diff --git a/lua/oil/adapters/files.lua b/lua/oil/adapters/files.lua
index d483852..ffc970d 100644
--- a/lua/oil/adapters/files.lua
+++ b/lua/oil/adapters/files.lua
@@ -1,13 +1,16 @@
 local cache = require("oil.cache")
 local columns = require("oil.columns")
 local config = require("oil.config")
+local constants = require("oil.constants")
 local fs = require("oil.fs")
 local permissions = require("oil.adapters.files.permissions")
 local trash = require("oil.adapters.files.trash")
 local util = require("oil.util")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_META = constants.FIELD_META
+
 local function read_link_data(path, cb)
   vim.loop.fs_readlink(
     path,
@@ -44,7 +47,7 @@ local fs_stat_meta_fields = {
   stat = function(parent_url, entry, cb)
     local _, path = util.parse_url(parent_url)
     local dir = fs.posix_to_os_path(path)
-    vim.loop.fs_stat(fs.join(dir, entry[FIELD.name]), cb)
+    vim.loop.fs_stat(fs.join(dir, entry[FIELD_NAME]), cb)
   end,
 }
 
@@ -52,7 +55,7 @@ file_columns.size = {
   meta_fields = fs_stat_meta_fields,
 
   render = function(entry, conf)
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     local stat = meta.stat
     if not stat then
       return ""
@@ -79,7 +82,7 @@ if not fs.is_windows then
     meta_fields = fs_stat_meta_fields,
 
     render = function(entry, conf)
-      local meta = entry[FIELD.meta]
+      local meta = entry[FIELD_META]
       local stat = meta.stat
       if not stat then
         return ""
@@ -92,7 +95,7 @@ if not fs.is_windows then
     end,
 
     compare = function(entry, parsed_value)
-      local meta = entry[FIELD.meta]
+      local meta = entry[FIELD_META]
       if parsed_value and meta.stat and meta.stat.mode then
         local mask = bit.lshift(1, 12) - 1
         local old_mode = bit.band(meta.stat.mode, mask)
@@ -135,7 +138,7 @@ for _, time_key in ipairs({ "ctime", "mtime", "atime", "birthtime" }) do
     meta_fields = fs_stat_meta_fields,
 
     render = function(entry, conf)
-      local meta = entry[FIELD.meta]
+      local meta = entry[FIELD_META]
       local stat = meta.stat
       local fmt = conf and conf.format
       local ret
@@ -253,7 +256,7 @@ M.list = function(url, column_defs, callback)
               if err then
                 poll(meta_err)
               else
-                local meta = cache_entry[FIELD.meta]
+                local meta = cache_entry[FIELD_META]
                 -- Make sure we always get fs_stat info for links
                 if entry.type == "link" then
                   read_link_data(fs.join(dir, entry.name), function(link_err, link, link_stat)
@@ -262,7 +265,7 @@ M.list = function(url, column_defs, callback)
                     else
                       if not meta then
                         meta = {}
-                        cache_entry[FIELD.meta] = meta
+                        cache_entry[FIELD_META] = meta
                       end
                       meta.link = link
                       meta.link_stat = link_stat
diff --git a/lua/oil/adapters/ssh.lua b/lua/oil/adapters/ssh.lua
index 8d04c27..88b1836 100644
--- a/lua/oil/adapters/ssh.lua
+++ b/lua/oil/adapters/ssh.lua
@@ -1,5 +1,6 @@
 local cache = require("oil.cache")
 local config = require("oil.config")
+local constants = require("oil.constants")
 local fs = require("oil.fs")
 local files = require("oil.adapters.files")
 local loading = require("oil.loading")
@@ -8,9 +9,10 @@ local sshfs = require("oil.adapters.ssh.sshfs")
 local pathutil = require("oil.pathutil")
 local shell = require("oil.shell")
 local util = require("oil.util")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_META = constants.FIELD_META
+
 ---@class oil.sshUrl
 ---@field scheme string
 ---@field host string
@@ -96,7 +98,7 @@ end
 local ssh_columns = {}
 ssh_columns.permissions = {
   render = function(entry, conf)
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     return permissions.mode_to_str(meta.mode)
   end,
 
