feat: improvements to loading project-local settings

CHANGELOG.md

@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- [Experimental] Load rust-analyzer settings from `.vscode/settings.json`.
+  Can be enabled by setting `vim.g.rustaceanvim.server.load_vscode_settings`
+  to `true` [[#286](https://github.com/mrcjkb/rustaceanvim/issues/286)].
+
 ## [4.13.0] - 2024-03-15
 
 ### Added
@@ -14,6 +22,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   The `server.settings` function can now take a `default_settings` tabe
   to be merged.
 
+### Fixed
+
+- Loading settings from `rust-analyzer.json`:
+  Potential for duplicate lua config keys if json keys are of the format:
+  `"rust-analyzer.foo.bar"`
+
 ## [4.12.2] - 2024-03-11
 
 ### Fixed

doc/rustaceanvim.txt

@@ -209,11 +209,12 @@ RustcOpts                                                            *RustcOpts*
 RustaceanLspClientOpts                                  *RustaceanLspClientOpts*
 
     Fields: ~
-        {auto_attach?}  (boolean|fun(bufnr:integer):boolean)                               Whether to automatically attach the LSP client. Defaults to `true` if the `rust-analyzer` executable is found.
-        {cmd?}          (string[]|fun():string[])                                          Command and arguments for starting rust-analyzer
-        {settings?}     (table|fun(project_root:string|nil,default_settings:table):table)  Setting passed to rust-analyzer. Defaults to a function that looks for a `rust-analyzer.json` file or returns an empty table. See https://rust-analyzer.github.io/manual.html#configuration.
-        {standalone?}   (boolean)                                                          Standalone file support (enabled by default). Disabling it may improve rust-analyzer's startup time.
-        {logfile?}      (string)                                                           The path to the rust-analyzer log file.
+        {auto_attach?}           (boolean|fun(bufnr:integer):boolean)                               Whether to automatically attach the LSP client. Defaults to `true` if the `rust-analyzer` executable is found.
+        {cmd?}                   (string[]|fun():string[])                                          Command and arguments for starting rust-analyzer
+        {settings?}              (table|fun(project_root:string|nil,default_settings:table):table)  Setting passed to rust-analyzer. Defaults to a function that looks for a `rust-analyzer.json` file or returns an empty table. See https://rust-analyzer.github.io/manual.html#configuration.
+        {standalone?}            (boolean)                                                          Standalone file support (enabled by default). Disabling it may improve rust-analyzer's startup time.
+        {logfile?}               (string)                                                           The path to the rust-analyzer log file.
+        {load_vscode_settings?}  (boolean)                                                          Whether to search (upward from the buffer) for rust-analyzer settings in .vscode/settings json. If found, loaded settings will override configured options. Default: false
 
 
 RustaceanDapOpts                                              *RustaceanDapOpts*

lua/rustaceanvim/config/init.lua

@@ -105,6 +105,7 @@ vim.g.rustaceanvim = vim.g.rustaceanvim
 ---@field settings? table | fun(project_root:string|nil, default_settings: table):table Setting passed to rust-analyzer. Defaults to a function that looks for a `rust-analyzer.json` file or returns an empty table. See https://rust-analyzer.github.io/manual.html#configuration.
 ---@field standalone? boolean Standalone file support (enabled by default). Disabling it may improve rust-analyzer's startup time.
 ---@field logfile? string The path to the rust-analyzer log file.
+---@field load_vscode_settings? boolean Whether to search (upward from the buffer) for rust-analyzer settings in .vscode/settings json. If found, loaded settings will override configured options. Default: false
 
 ---@class RustaceanDapOpts
 --- @field autoload_configurations boolean Whether to autoload nvim-dap configurations when rust-analyzer has attached? Default: `true`.

lua/rustaceanvim/config/internal.lua

@@ -271,6 +271,8 @@ local RustaceanDefaultConfig = {
       --- @type table
       ['rust-analyzer'] = {},
     },
+    ---@type boolean Whether to search (upward from the buffer) for rust-analyzer settings in .vscode/settings json.
+    load_vscode_settings = false,
   },
 
