refactor(lsp): rename `offset_encoding` to `position_encoding` #31286

Problem:
LSP spec uses the term "position encoding" where we say "offset encoding".

Solution:
- Rename it everywhere except `vim.lsp.Client.offset_encoding` (which would be breaking).
- Mention "position encoding" in the documentation for `vim.lsp.Client.offset_encoding`.

12 files changed, 188 insertions, 175 deletions

diff --git a/runtime/doc/lsp.txt b/runtime/doc/lsp.txt
index 3cb3e590f4..1253c01547 100644
--- a/runtime/doc/lsp.txt
+++ b/runtime/doc/lsp.txt
@@ -904,8 +904,9 @@ Lua module: vim.lsp.client                                        *lsp-client*
       • {rpc}                   (`vim.lsp.rpc.PublicClient`) RPC client
                                 object, for low level interaction with the
                                 client. See |vim.lsp.rpc.start()|.
-      • {offset_encoding}       (`string`) The encoding used for communicating
-                                with the server. You can modify this in the
+      • {offset_encoding}       (`string`) Called "position encoding" in LSP
+                                spec, the encoding used for communicating with
+                                the server. You can modify this in the
                                 `config`'s `on_init` method before text is
                                 sent to the server.
       • {handlers}              (`table<string,lsp.Handler>`) The handlers
@@ -1062,9 +1063,10 @@ Lua module: vim.lsp.client                                        *lsp-client*
       • {get_language_id}?    (`fun(bufnr: integer, filetype: string): string`)
                               Language ID as string. Defaults to the buffer
                               filetype.
-      • {offset_encoding}?    (`'utf-8'|'utf-16'|'utf-32'`) The encoding that
-                              the LSP server expects. Client does not verify
-                              this is correct.
+      • {offset_encoding}?    (`'utf-8'|'utf-16'|'utf-32'`) Called "position
+                              encoding" in LSP spec, the encoding that the LSP
+                              server expects. Client does not verify this is
+                              correct.
       • {on_error}?           (`fun(code: integer, err: string)`) Callback
                               invoked when the client operation throws an
                               error. `code` is a number describing the error.
@@ -1840,7 +1842,7 @@ Lua module: vim.lsp.util                                            *lsp-util*
 
 
                                      *vim.lsp.util.apply_text_document_edit()*
-apply_text_document_edit({text_document_edit}, {index}, {offset_encoding})
+apply_text_document_edit({text_document_edit}, {index}, {position_encoding})
     Applies a `TextDocumentEdit`, which is a list of changes to a single
     document.
 
@@ -1848,30 +1850,30 @@ apply_text_document_edit({text_document_edit}, {index}, {offset_encoding})
       • {text_document_edit}  (`lsp.TextDocumentEdit`)
       • {index}               (`integer?`) Optional index of the edit, if from
                               a list of edits (or nil, if not from a list)
-      • {offset_encoding}     (`'utf-8'|'utf-16'|'utf-32'?`)
+      • {position_encoding}   (`'utf-8'|'utf-16'|'utf-32'?`)
 
     See also: ~
       • https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentEdit
 
                                              *vim.lsp.util.apply_text_edits()*
-apply_text_edits({text_edits}, {bufnr}, {offset_encoding})
+apply_text_edits({text_edits}, {bufnr}, {position_encoding})
     Applies a list of text edits to a buffer.
 
     Parameters: ~
-      • {text_edits}       (`lsp.TextEdit[]`)
-      • {bufnr}            (`integer`) Buffer id
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
+      • {text_edits}         (`lsp.TextEdit[]`)
+      • {bufnr}              (`integer`) Buffer id
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
 
     See also: ~
       • https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textEdit
 
                                          *vim.lsp.util.apply_workspace_edit()*
-apply_workspace_edit({workspace_edit}, {offset_encoding})
+apply_workspace_edit({workspace_edit}, {position_encoding})
     Applies a `WorkspaceEdit`.
 
     Parameters: ~
-      • {workspace_edit}   (`lsp.WorkspaceEdit`)
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'`) (required)
+      • {workspace_edit}     (`lsp.WorkspaceEdit`)
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'`) (required)
 
     See also: ~
       • https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_applyEdit
@@ -1883,13 +1885,13 @@ buf_clear_references({bufnr})            *vim.lsp.util.buf_clear_references()*
       • {bufnr}  (`integer?`) Buffer id
 
                                      *vim.lsp.util.buf_highlight_references()*
-buf_highlight_references({bufnr}, {references}, {offset_encoding})
+buf_highlight_references({bufnr}, {references}, {position_encoding})
     Shows a list of document highlights for a certain buffer.
 
     Parameters: ~
-      • {bufnr}            (`integer`) Buffer id
-      • {references}       (`lsp.DocumentHighlight[]`) objects to highlight
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
+      • {bufnr}              (`integer`) Buffer id
+      • {references}         (`lsp.DocumentHighlight[]`) objects to highlight
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
 
     See also: ~
       • https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
@@ -1964,7 +1966,7 @@ get_effective_tabstop({bufnr})          *vim.lsp.util.get_effective_tabstop()*
       • 'shiftwidth'
 
                                            *vim.lsp.util.locations_to_items()*
-locations_to_items({locations}, {offset_encoding})
+locations_to_items({locations}, {position_encoding})
     Returns the items with the byte position calculated correctly and in
     sorted order, for display in quickfix and location lists.
 
@@ -1975,9 +1977,9 @@ locations_to_items({locations}, {offset_encoding})
     |setloclist()|.
 
     Parameters: ~
-      • {locations}        (`lsp.Location[]|lsp.LocationLink[]`)
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'?`) default to first
-                           client of buffer
+      • {locations}          (`lsp.Location[]|lsp.LocationLink[]`)
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'?`) default to first
+                             client of buffer
 
     Return: ~
         (`vim.quickfix.entry[]`) See |setqflist()| for the format
@@ -2012,33 +2014,33 @@ make_formatting_params({options})
       • https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_formatting
 
                                       *vim.lsp.util.make_given_range_params()*
-make_given_range_params({start_pos}, {end_pos}, {bufnr}, {offset_encoding})
+make_given_range_params({start_pos}, {end_pos}, {bufnr}, {position_encoding})
     Using the given range in the current buffer, creates an object that is
     similar to |vim.lsp.util.make_range_params()|.
 
