feat: Add Nix DevShell and fix all lint issues

[kalbasit]

No description provided.

[gemini-code-assist]

Summary of Changes

Hello @kalbasit, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the project's development workflow and code quality. It establishes a reproducible development environment using Nix, ensuring all developers work with the same tool versions and dependencies. Concurrently, it enforces strict code style and identifies potential issues through a newly configured golangci-lint setup, integrated with pre-commit hooks. The internal code generation logic has also been refactored for improved maintainability and clarity, alongside updates to Go language features and error handling.

Highlights

• Nix Development Environment: Introduced a Nix DevShell configuration, including flake.nix, flake.lock, and related modules, to provide a reproducible development environment with pinned dependencies for Go, linters, and other tools.
• Linting and Formatting Enforcement: Added a comprehensive .golangci.yml configuration to enable a wide array of Go linters and formatters, and integrated these checks into pre-commit hooks via Nix modules to ensure consistent code quality.
• Code Refactoring and Modularity: Refactored the generator package by extracting parseQuerierInterface and parseStructType functions, improving code organization and readability. Exported internal helper functions as func instead of var for better testability.
• Improved Type Handling and Error Management: Added new constants for common Go types and sql.Null types, and introduced specific error types for better error handling within the generator logic, particularly for unsupported slice domain structs.
• Go Version Update: Updated the project's Go version requirement from 1.25.5 to 1.25.6 in go.mod.

Changelog

• .envrc
  • Added direnv configuration to watch the nix directory and use Nix flakes.
• .gitignore
  • Added new entries to ignore Nix-related build artifacts (/ncps, /result*, /.direnv), pre-commit configuration (/.pre-commit-config.yaml), Python cache directories, and agent settings.
• .golangci.yml
  • Added a new golangci-lint configuration file, enabling numerous linters and formatters like gci, gofumpt, err113, gosec, lll, misspell, and staticcheck, with specific exclusions for generated files.
• flake.lock
  • Added a new Nix flake lock file, pinning all Nix dependencies for reproducible builds.
• flake.nix
  • Added a new Nix flake definition, including inputs for flake-parts, git-hooks-nix, nixpkgs, and treefmt-nix, and defining outputs for devshells, formatters, and pre-commit hooks across multiple systems.
• generator/constants.go
  • Added new constants for common Go primitive types and sql.Null types to centralize type definitions.
• generator/errors.go
  • Added new error variables (errInvalidDictCall, errDictKeysMustBeStrings, errSliceDomainStructNotSupported) and a helper function errUnsupportedSliceDomainStruct for improved error handling.
• generator/exports.go
  • Converted exported var declarations to func declarations for all helper functions (e.g., ExprToString, IsDomainStructFunc, ZeroValue), and imported the go/ast package.
• generator/generator.go
  • Moved the engines slice from a global variable to a local variable within the Run function.
  • Added new helper functions parseQuerierInterface and parseStructType to encapsulate parsing logic for interfaces and structs.
  • Refactored the parsePackage function to utilize the new parseQuerierInterface and parseStructType functions, improving modularity.
  • Added blank lines for better code formatting and readability.
• generator/generator_test.go
  • Updated imports to use errors package instead of fmt for error creation.
  • Added t.Parallel() calls to all test functions to enable parallel test execution.
  • Replaced fmt.Errorf with errors.New for test-specific error definitions.
  • Adjusted the joinParamsCall mock in TestWrapperTemplate to accept an unused _ string parameter.
• generator/helpers.go
  • Refactored toSnakeCase function to pre-allocate slice capacity for efficiency and improved logic for handling consecutive uppercase letters.
  • Added //nolint:gosec comment to os.WriteFile call in writeFile.
  • Extracted logic for joining domain struct parameters into a new joinDomainStructParam function.
  • Extracted logic for joining non-domain parameters into a new joinNonDomainParam function.
  • Introduced a new parseGoMod helper function to read module names from go.mod files.
  • Updated isDomainStructFunc to use the typeQuerier constant.
  • Updated zeroValue to use new type constants (typeAny, typeBool, typeString, zeroNil, typeQuerier).
  • Updated isNumeric, isStructType, isSQLNullType, getPrimitiveFromNullType, getNullTypeFromPrimitive, and getFieldNameForNullType to utilize the new type constants for consistency and clarity.
  • Refined generateFieldConversion logic to use new type constants and improve formatting for multi-line conversions.
• generator/types.go
  • Updated comments for Engine and MethodInfo structs for better clarity.
• go.mod
  • Updated the required Go version from 1.25.5 to 1.25.6.
• main.go
  • Added a blank line for formatting.
• nix/devshells/flake-module.nix
  • Added a new Nix flake module to define a default development shell, including delve, go, golangci-lint, and pre-commit as build inputs.
  • Configured hardeningDisable = [ "fortify" ] for Delve compatibility.
  • Added a shellHook to install pre-commit hooks and update go.mod with the correct Go version.
• nix/formatter/flake-module.nix
  • Added a new Nix flake module for code formatting using treefmt-nix, enabling actionlint, deadnix, gofumpt, mdformat, nixfmt, statix, and yamlfmt.
• nix/pre-commit/flake-module.nix
  • Added a new Nix flake module for pre-commit hooks using git-hooks-nix, enabling checks for merge conflicts, deadnix, golangci-lint, no-commit-to-branch, nixfmt-rfc-style, statix, and trim-trailing-whitespace.

Ignored Files

• Ignored by pattern: .github/workflows/** (1)
  • .github/workflows/flake-update.yml

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[gemini-code-assist]

Code Review

The pull request introduces a Nix development environment and addresses various linting issues in the Go codebase. The refactoring of the generator logic into smaller, more focused functions is a significant improvement for maintainability. I have identified a potential panic in the AST parsing logic and some minor efficiency improvements.