   --- debugging stuff

lua/rustaceanvim/config/json.lua

@@ -0,0 +1,50 @@
+local M = {}
+
+local function tbl_set(tbl, keys, value)
+  local next = table.remove(keys, 1)
+  if #keys > 0 then
+    tbl[next] = tbl[next] or {}
+    tbl_set(tbl[next], keys, value)
+  else
+    tbl[next] = value
+  end
+end
+
+---@param tbl table
+---@param json_key string e.g. "rust-analyzer.check.overrideCommand"
+---@param json_value unknown
+local function override_tbl_values(tbl, json_key, json_value)
+  local keys = vim.split(json_key, '%.')
+  tbl_set(tbl, keys, json_value)
+end
+
+---@param json_content string
+---@return table
+function M.silent_decode(json_content)
+  local ok, json_tbl = pcall(vim.json.decode, json_content)
+  if not ok or type(json_tbl) ~= 'table' then
+    return {}
+  end
+  return json_tbl
+end
+
+---@param tbl table
+---@param json_tbl { [string]: unknown }
+---@param key_predicate? fun(string): boolean
+function M.override_with_json_keys(tbl, json_tbl, key_predicate)
+  for json_key, value in pairs(json_tbl) do
+    if not key_predicate or key_predicate(json_key) then
+      override_tbl_values(tbl, json_key, value)
+    end
+  end
+end
+
+---@param tbl table
+---@param json_tbl { [string]: unknown }
+function M.override_with_rust_analyzer_json_keys(tbl, json_tbl)
+  M.override_with_json_keys(tbl, json_tbl, function(key)
+    return vim.startswith(key, 'rust-analyzer')
+  end)
+end
+
+return M

lua/rustaceanvim/config/server.lua

@@ -2,19 +2,6 @@
 
 local server = {}
 
----Read the content of a file
----@param filename string
----@return string|nil content
-local function read_file(filename)
-  local content
-  local f = io.open(filename, 'r')
-  if f then
-    content = f:read('*a')
-    f:close()
-  end
-  return content
-end
-
 ---@class LoadRASettingsOpts
 ---@field settings_file_pattern string|nil File name or pattern to search for. Defaults to 'rust-analyzer.json'
 ---@field default_settings table|nil Default settings to merge the loaded settings into
@@ -28,6 +15,7 @@ end
 function server.load_rust_analyzer_settings(project_root, opts)
   local config = require('rustaceanvim.config.internal')
   local compat = require('rustaceanvim.compat')
+  local os = require('rustaceanvim.os')
 
   local default_opts = { settings_file_pattern = 'rust-analyzer.json' }
   opts = vim.tbl_deep_extend('force', {}, default_opts, opts or {})
@@ -50,20 +38,27 @@ function server.load_rust_analyzer_settings(project_root, opts)
     return default_settings
   end
   local config_json = results[1]
-  local content = read_file(config_json)
-  local success, rust_analyzer_settings = pcall(vim.json.decode, content)
-  if not success or not rust_analyzer_settings then
-    local msg = 'Could not decode ' .. config_json .. '. Falling back to default settings.'
-    vim.notify('rustaceanvim: ' .. msg, vim.log.levels.ERROR)
+  local content = os.read_file(config_json)
+  if not content then
+    vim.notify('Could not read ' .. config_json, vim.log.levels.WARNING)
     return default_settings
   end
+  local json = require('rustaceanvim.config.json')
+  local rust_analyzer_settings = json.silent_decode(content)
   local ra_key = 'rust-analyzer'
-  if rust_analyzer_settings[ra_key] then
+  local has_ra_key = true
+  for key, _ in pairs(rust_analyzer_settings) do
+    if key:find(ra_key) ~= nil then
+      has_ra_key = true
+      break
+    end
+  end
+  if has_ra_key then
     -- Settings json with "rust-analyzer" key
-    default_settings[ra_key] = rust_analyzer_settings[ra_key]
+    json.override_with_rust_analyzer_json_keys(default_settings, rust_analyzer_settings)
   else
     -- "rust-analyzer" settings are top level
-    default_settings[ra_key] = rust_analyzer_settings
+    json.override_with_json_keys(default_settings, rust_analyzer_settings)
   end
   return default_settings
 end

lua/rustaceanvim/lsp.lua

@@ -35,6 +35,25 @@ local function is_in_workspace(client, root_dir)
   return false
 end
 
+---@Searches upward for a .vscode/settings.json that contains rust-analyzer
+--- settings and applies them.
+---@param bufname string
+---@return table server_settings or an empty table if no settings were found
+local function find_vscode_settings(bufname)
+  local settings = {}
+  local found_dirs = vim.fs.find({ '.vscode' }, { upward = true, path = vim.fs.dirname(bufname), type = 'directory' })
+  if vim.tbl_isempty(found_dirs) then
+    return settings
+  end
+  local vscode_dir = found_dirs[1]
+  local results = vim.fn.glob(compat.joinpath(vscode_dir, 'settings.json'), true, true)
+  if vim.tbl_isempty(results) then
+    return settings
+  end
+  local content = os.read_file(results[1])
+  return content and require('rustaceanvim.config.json').silent_decode(content) or {}
+end
+
 ---@class LspStartConfig: RustaceanLspClientConfig
 ---@field root_dir string | nil
 ---@field init_options? table
@@ -53,23 +72,30 @@ end
 ---@return integer|nil client_id The LSP client ID
 M.start = function(bufnr)
   bufnr = bufnr or vim.api.nvim_get_current_buf()
+  local bufname = vim.api.nvim_buf_get_name(bufnr)
   local client_config = config.server
   ---@type LspStartConfig
   local lsp_start_config = vim.tbl_deep_extend('force', {}, client_config)
-  local root_dir = cargo.get_root_dir(vim.api.nvim_buf_get_name(bufnr))
+  local root_dir = cargo.get_root_dir(bufname)
   root_dir = root_dir and os.normalize_path_on_windows(root_dir)
   lsp_start_config.root_dir = root_dir
   if not root_dir then
     --- No project root found. Start in detached/standalone mode.
-    lsp_start_config.init_options = { detachedFiles = { vim.api.nvim_buf_get_name(bufnr) } }
+    lsp_start_config.init_options = { detachedFiles = { bufname } }
   end
 