@@ -105,7 +107,7 @@ ssh_columns.permissions = {
   end,
 
   compare = function(entry, parsed_value)
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     if parsed_value and meta.mode then
       local mask = bit.lshift(1, 12) - 1
       local old_mode = bit.band(meta.mode, mask)
@@ -129,7 +131,7 @@ ssh_columns.permissions = {
 
 ssh_columns.size = {
   render = function(entry, conf)
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     if not meta.size then
       return ""
     elseif meta.size >= 1e9 then
diff --git a/lua/oil/adapters/ssh/sshfs.lua b/lua/oil/adapters/ssh/sshfs.lua
index 5785c87..47eea01 100644
--- a/lua/oil/adapters/ssh/sshfs.lua
+++ b/lua/oil/adapters/ssh/sshfs.lua
@@ -1,10 +1,13 @@
 local cache = require("oil.cache")
+local constants = require("oil.constants")
 local permissions = require("oil.adapters.files.permissions")
 local SSHConnection = require("oil.adapters.ssh.connection")
 local util = require("oil.util")
-local FIELD = require("oil.constants").FIELD
 local SSHFS = {}
 
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
+
 local typechar_map = {
   l = "link",
   d = "directory",
@@ -143,7 +146,7 @@ function SSHFS:list_dir(url, path, callback)
           end
           local cache_entry = cache.create_entry(url, name, type)
           entries[name] = cache_entry
-          cache_entry[FIELD.meta] = meta
+          cache_entry[FIELD_META] = meta
           cache.store_entry(url, cache_entry)
         end
       end
@@ -161,8 +164,8 @@ function SSHFS:list_dir(url, path, callback)
             local ok, name, type, meta = pcall(parse_ls_line, line)
             if ok and name ~= "." and name ~= ".." then
               local cache_entry = entries[name]
-              if cache_entry[FIELD.type] == "link" then
-                cache_entry[FIELD.meta].link_stat = {
+              if cache_entry[FIELD_TYPE] == "link" then
+                cache_entry[FIELD_META].link_stat = {
                   type = type,
                   size = meta.size,
                 }
diff --git a/lua/oil/cache.lua b/lua/oil/cache.lua
index e878fc7..da04b49 100644
--- a/lua/oil/cache.lua
+++ b/lua/oil/cache.lua
@@ -1,7 +1,10 @@
+local constants = require("oil.constants")
 local util = require("oil.util")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_ID = constants.FIELD_ID
+local FIELD_NAME = constants.FIELD_NAME
+
 local next_id = 1
 
 -- Map<url, Map<entry name, oil.InternalEntry>>
@@ -64,8 +67,8 @@ M.store_entry = function(parent_url, entry)
     parent = {}
     url_directory[parent_url] = parent
   end
-  local id = entry[FIELD.id]
-  local name = entry[FIELD.name]
+  local id = entry[FIELD_ID]
+  local name = entry[FIELD_NAME]
   parent[name] = entry
   local tmp_dir = tmp_url_directory[parent_url]
   if tmp_dir and tmp_dir[name] then
@@ -97,7 +100,7 @@ M.end_update_url = function(parent_url)
     return
   end
   for _, old_entry in pairs(tmp_url_directory[parent_url]) do
-    local id = old_entry[FIELD.id]
+    local id = old_entry[FIELD_ID]
     parent_url_by_id[id] = nil
     entries_by_id[id] = nil
   end
@@ -146,8 +149,8 @@ M.perform_action = function(action)
     local name = vim.fn.fnamemodify(path, ":t")
     local entry = url_directory[parent_url][name]
     url_directory[parent_url][name] = nil
-    entries_by_id[entry[FIELD.id]] = nil
-    parent_url_by_id[entry[FIELD.id]] = nil
+    entries_by_id[entry[FIELD_ID]] = nil
+    parent_url_by_id[entry[FIELD_ID]] = nil
   elseif action.type == "move" then
     local src_scheme, src_path = util.parse_url(action.src_url)
     local src_parent_url = util.addslash(src_scheme .. vim.fn.fnamemodify(src_path, ":h"))
@@ -165,8 +168,8 @@ M.perform_action = function(action)
       url_directory[dest_parent_url] = dest_parent
     end
     dest_parent[dest_name] = entry
-    parent_url_by_id[entry[FIELD.id]] = dest_parent_url
-    entry[FIELD.name] = dest_name
+    parent_url_by_id[entry[FIELD_ID]] = dest_parent_url
+    entry[FIELD_NAME] = dest_name
     util.update_moved_buffers(action.entry_type, action.src_url, action.dest_url)
   elseif action.type == "copy" then
     local scheme, path = util.parse_url(action.dest_url)
diff --git a/lua/oil/columns.lua b/lua/oil/columns.lua
index 03c4620..fef42d8 100644
--- a/lua/oil/columns.lua
+++ b/lua/oil/columns.lua
@@ -1,9 +1,13 @@
 local config = require("oil.config")
+local constants = require("oil.constants")
 local util = require("oil.util")
 local has_devicons, devicons = pcall(require, "nvim-web-devicons")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
+
 local all_columns = {}
 
