shimbad

shimbad is a type-aware golangci-lint module plugin that detects suspicious Go function implementations: thin forwarding shims, empty bodies, constant-return stubs, placeholder panics, and not-yet-implemented results.

It intentionally stays focused on function-body smells. Use established golangci-lint analyzers such as govet, staticcheck, errcheck, unparam, revive, and godox for broader correctness and style checks.

All rules are enabled by default.

The default placeholder patterns recognize TODO, NYI, not implemented, not yet implemented, and unimplemented, case-insensitively.

The analyzers deliberately accept functions that validate, branch, mutate state, call methods, use parameters more than once, ignore only some forwarding parameters, or contain other domain behavior. Bodyless declarations are also accepted.

Module plugins are linked into a custom golangci-lint binary. They are not loaded dynamically by the standard binary.

Add .custom-gcl.yml to the consuming repository:

version: v2.12.2
name: golangci-lint-custom
destination: ./.bin
plugins:
 - module: go.ofkm.dev/shimbad
 version: v0.1.0

Use an available shimbad release in place of v0.1.0. For local development, replace version with a path:

plugins:
 - module: go.ofkm.dev/shimbad
 path: ../shimbad

Build the binary:

mkdir -p .bin
golangci-lint custom

Enable the custom linter in .golangci.yml:

version: "2"
linters:
 enable:
 - shimbad
 settings:
 custom:
 shimbad:
 type: module
 description: Detects suspicious Go function implementations.
 original-url: https://go.ofkm.dev/shimbad
 settings:
 disabled-rules:
 - constant-stub
 include-tests: false
 include-generated: false
 include-methods: false
 include-function-literals: false
 exclude-files:
 - /mocks/
 exclude-functions:
 - '\.IntentionalNoop$'
 additional-placeholder-patterns:
 - '(?i)\bpending implementation\b'

Then run the custom binary:

./.bin/golangci-lint-custom run ./...

Unknown settings, unknown rule names, duplicate disabled rules, empty regular expressions, and invalid regular expressions are configuration errors.

Function literals use synthetic names such as example.com/project/pkg.<func@file.go:12:10>. File exclusions are usually more stable when excluding groups of callbacks.

For a one-off intentional implementation, golangci-lint's normal suppression mechanism remains available:

func IntentionalNoop() { //nolint:shimbad // Required callback with no work.
}

Prefer a narrow function exclusion or a justified nolint directive over disabling a rule globally.

Format and test the plugin:

gofmt -w .
go test ./...
go vet ./...

The tests use golang.org/x/tools/go/analysis/analysistest. Each detected pattern has accepted counterexamples to protect against broadening a rule without considering false positives.

Keep the versions of golangci-lint, plugin-module-register, and x/tools compatible when updating dependencies.