1 files changed, 112 insertions, 0 deletions
diff --git a/lua/conform/lsp_format.lua b/lua/conform/lsp_format.lua
new file mode 100644
index 0000000..66be47d
--- /dev/null
+++ b/lua/conform/lsp_format.lua
@@ -0,0 +1,112 @@
+---This module replaces the default vim.lsp.buf.format() so that we can inject our own logic
+local util = require("vim.lsp.util")
+
+local M = {}
+
+local function apply_text_edits(text_edits, bufnr, offset_encoding)
+  if
+    #text_edits == 1
+    and text_edits[1].range.start.line == 0
+    and text_edits[1].range.start.character == 0
+    and text_edits[1].range["end"].line == vim.api.nvim_buf_line_count(bufnr) + 1
+    and text_edits[1].range["end"].character == 0
+  then
+    local original_lines = vim.api.nvim_buf_get_lines(bufnr, 0, -1, true)
+    local new_lines = vim.split(text_edits[1].newText, "\n", { plain = true })
+    require("conform.runner").apply_format(bufnr, original_lines, new_lines, nil, false)
+  else
+    vim.lsp.util.apply_text_edits(text_edits, bufnr, offset_encoding)
+  end
+end
+
+---@param options table
+---@return table[] clients
+function M.get_format_clients(options)
+  local method = options.range and "textDocument/rangeFormatting" or "textDocument/formatting"
+
+  local clients = vim.lsp.get_active_clients({
+    id = options.id,
+    bufnr = options.bufnr,
+    name = options.name,
+  })
+  if options.filter then
+    clients = vim.tbl_filter(options.filter, clients)
+  end
+  return vim.tbl_filter(function(client)
+    return client.supports_method(method, { bufnr = options.bufnr })
+  end, clients)
+end
+
+---@param options table
+---@param callback fun(err?: string)
+function M.format(options, callback)
+  options = options or {}
+  if not options.bufnr or options.bufnr == 0 then
+    options.bufnr = vim.api.nvim_get_current_buf()
+  end
+  local bufnr = options.bufnr
+  local range = options.range
+  local method = range and "textDocument/rangeFormatting" or "textDocument/formatting"
+
+  local clients = M.get_format_clients(options)
+
+  if #clients == 0 then
+    return callback("[LSP] Format request failed, no matching language servers.")
+  end
+
+  local function set_range(client, params)
+    if range then
+      local range_params =
+        util.make_given_range_params(range.start, range["end"], bufnr, client.offset_encoding)
+      params.range = range_params.range
+    end
+    return params
+  end
+
+  if options.async then
+    local changedtick = vim.b[bufnr].changedtick
+    local do_format
+    do_format = function(idx, client)
+      if not client then
+        return callback()
+      end
+      local params = set_range(client, util.make_formatting_params(options.formatting_options))
+      client.request(method, params, function(err, result, ctx, _)
+        if not result then
+          return callback(err or "No result returned from LSP formatter")
+        elseif not vim.api.nvim_buf_is_valid(bufnr) then
+          return callback("buffer was deleted")
+        elseif vim.b[bufnr].changedtick ~= changedtick then
+          return
+            callback(
+            string.format(
+              "Async LSP formatter discarding changes for %s: concurrent modification",
+              vim.api.nvim_buf_get_name(bufnr)
+            )
+          )
+        else
+          apply_text_edits(result, ctx.bufnr, client.offset_encoding)
+          changedtick = vim.b[bufnr].changedtick
+
+          do_format(next(clients, idx))
+        end
+      end, bufnr)
+    end
+    do_format(next(clients))
+  else
+    local timeout_ms = options.timeout_ms or 1000
+    for _, client in pairs(clients) do
+      local params = set_range(client, util.make_formatting_params(options.formatting_options))
+      local result, err = client.request_sync(method, params, timeout_ms, bufnr)
+      if result and result.result then
+        apply_text_edits(result.result, bufnr, client.offset_encoding)
+      elseif err then
+        vim.notify(string.format("[LSP][%s] %s", client.name, err), vim.log.levels.WARN)
+        return callback(string.format("[LSP][%s] %s", client.name, err))
+      end
+    end
+    callback()
+  end
+end
+
+return M