     Parameters: ~
-      • {start_pos}        (`[integer,integer]?`) {row,col} mark-indexed
-                           position. Defaults to the start of the last visual
-                           selection.
-      • {end_pos}          (`[integer,integer]?`) {row,col} mark-indexed
-                           position. Defaults to the end of the last visual
-                           selection.
-      • {bufnr}            (`integer?`) buffer handle or 0 for current,
-                           defaults to current
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
+      • {start_pos}          (`[integer,integer]?`) {row,col} mark-indexed
+                             position. Defaults to the start of the last
+                             visual selection.
+      • {end_pos}            (`[integer,integer]?`) {row,col} mark-indexed
+                             position. Defaults to the end of the last visual
+                             selection.
+      • {bufnr}              (`integer?`) buffer handle or 0 for current,
+                             defaults to current
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
 
     Return: ~
         (`{ textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }`)
 
                                          *vim.lsp.util.make_position_params()*
-make_position_params({window}, {offset_encoding})
+make_position_params({window}, {position_encoding})
     Creates a `TextDocumentPositionParams` object for the current buffer and
     cursor position.
 
     Parameters: ~
-      • {window}           (`integer?`) window handle or 0 for current,
-                           defaults to current
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
+      • {window}             (`integer?`) window handle or 0 for current,
+                             defaults to current
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'`)
 
     Return: ~
         (`lsp.TextDocumentPositionParams`)
@@ -2047,16 +2049,16 @@ make_position_params({window}, {offset_encoding})
       • https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentPositionParams
 
                                             *vim.lsp.util.make_range_params()*
-make_range_params({window}, {offset_encoding})
+make_range_params({window}, {position_encoding})
     Using the current position in the current buffer, creates an object that
     can be used as a building block for several LSP requests, such as
     `textDocument/codeAction`, `textDocument/colorPresentation`,
     `textDocument/rangeFormatting`.
 
     Parameters: ~
-      • {window}           (`integer?`) window handle or 0 for current,
-                           defaults to current
-      • {offset_encoding}  (`"utf-8"|"utf-16"|"utf-32"`)
+      • {window}             (`integer?`) window handle or 0 for current,
+                             defaults to current
+      • {position_encoding}  (`"utf-8"|"utf-16"|"utf-32"`)
 
     Return: ~
         (`{ textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }`)
@@ -2138,17 +2140,17 @@ rename({old_fname}, {new_fname}, {opts})               *vim.lsp.util.rename()*
                      • {ignoreIfExists}? (`boolean`)
 
                                                 *vim.lsp.util.show_document()*
-show_document({location}, {offset_encoding}, {opts})
+show_document({location}, {position_encoding}, {opts})
     Shows document and optionally jumps to the location.
 
     Parameters: ~
-      • {location}         (`lsp.Location|lsp.LocationLink`)
-      • {offset_encoding}  (`'utf-8'|'utf-16'|'utf-32'?`)
-      • {opts}             (`table?`) A table with the following fields:
-                           • {reuse_win}? (`boolean`) Jump to existing window
-                             if buffer is already open.
-                           • {focus}? (`boolean`) Whether to focus/jump to
-                             location if possible. (defaults: true)
+      • {location}           (`lsp.Location|lsp.LocationLink`)
+      • {position_encoding}  (`'utf-8'|'utf-16'|'utf-32'?`)
+      • {opts}               (`table?`) A table with the following fields:
+                             • {reuse_win}? (`boolean`) Jump to existing
+                               window if buffer is already open.
+                             • {focus}? (`boolean`) Whether to focus/jump to
+                               location if possible. (defaults: true)
 
     Return: ~
         (`boolean`) `true` if succeeded
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index c0d0f7b1bc..58ab7ef44c 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -100,7 +100,7 @@ LSP
     vim.diagnostic.config(config, vim.lsp.diagnostic.get_namespace(client_id))
 <
 • |vim.lsp.util.make_position_params()|, |vim.lsp.util.make_range_params()|
-  and |vim.lsp.util.make_given_range_params()| now require the `offset_encoding`
+  and |vim.lsp.util.make_given_range_params()| now require the `position_encoding`
   parameter.
 
 LUA
diff --git a/runtime/lua/vim/lsp/_changetracking.lua b/runtime/lua/vim/lsp/_changetracking.lua
index 8588502697..c2ff66b90e 100644
--- a/runtime/lua/vim/lsp/_changetracking.lua
+++ b/runtime/lua/vim/lsp/_changetracking.lua
@@ -18,14 +18,14 @@ local M = {}
 ---
 ---   None: One group for all clients
 ---   Full: One group for all clients
----   Incremental: One group per `offset_encoding`
+---   Incremental: One group per `position_encoding`
 ---
 --- Sending changes can be debounced per buffer. To simplify the implementation the
 --- smallest debounce interval is used and we don't group clients by different intervals.
 ---
 --- @class vim.lsp.CTGroup
 --- @field sync_kind integer TextDocumentSyncKind, considers config.flags.allow_incremental_sync
---- @field offset_encoding "utf-8"|"utf-16"|"utf-32"
+--- @field position_encoding "utf-8"|"utf-16"|"utf-32"
 ---
 --- @class vim.lsp.CTBufferState
 --- @field name string name of the buffer
@@ -46,7 +46,7 @@ local M = {}
 ---@return string
 local function group_key(group)
   if group.sync_kind == protocol.TextDocumentSyncKind.Incremental then
-    return tostring(group.sync_kind) .. '\0' .. group.offset_encoding
+    return tostring(group.sync_kind) .. '\0' .. group.position_encoding
   end
   return tostring(group.sync_kind)
 end
@@ -72,7 +72,7 @@ local function get_group(client)
   end
   return {
     sync_kind = sync_kind,
-    offset_encoding = client.offset_encoding,
+    position_encoding = client.offset_encoding,
   }
 end
 
