From 58d7029b1a72a97a48f26221ffeae503f0b90075 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tautvydas=20S=CC=8Cidlauskas?=
 <tautvydas.sidlauskas@gmail.com>
Date: Mon, 28 Sep 2026 20:39:59 +0300
Subject: [PATCH] feat(guides): allow configuring widget guide characters

Closes #555
---
 README.md                    |  3 ++
 lua/flutter-tools/config.lua |  8 ++++-
 lua/flutter-tools/guides.lua |  8 +----
 tests/guides_spec.lua        | 63 ++++++++++++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 8 deletions(-)
 create mode 100644 tests/guides_spec.lua

diff --git a/README.md b/README.md
index 539cafb2..f0011c51 100644
--- a/README.md
+++ b/README.md
@@ -265,6 +265,9 @@ require("flutter-tools").setup {
   analyzer_web_port = nil, -- if set, the analysis server is started with `--port=<value>` so it can be inspected in the browser
   widget_guides = {
     enabled = false,
+    -- characters used to draw the guides, each must be a single cell wide
+    -- e.g. `{ vertical = "┆", horizontal = "┄" }` for dashed lines
+    markers = { bottom = "└", middle = "├", vertical = "│", horizontal = "─" },
   },
   closing_tags = {
     highlight = "ErrorMsg", -- highlight for the closing tag
diff --git a/lua/flutter-tools/config.lua b/lua/flutter-tools/config.lua
index 75ddbb72..86ef260b 100644
--- a/lua/flutter-tools/config.lua
+++ b/lua/flutter-tools/config.lua
@@ -44,7 +44,7 @@ local utils = lazy.require("flutter-tools.utils") ---@module "flutter-tools.util
 ---@field root_patterns? string[] Patterns to find project root
 ---@field fvm? boolean Whether to use FVM (Flutter Version Manager)
 ---@field default_run_args? flutter.RunArgsOpts Default options for run command
----@field widget_guides? {enabled: boolean, debug: boolean}
+---@field widget_guides? {enabled: boolean, debug: boolean, markers?: {bottom?: string, middle?: string, vertical?: string, horizontal?: string}}
 ---@field ui? {border: string}
 ---@field decorations? {statusline: {app_version: boolean, device: boolean, project_config: boolean}}
 ---@field debugger? {enabled: boolean, exception_breakpoints?: table, evaluate_to_string_in_debug_views?: boolean, register_configurations?: fun(paths: table)}
@@ -116,6 +116,12 @@ local config = {
   widget_guides = {
     enabled = false,
     debug = false,
+    markers = {
+      bottom = "└",
+      middle = "├",
+      vertical = "│",
+      horizontal = "─",
+    },
   },
   ui = {
     border = "single",
diff --git a/lua/flutter-tools/guides.lua b/lua/flutter-tools/guides.lua
index 336cac87..d0ef9df2 100644
--- a/lua/flutter-tools/guides.lua
+++ b/lua/flutter-tools/guides.lua
@@ -12,13 +12,6 @@ local widget_kind = "NEW_INSTANCE"
 local hl_group = "FlutterWidgetGuides"
 local widget_outline_ns_id = api.nvim_create_namespace("flutter_tools_outline_guides")
 
-local markers = {
-  bottom = "└",
-  middle = "├",
-  vertical = "│",
-  horizontal = "─",
-}
-
 -- These offsets represent the points at which each character
 -- should should be added relative to the symbol it is for
 --
@@ -53,6 +46,7 @@ end
 ---@param children table[]
 ---@return string
 local function get_guide_character(lnum, end_line, parent_start, indent_size, children, lines)
+  local markers = config.widget_guides.markers
   for index, child in ipairs(children) do
     -- if the child is within the parent range but not at the end
     local child_lnum = child.range.start.line
diff --git a/tests/guides_spec.lua b/tests/guides_spec.lua
new file mode 100644
index 00000000..559d0dbb
--- /dev/null
+++ b/tests/guides_spec.lua
@@ -0,0 +1,63 @@
+describe("widget guides", function()
+  local config
+  local guides
+  local bufnr
+  local api = vim.api
+
+  local function widget(line, children)
+    return {
+      kind = "NEW_INSTANCE",
+      range = { start = { line = line, character = 0 } },
+      children = children,
+    }
+  end
+
+  local function render(guides_config)
+    config.set({ widget_guides = vim.tbl_extend("force", { enabled = true }, guides_config or {}) })
+    guides.widget_guides(nil, {
+      uri = vim.uri_from_bufnr(bufnr),
+      outline = { children = { widget(0, { widget(2), widget(3) }) } },
+    })
+    local ns = api.nvim_get_namespaces()["flutter_tools_outline_guides"]
+    local result = {}
+    for _, mark in ipairs(api.nvim_buf_get_extmarks(bufnr, ns, 0, -1, { details = true })) do
+      result[mark[2]] = mark[4].virt_text[1][1]
+    end
+    return result
+  end
+
+  before_each(function()
+    package.loaded["flutter-tools.config"] = nil
+    package.loaded["flutter-tools.guides"] = nil
+    config = require("flutter-tools.config")
+    guides = require("flutter-tools.guides")
+    bufnr = api.nvim_create_buf(true, false)
+    api.nvim_buf_set_name(bufnr, "/tmp/guides_spec.dart")
+    api.nvim_buf_set_lines(bufnr, 0, -1, false, {
+      "Column(",
+      "  children: [",
+      '    Text("a"),',
+      '    Text("b"),',
+      "  ],",
+      ")",
+    })
+    api.nvim_set_current_buf(bufnr)
+  end)
+
+  after_each(function() api.nvim_buf_delete(bufnr, { force = true }) end)
+
+  it("draws solid guides by default", function()
+    local result = render()
+    assert.are.same({ [1] = "│", [2] = "├───", [3] = "└───" }, result)
+  end)
+
+  it("uses marker overrides and falls back to the defaults", function()
+    local result = render({ markers = { vertical = "┆", horizontal = "┄" } })
+    assert.are.same({ [1] = "┆", [2] = "├┄┄┄", [3] = "└┄┄┄" }, result)
+  end)
+
+  it("draws nothing when disabled", function()
+    local result = render({ enabled = false })
+    assert.are.same({}, result)
+  end)
+end)