gomop

gomop

⚠️ Early Development: Expect bugs, missing features, and breaking changes. Not recommended for production use yet.

A high-performance, unified Go formatter that combines gofumpt, golines, and goimports into a single tool.

Features

• Import fixing - Adds missing imports and removes unused ones
• Import grouping - Strict 3-block grouping: stdlib, third-party, local
• Line shortening - Splits long lines based on configurable width
  • Function calls and composite literals
  • String literals (word-aware splitting)
  • Method chains (dot-first style)
• gofumpt rules - Stricter formatting for consistent style
  • Short case clauses collapsed to single line
  • No empty lines around function bodies
  • Empty interfaces/structs on single line
• Single pass - All transformations in one AST walk for speed
• Fast - Sub-10ms formatting for typical files

Installation

go install github.com/nijaru/gomop/cmd/gomop@latest

Usage

# Format files (prints to stdout)
gomop file.go

# Write changes in-place
gomop -w file.go

# List files that need formatting
gomop -l ./...

# Show diffs
gomop -d file.go

# Use glob patterns
gomop '**/*.go'

Options

Performance

gomop uses a tiered import resolution strategy to avoid the ~40ms overhead of packages.Load:

1. AST-only pass - Fast, always runs
2. Sibling files - Parse other files in directory
3. Stdlib lookup - O(1) in-memory index
4. Full type info - Only as last resort

Result: ~6.6ms for a 30K file (8.3x faster than baseline).

License

MIT