@@ -310,7 +310,7 @@ local function send_changes_for_group(bufnr, firstline, lastline, new_lastline,
     -- The contents would further change and startline/endline may no longer fit
     local changes = incremental_changes(
       buf_state,
-      group.offset_encoding,
+      group.position_encoding,
       bufnr,
       firstline,
       lastline,
diff --git a/runtime/lua/vim/lsp/_tagfunc.lua b/runtime/lua/vim/lsp/_tagfunc.lua
index f6ffc63824..554f0cb991 100644
--- a/runtime/lua/vim/lsp/_tagfunc.lua
+++ b/runtime/lua/vim/lsp/_tagfunc.lua
@@ -6,12 +6,12 @@ local ms = lsp.protocol.Methods
 ---@param name string
 ---@param range lsp.Range
 ---@param uri string
----@param offset_encoding string
+---@param position_encoding string
 ---@return {name: string, filename: string, cmd: string, kind?: string}
-local function mk_tag_item(name, range, uri, offset_encoding)
+local function mk_tag_item(name, range, uri, position_encoding)
   local bufnr = vim.uri_to_bufnr(uri)
   -- This is get_line_byte_from_position is 0-indexed, call cursor expects a 1-indexed position
-  local byte = util._get_line_byte_from_position(bufnr, range.start, offset_encoding) + 1
+  local byte = util._get_line_byte_from_position(bufnr, range.start, position_encoding) + 1
   return {
     name = name,
     filename = vim.uri_to_fname(uri),
@@ -32,9 +32,9 @@ local function query_definition(pattern)
 
   --- @param range lsp.Range
   --- @param uri string
-  --- @param offset_encoding string
-  local add = function(range, uri, offset_encoding)
-    table.insert(results, mk_tag_item(pattern, range, uri, offset_encoding))
+  --- @param position_encoding string
+  local add = function(range, uri, position_encoding)
+    table.insert(results, mk_tag_item(pattern, range, uri, position_encoding))
   end
 
   local remaining = #clients
@@ -78,11 +78,11 @@ local function query_workspace_symbols(pattern)
   local results = {}
   for client_id, responses in pairs(assert(results_by_client)) do
     local client = lsp.get_client_by_id(client_id)
-    local offset_encoding = client and client.offset_encoding or 'utf-16'
+    local position_encoding = client and client.offset_encoding or 'utf-16'
     local symbols = responses.result --[[@as lsp.SymbolInformation[]|nil]]
     for _, symbol in pairs(symbols or {}) do
       local loc = symbol.location
-      local item = mk_tag_item(symbol.name, loc.range, loc.uri, offset_encoding)
+      local item = mk_tag_item(symbol.name, loc.range, loc.uri, position_encoding)
       item.kind = lsp.protocol.SymbolKind[symbol.kind] or 'Unknown'
       table.insert(results, item)
     end
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 10c0dbefdc..aca6bf27f4 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -638,14 +638,14 @@ function M.rename(new_name, opts)
   local cword = vim.fn.expand('<cword>')
 
   --- @param range lsp.Range
-  --- @param offset_encoding string
-  local function get_text_at_range(range, offset_encoding)
+  --- @param position_encoding string
+  local function get_text_at_range(range, position_encoding)
     return api.nvim_buf_get_text(
       bufnr,
       range.start.line,
-      util._get_line_byte_from_position(bufnr, range.start, offset_encoding),
+      util._get_line_byte_from_position(bufnr, range.start, position_encoding),
       range['end'].line,
-      util._get_line_byte_from_position(bufnr, range['end'], offset_encoding),
+      util._get_line_byte_from_position(bufnr, range['end'], position_encoding),
       {}
     )[1]
   end
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index 3b79da99ea..7c2b7192f5 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -94,7 +94,8 @@ local validate = vim.validate
 --- Language ID as string. Defaults to the buffer filetype.
 --- @field get_language_id? fun(bufnr: integer, filetype: string): string
 ---
---- The encoding that the LSP server expects. Client does not verify this is correct.
+--- Called "position encoding" in LSP spec, the encoding that the LSP server expects.
+--- Client does not verify this is correct.
 --- @field offset_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---
 --- Callback invoked when the client operation throws an error. `code` is a number describing the error.
@@ -148,8 +149,10 @@ local validate = vim.validate
 --- See |vim.lsp.rpc.start()|.
 --- @field rpc vim.lsp.rpc.PublicClient
 ---
---- The encoding used for communicating with the server. You can modify this in
---- the `config`'s `on_init` method before text is sent to the server.
+--- Called "position encoding" in LSP spec,
+--- the encoding used for communicating with the server.
+--- You can modify this in the `config`'s `on_init` method
+--- before text is sent to the server.
 --- @field offset_encoding string
 ---
 --- The handlers used by the client as described in |lsp-handler|.
@@ -278,7 +281,7 @@ local function validate_encoding(encoding)
   return valid_encodings[encoding:lower()]
     or error(
       string.format(
-        "Invalid offset encoding %q. Must be one of: 'utf-8', 'utf-16', 'utf-32'",
+        "Invalid position encoding %q. Must be one of: 'utf-8', 'utf-16', 'utf-32'",
         encoding
       )
     )
diff --git a/runtime/lua/vim/lsp/completion.lua b/runtime/lua/vim/lsp/completion.lua
index 0f388a88fd..1e950f625e 100644
--- a/runtime/lua/vim/lsp/completion.lua
+++ b/runtime/lua/vim/lsp/completion.lua
@@ -550,7 +550,7 @@ local function on_complete_done()
     return
   end
 
