Batch quickfix actions and LSP formatting across your entire project.

Biscuit loads files into LSP for project-wide diagnostics and lets you batch-apply quickfix actions for specific diagnostic codes (like gopls's any, slicescontains, etc.) across hundreds of files at once.

The Problem

You have 200 Go files with interface{} that should be any. Opening each file, waiting for LSP, and applying the quickfix manually would take hours.

The Solution

:LoadLSP                  " Load all Go files into LSP
:ApplyFixes any           " Fix all 200 files in seconds

Features

• Load files into LSP — Get diagnostics for your entire project
• Batch quickfix by diagnostic code — Specify codes like any, slicescontains, printf
• Safe by default — Only applies quickfix-kind actions, picking the first match
• Batch LSP formatting — Run textDocument/formatting on all loaded buffers
• Dry run mode — Preview changes before applying

Requirements

• Neovim >= 0.10.0
• fd (recommended) or find for file discovery
• LSP server(s) configured for your filetypes

Installation

lazy.nvim

{
  "taigrr/biscuit.nvim",
  cmd = { "LoadLSP", "ApplyFixes", "ListDiagnosticCodes", "FormatBuffers" },
  opts = {
    codes = {
      "any",              -- interface{} -> any
      "slicescontains",   -- Use slices.Contains
      "printf",           -- Printf format issues
    },
  },
}

Quick Start

" 1. Open a Go file to set filetype
:e main.go

" 2. Load all Go files into LSP
:LoadLSP

" 3. See what diagnostic codes are available
:ListDiagnosticCodes

" 4. Apply fixes (dry run first)
:ApplyFixes! any
:ApplyFixes any

" 5. Or apply all configured codes
:ApplyFixes

" 6. Format all loaded buffers
:FormatBuffers

" 7. Clean up
:UnloadHidden

Commands

Command	Description
:LoadLSP [dir] [exts...]	Load files into LSP (uses current filetype if no args)
:UnloadHidden	Unload hidden buffers to free resources
:UnloadTracked	Unload buffers loaded by :LoadLSP
:ApplyFixes[!] [codes...]	Apply quickfixes for diagnostic codes. ! for dry run
:ListDiagnosticCodes	List diagnostic codes from loaded buffers
:ListConfiguredCodes	List configured codes
:FormatBuffers[!]	Format all loaded buffers using LSP. ! for dry run

Configuration

require("biscuit").setup({
  -- Diagnostic codes to auto-fix (exact match)
  -- These are the "code" field from LSP diagnostics
  codes = {
    "any",              -- gopls: interface{} -> any
    "slicescontains",   -- gopls: Use slices.Contains
    "printf",           -- gopls: Printf format specifier issues
    "unusedwrite",      -- gopls: Unused write to variable
  },
  
  -- Performance options
  batch_size = 10,       -- Files per batch when loading
  batch_delay = 50,      -- Ms between batches
  max_files = 0,         -- Limit files (0 = unlimited)
  auto_save = true,      -- Save after applying actions/formatting
  
  -- Directories to skip
  exclude_dirs = {
    "node_modules", ".git", "dist", "build",
    "__pycache__", ".venv", "vendor", ".next", "coverage",
  },
})

Common Diagnostic Codes

gopls (Go)

Code	Description
any	Use any instead of interface{}
slicescontains	Use slices.Contains instead of loop
printf	Printf format specifier issues
unusedwrite	Unused write to variable
fillstruct	Fill struct with zero values
undeclaredname	Undeclared name

typescript-language-server

Code	Description
6133	Unused variable
6196	Unused import

Run :ListDiagnosticCodes after :LoadLSP to see what codes your LSP provides.

How It Works

1. Load files — :LoadLSP loads matching files into buffers for LSP analysis
2. Filter diagnostics — Finds diagnostics matching your configured codes
3. Request code actions — For each matching diagnostic, requests quickfix actions
4. Apply if unique — Only applies when exactly ONE quickfix action exists
5. Auto-save — Optionally saves modified files

Health Check

:checkhealth biscuit

Troubleshooting

EMFILE: Too many open files (macOS)

macOS defaults to a file descriptor limit of 256. Loading hundreds of files will exceed this. Add to your ~/.zshrc or ~/.bashrc:

ulimit -n 4096

Biscuit detects low limits and warns you via :checkhealth biscuit. You can also reduce batch_size or set max_files to stay under the limit.

Tips

• Discover codes: Run :ListDiagnosticCodes to see what your LSP provides
• Start with dry run: Use ! to preview changes first
• Clean up: Run :UnloadTracked after batch operations to free memory
• Health check: Run :checkhealth biscuit to verify your setup

License

0BSD (c) Tai Groot