Move import-boss to k/k, retool to not use gengo

* Moved code and tests out of gengo -> code_generator
* Reworked it to use packages.Load
* Reworked tests (still not comprehensive but pretty good?)
* Dropped test support from gengo (support for tests in
  x/tools/go/packages is pretty hostile to gengo, and nobody used it)

build/tools.go

@@ -25,9 +25,9 @@ import (
 	_ "github.com/onsi/ginkgo/v2/ginkgo"
 	_ "k8s.io/code-generator/cmd/go-to-protobuf"
 	_ "k8s.io/code-generator/cmd/go-to-protobuf/protoc-gen-gogo"
+	_ "k8s.io/code-generator/cmd/import-boss"
 	_ "k8s.io/gengo/v2/examples/deepcopy-gen/generators"
 	_ "k8s.io/gengo/v2/examples/defaulter-gen/generators"
-	_ "k8s.io/gengo/v2/examples/import-boss/generators"
 	_ "k8s.io/kube-openapi/cmd/openapi-gen"
 
 	// submodule test dependencies

hack/verify-import-boss.sh

@@ -27,16 +27,14 @@ KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
 source "${KUBE_ROOT}/hack/lib/init.sh"
 
 kube::golang::setup_env
+kube::util::require-jq
 
-GOPROXY=off go install k8s.io/code-generator/cmd/import-boss
+# Doing it this way is MUCH faster than simply saying "all", and there doesn't
+# seem to be a simpler way to express "this whole workspace".
+packages=()
+kube::util::read-array packages < <(
+    go work edit -json | jq -r '.Use[].DiskPath + "/..."'
+)
 
-$(kube::util::find-binary "import-boss") \
-    -v "${KUBE_VERBOSE:-0}" \
-    --include-test-files \
-    --input-dirs "./pkg/..." \
-    --input-dirs "./cmd/..." \
-    --input-dirs "./plugin/..." \
-    --input-dirs "./test/e2e_node/..." \
-    --input-dirs "./test/e2e/framework/..." \
-    --input-dirs "./test/integration/..." \
-    --input-dirs "./staging/src/..."
+GOPROXY=off \
+    go run k8s.io/code-generator/cmd/import-boss -v "${KUBE_VERBOSE:-0}" "${packages[@]}"

staging/src/k8s.io/apiextensions-apiserver/pkg/apis/.import-restrictions

@@ -3,6 +3,10 @@ inverseRules:
   - selectorRegexp: k8s[.]io/apiextensions-apiserver
     allowedPrefixes:
       - ''
+  # Allow use from within e2e tests.
+  - selectorRegexp: k8s[.]io/kubernetes/test
+    allowedPrefixes:
+      - k8s.io/kubernetes/test/e2e/apimachinery
   # Forbid use of this package in other k8s.io packages.
   - selectorRegexp: k8s[.]io
     forbiddenPrefixes:

staging/src/k8s.io/code-generator/cmd/import-boss/README.md

@@ -1,97 +1,104 @@
 ## Purpose
 
-- `import-boss` enforces import restrictions against all pull requests submitted to the [k/k](https://github.com/kubernetes/kubernetes) repository. There are a number of `.import-restrictions` files that in the [k/k](https://github.com/kubernetes/kubernetes) repository, all of which are defined in `YAML` (or `JSON`) format.
+`import-boss` enforces optional import restrictions between packages.  This is
+useful to manage the dependency graph within a large repository, such as
+[kubernetes](https://github.com/kubernetes/kubernetes).
 
 ## How does it work?
 
-- When a directory is verified, `import-boss` looks for a file called `.import-restrictions`. If this file is not found, `import-boss` will go up to the parent directory until it finds this `.import-restrictions` file.
+When a package is verified, `import-boss` looks for a file called
+`.import-restrictions` in the same directory and all parent directories, up to
+the module root (defined by the presence of a go.mod file).  These files
+contain rules which are evaluated against each dependency of the package in
+question.
 