-  local offset_encoding = client.offset_encoding or 'utf-16'
+  local position_encoding = client.offset_encoding or 'utf-16'
   local resolve_provider = (client.server_capabilities.completionProvider or {}).resolveProvider
 
   local function clear_word()
@@ -576,7 +576,7 @@ local function on_complete_done()
 
   if completion_item.additionalTextEdits and next(completion_item.additionalTextEdits) then
     clear_word()
-    lsp.util.apply_text_edits(completion_item.additionalTextEdits, bufnr, offset_encoding)
+    lsp.util.apply_text_edits(completion_item.additionalTextEdits, bufnr, position_encoding)
     apply_snippet_and_command()
   elseif resolve_provider and type(completion_item) == 'table' then
     local changedtick = vim.b[bufnr].changedtick
@@ -591,7 +591,7 @@ local function on_complete_done()
       if err then
         vim.notify_once(err.message, vim.log.levels.WARN)
       elseif result and result.additionalTextEdits then
-        lsp.util.apply_text_edits(result.additionalTextEdits, bufnr, offset_encoding)
+        lsp.util.apply_text_edits(result.additionalTextEdits, bufnr, position_encoding)
         if result.command then
           completion_item.command = result.command
         end
diff --git a/runtime/lua/vim/lsp/diagnostic.lua b/runtime/lua/vim/lsp/diagnostic.lua
index 8fd30c7668..12984f8c26 100644
--- a/runtime/lua/vim/lsp/diagnostic.lua
+++ b/runtime/lua/vim/lsp/diagnostic.lua
@@ -77,7 +77,7 @@ end
 local function diagnostic_lsp_to_vim(diagnostics, bufnr, client_id)
   local buf_lines = get_buf_lines(bufnr)
   local client = vim.lsp.get_client_by_id(client_id)
-  local offset_encoding = client and client.offset_encoding or 'utf-16'
+  local position_encoding = client and client.offset_encoding or 'utf-16'
   --- @param diagnostic lsp.Diagnostic
   --- @return vim.Diagnostic
   return vim.tbl_map(function(diagnostic)
@@ -95,9 +95,9 @@ local function diagnostic_lsp_to_vim(diagnostics, bufnr, client_id)
     --- @type vim.Diagnostic
     return {
       lnum = start.line,
-      col = vim.str_byteindex(line, offset_encoding, start.character, false),
+      col = vim.str_byteindex(line, position_encoding, start.character, false),
       end_lnum = _end.line,
-      end_col = vim.str_byteindex(line, offset_encoding, _end.character, false),
+      end_col = vim.str_byteindex(line, position_encoding, _end.character, false),
       severity = severity_lsp_to_vim(diagnostic.severity),
       message = message,
       source = diagnostic.source,
diff --git a/runtime/lua/vim/lsp/sync.lua b/runtime/lua/vim/lsp/sync.lua
index 3df45ebff0..621f63b25f 100644
--- a/runtime/lua/vim/lsp/sync.lua
+++ b/runtime/lua/vim/lsp/sync.lua
@@ -48,21 +48,21 @@ local str_utfindex = vim.str_utfindex
 local str_utf_start = vim.str_utf_start
 local str_utf_end = vim.str_utf_end
 
--- Given a line, byte idx, alignment, and offset_encoding convert to the aligned
+-- Given a line, byte idx, alignment, and position_encoding convert to the aligned
 -- utf-8 index and either the utf-16, or utf-32 index.
 ---@param line string the line to index into
 ---@param byte integer the byte idx
----@param offset_encoding string utf-8|utf-16|utf-32|nil (default: utf-8)
+---@param position_encoding string utf-8|utf-16|utf-32|nil (default: utf-8)
 ---@return integer byte_idx of first change position
 ---@return integer char_idx of first change position
-local function align_end_position(line, byte, offset_encoding)
+local function align_end_position(line, byte, position_encoding)
   local char --- @type integer
   -- If on the first byte, or an empty string: the trivial case
   if byte == 1 or #line == 0 then
     char = byte
     -- Called in the case of extending an empty line "" -> "a"
   elseif byte == #line + 1 then
-    char = str_utfindex(line, offset_encoding) + 1
+    char = str_utfindex(line, position_encoding) + 1
   else
     -- Modifying line, find the nearest utf codepoint
     local offset = str_utf_start(line, byte)
@@ -73,9 +73,9 @@ local function align_end_position(line, byte, offset_encoding)
     end
     if byte <= #line then
       --- Convert to 0 based for input, and from 0 based for output
-      char = str_utfindex(line, offset_encoding, byte - 1) + 1
+      char = str_utfindex(line, position_encoding, byte - 1) + 1
     else
-      char = str_utfindex(line, offset_encoding) + 1
+      char = str_utfindex(line, position_encoding) + 1
     end
     -- Extending line, find the nearest utf codepoint for the last valid character
   end
@@ -93,7 +93,7 @@ end
 ---@param firstline integer firstline from on_lines, adjusted to 1-index
 ---@param lastline integer lastline from on_lines, adjusted to 1-index
 ---@param new_lastline integer new_lastline from on_lines, adjusted to 1-index
----@param offset_encoding string utf-8|utf-16|utf-32|nil (fallback to utf-8)
+---@param position_encoding string utf-8|utf-16|utf-32|nil (fallback to utf-8)
 ---@return vim.lsp.sync.Range result table include line_idx, byte_idx, and char_idx of first change position
 local function compute_start_range(
   prev_lines,
@@ -101,7 +101,7 @@ local function compute_start_range(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding
+  position_encoding
 )
   local char_idx --- @type integer?
   local byte_idx --- @type integer?
@@ -115,7 +115,7 @@ local function compute_start_range(
     if line then
       line_idx = firstline - 1
       byte_idx = #line + 1
-      char_idx = str_utfindex(line, offset_encoding) + 1
+      char_idx = str_utfindex(line, position_encoding) + 1
     else
       line_idx = firstline
       byte_idx = 1
@@ -152,11 +152,11 @@ local function compute_start_range(
     char_idx = 1
   elseif start_byte_idx == #prev_line + 1 then
     byte_idx = start_byte_idx
-    char_idx = str_utfindex(prev_line, offset_encoding) + 1
+    char_idx = str_utfindex(prev_line, position_encoding) + 1
   else
     byte_idx = start_byte_idx + str_utf_start(prev_line, start_byte_idx)
     --- Convert to 0 based for input, and from 0 based for output
-    char_idx = vim.str_utfindex(prev_line, offset_encoding, byte_idx - 1) + 1
+    char_idx = vim.str_utfindex(prev_line, position_encoding, byte_idx - 1) + 1
   end
 
