From 9b0a22d6e9c858526704a79e61708fb96a016763 Mon Sep 17 00:00:00 2001
From: Dekara VanHoc <vanhocgames@gmail.com>
Date: Thu, 26 Feb 2026 16:34:25 +0100
Subject: [PATCH] fix: harden render against stale window and node inputs

Add compatibility fallbacks and defensive guards so mixed plugin states or transient windows do not crash scheduled renders, and keep tests runnable on Neovim builds that use --clean instead of --noplugin.
---
 justfile                             |  2 +-
 lua/render-markdown/lib/env.lua      |  6 ++++++
 lua/render-markdown/render/base.lua  |  9 ++++++++
 lua/render-markdown/request/view.lua | 12 +++++++++--
 tests/unit/base_spec.lua             | 32 ++++++++++++++++++++++++++++
 tests/unit/view_spec.lua             | 10 +++++++++
 6 files changed, 68 insertions(+), 3 deletions(-)
 create mode 100644 tests/unit/base_spec.lua

diff --git a/justfile b/justfile
index a7e2e810..5f283be8 100644
--- a/justfile
+++ b/justfile
@@ -24,7 +24,7 @@ bench:
 
 [private]
 busted path:
-  nvim --headless --noplugin -u {{init}} -c "PlenaryBustedDirectory {{path}} {{settings}}"
+  nvim --headless --clean -u {{init}} -c "PlenaryBustedDirectory {{path}} {{settings}}"
 
 health:
   nvim -c "checkhealth render-markdown" -- -
diff --git a/lua/render-markdown/lib/env.lua b/lua/render-markdown/lib/env.lua
index a919bd6a..c6411f9d 100644
--- a/lua/render-markdown/lib/env.lua
+++ b/lua/render-markdown/lib/env.lua
@@ -207,6 +207,12 @@ function M.buf.wins(buf)
     return vim.fn.win_findbuf(buf)
 end
 
+---@param buf integer
+---@return integer[]
+function M.buf.windows(buf)
+    return M.buf.wins(buf)
+end
+
 ---@class render.md.env.Win
 M.win = {}
 
diff --git a/lua/render-markdown/render/base.lua b/lua/render-markdown/render/base.lua
index 8f3445ec..ad09b1c4 100644
--- a/lua/render-markdown/render/base.lua
+++ b/lua/render-markdown/render/base.lua
@@ -13,6 +13,15 @@ Base.__index = Base
 ---@param node render.md.Node
 ---@return boolean
 function Base:execute(context, marks, node)
+    if type(node) ~= 'table' or type(node.height) ~= 'function' then
+        local Node = require('render-markdown.lib.node')
+        local ok, wrapped = pcall(Node.new, context.buf, node)
+        if not ok or not wrapped then
+            return false
+        end
+        node = wrapped
+    end
+
     local instance = setmetatable({}, self)
     instance.context = context
     instance.marks = marks
diff --git a/lua/render-markdown/request/view.lua b/lua/render-markdown/request/view.lua
index 81ec79b6..cb2e46fb 100644
--- a/lua/render-markdown/request/view.lua
+++ b/lua/render-markdown/request/view.lua
@@ -14,9 +14,14 @@ View.__index = View
 function View.new(buf)
     local self = setmetatable({}, View)
     self.buf = buf
+    local wins = env.buf.wins and env.buf.wins(buf)
+        or (env.buf.windows and env.buf.windows(buf))
+        or {}
     local ranges = {} ---@type render.md.Range[]
-    for _, win in ipairs(env.buf.wins(buf)) do
-        ranges[#ranges + 1] = env.range(buf, win, 10)
+    for _, win in ipairs(wins) do
+        if not env.valid or env.valid(buf, win) then
+            ranges[#ranges + 1] = env.range(buf, win, 10)
+        end
     end
     self.ranges = interval.coalesce(ranges)
     return self
@@ -34,6 +39,9 @@ end
 ---@param win integer
 ---@return boolean
 function View:contains(win)
+    if env.valid and not env.valid(self.buf, win) then
+        return false
+    end
     local rows = env.range(self.buf, win, 0)
     for _, range in ipairs(self.ranges) do
         if interval.contains(range, rows) then
diff --git a/tests/unit/base_spec.lua b/tests/unit/base_spec.lua
new file mode 100644
index 00000000..d2bc4609
--- /dev/null
+++ b/tests/unit/base_spec.lua
@@ -0,0 +1,32 @@
+---@module 'luassert'
+
+local Base = require('render-markdown.render.base')
+local mock = require('luassert.mock')
+
+describe('base', function()
+    it('normalizes raw nodes before setup', function()
+        local Node = mock(require('render-markdown.lib.node'), true)
+        local wrapped = {
+            height = function()
+                return 3
+            end,
+        }
+        Node.new.on_call_with(1, 'raw-node').returns(wrapped)
+
+        local ran = false
+        local Render = setmetatable({}, Base)
+        Render.__index = Render
+
+        function Render:setup()
+            return type(self.node.height) == 'function'
+        end
+
+        function Render:run()
+            ran = true
+        end
+
+        local ok = Render:execute({ buf = 1 }, {}, 'raw-node')
+        assert.is_true(ok)
+        assert.is_true(ran)
+    end)
+end)
diff --git a/tests/unit/view_spec.lua b/tests/unit/view_spec.lua
index e527a8be..1b7e2514 100644
--- a/tests/unit/view_spec.lua
+++ b/tests/unit/view_spec.lua
@@ -9,6 +9,7 @@ describe('view', function()
         local env = mock(require('render-markdown.lib.env'), true)
         env.buf.wins.on_call_with(0).returns(vim.tbl_keys(ranges))
         for win, range in pairs(ranges) do
+            env.valid.on_call_with(0, win).returns(true)
             env.range.on_call_with(0, win, 10).returns(range)
         end
     end
@@ -22,4 +23,13 @@ describe('view', function()
         })
         assert.same('[0->15,20->30,35->45]', tostring(View.new(0)))
     end)
+
+    it('contains invalid window', function()
+        local env = mock(require('render-markdown.lib.env'), true)
+        env.buf.wins.on_call_with(0).returns({ 1000 })
+        env.valid.on_call_with(0, 1000).returns(true)
+        env.range.on_call_with(0, 1000, 10).returns({ 5, 10 })
+        env.valid.on_call_with(0, 1001).returns(false)
+        assert.is_false(View.new(0):contains(1001))
+    end)
 end)