-- Adding `.import-restrictions` files does not add them to CI runs. They need to be explicitly added to `hack/verify-import-boss.sh`. Once an `.import-restrictions` file is added, all of the sub-packages of this file's directory are added as well.
+Evaluation starts with the rules file closest to the package.  If that file
+makes a determination to allow or forbid the import, evaluation is done.  If
+the import does not match any rule, the next-closest rules file is consulted,
+and so forth.  If the rules files are exhausted and no determination has been
+made, the import will be flagged as an error.
+
+### What are rules files?
+
+A rules file is a JSON or YAML document with two top-level keys, both optional:
+* `Rules`
+* `InverseRules`
 
 ### What are Rules?
 
-- If an `.import-restrictions` file is found, then all imports of the package are checked against each `rule` in the file. A `rule` consists of three parts:
+A `rule` defines a policy to be enforced on packages which are depended on by
+the package in question.  It consists of three parts:
   - A `SelectorRegexp`, to select the import paths that the rule applies to.
   - A list of `AllowedPrefixes`
   - A list of `ForbiddenPrefixes`
 
-- An import is allowed if it matches at least one allowed prefix and does not match any forbidden prefixes. An example `.import-restrictions` file looks like this:
+An import is allowed if it matches at least one allowed prefix and does not
+match any forbidden prefixes.
+
+Rules also have a boolean `Transitive` option. When this option is true, the
+rule is applied to transitive imports.
+
+Example:
 
 ```json
 {
   "Rules": [
     {
-      "SelectorRegexp": "k8s[.]io",
+      "SelectorRegexp": "example[.]com",
       "AllowedPrefixes": [
-        "k8s.io/gengo/v2/examples",
-        "k8s.io/kubernetes/third_party"
+        "example.com/project/package",
+        "example.com/other/package"
       ],
       "ForbiddenPrefixes": [
-        "k8s.io/kubernetes/pkg/third_party/deprecated"
+        "example.com/legacy/package"
       ]
     },
     {
       "SelectorRegexp": "^unsafe$",
-      "AllowedPrefixes": [
-      ],
-      "ForbiddenPrefixes": [
-        ""
-      ]
+      "AllowedPrefixes": [],
+      "ForbiddenPrefixes": [ "" ],
+      "Transitive": true
     }
   ]
 }
 ```
-- Take note of `"SelectorRegexp": "k8s[.]io"` in the first block. This specifies that we are applying these rules to the `"k8s.io"` import path.
-- The second block explicitly matches the "unsafe" package, and forbids it ("" is a prefix of everything).
 
-### What are Inverse Rules?
+The `SelectorRegexp` specifies that this rule applies only to imports which
+match that regex.
 
-- In contrast to non-inverse rules, which are defined in importing packages, inverse rules are defined in imported packages.
+Note: an empty list (`[]`) matches nothing, and an empty string (`""`) is a
+prefix of everything.
 
-- Inverse rules allow for fine-grained import restrictions for "private packages" where we don't want to spread use inside of [kubernetes/kubernetes](https://github.com/kubernetes/kubernetes).
+### What are InverseRules?
 
-- If an `.import-restrictions` file is found, then all imports of the package are checked against each `inverse rule` in the file. This check will continue, climbing up the directory tree, until a match is found and accepted.
+In contrast to rules, which are defined in terms of "things this package
+depends on", inverse rules are defined in terms of "things which import this
+package".  This allows for fine-grained import restrictions for "semi-private
+packages" which are more sophisticated than Go's `internal` convention.
 
-- Inverse rules also have a boolean `transitive` option. When this option is true, the import rule is also applied to `transitive` imports.
-  - `transitive` imports are dependencies not directly depended on by the code, but are needed to run the application. Use this option if you want to apply restrictions to those indirect dependencies.
+If inverse rules are found, then all known imports of the package are checked
+against each such rule, in the same fashion as regular rules.  Note that this
+can only handle known imports, which is defined as any package which is also
+being considered by this `import-boss` run.  For most repositories, `./...` will
+suffice.
+
+Example:
 
 ```yaml
-rules:
-  - selectorRegexp: k8s[.]io
-    allowedPrefixes:
-      - k8s.io/gengo/v2/examples
-      - k8s.io/kubernetes/third_party
-    forbiddenPrefixes:
-      - k8s.io/kubernetes/pkg/third_party/deprecated
-  - selectorRegexp: ^unsafe$
-    forbiddenPrefixes:
-      - ""
 inverseRules:
-  - selectorRegexp: k8s[.]io
+  - selectorRegexp: example[.]com
     allowedPrefixes:
-      - k8s.io/same-repo
-      - k8s.io/kubernetes/pkg/legacy
+      - example.com/this-same-repo
+      - example.com/close-friend/legacy
     forbiddenPrefixes:
-      - k8s.io/kubernetes/pkg/legacy/subpkg
-  - selectorRegexp: k8s[.]io
+      - example.com/other-project
+  - selectorRegexp: example[.]com
     transitive: true
     forbiddenPrefixes:
-      - k8s.io/kubernetes/cmd/kubelet
-      - k8s.io/kubernetes/cmd/kubectl
+      - example.com/other-team
 ```
 
-## How do I run import-boss within the k/k repo?
+## How do I run import-boss?
 