   -- Return the start difference (shared for new and prev lines)
@@ -174,7 +174,7 @@ end
 ---@param firstline integer
 ---@param lastline integer
 ---@param new_lastline integer
----@param offset_encoding string
+---@param position_encoding string
 ---@return vim.lsp.sync.Range prev_end_range
 ---@return vim.lsp.sync.Range curr_end_range
 local function compute_end_range(
@@ -184,7 +184,7 @@ local function compute_end_range(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding
+  position_encoding
 )
   -- A special case for the following `firstline == new_lastline` case where lines are deleted.
   -- Even if the buffer has become empty, nvim behaves as if it has an empty line with eol.
@@ -193,7 +193,7 @@ local function compute_end_range(
     return {
       line_idx = lastline - 1,
       byte_idx = #prev_line + 1,
-      char_idx = str_utfindex(prev_line, offset_encoding) + 1,
+      char_idx = str_utfindex(prev_line, position_encoding) + 1,
     }, { line_idx = 1, byte_idx = 1, char_idx = 1 }
   end
   -- If firstline == new_lastline, the first change occurred on a line that was deleted.
@@ -259,7 +259,7 @@ local function compute_end_range(
     prev_end_byte_idx = 1
   end
   local prev_byte_idx, prev_char_idx =
-    align_end_position(prev_line, prev_end_byte_idx, offset_encoding)
+    align_end_position(prev_line, prev_end_byte_idx, position_encoding)
   local prev_end_range =
     { line_idx = prev_line_idx, byte_idx = prev_byte_idx, char_idx = prev_char_idx }
 
@@ -274,7 +274,7 @@ local function compute_end_range(
       curr_end_byte_idx = 1
     end
     local curr_byte_idx, curr_char_idx =
-      align_end_position(curr_line, curr_end_byte_idx, offset_encoding)
+      align_end_position(curr_line, curr_end_byte_idx, position_encoding)
     curr_end_range =
       { line_idx = curr_line_idx, byte_idx = curr_byte_idx, char_idx = curr_char_idx }
   end
@@ -317,7 +317,7 @@ local function extract_text(lines, start_range, end_range, line_ending)
   end
 end
 
--- rangelength depends on the offset encoding
+-- rangelength depends on the position encoding
 -- bytes for utf-8 (clangd with extension)
 -- codepoints for utf-16
 -- codeunits for utf-32
@@ -326,10 +326,10 @@ end
 ---@param lines string[]
 ---@param start_range vim.lsp.sync.Range
 ---@param end_range vim.lsp.sync.Range
----@param offset_encoding string
+---@param position_encoding string
 ---@param line_ending string
 ---@return integer
-local function compute_range_length(lines, start_range, end_range, offset_encoding, line_ending)
+local function compute_range_length(lines, start_range, end_range, position_encoding, line_ending)
   local line_ending_length = #line_ending
   -- Single line case
   if start_range.line_idx == end_range.line_idx then
@@ -339,7 +339,7 @@ local function compute_range_length(lines, start_range, end_range, offset_encodi
   local start_line = lines[start_range.line_idx]
   local range_length --- @type integer
   if start_line and #start_line > 0 then
-    range_length = str_utfindex(start_line, offset_encoding)
+    range_length = str_utfindex(start_line, position_encoding)
       - start_range.char_idx
       + 1
       + line_ending_length
@@ -352,7 +352,7 @@ local function compute_range_length(lines, start_range, end_range, offset_encodi
   for idx = start_range.line_idx + 1, end_range.line_idx - 1 do
     -- Length full line plus newline character
     if #lines[idx] > 0 then
-      range_length = range_length + str_utfindex(lines[idx], offset_encoding) + #line_ending
+      range_length = range_length + str_utfindex(lines[idx], position_encoding) + #line_ending
     else
       range_length = range_length + line_ending_length
     end
@@ -372,7 +372,7 @@ end
 ---@param firstline integer line to begin search for first difference
 ---@param lastline integer line to begin search in old_lines for last difference
 ---@param new_lastline integer line to begin search in new_lines for last difference
----@param offset_encoding string encoding requested by language server
+---@param position_encoding string encoding requested by language server
 ---@param line_ending string
 ---@return lsp.TextDocumentContentChangeEvent : see https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
 function M.compute_diff(
@@ -381,7 +381,7 @@ function M.compute_diff(
   firstline,
   lastline,
   new_lastline,
-  offset_encoding,
+  position_encoding,
   line_ending
 )
   -- Find the start of changes between the previous and current buffer. Common between both.
@@ -393,7 +393,7 @@ function M.compute_diff(
     firstline + 1,
     lastline + 1,
     new_lastline + 1,
-    offset_encoding
+    position_encoding
   )
   -- Find the last position changed in the previous and current buffer.
   -- prev_end_range is sent to the server as as the end of the changed range.
@@ -405,7 +405,7 @@ function M.compute_diff(
     firstline + 1,
     lastline + 1,
     new_lastline + 1,
-    offset_encoding
+    position_encoding
   )
 
   -- Grab the changed text of from start_range to curr_end_range in the current buffer.
@@ -414,7 +414,7 @@ function M.compute_diff(
 
   -- Compute the range of the replaced text. Deprecated but still required for certain language servers
   local range_length =
-    compute_range_length(prev_lines, start_range, prev_end_range, offset_encoding, line_ending)
+    compute_range_length(prev_lines, start_range, prev_end_range, position_encoding, line_ending)
 
   -- convert to 0 based indexing
   local result = {
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 0f608ffbd1..3de76f93a6 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -277,9 +277,9 @@ end
 
