go-analyzers

README

go-analyzers

Custom Go static analyzers for modern Go 1.25+ idioms. These analyzers detect patterns that can be simplified using newer standard library functions.

Usable standalone via go vet or with Bazel's nogo for build-time analysis.

Analyzers

Analyzer	Detects	Suggests
makecopy	make([]T, len(s)); copy(dst, s) (including subslice variants)	slices.Clone(s)
searchmigrate	sort.Search(n, func(i int) bool { ... })	slices.BinarySearch(s, v)
clampcheck	if-else-if clamp chains and consecutive if-return clamp patterns	min(max(x, lo), hi)
sortmigrate	sort.Strings, sort.Ints, sort.Slice, etc.	slices.Sort, slices.SortFunc, etc.

Why these analyzers?

The official modernize suite and revive's use-slices-sort rule cover most Go 1.21+ modernization patterns. These analyzers fill the remaining gaps:

• makecopy: modernize's appendclipped only catches append-based clones, not make+copy. Also detects subslice variants like make([]T, len(s)-idx); copy(dst, s[idx:]).
• searchmigrate: No existing linter detects sort.Search → slices.BinarySearch.
• clampcheck: modernize's minmax handles simple if/else → min/max but deliberately excludes nested if-elseif-else clamp patterns. Also detects consecutive if-return clamp patterns.
• sortmigrate: Detects deprecated sort.Strings, sort.Ints, sort.Float64s, sort.Slice, sort.SliceStable, sort.SliceIsSorted, and their AreSorted variants, suggesting slices.Sort, slices.SortFunc, slices.IsSorted, etc.

Installation

Standalone

go install github.com/albertocavalcante/go-analyzers/cmd/go-analyzers@latest
go vet -vettool=$(which go-analyzers) ./...

golangci-lint v2 module plugin

For golangci-lint integration, see go-analyzers-gcl.

Bazel nogo (build-time analysis)

nogo runs go/analysis analyzers as part of bazel build, failing the build on any diagnostic. Each of our analyzer packages exports a var Analyzer compatible with nogo's requirements.

Bzlmod (MODULE.bazel) -- recommended

1. Add this module as a dependency in your MODULE.bazel:

bazel_dep(name = "go-analyzers", version = "0.1.0")

go_deps = use_extension("@gazelle//:extensions.bzl", "go_deps")
go_deps.from_file(go_mod = "//:go.mod")
# If not using go.mod, add the module directly:
# go_deps.module(
#     path = "github.com/albertocavalcante/go-analyzers",
#     version = "v0.1.0",
# )

1. Define a nogo() target in your root BUILD.bazel:

load("@rules_go//go:def.bzl", "nogo", "TOOLS_NOGO")

nogo(
    name = "my_nogo",
    deps = TOOLS_NOGO + [
        "@com_github_albertocavalcante_go_analyzers//makecopy",
        "@com_github_albertocavalcante_go_analyzers//searchmigrate",
        "@com_github_albertocavalcante_go_analyzers//clampcheck",
        "@com_github_albertocavalcante_go_analyzers//sortmigrate",
    ],
    config = ":nogo_config.json",
    vet = True,
    visibility = ["//visibility:public"],
)

1. Register nogo with the Go SDK in MODULE.bazel:

go_sdk = use_extension("@rules_go//go:extensions.bzl", "go_sdk")
go_sdk.nogo(nogo = "//:my_nogo")

WORKSPACE (legacy)

1. Add this module via go_repository (typically managed by Gazelle):

load("@bazel_gazelle//:deps.bzl", "go_repository")

go_repository(
    name = "com_github_albertocavalcante_go_analyzers",
    importpath = "github.com/albertocavalcante/go-analyzers",
    sum = "h1:...",
    version = "v0.1.0",
)

1. Define the nogo() target in your root BUILD file (same as Bzlmod above).

2. Register nogo in your WORKSPACE:

load("@io_bazel_rules_go//go:deps.bzl", "go_register_nogo")
go_register_nogo(nogo = "@//:my_nogo")

nogo config JSON

Create nogo_config.json in your repository root to control analyzer behavior:

{
  "_base": {
    "exclude_files": {
      "external/": "skip external dependencies",
      "third_party/": "skip vendored code"
    }
  },
  "makecopy": {},
  "searchmigrate": {},
  "clampcheck": {},
  "sortmigrate": {}
}

See the nogo documentation for the full config format (only_files, exclude_files, analyzer_flags).

Notes

• nogo runs automatically on every bazel build -- no separate lint step needed.
• Diagnostics are build failures. Use exclude_files to suppress false positives rather than //nolint comments (which nogo does not support).
• Add tags = ["no-nogo"] to any target where analysis should be skipped.
• Use --norun_validations to temporarily skip nogo during a build.

License

MIT