feat: disable preview for large files (#511)

* feat: disable preview for large files

fix: update oil.PreviewWindowConfig

* refactor: remove unnecessary shim in config.lua

* refactor: revert changes to shim

---------

Co-authored-by: Steve Walker <65963536+etherswangel@users.noreply.github.com>
Co-authored-by: Steven Arcangeli <506791+stevearc@users.noreply.github.com>

README.md

@@ -271,6 +271,8 @@ require("oil").setup({
   preview_win = {
     -- Whether the preview window is automatically updated when the cursor is moved
     update_on_cursor_moved = true,
+    -- Maximum file size in megabytes to preview
+    max_file_size_mb = 100,
   },
   -- Configuration for the floating action confirmation window
   confirmation = {

doc/oil.txt

@@ -156,6 +156,8 @@ CONFIG                                                                *oil-confi
       preview_win = {
         -- Whether the preview window is automatically updated when the cursor is moved
         update_on_cursor_moved = true,
+        -- Maximum file size in megabytes to preview
+        max_file_size_mb = 100,
       },
       -- Configuration for the floating action confirmation window
       confirmation = {

lua/oil/config.lua

@@ -141,6 +141,8 @@ local default_config = {
   preview_win = {
     -- Whether the preview window is automatically updated when the cursor is moved
     update_on_cursor_moved = true,
+    -- Maximum file size in megabytes to preview
+    max_file_size_mb = 100,
   },
   -- Configuration for the floating action confirmation window
   confirmation = {
@@ -323,11 +325,13 @@ local M = {}
 
 ---@class (exact) oil.PreviewWindowConfig
 ---@field update_on_cursor_moved boolean
+---@field max_file_size_mb number
 
 ---@class (exact) oil.ConfirmationWindowConfig : oil.WindowConfig
 
 ---@class (exact) oil.SetupPreviewWindowConfig
 ---@field update_on_cursor_moved? boolean Whether the preview window is automatically updated when the cursor is moved
+---@field max_file_size_mb? number Maximum file size in megabytes to preview
 
 ---@class (exact) oil.SetupConfirmationWindowConfig : oil.SetupWindowConfig
 

lua/oil/init.lua

@@ -452,6 +452,13 @@ M.open_preview = function(opts, callback)
   if not entry then
     return finish("Could not find entry under cursor")
   end
+  if entry.meta ~= nil and entry.meta.stat ~= nil then
+    if entry.meta.stat.size >= config.preview_win.max_file_size_mb * 1e6 then
+      return finish(
+        "File over " .. config.preview_win.max_file_size_mb .. "MB is too large to preview"
+      )
+    end
+  end
   local entry_title = entry.name
   if entry.type == "directory" then
     entry_title = entry_title .. "/"