-- In order to include _test.go files, make sure to pass in the `include-test-files` flag:
-  ```sh
-  hack/verify-import-boss.sh --include-test-files=true
-  ```
-
-- To include other directories, pass in a directory or directories using the `input-dirs` flag:
-  ```sh
-  hack/verify-import-boss.sh --input-dirs="k8s.io/kubernetes/test/e2e/framework/..."
-  ```
-
-## Reference
-
-- [import-boss](https://github.com/kubernetes/gengo/tree/master/examples/import-boss)
+For most scenarios, simply running `import-boss ./...` will work.  For projects
+which use Go workspaces, this can even span multiple modules.

staging/src/k8s.io/code-generator/cmd/import-boss/main.go

@@ -21,32 +21,565 @@ import (
 	"flag"
 	"os"
 
-	"github.com/spf13/pflag"
-	"k8s.io/gengo/v2/args"
-	"k8s.io/gengo/v2/examples/import-boss/generators"
+	"errors"
+	"fmt"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
 
+	"github.com/spf13/pflag"
+	"golang.org/x/tools/go/packages"
 	"k8s.io/klog/v2"
+	"sigs.k8s.io/yaml"
+)
+
+const (
+	rulesFileName = ".import-restrictions"
+	goModFile     = "go.mod"
 )
 
 func main() {
 	klog.InitFlags(nil)
-	arguments := args.Default()
-
-	pflag.CommandLine.BoolVar(&arguments.IncludeTestFiles, "include-test-files", false, "If true, include *_test.go files.")
-
-	// Collect and parse flags.
-	arguments.AddFlags(pflag.CommandLine)
 	pflag.CommandLine.AddGoFlagSet(flag.CommandLine)
 	pflag.Parse()
 
