expand('<sfile>') .
+      \ ' More information can be found in elixir host log file.'
+  endfunction
+
+  call remote#host#Register('elixir', '{scripts/*.exs,apps/*}', function('s:RequireElixirHost'))
+
+  function! UpdateElixirPlugins()
+    execute '!cd ' . s:nvim_path . '/rplugin/elixir/apps/host && MIX_ENV=prod mix do deps.get, nvim.build_host --xdg-home-path ' . s:xdg_home_path . ' --vim-rc-path ' . s:nvim_path . '/init.vim'
+  endfunction
+  command! UpdateElixirPlugins call UpdateElixirPlugins()
+  """
+end

installer/lib/remove.ex

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+defmodule Mix.Tasks.Nvim.Remove do
+  use Mix.Task
+
+  @shortdoc "Removes the host(include ALL installed plugins) for provided nvim config path."
+
+  def run(argv) do
+    {_opts, argv} = OptionParser.parse!(argv)
+
+    case argv do
+      [] ->
+        Mix.raise "Expected NVIM_CONFIG_PATH to be given, please use \"mix nvim.remove NVIM_CONFIG_PATH\""
+      [nvim_config_path | _] ->
+        File.rm Path.join(nvim_config_path, "plugin/elixir_host.vim")
+
+        File.rm Path.join(nvim_config_path, "rplugin/elixir/mix.exs")
+        safely_remove_directory(Path.join(nvim_config_path, "rplugin/elixir/scripts"))
+
+        File.rm_rf Path.join(nvim_config_path, "rplugin/elixir/_build")
+        File.rm_rf Path.join(nvim_config_path, "rplugin/elixir/config")
+        File.rm_rf Path.join(nvim_config_path, "rplugin/elixir/apps/host")
+        safely_remove_directory(Path.join(nvim_config_path, "rplugin/elixir/apps"))
+
+        Mix.shell.info "Elixir host succesfully removed."
+    end
+  end
+
+  defp safely_remove_directory(path) do
+    if directory_empty?(path) do
+      File.rm_rf(path)
+    else
+      Mix.shell.info "#{path} is not removed because is not empty."
+    end
+  end
+
+  defp directory_empty?(path) do
+    Path.join(path, "*") |> Path.wildcard |> Enum.empty?
+  end
+end

installer/mix.exs

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+defmodule NVim.Installer.Mixfile do
+  use Mix.Project
+
+  def project do
+    [app: :nvim_installer,
+     version: "0.1.0",
+     elixir: "~> 1.3"]
+  end
+
+  def application do
+    [applications: []]
+  end
+end

installer/test/install_test.exs

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+defmodule Mix.Tasks.Nvim.InstallTest do
+  use ExUnit.Case
+
+  test "installs the host to a provided directory" do
+    in_tmp_dir("nvim_config", fn(path)->
+      output = ExUnit.CaptureIO.capture_io(fn-> Mix.Tasks.Nvim.Install.run [path] end)
+
+        assert_file_exists "#{path}/plugin/elixir_host.vim"
+        assert_directory_exists "#{path}/rplugin/elixir/scripts"
+        assert_directory_exists "#{path}/rplugin/elixir/apps/host"
+        assert_file_exists "#{path}/rplugin/elixir/config/config.exs"
+        assert_file_exists "#{path}/rplugin/elixir/mix.exs"
+
+      assert output =~ "Elixir host succesfully installed."
+    end)
+  end
+
+  defp in_tmp_dir(path, callback) do
+    expanded_path = Path.expand("../../tmp/#{path}", __DIR__)
+    File.rm_rf! expanded_path
+    File.mkdir! expanded_path
+
+    callback.(expanded_path)
+  end
+
+  defp assert_file_exists(path) do
+    assert File.exists?(path)
+  end
+
+  defp assert_directory_exists(path) do
+    assert File.dir?(path)
+  end
+end

installer/test/test_helper.exs

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+ExUnit.start

lib/host/handler.ex

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+defmodule NVim.Host.Handler do
+  require Logger
+  alias NVim.PluginManager
+
+  def on_call(_session, "poll", _params) do
+    {:ok, "ok"}
+  end
+
+  def on_call(_session, "specs", [plugin_path]) do
+    try do
+      {:ok, plugin} = PluginManager.lookup(plugin_path)
+      {:ok, plugin.specs}
+    rescue
+      any ->
+        Logger.error("Plugin path: #{plugin_path}, error: #{inspect any}")
+        {:error, "Troubles with load a plugin. See elixir host log for more information"}
+    end
+  end
+
+  def on_call(session, method, params) do
+    try do
+      on_action(session, method, params, sync: true)
+    catch
+      any ->
+        Logger.error("cathc error: #{inspect any}")
+    rescue
+      error ->
+        Logger.error("call error: #{inspect error}")
+        {:error, "Error: #{inspect error}"}
+    end
+  end
+
+  def on_notify(session, method, params) do
+    on_action(session, method, params, sync: false)
+  end
+
+  defp on_action(_session, method, params, sync: sync) do
+    [plugin_path, action_type, action_name | rest] = String.split(method, ":")
+    action_name = if rest != [], do: "#{action_name}:#{hd(rest)}", else: action_name
+
+    case PluginManager.lookup(plugin_path) do
+      {:ok, plugin} ->
+        response = plugin.handle_rpc_method(action_type, action_name, params)
+        if sync, do: handle_plugin_response(response)
+      _ ->
+        Logger.error("Plugin #{plugin_path} was not loaded")
+        {:error, "Problem with loading plugin for: #{method}"}
+    end
+  end
+
+  defp handle_plugin_response({status, _value}= response) when status in [:ok, :error], do: response
+  defp handle_plugin_response(_), do: {:error, "Problem with handle action by plugin"}
+end