complete neovim 0.12 compatibility audit

AGENTS.md

@@ -8,7 +8,7 @@ This repository is being migrated to a modern, minimal Neovim setup driven by Lu
 - Modern Lua-first config; avoid Vimscript unless explicitly requested.
 - Keep it minimal, fast, and maintainable.
 - Base plugin management on `lazy.nvim` with modular plugin specs.
-- Support Telescope navigation, netrw for tree browsing, previews, and file operations, LSP, Treesitter, Copilot, and sane UX defaults.
+- Support Telescope navigation, netrw for tree browsing, previews, and file operations, LSP, native completion, Treesitter, Copilot, and sane UX defaults.
 - Native project-local configuration via `exrc` + `secure` (no external config plugins).
 
 ## Do Not Reintroduce
@@ -32,12 +32,12 @@ This repository is being migrated to a modern, minimal Neovim setup driven by Lu
     ├── keymaps.lua           -- non-plugin keymaps
     ├── autocmds.lua          -- non-plugin autocommands
     ├── abbreviations.lua     -- insert-mode abbreviations
+    ├── completion.lua        -- native insert-mode and LSP completion
     ├── netrw-config.lua      -- netrw configuration
     ├── utils.lua             -- helpers (only if needed)
     └── plugins/              -- one file per plugin or domain
         ├── telescope.lua
         ├── treesitter.lua
-        ├── cmp.lua
         ├── lsp.lua
         ├── copilot.lua
         ├── ufo.lua
@@ -80,12 +80,12 @@ This repository is being migrated to a modern, minimal Neovim setup driven by Lu
 - Rejected: `folke/neoconf.nvim` (incompatible with Neovim 0.11+ vim.lsp.config API).
 
 ## Required Plugin Categories
-- Core: `nvim-lspconfig`, `nvim-cmp`, `cmp-nvim-lsp`, `cmp-buffer`, `cmp-path`, `LuaSnip`.
+- Core: `nvim-lspconfig`; use Neovim 0.12 native insert-mode/LSP completion and snippets instead of the nvim-cmp stack.
 - Navigation: `telescope.nvim` + `telescope-fzf-native.nvim`; netrw is the sole file explorer.
 - Treesitter: `nvim-treesitter`, `nvim-treesitter-textobjects`, `nvim-ts-autotag`.
-- UX/Editing: `Comment.nvim`, `nvim-surround`, `nvim-autopairs`, `indent-blankline.nvim`, `nvim-ufo`, `undotree`.
+- UX/Editing: `Comment.nvim`, `nvim-surround`, `nvim-autopairs`, `indent-blankline.nvim`, `nvim-ufo`; use Neovim 0.12's native optional `nvim.undotree` package.
 - Git: `gitsigns.nvim`.
-- Copilot: `copilot.lua`, `copilot-cmp`.
+- Copilot: `copilot.lua` with inline suggestions; do not integrate Copilot into the native completion popup.
 - Formatting/Linting: `conform.nvim`, `nvim-lint`.
 - LSP Management: `mason.nvim`, `mason-lspconfig.nvim`, `mason-tool-installer.nvim`.
 
@@ -106,7 +106,7 @@ This repository is being migrated to a modern, minimal Neovim setup driven by Lu
 - Spell & text: `spelllang=en_gb`, custom `listchars`, `showbreak`.
 - Keyword characters: `iskeyword+=$` (for PHP/shell variables), `iskeyword+=-` (for CSS/HTML/config files).
 
-## Current Status (Phase 12 In Progress)
+## Current Status (Phase 13 In Progress)
 - ✅ Phase 1-2: Archive legacy, bootstrap lazy.nvim
 - ✅ Phase 3: Core editing & LSP (native exrc + vim.lsp.config migration complete)
 - ✅ Phase 4: Navigation (Telescope and netrw)
@@ -118,7 +118,8 @@ This repository is being migrated to a modern, minimal Neovim setup driven by Lu
 - ✅ Phase 10: Migrate kept behaviors (abbreviations, templates, custom Treesitter queries)
 - ✅ Phase 11: Modern Paper Tonic colorscheme
 - ⏳ Phase 12: Cleanup and validation (repository cleanup and automated checks complete; interactive workflow checks remain)
-- 📋 Phase 13: Controlled Neovim 0.12.6 upgrade (planned)
+- ⏳ Phase 13: Controlled Neovim 0.12.6 upgrade (configuration audit complete; isolated plugin validation and activation remain)
+- 📋 Phase 13.9: Native Undotree and completion consolidation after activation
 - 📋 Phase 14: Netrw live previews and directory summaries (planned after upgrade)
 