   local settings = client_config.settings
   local evaluated_settings = type(settings) == 'function' and settings(root_dir, client_config.default_settings)
     or settings
+
   ---@cast evaluated_settings table
   lsp_start_config.settings = evaluated_settings
 
+  if config.server.load_vscode_settings then
+    local json_settings = find_vscode_settings(bufname)
+    require('rustaceanvim.config.json').override_with_rust_analyzer_json_keys(lsp_start_config.settings, json_settings)
+  end
+
   -- Check if a client is already running and add the workspace folder if necessary.
   for _, client in pairs(rust_analyzer.get_active_rustaceanvim_clients()) do
     if root_dir and not is_in_workspace(client, root_dir) then

lua/rustaceanvim/os.lua

@@ -60,4 +60,17 @@ function os.is_valid_file_path(path)
   return vim.startswith(normalized_path, '/')
 end
 
+---Read the content of a file
+---@param filename string
+---@return string|nil content
+function os.read_file(filename)
+  local content
+  local f = io.open(filename, 'r')
+  if f then
+    content = f:read('*a')
+    f:close()
+  end
+  return content
+end
+
 return os

spec/config_server_spec.lua

@@ -0,0 +1,18 @@
+local config = require('rustaceanvim.config.server')
+local compat = require('rustaceanvim.compat')
+describe('Decode rust-analyzer settings from json', function()
+  local function expect_correct_loading(json_path)
+    local settings = config.load_rust_analyzer_settings(json_path)
+    assert.True(settings['rust-analyzer'].cargo.targetDir)
+    assert.same({ 'leptosfmt', '--stdin', '--rustfmt' }, settings['rust-analyzer'].rustfmt.overrideCommand)
+    assert.True(settings['rust-analyzer'].checkOnSave)
+  end
+  it('Fixture: rust-analyzer key', function()
+    local json_path = compat.joinpath(vim.fn.getcwd(), 'spec', 'fixtures', 'rust-analyzer-json')
+    expect_correct_loading(json_path)
+  end)
+  it('Fixture: top-level settings', function()
+    local json_path = compat.joinpath(vim.fn.getcwd(), 'spec', 'fixtures', 'rust-analyzer-json-top-level')
+    expect_correct_loading(json_path)
+  end)
+end)

spec/fixtures/rust-analyzer-json-top-level/rust-analyzer.json

@@ -0,0 +1,5 @@
+{
+  "cargo.targetDir": true,
+  "rustfmt.overrideCommand": ["leptosfmt", "--stdin", "--rustfmt"],
+  "checkOnSave": true
+}

spec/fixtures/rust-analyzer-json/rust-analyzer.json

@@ -0,0 +1,5 @@
+{
+  "rust-analyzer.cargo.targetDir": true,
+  "rust-analyzer.rustfmt.overrideCommand": ["leptosfmt", "--stdin", "--rustfmt"],
+  "rust-analyzer.checkOnSave": true
+}

spec/json_spec.lua

@@ -0,0 +1,45 @@
+local json = require('rustaceanvim.config.json')
+describe('Decode rust-analyzer settings from json', function()
+  it('can extract rust-analyzer key from index', function()
+    local json_content = [[
+{
+	"rust-analyzer.check.overrideCommand": [
+		"cargo",
+		"check",
+		"-p",
+		"service_b",
+		"--message-format=json"
+	],
+	"rust-analyzer.foo.enable": true,
+	"rust-analyzer.foo.bar.enable": true,
+	"rust-analyzer.foo.bar.baz.bat": "something deeply nested",
+	"some-other-key.foo.bar.baz.bat": "should not be included"
+}
+]]
+    local tbl = {}
+    local json_tbl = json.silent_decode(json_content)
+    json.override_with_rust_analyzer_json_keys(tbl, json_tbl)
+    assert.same({
+      ['rust-analyzer'] = {
+        check = {
+          overrideCommand = {
+            'cargo',
+            'check',
+            '-p',
+            'service_b',
+            '--message-format=json',
+          },
+        },
+        foo = {
+          enable = true,
+          bar = {
+            enable = true,
+            baz = {
+              bat = 'something deeply nested',
+            },
+          },
+        },
+      },
+    }, tbl)
+  end)
+end)