 ---@alias oil.ColumnSpec string|table
@@ -71,7 +75,7 @@ M.get_metadata_fetcher = function(adapter, column_defs)
   return function(parent_url, entry, cb)
     cb = util.cb_collect(num_keys, cb)
     local meta = {}
-    entry[FIELD.meta] = meta
+    entry[FIELD_META] = meta
     for k, v in pairs(keyfetches) do
       v(parent_url, entry, function(err, value)
         if err then
@@ -101,7 +105,7 @@ M.render_col = function(adapter, col_def, entry)
 
   -- Make sure all the required metadata exists before attempting to render
   if column.meta_fields then
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     if not meta then
       return EMPTY
     end
@@ -193,9 +197,9 @@ end
 if has_devicons then
   M.register("icon", {
     render = function(entry, conf)
-      local type = entry[FIELD.type]
-      local name = entry[FIELD.name]
-      local meta = entry[FIELD.meta]
+      local type = entry[FIELD_TYPE]
+      local name = entry[FIELD_NAME]
+      local meta = entry[FIELD_META]
       if type == "link" and meta then
         if meta.link then
           name = meta.link
@@ -228,7 +232,7 @@ local default_type_icons = {
 }
 M.register("type", {
   render = function(entry, conf)
-    local entry_type = entry[FIELD.type]
+    local entry_type = entry[FIELD_TYPE]
     if conf and conf.icons then
       return conf.icons[entry_type] or entry_type
     else
diff --git a/lua/oil/constants.lua b/lua/oil/constants.lua
index a83ee67..e1ef56b 100644
--- a/lua/oil/constants.lua
+++ b/lua/oil/constants.lua
@@ -1,10 +1,13 @@
 local M = {}
 
-M.FIELD = {
-  id = 1,
-  name = 2,
-  type = 3,
-  meta = 4,
-}
+---Store entries as a list-like table for maximum space efficiency and retrieval speed.
+---We use the constants below to index into the table.
+---@alias oil.InternalEntry any[]
+
+-- Indexes into oil.InternalEntry
+M.FIELD_ID = 1
+M.FIELD_NAME = 2
+M.FIELD_TYPE = 3
+M.FIELD_META = 4
 
 return M
diff --git a/lua/oil/init.lua b/lua/oil/init.lua
index ec625ee..9953075 100644
--- a/lua/oil/init.lua
+++ b/lua/oil/init.lua
@@ -1,7 +1,5 @@
 local M = {}
 