 ## Migration Notes

LOG.md

@@ -192,6 +192,13 @@ Record every decision here with a short rationale. Append new entries; do not re
 - 2026-10-28: Installed the verified official Neovim 0.12.6 archive alongside the untouched 0.11.5 installation at `/opt/neovim/nvim-0.12.6`. Initial interactive startup with the existing configuration succeeded. Removed redundant `vim.lsp.with()` wrappers for hover and signature-help borders after 0.12 reported their deprecation; the shared `vim.lsp.util.open_floating_preview` override already applies the same border on both 0.11 and 0.12. Clean headless startup then passed with the existing locked plugins under both binaries.
 - 2026-10-28: The 0.12 health review exposed overlapping LSP activation: mason-lspconfig v2 automatically enabled every installed server while `lsp.lua` explicitly configured and enabled the selected set. Disabled mason-lspconfig automatic activation, removed its obsolete `automatic_installation` option, and aligned it with nvim-lspconfig's buffer events. This prevents unintended activation of installed tools such as StyLua's LSP mode and leaves `lsp.lua` as the single activation authority.
 - 2026-10-28: Live Intelephense attachment passed under both Neovim 0.11.5 and 0.12.6 after the LSP activation cleanup. The test also exposed the deprecated function-style `client.notify(...)` call in the project-settings callback; changed it to `client:notify(...)`, which works on both supported versions.
+- 2026-10-28: Replaced the remaining `vim.loop.fs_stat` calls with `vim.uv.fs_stat` and migrated `[d`/`]d` from deprecated diagnostic navigation functions to `vim.diagnostic.jump({ count = -1/1 })`. Both APIs remain compatible with the rollback runtime, Neovim 0.11.5.
+- 2026-10-28: Validated Neovim 0.12 project configuration using a disposable nested workspace and isolated trust database. With `exrc` and `secure` enabled through a normal XDG config, a trusted parent `.nvim.lua` executed exactly once and `vim.secure.read()` returned its contents. The live Intelephense test separately confirmed that the repository's project-local settings loader still receives trusted settings from the client's root.
+- 2026-10-28: Validated the netrw workflow on Neovim 0.12.6. The default runtime wrapper automatically loads bundled netrw v184 from its optional package, so adding a configuration-level `packadd netrw` would be redundant and would complicate 0.11 rollback compatibility. `:Explore` opened the configured tree view, `p` created a real preview window, and `<C-6>` returned from the explorer to the source file.
+- 2026-10-28: Kept `mbbill/undotree` after checking Neovim 0.12's built-in alternative. The native `nvim.undotree` package is optional and remains unloaded; it exposes `:Undotree`, whereas the configured plugin's `:UndotreeToggle` command, focused panel, and diff layout still open successfully under 0.12.6. There is no active command or runtime conflict.
+- 2026-10-28: Completed the configuration-level Neovim 0.12 breaking-change audit. Diagnostic jump behavior passed under both 0.11.5 and 0.12.6, and a loaded-plugin `vim.deprecated` scan now reports only `copilot-cmp`'s upstream `client.is_stopped` call. That plugin warning is safe on 0.12 but remains a tracked compatibility concern before Neovim 0.13.
+- 2026-10-28: Final Phase 13.3 smoke tests passed: both 0.11.5 and 0.12.6 start with the updated configuration, 0.12 attaches Intelephense with project settings, `git diff --check` is clean, and the measured 0.12 headless startup reached `NVIM STARTED` in approximately 43 ms with the existing locked plugins.
+- 2026-10-28: Chose the post-activation native-feature direction for 0.12. Keep lazy.nvim because the configuration still benefits from its event/command loading, dependency ordering, and build hooks; do not mix the runtime upgrade with an experimental `vim.pack` migration. After activating 0.12, replace `mbbill/undotree` with the native optional package and trial native insert-mode/LSP completion plus built-in snippets. Copilot will use inline suggestions with a separate accept key rather than appearing in the completion popup; remove the cmp stack only after interactive language and editing validation.
 
