[linter-miner] feat(linters): add osexitinlibrary linter

cmd/linters/main.go

@@ -18,11 +18,13 @@ import (
 
 	"github.com/github/gh-aw/pkg/linters/excessivefuncparams"
 	"github.com/github/gh-aw/pkg/linters/largefunc"
+	"github.com/github/gh-aw/pkg/linters/osexitinlibrary"
 )
 
 func main() {
 	multichecker.Main(
 		excessivefuncparams.Analyzer,
 		largefunc.Analyzer,
+		osexitinlibrary.Analyzer,
 	)
 }

pkg/linters/osexitinlibrary/osexitinlibrary.go

@@ -0,0 +1,56 @@
+// Package osexitinlibrary implements a Go analysis linter that flags
+// os.Exit calls in library (pkg/) packages.
+package osexitinlibrary
+
+import (
+	"go/ast"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/tools/go/analysis"
+	"golang.org/x/tools/go/analysis/passes/inspect"
+	"golang.org/x/tools/go/ast/inspector"
+)
+
+// Analyzer is the os-exit-in-library analysis pass.
+var Analyzer = &analysis.Analyzer{
+	Name:     "osexitinlibrary",
+	Doc:      "reports os.Exit calls inside library packages where they bypass deferred cleanup and prevent testing",
+	URL:      "https://github.com/github/gh-aw/tree/main/pkg/linters/osexitinlibrary",
+	Requires: []*analysis.Analyzer{inspect.Analyzer},
+	Run:      run,
+}
+
+func run(pass *analysis.Pass) (any, error) {
+	pkgPath := pass.Pkg.Path()
+	// Skip packages under cmd/ entry-points — they are allowed to call os.Exit.
+	if strings.HasSuffix(pkgPath, "/main") || strings.Contains(pkgPath, "/cmd/") {
+		return nil, nil
+	}
+
+	insp := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+
+	nodeFilter := []ast.Node{
+		(*ast.CallExpr)(nil),
+	}
+
+	insp.Preorder(nodeFilter, func(n ast.Node) {
+		call := n.(*ast.CallExpr)
+		if strings.HasSuffix(pkgPath, ".test") || strings.HasSuffix(filepath.Base(pass.Fset.Position(call.Pos()).Filename), "_test.go") {
+			return
+		}
+		sel, ok := call.Fun.(*ast.SelectorExpr)
+		if !ok {
+			return
+		}
+		ident, ok := sel.X.(*ast.Ident)
+		if !ok {
+			return
+		}
+		if ident.Name == "os" && sel.Sel.Name == "Exit" {
+			pass.Reportf(call.Pos(), "os.Exit called in library package %s; move process termination to a cmd/ entry-point", pkgPath)
+		}
+	})
+
+	return nil, nil
+}

pkg/linters/osexitinlibrary/osexitinlibrary_test.go

@@ -0,0 +1,16 @@
+//go:build !integration
+
+package osexitinlibrary_test
+
+import (
+	"testing"
+
+	"golang.org/x/tools/go/analysis/analysistest"
+
+	"github.com/github/gh-aw/pkg/linters/osexitinlibrary"
+)
+
+func TestOsExitInLibrary(t *testing.T) {
+	testdata := analysistest.TestData()
+	analysistest.Run(t, testdata, osexitinlibrary.Analyzer, "osexitinlibrary")
+}

pkg/linters/osexitinlibrary/testdata/src/osexitinlibrary/osexitinlibrary.go

@@ -0,0 +1,13 @@
+package osexitinlibrary
+
+import "os"
+
+// bad: os.Exit in a pkg/ package.
+func stopProcess() {
+	os.Exit(1) // want `os.Exit called in library package`
+}
+
+// ok: helper that does NOT call os.Exit.
+func doWork() error {
+	return nil
+}

pkg/linters/osexitinlibrary/testdata/src/osexitinlibrary/osexitinlibrary_test.go

@@ -0,0 +1,10 @@
+package osexitinlibrary
+
+import (
+	"os"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	os.Exit(m.Run())
+}