-	if err := arguments.Execute(
-		generators.NameSystems(),
-		generators.DefaultNameSystem(),
-		generators.GetTargets,
-		"",
-	); err != nil {
-		klog.Errorf("Error: %v", err)
+	pkgs, err := loadPkgs(pflag.Args()...)
+	if err != nil {
+		klog.Errorf("failed to load packages: %v", err)
+	}
+
+	pkgs = massage(pkgs)
+	boss := newBoss(pkgs)
+
+	var allErrs []error
+	for _, pkg := range pkgs {
+		if pkgErrs := boss.Verify(pkg); pkgErrs != nil {
+			allErrs = append(allErrs, pkgErrs...)
+		}
+	}
+
+	fail := false
+	for _, err := range allErrs {
+		if lister, ok := err.(interface{ Unwrap() []error }); ok {
+			for _, err := range lister.Unwrap() {
+				fmt.Printf("ERROR: %v\n", err)
+			}
+		} else {
+			fmt.Printf("ERROR: %v\n", err)
+		}
+		fail = true
+	}
+
+	if fail {
 		os.Exit(1)
 	}
+
 	klog.V(2).Info("Completed successfully.")
 }
+
+func loadPkgs(patterns ...string) ([]*packages.Package, error) {
+	cfg := packages.Config{
+		Mode: packages.NeedName | packages.NeedFiles | packages.NeedImports |
+			packages.NeedDeps | packages.NeedModule,
+		Tests: true,
+	}
+
+	klog.V(1).Infof("loading: %v", patterns)
+	tBefore := time.Now()
+	pkgs, err := packages.Load(&cfg, patterns...)
+	if err != nil {
+		return nil, err
+	}
+	klog.V(2).Infof("loaded %d pkg(s) in %v", len(pkgs), time.Since(tBefore))
+
+	var allErrs []error
+	for _, pkg := range pkgs {
+		var errs []error
+		for _, e := range pkg.Errors {
+			if e.Kind == packages.ListError || e.Kind == packages.ParseError {
+				errs = append(errs, e)
+			}
+		}
+		if len(errs) > 0 {
+			allErrs = append(allErrs, fmt.Errorf("error(s) in %q: %v", pkg.PkgPath, errors.Join(errs...)))
+		}
+	}
+	if len(allErrs) > 0 {
+		return nil, errors.Join(allErrs...)
+	}
+
+	return pkgs, nil
+}
+
+func massage(in []*packages.Package) []*packages.Package {
+	out := []*packages.Package{}
+
+	for _, pkg := range in {
+		klog.V(2).Infof("considering pkg: %q", pkg.PkgPath)
+
+		// Discard packages which represent the <pkg>.test result.  They don't seem
+		// to hold any interesting source info.
+		if strings.HasSuffix(pkg.PkgPath, ".test") {
+			klog.V(3).Infof("ignoring testbin pkg: %q", pkg.PkgPath)
+			continue
+		}
+
+		// Packages which end in "_test" have tests which use the special "_test"
+		// package suffix.  Packages which have test files must be tests.  Don't
+		// ask me, this is what packages.Load produces.
+		if strings.HasSuffix(pkg.PkgPath, "_test") || hasTestFiles(pkg.GoFiles) {
+			// NOTE: This syntax can be undone with unmassage().
+			pkg.PkgPath = strings.TrimSuffix(pkg.PkgPath, "_test") + " ((tests:" + pkg.Name + "))"
+			klog.V(3).Infof("renamed to: %q", pkg.PkgPath)
+		}
+		out = append(out, pkg)
+	}
+
+	return out
+}
+
+func unmassage(str string) string {
+	idx := strings.LastIndex(str, " ((")
+	if idx == -1 {
+		return str
+	}
+	return str[0:idx]
+}
+
+type ImportBoss struct {
+	// incomingImports holds all the packages importing the key.
+	incomingImports map[string][]string
+
+	// transitiveIncomingImports holds the transitive closure of
+	// incomingImports.
+	transitiveIncomingImports map[string][]string
+}
+
+func newBoss(pkgs []*packages.Package) *ImportBoss {
+	boss := &ImportBoss{
+		incomingImports:           map[string][]string{},
+		transitiveIncomingImports: map[string][]string{},
+	}
+
+	for _, pkg := range pkgs {
+		// Accumulate imports
+		for imp := range pkg.Imports {
+			boss.incomingImports[imp] = append(boss.incomingImports[imp], pkg.PkgPath)
+		}
+	}
+
+	boss.transitiveIncomingImports = transitiveClosure(boss.incomingImports)
+
+	return boss
+}
+
+func hasTestFiles(files []string) bool {
+	for _, f := range files {
+		if strings.HasSuffix(f, "_test.go") {
+			return true
+		}
+	}
+	return false
+}
+
+func (boss *ImportBoss) Verify(pkg *packages.Package) []error {
+	pkgDir := packageDir(pkg)
+	if pkgDir == "" {
+		// This Package has no usable files, e.g. only tests, which are modelled in
+		// a distinct Package.
+		return nil
+	}
+
+	restrictionFiles, err := recursiveRead(filepath.Join(pkgDir, rulesFileName))
+	if err != nil {
+		return []error{fmt.Errorf("error finding rules file: %v", err)}
+	}
+	if len(restrictionFiles) == 0 {
+		return nil
+	}
+
+	klog.V(2).Infof("verifying pkg %q (%s)", pkg.PkgPath, pkgDir)
+	var errs []error
+	errs = append(errs, boss.verifyRules(pkg, restrictionFiles)...)
+	errs = append(errs, boss.verifyInverseRules(pkg, restrictionFiles)...)
+	return errs
+}
+
+// packageDir tries to figure out the directory of the specified package.
+func packageDir(pkg *packages.Package) string {
+	if len(pkg.GoFiles) > 0 {
+		return filepath.Dir(pkg.GoFiles[0])
+	}
+	if len(pkg.IgnoredFiles) > 0 {
+		return filepath.Dir(pkg.IgnoredFiles[0])
+	}
+	return ""
+}
+
+type FileFormat struct {
+	Rules        []Rule
+	InverseRules []Rule
+
+	path string
+}
+
+// A single import restriction rule.
+type Rule struct {
+	// All import paths that match this regexp...