 ## Project-Local Configuration
 

MIGRATION_PLAN.md

@@ -518,17 +518,17 @@ Source of truth for the step-by-step rebuild. Keep this concise and up to date.
 - [x] Do not remove or overwrite the working 0.11.5 installation
 
 ## Phase 13.3 — Audit 0.12 compatibility before switching
-- [ ] Review the Neovim 0.12 breaking changes against the active configuration
+- [x] Review the Neovim 0.12 breaking changes against the active configuration
 - [x] Remove deprecated `vim.lsp.with()` handler wrappers; the shared floating-preview override already supplies the configured border
 - [x] Disable mason-lspconfig's automatic server activation and remove its obsolete `automatic_installation` option; `lsp.lua` remains the sole activation authority
 - [x] Replace deprecated `client.notify(...)` with the 0.12-compatible `client:notify(...)` method for project-local settings
-- [ ] Replace deprecated `vim.loop` usage with `vim.uv`
-- [ ] Replace deprecated diagnostic navigation APIs with the current diagnostic jump API
-- [ ] Revalidate native `exrc` behavior now that 0.12 searches parent directories
-- [ ] Verify `vim.secure.read()` behavior in the project-local LSP settings loader
-- [ ] Determine how Neovim 0.12's built-in directory buffers interact with opt-in legacy netrw
-- [ ] Explicitly load netrw with `:packadd netrw` from Lua if 0.12 no longer loads it automatically
-- [ ] Check for conflicts or redundancy with Neovim 0.12's built-in `:Undotree`; do not remove the plugin without a separate decision
+- [x] Replace deprecated `vim.loop` usage with `vim.uv`
+- [x] Replace deprecated diagnostic navigation APIs with the current diagnostic jump API
+- [x] Revalidate native `exrc` behavior now that 0.12 searches parent directories
+- [x] Verify `vim.secure.read()` behavior in the project-local LSP settings loader
+- [x] Determine how Neovim 0.12's bundled optional netrw package behaves with the configured explorer workflow
+- [x] Confirm no explicit `:packadd netrw` is needed: Neovim's default runtime wrapper loads netrw automatically
+- [x] Keep the existing Undotree plugin: Neovim 0.12's built-in `:Undotree` is an inactive optional package, while the configured plugin's richer `:UndotreeToggle` workflow still opens cleanly
 
 ## Phase 13.4 — Install Neovim 0.12.6 alongside 0.11.5
 - [x] Download the official `nvim-linux-x86_64.tar.gz` release archive
@@ -550,10 +550,10 @@ Proposed layout:
 - [ ] Use isolated `XDG_DATA_HOME`, `XDG_CACHE_HOME`, and `XDG_STATE_HOME` directories
 - [ ] Install the currently locked plugin revisions into the isolated data directory
 - [ ] Keep the production plugin and Mason directories untouched
-- [ ] Validate headless startup and capture startup time
+- [x] Validate headless startup and capture startup time
 - [x] Run `:checkhealth` and review every relevant warning/error
-- [ ] Verify netrw can be loaded and `:Explore` opens the expected tree browser
-- [ ] Fix core/config compatibility issues before updating plugins
+- [x] Verify netrw can be loaded and `:Explore` opens the expected tree browser
+- [x] Fix core/config compatibility issues before updating plugins
 
 ## Phase 13.6 — Update plugins in isolation
 - [ ] Use a temporary branch or worktree based on the rollback checkpoint
@@ -569,7 +569,7 @@ Proposed layout:
 - [ ] Validate netrw tree browsing, previews, alternate-buffer behavior, and file operations
 - [ ] Validate Telescope files, grep, buffers, and LSP symbol pickers
 - [ ] Validate LSP attachment, `gd`, `gr`, `K`, diagnostics, and project-local `.nvim.lua` settings
-- [ ] Validate nvim-cmp, LuaSnip, and Copilot completion
+- [ ] Validate the current completion stack before activation; native completion migration follows in Phase 13.9
 - [ ] Validate conform format-on-save and nvim-lint/Ruff diagnostics
 - [ ] Validate Treesitter highlighting, text objects, autotag, folding, and custom HTML/CSS queries
 - [ ] Validate the Paper Tonic colorscheme, plugin highlights, sessions, persistent undo, and shell templates
@@ -582,7 +582,16 @@ Proposed layout:
 - [ ] Update AGENTS.md, README.md, and LOG.md with the final supported version and upgrade procedure
 - [ ] Remove 0.11.5 only after an explicit later decision
 
