Follow-up: Require Different Reviewers

This plugin previously only supported the Delta reviewer. Thanks to work
from @mrparalon it now supports Diffview also. This MR adjusts the
requirements to account for this, and the README.

It also addresses a small bug in the original implementation regarding
an async file opening action, and applies formatting to the diffview
file consistent with the rest of the project

README.md

@@ -17,11 +17,11 @@ https://github.com/harrisoncramer/gitlab.nvim/assets/32515581/ab5a8597-32fa-4a28
 
 - <a href="https://go.dev/">Go >= v1.19</a>
 - <a href="https://www.gnu.org/software/make/manual/make.html">make (for install)</a>
-- <a href="https://github.com/dandavison/delta">delta</a>
 
 ## Quick Start
 
-1. Install Go and Delta Dependencies
+1. Install Go
+2. Install reviewer: <a href="https://github.com/dandavison/delta">delta</a> or <a href="https://github.com/sindrets/diffview.nvim">diffview</a>
 2. Add configuration (see Installation section)
 3. Checkout your feature branch: `git checkout feature-branch`
 4. Open Neovim
@@ -42,7 +42,7 @@ return {
   },
   build = function () require("gitlab.server").build(true) end, -- Builds the Go binary
   config = function()
-    require("gitlab").setup()
+    require("gitlab").setup() -- Uses delta reviewer by default
   end,
 }
 ```
@@ -87,7 +87,7 @@ Here is the default setup function. All of these values are optional, and if you
 require("gitlab").setup({
   port = 21036, -- The port of the Go server, which runs in the background
   log_path = vim.fn.stdpath("cache") .. "/gitlab.nvim.log", -- Log path for the Go server
-  reviewer = "delta", -- The reviewer type (only delta is currently supported)
+  reviewer = "delta", -- The reviewer type ("delta" or "diffview")
   popup = { -- The popup for comment creation, editing, and replying
     exit = "<Esc>",
     perform_action = "<leader>s", -- Once in normal mode, does action (like saving comment or editing description, etc)
@@ -108,7 +108,7 @@ require("gitlab").setup({
     resolved = '✓', -- Symbol to show next to resolved discussions
     unresolved = '✖', -- Symbol to show next to unresolved discussions
   },
-  review_pane = { -- Specific settings for different reviewers, only delta currently supported
+  review_pane = { -- Specific settings for different reviewers
     delta = {
       added_file = "", -- The symbol to show next to added files
       modified_file = "", -- The symbol to show next to modified files

lua/gitlab/async.lua

@@ -3,6 +3,7 @@
 local server = require("gitlab.server")
 local job    = require("gitlab.job")
 local state  = require("gitlab.state")
+local u      = require("gitlab.utils")
 
 local M      = {}
 

lua/gitlab/init.lua

@@ -20,6 +20,7 @@ return {
     state.setPluginConfiguration() -- Sets configuration from `.gitlab.nvim` file
     state.merge_settings(args)     -- Sets keymaps and other settings from setup function
     reviewer.init()                -- Picks and initializes reviewer (default is Delta)
+    u.has_reviewer(args.reviewer or "delta")
   end,
   -- Global Actions 🌎
   summary            = async.sequence({ info }, summary.summary),

lua/gitlab/reviewer/diffview.lua

@@ -1,6 +1,6 @@
--- This Module contains all of the code specific to the Delta reviewer.
+-- This Module contains all of the code specific to the Diffview reviewer.
 local state           = require("gitlab.state")
-local u        = require("gitlab.utils")
+local async_ok, async = pcall(require, "diffview.async")
 
 local M               = {
   bufnr = nil,
@@ -32,7 +32,11 @@ M.jump         = function(file_name, new_line, old_line)
   local layout = view.cur_layout
   for _, file in ipairs(files) do
     if file.path == file_name then
-            view:set_file(file)
+      if not async_ok then
+        vim.notify("Could not load Diffview async", vim.log.levels.ERROR)
+        return
+      end
+      async.await(view:set_file(file))
       if new_line ~= nil then
         layout.b:focus()
         vim.api.nvim_win_set_cursor(0, { tonumber(new_line), 0 })
@@ -53,6 +57,10 @@ M.get_location = function()
   if tabnr ~= M.tabnr then return nil, nil, "Line location can only be determined within reviewer window" end
   -- check if we are in the diffview buffer
   local view = require("diffview.lib").get_current_view()
+  if view == nil then
+    vim.notify("Could not find Diffview view", vim.log.levels.ERROR)
+    return
+  end
   local layout = view.cur_layout
   local file_name = nil
   local current_line_changes = nil

lua/gitlab/server.lua

@@ -43,11 +43,6 @@ end
 
 -- Builds the Go binary
 M.build = function(override)
-  if not u.has_delta() then
-    vim.notify("Please install delta to use gitlab.nvim!", vim.log.levels.ERROR)
-    return
-  end
-
   local file_path = u.current_file_path()
   local parent_dir = vim.fn.fnamemodify(file_path, ":h:h:h:h")
   state.settings.bin_path = parent_dir

lua/gitlab/utils/init.lua

@@ -4,8 +4,19 @@ M.get_current_line_number = function()
   return vim.api.nvim_call_function('line', { '.' })
 end
 
-M.has_delta = function()
-  return vim.fn.executable("delta") == 1
+M.has_reviewer = function(reviewer)
+  local has_reviewer = false
+  if reviewer == "diffview" then
+    has_reviewer = vim.fn.exists(":DiffviewOpen") ~= 0
+  else
+    has_reviewer = vim.fn.executable("delta") == 1
+  end
+
+  if not has_reviewer then
+    error(string.format("Please install %s or change your reviewer", reviewer))
+  end
+
+  return has_reviewer
 end
 
 M.P = function(...)