+	SelectorRegexp string
+	// ... must have one of these prefixes ...
+	AllowedPrefixes []string
+	// ... and must not have one of these prefixes.
+	ForbiddenPrefixes []string
+	// True if the rule is to be applied to transitive imports.
+	Transitive bool
+}
+
+// Disposition represents a decision or non-decision.
+type Disposition int
+
+const (
+	// DepForbidden means the dependency was explicitly forbidden by a rule.
+	DepForbidden Disposition = iota
+	// DepAllowed means the dependency was explicitly allowed by a rule.
+	DepAllowed
+	// DepAllowed means the dependency did not match any rule.
+	DepUnknown
+)
+
+// Evaluate considers this rule and decides if this dependency is allowed.
+func (r Rule) Evaluate(imp string) Disposition {
+	// To pass, an import muct be allowed and not forbidden.
+	// Check forbidden first.
+	for _, forbidden := range r.ForbiddenPrefixes {
+		klog.V(5).Infof("checking %q against forbidden prefix %q", imp, forbidden)
+		if hasPathPrefix(imp, forbidden) {
+			klog.V(5).Infof("this import of %q is forbidden", imp)
+			return DepForbidden
+		}
+	}
+	for _, allowed := range r.AllowedPrefixes {
+		klog.V(5).Infof("checking %q against allowed prefix %q", imp, allowed)
+		if hasPathPrefix(imp, allowed) {
+			klog.V(5).Infof("this import of %q is allowed", imp)
+			return DepAllowed
+		}
+	}
+	return DepUnknown
+}
+
+// recursiveRead collects all '.import-restriction' files, between the current directory,
+// and the module root.
+func recursiveRead(path string) ([]*FileFormat, error) {
+	restrictionFiles := make([]*FileFormat, 0)
+
+	for {
+		if _, err := os.Stat(path); err == nil {
+			rules, err := readFile(path)
+			if err != nil {
+				return nil, err
+			}
+
+			restrictionFiles = append(restrictionFiles, rules)
+		}
+
+		nextPath, removedDir := removeLastDir(path)
+		if nextPath == path || isGoModRoot(path) || removedDir == "src" {
+			break
+		}
+
+		path = nextPath
+	}
+
+	return restrictionFiles, nil
+}
+
+func readFile(path string) (*FileFormat, error) {
+	currentBytes, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("couldn't read %v: %v", path, err)
+	}
+
+	var current FileFormat
+	err = yaml.Unmarshal(currentBytes, &current)
+	if err != nil {
+		return nil, fmt.Errorf("couldn't unmarshal %v: %v", path, err)
+	}
+	current.path = path
+	return &current, nil
+}
+
+// isGoModRoot checks if a directory is the root directory for a package
+// by checking for the existence of a 'go.mod' file in that directory.
+func isGoModRoot(path string) bool {
+	_, err := os.Stat(filepath.Join(filepath.Dir(path), goModFile))
+	return err == nil
+}
+
+// removeLastDir removes the last directory, but leaves the file name
+// unchanged. It returns the new path and the removed directory. So:
+// "a/b/c/file" -> ("a/b/file", "c")
+func removeLastDir(path string) (newPath, removedDir string) {
+	dir, file := filepath.Split(path)
+	dir = strings.TrimSuffix(dir, string(filepath.Separator))
+	return filepath.Join(filepath.Dir(dir), file), filepath.Base(dir)
+}
+
+func (boss *ImportBoss) verifyRules(pkg *packages.Package, restrictionFiles []*FileFormat) []error {
+	klog.V(3).Infof("verifying pkg %q rules", pkg.PkgPath)
+
+	// compile all Selector regex in all restriction files
+	selectors := make([][]*regexp.Regexp, len(restrictionFiles))
+	for i, restrictionFile := range restrictionFiles {
+		for _, r := range restrictionFile.Rules {
+			re, err := regexp.Compile(r.SelectorRegexp)
+			if err != nil {
+				return []error{
+					fmt.Errorf("regexp `%s` in file %q doesn't compile: %w", r.SelectorRegexp, restrictionFile.path, err),
+				}
+			}
+
+			selectors[i] = append(selectors[i], re)
+		}
+	}
+
+	realPkgPath := unmassage(pkg.PkgPath)
+
+	direct, indirect := transitiveImports(pkg)
+	isDirect := map[string]bool{}
+	for _, imp := range direct {
+		isDirect[imp] = true
+	}
+	relate := func(imp string) string {
+		if isDirect[imp] {
+			return "->"
+		}
+		return "-->"
+	}
+
+	var errs []error
+	for _, imp := range uniq(direct, indirect) {
+		if unmassage(imp) == realPkgPath {
+			// Tests in package "foo_test" depend on the test package for
+			// "foo" (if both exist in a giver directory).
+			continue
+		}
+		klog.V(4).Infof("considering import %q %s %q", pkg.PkgPath, relate(imp), imp)
+		matched := false
+		decided := false
+		for i, file := range restrictionFiles {
+			klog.V(4).Infof("rules file %s", file.path)
+			for j, rule := range file.Rules {
+				if !rule.Transitive && !isDirect[imp] {
+					continue
+				}
+				matching := selectors[i][j].MatchString(imp)
+				if !matching {
+					continue
+				}
+				matched = true
+				klog.V(6).Infof("selector %v matches %q", rule.SelectorRegexp, imp)
+
+				disp := rule.Evaluate(imp)
+				if disp == DepAllowed {
+					decided = true
+					break // no further rules, next file
+				} else if disp == DepForbidden {