 --- Position is a https://microsoft.github.io/language-server-protocol/specifications/specification-current/#position
 ---@param position lsp.Position
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return integer
-local function get_line_byte_from_position(bufnr, position, offset_encoding)
+local function get_line_byte_from_position(bufnr, position, position_encoding)
   -- LSP's line and characters are 0-indexed
   -- Vim's line and columns are 1-indexed
   local col = position.character
@@ -287,7 +287,7 @@ local function get_line_byte_from_position(bufnr, position, offset_encoding)
   -- character
   if col > 0 then
     local line = get_line(bufnr, position.line) or ''
-    return vim.str_byteindex(line, offset_encoding, col, false)
+    return vim.str_byteindex(line, position_encoding, col, false)
   end
   return col
 end
@@ -295,12 +295,12 @@ end
 --- Applies a list of text edits to a buffer.
 ---@param text_edits lsp.TextEdit[]
 ---@param bufnr integer Buffer id
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textEdit
-function M.apply_text_edits(text_edits, bufnr, offset_encoding)
+function M.apply_text_edits(text_edits, bufnr, position_encoding)
   validate('text_edits', text_edits, 'table', false)
   validate('bufnr', bufnr, 'number', false)
-  validate('offset_encoding', offset_encoding, 'string', false)
+  validate('position_encoding', position_encoding, 'string', false)
 
   if not next(text_edits) then
     return
@@ -359,9 +359,9 @@ function M.apply_text_edits(text_edits, bufnr, offset_encoding)
 
     -- Convert from LSP style ranges to Neovim style ranges.
     local start_row = text_edit.range.start.line
-    local start_col = get_line_byte_from_position(bufnr, text_edit.range.start, offset_encoding)
+    local start_col = get_line_byte_from_position(bufnr, text_edit.range.start, position_encoding)
     local end_row = text_edit.range['end'].line
-    local end_col = get_line_byte_from_position(bufnr, text_edit.range['end'], offset_encoding)
+    local end_col = get_line_byte_from_position(bufnr, text_edit.range['end'], position_encoding)
     local text = vim.split(text_edit.newText, '\n', { plain = true })
 
     local max = api.nvim_buf_line_count(bufnr)
@@ -430,14 +430,14 @@ end
 ---
 ---@param text_document_edit lsp.TextDocumentEdit
 ---@param index? integer: Optional index of the edit, if from a list of edits (or nil, if not from a list)
----@param offset_encoding? 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentEdit
-function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
+function M.apply_text_document_edit(text_document_edit, index, position_encoding)
   local text_document = text_document_edit.textDocument
   local bufnr = vim.uri_to_bufnr(text_document.uri)
-  if offset_encoding == nil then
+  if position_encoding == nil then
     vim.notify_once(
-      'apply_text_document_edit must be called with valid offset encoding',
+      'apply_text_document_edit must be called with valid position encoding',
       vim.log.levels.WARN
     )
     return
@@ -459,7 +459,7 @@ function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
     return
   end
 
-  M.apply_text_edits(text_document_edit.edits, bufnr, offset_encoding)
+  M.apply_text_edits(text_document_edit.edits, bufnr, position_encoding)
 end
 
 local function path_components(path)
@@ -619,12 +619,12 @@ end
 --- Applies a `WorkspaceEdit`.
 ---
 ---@param workspace_edit lsp.WorkspaceEdit
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32' (required)
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32' (required)
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_applyEdit
-function M.apply_workspace_edit(workspace_edit, offset_encoding)
-  if offset_encoding == nil then
+function M.apply_workspace_edit(workspace_edit, position_encoding)
+  if position_encoding == nil then
     vim.notify_once(
-      'apply_workspace_edit must be called with valid offset encoding',
+      'apply_workspace_edit must be called with valid position encoding',
       vim.log.levels.WARN
     )
     return
@@ -641,7 +641,7 @@ function M.apply_workspace_edit(workspace_edit, offset_encoding)
       elseif change.kind then --- @diagnostic disable-line:undefined-field
         error(string.format('Unsupported change: %q', vim.inspect(change)))
       else
-        M.apply_text_document_edit(change, idx, offset_encoding)
+        M.apply_text_document_edit(change, idx, position_encoding)
       end
     end
     return
@@ -654,7 +654,7 @@ function M.apply_workspace_edit(workspace_edit, offset_encoding)
 
   for uri, changes in pairs(all_changes) do
     local bufnr = vim.uri_to_bufnr(uri)
-    M.apply_text_edits(changes, bufnr, offset_encoding)
+    M.apply_text_edits(changes, bufnr, position_encoding)
   end
 end
 
@@ -904,17 +904,20 @@ end
 --- Shows document and optionally jumps to the location.
 ---
 ---@param location lsp.Location|lsp.LocationLink
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'?
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'?
 ---@param opts? vim.lsp.util.show_document.Opts
 ---@return boolean `true` if succeeded
-function M.show_document(location, offset_encoding, opts)
+function M.show_document(location, position_encoding, opts)
   -- location may be Location or LocationLink
   local uri = location.uri or location.targetUri
   if uri == nil then
     return false
   end
-  if offset_encoding == nil then
-    vim.notify_once('show_document must be called with valid offset encoding', vim.log.levels.WARN)
+  if position_encoding == nil then
+    vim.notify_once(
+      'show_document must be called with valid position encoding',
+      vim.log.levels.WARN
+    )
     return false
   end
   local bufnr = vim.uri_to_bufnr(uri)
@@ -946,7 +949,7 @@ function M.show_document(location, offset_encoding, opts)
   if range then
     -- Jump to new location (adjusting for encoding of characters)
     local row = range.start.line
-    local col = get_line_byte_from_position(bufnr, range.start, offset_encoding)
+    local col = get_line_byte_from_position(bufnr, range.start, position_encoding)
     api.nvim_win_set_cursor(win, { row + 1, col })
     vim._with({ win = win }, function()
       -- Open folds under the cursor
@@ -961,12 +964,12 @@ end
 ---
 ---@deprecated use `vim.lsp.util.show_document` with `{focus=true}` instead
 ---@param location lsp.Location|lsp.LocationLink
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'?
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'?
 ---@param reuse_win boolean? Jump to existing window if buffer is already open.
 ---@return boolean `true` if the jump succeeded
-function M.jump_to_location(location, offset_encoding, reuse_win)
+function M.jump_to_location(location, position_encoding, reuse_win)
   vim.deprecate('vim.lsp.util.jump_to_location', nil, '0.12')
-  return M.show_document(location, offset_encoding, { reuse_win = reuse_win, focus = true })
+  return M.show_document(location, position_encoding, { reuse_win = reuse_win, focus = true })
 end
 
