Neovim Tabs Reopening Closed Buffers: A Bug Report

by Alex Johnson 51 views

Hello Neovim enthusiasts! If you're diving deep into the world of powerful text editors, you've likely encountered Neovim, a fantastic and highly customizable environment. Recently, a user reported an interesting quirk within their Neovim setup: switching between tabs can sometimes lead to recently closed buffers being reopened. This might sound a bit confusing, so let's break down what's happening and explore the potential causes and solutions. This discussion is particularly relevant for users of plugins like syntaxpresso/bufstate.nvim and those who manage buffer states actively.

Understanding the Issue: The Reappearing Buffer

Imagine this scenario: you're working on a project in Neovim, juggling multiple files across different tabs. You open up a few files in your first tab, then decide to switch to a second tab to work on something else. You open another file in this new tab. So far, so good. Now, here's where the peculiar behavior surfaces. If you then go back to your first tab and close a buffer – let's call it file_a.txt – you might expect it to be gone for good. However, upon switching back to the second tab and then returning to the first tab again, you might find file_a.txt mysteriously reopened!

This behavior suggests that the buffer closing mechanism isn't behaving as expected when combined with tab navigation. While opening new files and switching between tabs works smoothly, the act of closing a buffer seems to be intermittently 'undone' by the tab-switching process. It's as if Neovim, or a plugin managing buffer states, is getting confused about which buffers should remain closed in a specific tab context. This can be quite disruptive to a workflow, especially if you rely on a clean buffer list to manage your tasks.

Reproduction Steps: Pinpointing the Problem

To help diagnose this, the user provided a clear set of steps to reproduce the issue. Let's walk through them:

  1. Start Neovim: Open a fresh Neovim session.
  2. Initial Setup: Open a few files. This establishes your initial working set.
  3. Create a New Tab: Open a second tab (let's call it tab2) and open another file within it. Then, navigate back to the first tab (tab1).
  4. Close a Buffer: In tab1, close one of the buffers you had open. For instance, using the command <leader>bd (which is LazyVim's default for closing a buffer).
  5. Switch Tabs: Navigate to tab2.
  6. Switch Back: Return to tab1.

At this point, the issue manifests: the buffer you closed in tab1 is found to be reopened. This sequence is crucial for anyone trying to help debug this behavior. The key trigger seems to be the combination of closing a buffer and then switching tabs before returning to the original tab where the buffer was closed.

Setup Details: The Ecosystem at Play

Understanding the environment where this bug occurs is vital for troubleshooting. The user is employing the LazyVim distribution for Neovim. LazyVim is a popular choice for its opinionated and streamlined setup, which often includes various plugins for enhanced functionality. In this case, the user has specifically disabled the default persistence.nvim plugin provided by LazyVim. This is an important detail, as persistence plugins are designed to save and restore your Neovim session, including open buffers and their states, which could potentially interact with buffer management.

Operating System and Terminal: The setup is running on Windows 11 within the WezTerm terminal emulator. While Neovim is generally cross-platform, certain behaviors can sometimes be influenced by the underlying OS or terminal.

Bufferline Integration: A significant piece of the puzzle is the use of bufferline.nvim. LazyVim includes this plugin by default, and it provides a visually appealing tab-like bar at the top of the editor, displaying open buffers. The user rightly questions whether bufstate.nvim is compatible with bufferline.nvim. This is a common concern when using multiple plugins that manage the display or state of buffers, as they might have overlapping responsibilities or subtle conflicts.

Key Bindings: The user also specified their keybindings for common actions:

  • Closing Buffers: <leader>bd (LazyVim's default).
  • Creating Tabs: <leader><tab><tab>.

These details help to recreate the exact user experience and environment, which is essential for effective debugging.

Bufstate.nvim Configuration: A Closer Look

Let's examine the specific configuration for bufstate.nvim that the user has provided. This plugin is designed to manage the state of your buffers, potentially offering features like automatic saving and session restoration. The configuration is as follows:

return {
  "syntaxpresso/bufstate.nvim",
  dependencies = { "folke/snacks.nvim" },
  opts = {
    filter_by_tab = true, -- Enable tab-based buffer filtering
    autoload_last_session = false, -- Auto-load latest session on startup
    stop_lsp_on_tab_leave = false, -- Kills language server between tab changes
    autosave = {
      enabled = true, -- Enable autosave
      on_exit = true, -- Save on exit
      interval = 300000, -- Auto-save every 5 minutes
      debounce = 30000, -- Min 30s between saves
    },
  },
}

Several options here are particularly relevant to the observed issue:

  • filter_by_tab = true: This is a key setting. When enabled, bufstate.nvim attempts to manage buffer states on a per-tab basis. This means it should theoretically only show or restore buffers relevant to the currently active tab. The fact that this is enabled and the issue still occurs might indicate a bug in how this tab-based filtering is implemented or how it interacts with other Neovim events.

  • autoload_last_session = false: This setting ensures that bufstate.nvim is not automatically loading a session when Neovim starts. This is good, as it prevents potential conflicts with LazyVim's own session management or the default persistence.nvim being disabled.