+					errs = append(errs, fmt.Errorf("%q %s %q is forbidden by %s", pkg.PkgPath, relate(imp), imp, file.path))
+					decided = true
+					break // no further rules, next file
+				}
+			}
+			if decided {
+				break // no further files, next import
+			}
+		}
+		if matched && !decided {
+			klog.V(5).Infof("%q %s %q did not match any rule", pkg, relate(imp), imp)
+			errs = append(errs, fmt.Errorf("%q %s %q did not match any rule", pkg.PkgPath, relate(imp), imp))
+		}
+	}
+
+	if len(errs) > 0 {
+		return errs
+	}
+
+	return nil
+}
+
+func uniq(slices ...[]string) []string {
+	m := map[string]bool{}
+	for _, sl := range slices {
+		for _, str := range sl {
+			m[str] = true
+		}
+	}
+	ret := []string{}
+	for str := range m {
+		ret = append(ret, str)
+	}
+	sort.Strings(ret)
+	return ret
+}
+
+func hasPathPrefix(path, prefix string) bool {
+	if prefix == "" || path == prefix {
+		return true
+	}
+	if !strings.HasSuffix(path, string(filepath.Separator)) {
+		prefix = prefix + string(filepath.Separator)
+	}
+	return strings.HasPrefix(path, prefix)
+}
+
+func transitiveImports(pkg *packages.Package) ([]string, []string) {
+	direct := []string{}
+	indirect := []string{}
+	seen := map[string]bool{}
+	for _, imp := range pkg.Imports {
+		direct = append(direct, imp.PkgPath)
+		dfsImports(&indirect, seen, imp)
+	}
+	return direct, indirect
+}
+
+func dfsImports(dest *[]string, seen map[string]bool, p *packages.Package) {
+	for _, p2 := range p.Imports {
+		if seen[p2.PkgPath] {
+			continue
+		}
+		seen[p2.PkgPath] = true
+		*dest = append(*dest, p2.PkgPath)
+		dfsImports(dest, seen, p2)
+	}
+}
+
+// verifyInverseRules checks that all packages that import a package are allowed to import it.
+func (boss *ImportBoss) verifyInverseRules(pkg *packages.Package, restrictionFiles []*FileFormat) []error {
+	klog.V(3).Infof("verifying pkg %q inverse-rules", pkg.PkgPath)
+
+	// compile all Selector regex in all restriction files
+	selectors := make([][]*regexp.Regexp, len(restrictionFiles))
+	for i, restrictionFile := range restrictionFiles {
+		for _, r := range restrictionFile.InverseRules {
+			re, err := regexp.Compile(r.SelectorRegexp)
+			if err != nil {
+				return []error{
+					fmt.Errorf("regexp `%s` in file %q doesn't compile: %w", r.SelectorRegexp, restrictionFile.path, err),
+				}
+			}
+
+			selectors[i] = append(selectors[i], re)
+		}
+	}
+
+	realPkgPath := unmassage(pkg.PkgPath)
+
+	isDirect := map[string]bool{}
+	for _, imp := range boss.incomingImports[pkg.PkgPath] {
+		isDirect[imp] = true
+	}
+	relate := func(imp string) string {
+		if isDirect[imp] {
+			return "<-"
+		}
+		return "<--"
+	}
+
+	var errs []error
+	for _, imp := range boss.transitiveIncomingImports[pkg.PkgPath] {
+		if unmassage(imp) == realPkgPath {
+			// Tests in package "foo_test" depend on the test package for
+			// "foo" (if both exist in a giver directory).
+			continue
+		}
+		klog.V(4).Infof("considering import %q %s %q", pkg.PkgPath, relate(imp), imp)
+		matched := false
+		decided := false
+		for i, file := range restrictionFiles {
+			klog.V(4).Infof("rules file %s", file.path)
+			for j, rule := range file.InverseRules {
+				if !rule.Transitive && !isDirect[imp] {
+					continue
+				}
+				matching := selectors[i][j].MatchString(imp)
+				if !matching {
+					continue
+				}
+				matched = true
+				klog.V(6).Infof("selector %v matches %q", rule.SelectorRegexp, imp)
+
+				disp := rule.Evaluate(imp)
+				if disp == DepAllowed {
+					decided = true
+					break // no further rules, next file
+				} else if disp == DepForbidden {
+					errs = append(errs, fmt.Errorf("%q %s %q is forbidden by %s", pkg.PkgPath, relate(imp), imp, file.path))
+					decided = true
+					break // no further rules, next file
+				}
+			}
+			if decided {
+				break // no further files, next import
+			}
+		}
+		if matched && !decided {
+			klog.V(5).Infof("%q %s %q did not match any rule", pkg.PkgPath, relate(imp), imp)
+			errs = append(errs, fmt.Errorf("%q %s %q did not match any rule", pkg.PkgPath, relate(imp), imp))
+		}
+	}
+
+	if len(errs) > 0 {
+		return errs
+	}
+
+	return nil
+}
+
+func transitiveClosure(in map[string][]string) map[string][]string {
+	type edge struct {
+		from string
+		to   string
+	}
+
+	adj := make(map[edge]bool)
+	imports := make(map[string]struct{})
+	for from, tos := range in {
+		for _, to := range tos {
+			adj[edge{from, to}] = true
+			imports[to] = struct{}{}
+		}
+	}
+
+	// Warshal's algorithm
+	for k := range in {
+		for i := range in {
+			if !adj[edge{i, k}] {
+				continue
+			}
+			for j := range imports {
+				if adj[edge{i, j}] {
+					continue
+				}
+				if adj[edge{k, j}] {
+					adj[edge{i, j}] = true
+				}
+			}
+		}
+	}
+
+	out := make(map[string][]string, len(in))
+	for i := range in {
+		for j := range imports {
+			if adj[edge{i, j}] {
+				out[i] = append(out[i], j)
+			}
+		}
+
+		sort.Strings(out[i])
+	}
+
+	return out
+}