----@alias oil.InternalEntry string[]
-
 ---@class oil.Entry
 ---@field name string
 ---@field type oil.EntryType
diff --git a/lua/oil/mutator/init.lua b/lua/oil/mutator/init.lua
index 97205db..cca4bcb 100644
--- a/lua/oil/mutator/init.lua
+++ b/lua/oil/mutator/init.lua
@@ -1,6 +1,7 @@
 local cache = require("oil.cache")
 local columns = require("oil.columns")
 local config = require("oil.config")
+local constants = require("oil.constants")
 local oil = require("oil")
 local parser = require("oil.mutator.parser")
 local pathutil = require("oil.pathutil")
@@ -9,9 +10,11 @@ local Progress = require("oil.mutator.progress")
 local Trie = require("oil.mutator.trie")
 local util = require("oil.util")
 local view = require("oil.view")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+
 ---@alias oil.Action oil.CreateAction|oil.DeleteAction|oil.MoveAction|oil.CopyAction|oil.ChangeAction
 
 ---@class oil.CreateAction
@@ -129,17 +132,17 @@ M.create_actions_from_diffs = function(all_diffs)
         for i, diff in ipairs(diffs) do
           table.insert(actions, {
             type = i == #diffs and "move" or "copy",
-            entry_type = entry[FIELD.type],
+            entry_type = entry[FIELD_TYPE],
             dest_url = diff.dest,
-            src_url = cache.get_parent_url(id) .. entry[FIELD.name],
+            src_url = cache.get_parent_url(id) .. entry[FIELD_NAME],
           })
         end
       else
         -- DELETE when no create
         table.insert(actions, {
           type = "delete",
-          entry_type = entry[FIELD.type],
-          url = cache.get_parent_url(id) .. entry[FIELD.name],
+          entry_type = entry[FIELD_TYPE],
+          url = cache.get_parent_url(id) .. entry[FIELD_NAME],
         })
       end
     else
@@ -147,8 +150,8 @@ M.create_actions_from_diffs = function(all_diffs)
       for _, diff in ipairs(diffs) do
         table.insert(actions, {
           type = "copy",
-          entry_type = entry[FIELD.type],
-          src_url = cache.get_parent_url(id) .. entry[FIELD.name],
+          entry_type = entry[FIELD_TYPE],
+          src_url = cache.get_parent_url(id) .. entry[FIELD_NAME],
           dest_url = diff.dest,
         })
       end
diff --git a/lua/oil/mutator/parser.lua b/lua/oil/mutator/parser.lua
index ff16c48..60d163a 100644
--- a/lua/oil/mutator/parser.lua
+++ b/lua/oil/mutator/parser.lua
@@ -1,11 +1,16 @@
 local cache = require("oil.cache")
 local columns = require("oil.columns")
+local constants = require("oil.constants")
 local fs = require("oil.fs")
 local util = require("oil.util")
 local view = require("oil.view")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_ID = constants.FIELD_ID
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
+
 ---@alias oil.Diff oil.DiffNew|oil.DiffDelete|oil.DiffChange
 
 ---@class oil.DiffNew
@@ -102,8 +107,8 @@ M.parse_line = function(adapter, line, column_defs)
   end
 
   -- Parse the symlink syntax
-  local meta = entry[FIELD.meta]
-  local entry_type = entry[FIELD.type]
+  local meta = entry[FIELD_META]
+  local entry_type = entry[FIELD_TYPE]
   if entry_type == "link" and meta and meta.link then
     local name_pieces = vim.split(ret.name, " -> ", { plain = true })
     if #name_pieces ~= 2 then
@@ -118,7 +123,7 @@ M.parse_line = function(adapter, line, column_defs)
 
   -- Try to keep the same file type
   if entry_type ~= "directory" and entry_type ~= "file" and ret._type ~= "directory" then
-    ret._type = entry[FIELD.type]
+    ret._type = entry[FIELD_TYPE]
   end
 