  • stop_lsp_on_tab_leave = false: This option controls whether Language Server Protocol (LSP) servers are stopped when you leave a tab. Setting it to false means the LSP remains active. While unlikely to be the direct cause of buffer reopening, complex interactions between LSP and buffer state management can sometimes lead to unexpected side effects.

  • autosave: The autosave configuration is enabled. While autosaving itself shouldn't cause buffers to reappear after being closed, it's another layer of state management that could potentially interact with buffer closing events. The interval and debounce settings are quite long, suggesting that autosaving isn't happening very frequently, which might reduce the chance of it directly interfering, but it's still a factor to consider.

Potential Areas of Conflict

Given this setup, several areas could be contributing to the problem:

  1. bufstate.nvim and bufferline.nvim Interaction: As mentioned, these two plugins both deal with buffer display and management. It's possible that when a buffer is closed, bufferline.nvim removes it from the visual list, but bufstate.nvim still retains a record of it, especially with filter_by_tab = true. When switching tabs and returning, bufstate.nvim might be attempting to 'restore' the perceived state for that tab, inadvertently reopening the buffer.

  2. Neovim's Internal Tab/Buffer Handling: Even without plugins, Neovim's tab and buffer management can sometimes be intricate. Plugins that hook into these events need to be very careful. A slight timing issue or an incorrect event handler could lead to buffers being re-listed.

  3. LazyVim's Defaults and Customizations: While persistence.nvim was disabled, LazyVim still has its own way of handling sessions and configurations. There might be other LazyVim settings or default plugins that are interacting with bufstate.nvim in unforeseen ways.

  4. Windows-Specific Behavior: Although less common, it's always a remote possibility that the behavior is influenced by the operating system or terminal emulator. Testing on a different OS or terminal could help rule this out.

Debugging and Potential Solutions

This is a classic case where a combination of plugin settings and Neovim's core functionality is leading to unexpected results. Let's explore some avenues for debugging and potential fixes.

1. Isolate bufstate.nvim

The first step in debugging is often to isolate the problematic component. Since the issue seems tied to bufstate.nvim and its filter_by_tab option, try temporarily disabling it. If the problem disappears, you've confirmed bufstate.nvim is the culprit. If the problem persists, the issue might lie deeper within Neovim or another plugin's interaction.

2. Tweak filter_by_tab Settings

If bufstate.nvim is indeed the cause, the filter_by_tab = true setting is the most suspicious. You could try:

  • Setting filter_by_tab = false: This would disable tab-specific filtering. While it might resolve the reopening issue, it could also change how bufstate.nvim manages buffers across tabs, potentially leading to a different, less desirable user experience. Test this thoroughly to see if the trade-off is acceptable.

  • Exploring bufstate.nvim's other options: Review the plugin's documentation for any other settings related to buffer lifecycle management, persistence, or tab handling. There might be a subtle option that controls how closed buffers are treated.

3. Investigate Plugin Compatibility

Given the use of bufferline.nvim, it's essential to check for known compatibility issues between bufstate.nvim and bufferline.nvim.

  • Check bufstate.nvim's GitHub Issues: Search the syntaxpresso/bufstate.nvim repository for discussions about bufferline.nvim or similar tab/buffer management plugins. Other users might have encountered and solved this already.
  • Check bufferline.nvim's GitHub Issues: Do the same on the bufferline.nvim repository.
  • Manual Testing: Try temporarily disabling bufferline.nvim to see if the issue with bufstate.nvim persists. If it doesn't, then the conflict is likely between these two plugins.

4. Examine LazyVim's Configuration

Even though persistence.nvim was disabled, LazyVim has many other configurations.

  • Review LazyVim's Buffer Management: Check LazyVim's documentation or configuration files for any settings related to buffer handling, session management, or tab behavior that might be interfering.
  • Simplify LazyVim Setup: For testing purposes, you could try running Neovim with a more minimal configuration (e.g., disabling other plugins one by one) to see if the issue can be reproduced in a simpler environment. This helps pinpoint if the problem is an interaction with a different plugin.

5. Report the Issue

If you've tried the above steps and the issue persists, the best course of action is to report it.

  • Provide Detailed Information: When reporting, include all the details mentioned here: your Neovim version, OS, terminal, LazyVim version, bufstate.nvim configuration, bufferline.nvim configuration, and the exact steps to reproduce the bug.
  • Link to Relevant Repositories: Provide links to the GitHub repositories for bufstate.nvim and bufferline.nvim so developers can easily access them.

Conclusion: Towards a Smoother Workflow

Dealing with unexpected behavior like closed buffers reappearing can be frustrating, but it's often a solvable puzzle. The interaction between tab management, buffer closing, and state-saving plugins like bufstate.nvim can be complex. By systematically isolating components, tweaking configurations, and understanding potential plugin conflicts, you can work towards resolving this issue.

Remember to always check the documentation and issue trackers of the plugins you use, as they are invaluable resources for troubleshooting. If you're looking for more general tips on customizing Neovim or understanding its core features, the official Neovim documentation is an excellent place to start. For discussions around Neovim plugins and configurations, the Neovim subreddit is a very active and helpful community.