feat: some options can be set on a per-buffer basis (#280)

doc/aerial.txt

@@ -651,14 +651,20 @@ NOTES                                                               *aerial-note
                                                             *aerial-filetype-map*
 Certain options can be configured per-filetype by passing in a table. "_" will
 be used as the default if the filetype is not present.
->
+>lua
         backends = {
             ['_']  = {"lsp", "treesitter"},
             python = {"treesitter"},
             rust   = {"lsp"},
         }
 <
 
+You can also specify a value on a per-buffer basis by setting a buffer-local
+variable. For example: >lua
+
+        vim.b.aerial_backends = { "lsp" }
+<
+
                                                                   *aerial-filter*
 If you don't see any symbols in aerial when you expect to, it could be that
 the symbol kinds are being filtered out. Aerial only shows a subset of symbols
@@ -670,7 +676,7 @@ filtering.
 Aerial can be configured to open automatically in certain conditions. To
 replicate the old behavior you could get with `open_automatic_min_lines` and
 `open_automatic_min_symbols`, use the following:
->
+>lua
         local aerial = require("aerial")
         aerial.setup({
           open_automatic = function(bufnr)

lua/aerial/config.lua

@@ -417,13 +417,27 @@ M.get_filetypes = function(bufnr)
   return vim.split(ft, "%.")
 end
 
-local function create_filetype_opt_getter(option, default)
+---@param name string
+---@param option any
+---@param default any
+local function create_filetype_opt_getter(name, option, default)
+  local buffer_option_name = string.format("aerial_%s", name)
   if type(option) ~= "table" or vim.tbl_islist(option) then
-    return function()
-      return option
+    return function(bufnr)
+      local has_buf_option, buf_option = pcall(vim.api.nvim_buf_get_var, bufnr, buffer_option_name)
+      print(buffer_option_name, has_buf_option, vim.inspect(buf_option))
+      if has_buf_option then
+        return buf_option
+      else
+        return option
+      end
     end
   else
     return function(bufnr)
+      local has_buf_option, buf_option = pcall(vim.api.nvim_buf_get_var, bufnr, buffer_option_name)
+      if has_buf_option then
+        return buf_option
+      end
       for _, ft in ipairs(M.get_filetypes(bufnr)) do
         if option[ft] ~= nil then
           return option[ft]
@@ -523,10 +537,12 @@ M.setup = function(opts)
   for k, v in pairs(newconf) do
     M[k] = v
   end
-  M.manage_folds = create_filetype_opt_getter(M.manage_folds, default_options.manage_folds)
-  M.backends = create_filetype_opt_getter(M.backends, default_options.backends)
+  M.manage_folds =
+    create_filetype_opt_getter("manage_folds", M.manage_folds, default_options.manage_folds)
+  M.backends = create_filetype_opt_getter("backends", M.backends, default_options.backends)
   local get_filter_kind_list =
-    create_filetype_opt_getter(M.filter_kind, default_options.filter_kind)
+    create_filetype_opt_getter("filter_kind", M.filter_kind, default_options.filter_kind)
+  ---@param bufnr integer
   M.get_filter_kind_map = function(bufnr)
     local fk = get_filter_kind_list(bufnr)
     if fk == false or fk == 0 then

lua/aerial/init.lua

@@ -434,7 +434,7 @@ end
 M.info = function()
   do_setup()
   local util = require("aerial.util")
-  local bufnr = util.get_buffers(0)
+  local bufnr = util.get_buffers(0) or 0
   local filetype = vim.bo[bufnr].filetype
   local ignored, message = util.is_ignored_win()
   return {
@@ -443,7 +443,7 @@ M.info = function()
       message = message,
     },
     filetype = filetype,
-    filter_kind_map = require("aerial.config").get_filter_kind_map(),
+    filter_kind_map = require("aerial.config").get_filter_kind_map(bufnr),
     backends = require("aerial.backends").get_status(bufnr),
   }
 end

tests/config_spec.lua

@@ -61,7 +61,7 @@ describe("config", function()
     config.setup({
       filter_kind = { "Function" },
     })
-    local fk = config.get_filter_kind_map()
+    local fk = config.get_filter_kind_map(0)
     assert.equals(nil, fk.Class)
     assert.equals(true, fk.Function)
   end)
@@ -70,7 +70,7 @@ describe("config", function()
       filter_kind = { foo = { "Function" } },
     })
     vim.api.nvim_buf_set_option(0, "filetype", "foo")
-    local fk = config.get_filter_kind_map()
+    local fk = config.get_filter_kind_map(0)
     assert.equals(nil, fk.Class)
     assert.equals(true, fk.Function)
   end)
@@ -79,7 +79,7 @@ describe("config", function()
       filter_kind = { foo = false },
     })
     vim.api.nvim_buf_set_option(0, "filetype", "foo")
-    local fk = config.get_filter_kind_map()
+    local fk = config.get_filter_kind_map(0)
     assert.equals(true, fk.Class)
     assert.equals(true, fk.Function)
   end)