   return { data = ret, entry = entry, ranges = ranges }
@@ -148,7 +153,7 @@ M.parse = function(bufnr)
   local original_entries = {}
   for _, child in pairs(children) do
     if view.should_display(child, bufnr) then
-      original_entries[child[FIELD.name]] = child[FIELD.id]
+      original_entries[child[FIELD_NAME]] = child[FIELD_ID]
     end
   end
   local seen_names = {}
@@ -193,9 +198,9 @@ M.parse = function(bufnr)
         goto continue
       end
       check_dupe(parsed_entry.name, i)
-      local meta = entry[FIELD.meta]
+      local meta = entry[FIELD_META]
       if original_entries[parsed_entry.name] == parsed_entry.id then
-        if entry[FIELD.type] == "link" and not compare_link_target(meta, parsed_entry) then
+        if entry[FIELD_TYPE] == "link" and not compare_link_target(meta, parsed_entry) then
           table.insert(diffs, {
             type = "new",
             name = parsed_entry.name,
@@ -221,7 +226,7 @@ M.parse = function(bufnr)
           table.insert(diffs, {
             type = "change",
             name = parsed_entry.name,
-            entry_type = entry[FIELD.type],
+            entry_type = entry[FIELD_TYPE],
             column = col_name,
             value = parsed_entry[col_name],
           })
diff --git a/lua/oil/util.lua b/lua/oil/util.lua
index 97d87b4..a51031d 100644
--- a/lua/oil/util.lua
+++ b/lua/oil/util.lua
@@ -1,6 +1,13 @@
 local config = require("oil.config")
+local constants = require("oil.constants")
+
 local M = {}
 
+local FIELD_ID = constants.FIELD_ID
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
+
 ---@param url string
 ---@return nil|string
 ---@return nil|string
@@ -84,12 +91,11 @@ end
 ---@param entry oil.InternalEntry
 ---@return oil.Entry
 M.export_entry = function(entry)
-  local FIELD = require("oil.constants").FIELD
   return {
-    name = entry[FIELD.name],
-    type = entry[FIELD.type],
-    id = entry[FIELD.id],
-    meta = entry[FIELD.meta],
+    name = entry[FIELD_NAME],
+    type = entry[FIELD_TYPE],
+    id = entry[FIELD_ID],
+    meta = entry[FIELD_META],
   }
 end
 
diff --git a/lua/oil/view.lua b/lua/oil/view.lua
index bdae78d..a3208f2 100644
--- a/lua/oil/view.lua
+++ b/lua/oil/view.lua
@@ -1,12 +1,17 @@
 local cache = require("oil.cache")
 local columns = require("oil.columns")
 local config = require("oil.config")
+local constants = require("oil.constants")
 local keymap_util = require("oil.keymap_util")
 local loading = require("oil.loading")
 local util = require("oil.util")
-local FIELD = require("oil.constants").FIELD
 local M = {}
 
+local FIELD_ID = constants.FIELD_ID
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
+
 -- map of path->last entry under cursor
 local last_cursor_entry = {}
 
@@ -14,7 +19,7 @@ local last_cursor_entry = {}
 ---@param bufnr integer
 ---@return boolean
 M.should_display = function(entry, bufnr)
-  local name = entry[FIELD.name]
+  local name = entry[FIELD_NAME]
   return not config.view_options.is_always_hidden(name, bufnr)
     and (not config.view_options.is_hidden_file(name, bufnr) or config.view_options.show_hidden)
 end
@@ -349,11 +354,11 @@ end
 ---@param entry oil.InternalEntry
 ---@return boolean
 local function is_entry_directory(entry)
-  local type = entry[FIELD.type]
+  local type = entry[FIELD_TYPE]
   if type == "directory" then
     return true
   elseif type == "link" then
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     return meta and meta.link_stat and meta.link_stat.type == "directory"
   else
     return false
@@ -391,7 +396,7 @@ local function render_buffer(bufnr, opts)
     if a_isdir ~= b_isdir then
       return a_isdir
     end
-    return a[FIELD.name] < b[FIELD.name]
+    return a[FIELD_NAME] < b[FIELD_NAME]
   end)
 
   local jump_idx
@@ -414,7 +419,7 @@ local function render_buffer(bufnr, opts)
     local cols = M.format_entry_cols(entry, column_defs, col_width, adapter)
     table.insert(line_table, cols)
 