-## Phase 13.9 — Update external tools separately
+## Phase 13.9 — Consolidate on Neovim 0.12 native features
+- [x] Keep lazy.nvim as the plugin manager; do not combine the runtime upgrade with a migration to experimental `vim.pack`
+- [ ] Replace `mbbill/undotree` with the optional native `nvim.undotree` package while preserving `<leader>u`
+- [ ] Trial native automatic/LSP completion with explicit selection and built-in snippet expansion
+- [ ] Enable Copilot inline suggestions with a distinct accept key and hide them while the native completion menu is visible
+- [ ] Validate PHP, HTML, JavaScript/TypeScript, Markdown, Lua, paths, snippets, autopairs, and Copilot interactively
+- [ ] Remove nvim-cmp, cmp-nvim-lsp, cmp-buffer, cmp-path, LuaSnip, and copilot-cmp only after the native workflow passes
+- [ ] Remove obsolete completion integrations, lockfile entries, highlights, and documentation
+
+## Phase 13.10 — Update external tools separately
 - [ ] Review Mason package updates only after Neovim and plugin revisions are stable
 - [ ] Update language servers, formatters, and linters in small groups
 - [ ] Revalidate PHP, JavaScript/TypeScript, HTML/CSS, Markdown, Lua, and Python after each group

README.md

@@ -48,8 +48,8 @@ Core keymaps available globally (not plugin-specific). These provide fallbacks f
 | n | `<leader>xX` | Diagnostics → quickfix | Populates project-wide diagnostics |
 | n | `<leader>xe` | Diagnostics → buffer errors | Location list filtered to errors |
 | n | `<leader>xE` | Diagnostics → all errors | Quickfix filtered to errors |
-| n | `[d` | Diagnostics: previous item | Uses `vim.diagnostic.goto_prev` |
-| n | `]d` | Diagnostics: next item | Uses `vim.diagnostic.goto_next` |
+| n | `[d` | Diagnostics: previous item | Uses `vim.diagnostic.jump` with a negative count |
+| n | `]d` | Diagnostics: next item | Uses `vim.diagnostic.jump` with a positive count |
 | n | `<leader>xd` | Diagnostic float | Opens hover window for cursor diagnostic |
 | n | `<leader>xt` | Toggle diagnostics | Flips `vim.diagnostic.enable()` |
 | n | `<leader>gg` | Git: Changed files → quickfix | Lists all modified/deleted/untracked files with status |

init.lua

@@ -12,7 +12,7 @@ require('keymaps_reference')
 
 -- Bootstrap lazy.nvim
 local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'
-if not vim.loop.fs_stat(lazypath) then
+if not vim.uv.fs_stat(lazypath) then
   vim.fn.system({
     'git', 'clone', '--filter=blob:none', '--single-branch',
     'https://github.com/folke/lazy.nvim.git', lazypath,

lua/keymaps.lua

@@ -50,10 +50,10 @@ map('n', '<leader>xE', function()
   vim.diagnostic.setqflist({ severity = vim.diagnostic.severity.ERROR })
 end, { desc = 'Diagnostics: All errors (quickfix)', silent = true })
 map('n', '[d', function()
-  vim.diagnostic.goto_prev({ float = false })
+  vim.diagnostic.jump({ count = -1, float = false })
 end, { desc = 'Diagnostics: Previous diagnostic', silent = true })
 map('n', ']d', function()
-  vim.diagnostic.goto_next({ float = false })
+  vim.diagnostic.jump({ count = 1, float = false })
 end, { desc = 'Diagnostics: Next diagnostic', silent = true })
 map('n', '<leader>xd', function()
   pcall(vim.diagnostic.open_float)

lua/plugins/nvim-lint.lua

@@ -52,8 +52,8 @@ return {
     -- Note: This runs once at config load, checks cwd for phpcs.xml
     local cwd = vim.fn.getcwd()
     local has_project_ruleset =
-      vim.loop.fs_stat(cwd .. "/phpcs.xml")
-      or vim.loop.fs_stat(cwd .. "/phpcs.xml.dist")
+      vim.uv.fs_stat(cwd .. "/phpcs.xml")
+      or vim.uv.fs_stat(cwd .. "/phpcs.xml.dist")
     
     local phpcs_args = { "-q", "--report=json" }
     if not has_project_ruleset then

lua/plugins/treesitter.lua

@@ -39,7 +39,7 @@ return {
           -- Disable for very large files
           disable = function(lang, buf)
             local max_filesize = 100 * 1024 -- 100 KB
-            local ok, stats = pcall(vim.loop.fs_stat, vim.api.nvim_buf_get_name(buf))
+            local ok, stats = pcall(vim.uv.fs_stat, vim.api.nvim_buf_get_name(buf))
             if ok and stats and stats.size > max_filesize then
               return true
             end