 --- Previews a location in a floating window
@@ -1661,18 +1664,18 @@ do --[[ References ]]
   ---
   ---@param bufnr integer Buffer id
   ---@param references lsp.DocumentHighlight[] objects to highlight
-  ---@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+  ---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
   ---@see https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
-  function M.buf_highlight_references(bufnr, references, offset_encoding)
+  function M.buf_highlight_references(bufnr, references, position_encoding)
     validate('bufnr', bufnr, 'number', true)
-    validate('offset_encoding', offset_encoding, 'string', false)
+    validate('position_encoding', position_encoding, 'string', false)
     for _, reference in ipairs(references) do
       local range = reference.range
       local start_line = range.start.line
       local end_line = range['end'].line
 
-      local start_idx = get_line_byte_from_position(bufnr, range.start, offset_encoding)
-      local end_idx = get_line_byte_from_position(bufnr, range['end'], offset_encoding)
+      local start_idx = get_line_byte_from_position(bufnr, range.start, position_encoding)
+      local end_idx = get_line_byte_from_position(bufnr, range['end'], position_encoding)
 
       local document_highlight_kind = {
         [protocol.DocumentHighlightKind.Text] = 'LspReferenceText',
@@ -1706,16 +1709,16 @@ end)
 --- |setloclist()|.
 ---
 ---@param locations lsp.Location[]|lsp.LocationLink[]
----@param offset_encoding? 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding? 'utf-8'|'utf-16'|'utf-32'
 ---                         default to first client of buffer
 ---@return vim.quickfix.entry[] # See |setqflist()| for the format
-function M.locations_to_items(locations, offset_encoding)
-  if offset_encoding == nil then
+function M.locations_to_items(locations, position_encoding)
+  if position_encoding == nil then
     vim.notify_once(
-      'locations_to_items must be called with valid offset encoding',
+      'locations_to_items must be called with valid position encoding',
       vim.log.levels.WARN
     )
-    offset_encoding = vim.lsp.get_clients({ bufnr = 0 })[1].offset_encoding
+    position_encoding = vim.lsp.get_clients({ bufnr = 0 })[1].offset_encoding
   end
 
   local items = {} --- @type vim.quickfix.entry[]
@@ -1752,8 +1755,8 @@ function M.locations_to_items(locations, offset_encoding)
       local end_row = end_pos.line
       local line = lines[row] or ''
       local end_line = lines[end_row] or ''
-      local col = vim.str_byteindex(line, offset_encoding, pos.character, false)
-      local end_col = vim.str_byteindex(end_line, offset_encoding, end_pos.character, false)
+      local col = vim.str_byteindex(line, position_encoding, pos.character, false)
+      local end_col = vim.str_byteindex(end_line, position_encoding, end_pos.character, false)
 
       items[#items + 1] = {
         filename = filename,
@@ -1864,8 +1867,8 @@ function M.try_trim_markdown_code_blocks(lines)
 end
 
 ---@param window integer?: window handle or 0 for current, defaults to current
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
-local function make_position_param(window, offset_encoding)
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
+local function make_position_param(window, position_encoding)
   window = window or 0
   local buf = api.nvim_win_get_buf(window)
   local row, col = unpack(api.nvim_win_get_cursor(window))
@@ -1875,7 +1878,7 @@ local function make_position_param(window, offset_encoding)
     return { line = 0, character = 0 }
   end
 
-  col = vim.str_utfindex(line, offset_encoding, col, false)
+  col = vim.str_utfindex(line, position_encoding, col, false)
 
   return { line = row, character = col }
 end
@@ -1883,22 +1886,22 @@ end
 --- Creates a `TextDocumentPositionParams` object for the current buffer and cursor position.
 ---
 ---@param window integer?: window handle or 0 for current, defaults to current
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return lsp.TextDocumentPositionParams
 ---@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocumentPositionParams
-function M.make_position_params(window, offset_encoding)
+function M.make_position_params(window, position_encoding)
   window = window or 0
   local buf = api.nvim_win_get_buf(window)
-  if offset_encoding == nil then
+  if position_encoding == nil then
     vim.notify_once(
-      'warning: offset_encoding is required, using the offset_encoding from the first client',
+      'warning: position_encoding is required, using the offset_encoding from the first client',
       vim.log.levels.WARN
     )
-    offset_encoding = M._get_offset_encoding(buf)
+    position_encoding = M._get_offset_encoding(buf)
   end
   return {
     textDocument = M.make_text_document_params(buf),
-    position = make_position_param(window, offset_encoding),
+    position = make_position_param(window, position_encoding),
   }
 end
 