-    local name = entry[FIELD.name]
+    local name = entry[FIELD_NAME]
     if seek_after_render == name then
       seek_after_render_found = true
       jump_idx = #line_table
@@ -448,7 +453,7 @@ local function render_buffer(bufnr, opts)
           if id then
             local entry = cache.get_entry_by_id(id)
             if entry then
-              local name = entry[FIELD.name]
+              local name = entry[FIELD_NAME]
               local col = line:find(name, 1, true) or (id_str:len() + 1)
               vim.api.nvim_win_set_cursor(winid, { lnum, col - 1 })
             end
@@ -467,10 +472,10 @@ end
 ---@param adapter oil.Adapter
 ---@return oil.TextChunk[]
 M.format_entry_cols = function(entry, column_defs, col_width, adapter)
-  local name = entry[FIELD.name]
+  local name = entry[FIELD_NAME]
   -- First put the unique ID
   local cols = {}
-  local id_key = cache.format_id(entry[FIELD.id])
+  local id_key = cache.format_id(entry[FIELD_ID])
   col_width[1] = id_key:len()
   table.insert(cols, id_key)
   -- Then add all the configured columns
@@ -481,13 +486,13 @@ M.format_entry_cols = function(entry, column_defs, col_width, adapter)
     table.insert(cols, chunk)
   end
   -- Always add the entry name at the end
-  local entry_type = entry[FIELD.type]
+  local entry_type = entry[FIELD_TYPE]
   if entry_type == "directory" then
     table.insert(cols, { name .. "/", "OilDir" })
   elseif entry_type == "socket" then
     table.insert(cols, { name, "OilSocket" })
   elseif entry_type == "link" then
-    local meta = entry[FIELD.meta]
+    local meta = entry[FIELD_META]
     local link_text
     if meta then
       if meta.link_stat and meta.link_stat.type == "directory" then
diff --git a/tests/mutator_spec.lua b/tests/mutator_spec.lua
index 167253a..00e8932 100644
--- a/tests/mutator_spec.lua
+++ b/tests/mutator_spec.lua
@@ -1,11 +1,16 @@
 require("plenary.async").tests.add_to_env()
-local FIELD = require("oil.constants").FIELD
-local view = require("oil.view")
 local cache = require("oil.cache")
+local constants = require("oil.constants")
 local mutator = require("oil.mutator")
 local parser = require("oil.mutator.parser")
 local test_adapter = require("oil.adapters.test")
 local util = require("oil.util")
+local view = require("oil.view")
+
+local FIELD_ID = constants.FIELD_ID
+local FIELD_NAME = constants.FIELD_NAME
+local FIELD_TYPE = constants.FIELD_TYPE
+local FIELD_META = constants.FIELD_META
 
 local function set_lines(bufnr, lines)
   vim.bo[bufnr].modifiable = true
@@ -61,7 +66,7 @@ a.describe("mutator", function()
       set_lines(bufnr, {})
       local diffs = parser.parse(bufnr)
       assert.are.same({
-        { name = "a.txt", type = "delete", id = file[FIELD.id] },
+        { name = "a.txt", type = "delete", id = file[FIELD_ID] },
       }, diffs)
     end)
 
@@ -72,19 +77,19 @@ a.describe("mutator", function()
       set_lines(bufnr, {})
       local diffs = parser.parse(bufnr)
       assert.are.same({
-        { name = "bar", type = "delete", id = dir[FIELD.id] },
+        { name = "bar", type = "delete", id = dir[FIELD_ID] },
       }, diffs)
     end)
 
     it("detects deleted links", function()
       local file = cache.create_and_store_entry("oil-test:///foo/", "a.txt", "link")
-      file[FIELD.meta] = { link = "b.txt" }
+      file[FIELD_META] = { link = "b.txt" }
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       set_lines(bufnr, {})
       local diffs = parser.parse(bufnr)
       assert.are.same({
-        { name = "a.txt", type = "delete", id = file[FIELD.id] },
+        { name = "a.txt", type = "delete", id = file[FIELD_ID] },
       }, diffs)
     end)
 
@@ -156,7 +161,7 @@ a.describe("mutator", function()
       local bufnr = vim.api.nvim_get_current_buf()
       set_lines(bufnr, {
         "a.txt",
-        string.format("/%d a.txt", file[FIELD.id]),
+        string.format("/%d a.txt", file[FIELD_ID]),
       })
       local _, errors = parser.parse(bufnr)
       assert.are.same({
@@ -183,12 +188,12 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       set_lines(bufnr, {
-        string.format("/%d b.txt", file[FIELD.id]),
+        string.format("/%d b.txt", file[FIELD_ID]),
       })
       local diffs = parser.parse(bufnr)
       assert.are.same({
-        { type = "new", id = file[FIELD.id], name = "b.txt", entry_type = "file" },
-        { type = "delete", id = file[FIELD.id], name = "a.txt" },
+        { type = "new", id = file[FIELD_ID], name = "b.txt", entry_type = "file" },
+        { type = "delete", id = file[FIELD_ID], name = "a.txt" },
       }, diffs)
     end)
 
@@ -198,8 +203,8 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       set_lines(bufnr, {
-        string.format("/%d a.txt", bfile[FIELD.id]),
-        string.format("/%d b.txt", afile[FIELD.id]),
+        string.format("/%d a.txt", bfile[FIELD_ID]),
+        string.format("/%d b.txt", afile[FIELD_ID]),
       })
       local diffs = parser.parse(bufnr)
       local first_two = { diffs[1], diffs[2] }
@@ -211,22 +216,22 @@ a.describe("mutator", function()
         return a.id < b.id
       end)
       assert.are.same({
-        { name = "b.txt", type = "new", id = afile[FIELD.id], entry_type = "file" },
-        { name = "a.txt", type = "new", id = bfile[FIELD.id], entry_type = "file" },
+        { name = "b.txt", type = "new", id = afile[FIELD_ID], entry_type = "file" },
+        { name = "a.txt", type = "new", id = bfile[FIELD_ID], entry_type = "file" },
       }, first_two)
       assert.are.same({
-        { name = "a.txt", type = "delete", id = afile[FIELD.id] },
-        { name = "b.txt", type = "delete", id = bfile[FIELD.id] },
+        { name = "a.txt", type = "delete", id = afile[FIELD_ID] },
+        { name = "b.txt", type = "delete", id = bfile[FIELD_ID] },
       }, last_two)
     end)
 