@@ -1941,18 +1944,18 @@ end
 --- `textDocument/rangeFormatting`.
 ---
 ---@param window integer? window handle or 0 for current, defaults to current
----@param offset_encoding "utf-8"|"utf-16"|"utf-32"
+---@param position_encoding "utf-8"|"utf-16"|"utf-32"
 ---@return { textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }
-function M.make_range_params(window, offset_encoding)
+function M.make_range_params(window, position_encoding)
   local buf = api.nvim_win_get_buf(window or 0)
-  if offset_encoding == nil then
+  if position_encoding == nil then
     vim.notify_once(
-      'warning: offset_encoding is required, using the offset_encoding from the first client',
+      'warning: position_encoding is required, using the offset_encoding from the first client',
       vim.log.levels.WARN
     )
-    offset_encoding = M._get_offset_encoding(buf)
+    position_encoding = M._get_offset_encoding(buf)
   end
-  local position = make_position_param(window, offset_encoding)
+  local position = make_position_param(window, position_encoding)
   return {
     textDocument = M.make_text_document_params(buf),
     range = { start = position, ['end'] = position },
@@ -1967,19 +1970,19 @@ end
 ---@param end_pos [integer,integer]? {row,col} mark-indexed position.
 --- Defaults to the end of the last visual selection.
 ---@param bufnr integer? buffer handle or 0 for current, defaults to current
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return { textDocument: { uri: lsp.DocumentUri }, range: lsp.Range }
-function M.make_given_range_params(start_pos, end_pos, bufnr, offset_encoding)
+function M.make_given_range_params(start_pos, end_pos, bufnr, position_encoding)
   validate('start_pos', start_pos, 'table', true)
   validate('end_pos', end_pos, 'table', true)
-  validate('offset_encoding', offset_encoding, 'string', true)
+  validate('position_encoding', position_encoding, 'string', true)
   bufnr = bufnr or api.nvim_get_current_buf()
-  if offset_encoding == nil then
+  if position_encoding == nil then
     vim.notify_once(
-      'warning: offset_encoding is required, using the offset_encoding from the first client',
+      'warning: position_encoding is required, using the offset_encoding from the first client',
       vim.log.levels.WARN
     )
-    offset_encoding = M._get_offset_encoding(bufnr)
+    position_encoding = M._get_offset_encoding(bufnr)
   end
   --- @type [integer, integer]
   local A = { unpack(start_pos or api.nvim_buf_get_mark(bufnr, '<')) }
@@ -1988,12 +1991,12 @@ function M.make_given_range_params(start_pos, end_pos, bufnr, offset_encoding)
   -- convert to 0-index
   A[1] = A[1] - 1
   B[1] = B[1] - 1
-  -- account for offset_encoding.
+  -- account for position_encoding.
   if A[2] > 0 then
-    A[2] = M.character_offset(bufnr, A[1], A[2], offset_encoding)
+    A[2] = M.character_offset(bufnr, A[1], A[2], position_encoding)
   end
   if B[2] > 0 then
-    B[2] = M.character_offset(bufnr, B[1], B[2], offset_encoding)
+    B[2] = M.character_offset(bufnr, B[1], B[2], position_encoding)
   end
   -- we need to offset the end character position otherwise we loose the last
   -- character of the selection, as LSP end position is exclusive
@@ -2100,9 +2103,9 @@ end
 ---@param bufnr integer
 ---@param start_line integer
 ---@param end_line integer
----@param offset_encoding 'utf-8'|'utf-16'|'utf-32'
+---@param position_encoding 'utf-8'|'utf-16'|'utf-32'
 ---@return lsp.Range
-local function make_line_range_params(bufnr, start_line, end_line, offset_encoding)
+local function make_line_range_params(bufnr, start_line, end_line, position_encoding)
   local last_line = api.nvim_buf_line_count(bufnr) - 1
 
   ---@type lsp.Position
@@ -2111,7 +2114,12 @@ local function make_line_range_params(bufnr, start_line, end_line, offset_encodi
   if end_line == last_line and not vim.bo[bufnr].endofline then
     end_pos = {
       line = end_line,
-      character = M.character_offset(bufnr, end_line, #get_line(bufnr, end_line), offset_encoding),
+      character = M.character_offset(
+        bufnr,
+        end_line,
+        #get_line(bufnr, end_line),
+        position_encoding
+      ),
     }
   else
     end_pos = { line = end_line + 1, character = 0 }
diff --git a/test/functional/plugin/lsp/incremental_sync_spec.lua b/test/functional/plugin/lsp/incremental_sync_spec.lua
index f60e159d64..0bca1fa4ca 100644
--- a/test/functional/plugin/lsp/incremental_sync_spec.lua
+++ b/test/functional/plugin/lsp/incremental_sync_spec.lua
@@ -23,7 +23,7 @@ before_each(function()
     -- local line_ending = format_line_ending[vim.api.nvim_get_option_value('fileformat', {})]
 
     --- @diagnostic disable-next-line:duplicate-set-field
-    function _G.test_register(bufnr, id, offset_encoding, line_ending)
+    function _G.test_register(bufnr, id, position_encoding, line_ending)
       local prev_lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, true)
 
       local function callback(_, bufnr0, _changedtick, firstline, lastline, new_lastline)
@@ -38,7 +38,7 @@ before_each(function()
           firstline,
           lastline,
           new_lastline,
-          offset_encoding,
+          position_encoding,
           line_ending
         )
 
@@ -63,15 +63,15 @@ local function test_edit(
   prev_buffer,
   edit_operations,
   expected_text_changes,
-  offset_encoding,
+  position_encoding,
   line_ending
 )
-  offset_encoding = offset_encoding or 'utf-16'
+  position_encoding = position_encoding or 'utf-16'
   line_ending = line_ending or '\n'
 
   api.nvim_buf_set_lines(0, 0, -1, true, prev_buffer)
   exec_lua(function()
-    return _G.test_register(0, 'test1', offset_encoding, line_ending)
+    return _G.test_register(0, 'test1', position_encoding, line_ending)
   end)
 
   for _, edit in ipairs(edit_operations) do
diff --git a/test/functional/script/luacats_grammar_spec.lua b/test/functional/script/luacats_grammar_spec.lua
index 8bc55879d4..6e73f6894b 100644
--- a/test/functional/script/luacats_grammar_spec.lua
+++ b/test/functional/script/luacats_grammar_spec.lua
@@ -118,9 +118,9 @@ describe('luacats grammar', function()
     type = '"rfc2396" | "rfc2732" | "rfc3986" | nil',
   })
 
-  test('@param offset_encoding "utf-8" | "utf-16" | "utf-32" | nil', {
+  test('@param position_encoding "utf-8" | "utf-16" | "utf-32" | nil', {
     kind = 'param',
-    name = 'offset_encoding',
+    name = 'position_encoding',
     type = '"utf-8" | "utf-16" | "utf-32" | nil',
   })