     it("views link targets with trailing slashes as the same", function()
       local file = cache.create_and_store_entry("oil-test:///foo/", "mydir", "link")
-      file[FIELD.meta] = { link = "dir/" }
+      file[FIELD_META] = { link = "dir/" }
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       set_lines(bufnr, {
-        string.format("/%d mydir/ -> dir/", file[FIELD.id]),
+        string.format("/%d mydir/ -> dir/", file[FIELD_ID]),
       })
       local diffs = parser.parse(bufnr)
       assert.are.same({}, diffs)
@@ -266,7 +271,7 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       local diffs = {
-        { type = "delete", name = "a.txt", id = file[FIELD.id] },
+        { type = "delete", name = "a.txt", id = file[FIELD_ID] },
       }
       local actions = mutator.create_actions_from_diffs({
         [bufnr] = diffs,
@@ -285,7 +290,7 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       local diffs = {
-        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD.id] },
+        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD_ID] },
       }
       local actions = mutator.create_actions_from_diffs({
         [bufnr] = diffs,
@@ -305,8 +310,8 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///foo/" } })
       local bufnr = vim.api.nvim_get_current_buf()
       local diffs = {
-        { type = "delete", name = "a.txt", id = file[FIELD.id] },
-        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD.id] },
+        { type = "delete", name = "a.txt", id = file[FIELD_ID] },
+        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD_ID] },
       }
       local actions = mutator.create_actions_from_diffs({
         [bufnr] = diffs,
@@ -326,8 +331,8 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///" } })
       local bufnr = vim.api.nvim_get_current_buf()
       local diffs = {
-        { type = "delete", name = "a.txt", id = file[FIELD.id] },
-        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD.id] },
+        { type = "delete", name = "a.txt", id = file[FIELD_ID] },
+        { type = "new", name = "b.txt", entry_type = "file", id = file[FIELD_ID] },
         { type = "new", name = "a.txt", entry_type = "file" },
       }
       local actions = mutator.create_actions_from_diffs({
@@ -354,10 +359,10 @@ a.describe("mutator", function()
       vim.cmd.edit({ args = { "oil-test:///" } })
       local bufnr = vim.api.nvim_get_current_buf()
       local diffs = {
-        { type = "delete", name = "a.txt", id = afile[FIELD.id] },
-        { type = "new", name = "b.txt", entry_type = "file", id = afile[FIELD.id] },
-        { type = "delete", name = "b.txt", id = bfile[FIELD.id] },
-        { type = "new", name = "a.txt", entry_type = "file", id = bfile[FIELD.id] },
+        { type = "delete", name = "a.txt", id = afile[FIELD_ID] },
+        { type = "new", name = "b.txt", entry_type = "file", id = afile[FIELD_ID] },
+        { type = "delete", name = "b.txt", id = bfile[FIELD_ID] },
+        { type = "new", name = "a.txt", entry_type = "file", id = bfile[FIELD_ID] },
       }
       math.randomseed(2983982)
       local actions = mutator.create_actions_from_diffs({
@@ -541,9 +546,9 @@ a.describe("mutator", function()
       local files = cache.list_url("oil-test:///")
       assert.are.same({
         ["a.txt"] = {
-          [FIELD.id] = 1,
-          [FIELD.type] = "file",
-          [FIELD.name] = "a.txt",
+          [FIELD_ID] = 1,
+          [FIELD_TYPE] = "file",
+          [FIELD_NAME] = "a.txt",
         },
       }, files)
     end)
@@ -556,9 +561,9 @@ a.describe("mutator", function()
       a.wrap(mutator.process_actions, 2)(actions)
       local files = cache.list_url("oil-test:///")
       assert.are.same({}, files)
-      assert.is_nil(cache.get_entry_by_id(file[FIELD.id]))
+      assert.is_nil(cache.get_entry_by_id(file[FIELD_ID]))
       assert.has_error(function()
-        cache.get_parent_url(file[FIELD.id])
+        cache.get_parent_url(file[FIELD_ID])
       end)
     end)
 
@@ -575,15 +580,15 @@ a.describe("mutator", function()
       a.wrap(mutator.process_actions, 2)(actions)
       local files = cache.list_url("oil-test:///")
       local new_entry = {
-        [FIELD.id] = file[FIELD.id],
-        [FIELD.type] = "file",
-        [FIELD.name] = "b.txt",
+        [FIELD_ID] = file[FIELD_ID],
+        [FIELD_TYPE] = "file",
+        [FIELD_NAME] = "b.txt",
       }
       assert.are.same({
         ["b.txt"] = new_entry,
       }, files)
-      assert.are.same(new_entry, cache.get_entry_by_id(file[FIELD.id]))
-      assert.equals("oil-test:///", cache.get_parent_url(file[FIELD.id]))
+      assert.are.same(new_entry, cache.get_entry_by_id(file[FIELD_ID]))
+      assert.equals("oil-test:///", cache.get_parent_url(file[FIELD_ID]))
     end)
 
     a.it("copies entries", function()
@@ -599,9 +604,9 @@ a.describe("mutator", function()
       a.wrap(mutator.process_actions, 2)(actions)
       local files = cache.list_url("oil-test:///")
       local new_entry = {
-        [FIELD.id] = file[FIELD.id] + 1,
-        [FIELD.type] = "file",
-        [FIELD.name] = "b.txt",
+        [FIELD_ID] = file[FIELD_ID] + 1,
+        [FIELD_TYPE] = "file",
+        [FIELD_NAME] = "b.txt",
       }
       assert.are.same({
         ["a.txt"] = file,