staging/src/k8s.io/code-generator/cmd/import-boss/main_test.go

@@ -0,0 +1,322 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+
+	"golang.org/x/tools/go/packages"
+)
+
+func TestRemoveLastDir(t *testing.T) {
+	table := map[string]struct{ newPath, removedDir string }{
+		"a/b/c": {"a/c", "b"},
+	}
+	for slashInput, expect := range table {
+		input := filepath.FromSlash(slashInput)
+
+		gotPath, gotRemoved := removeLastDir(input)
+		if e, a := filepath.FromSlash(expect.newPath), gotPath; e != a {
+			t.Errorf("%v: wanted %v, got %v", input, e, a)
+		}
+		if e, a := filepath.FromSlash(expect.removedDir), gotRemoved; e != a {
+			t.Errorf("%v: wanted %v, got %v", input, e, a)
+		}
+	}
+}
+
+func TestTransitiveClosure(t *testing.T) {
+	cases := []struct {
+		name     string
+		in       map[string][]string
+		expected map[string][]string
+	}{
+		{
+			name: "no transition",
+			in: map[string][]string{
+				"a": {"b"},
+				"c": {"d"},
+			},
+			expected: map[string][]string{
+				"a": {"b"},
+				"c": {"d"},
+			},
+		},
+		{
+			name: "simple",
+			in: map[string][]string{
+				"a": {"b"},
+				"b": {"c"},
+				"c": {"d"},
+			},
+			expected: map[string][]string{
+				"a": {"b", "c", "d"},
+				"b": {"c", "d"},
+				"c": {"d"},
+			},
+		},
+	}
+
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			out := transitiveClosure(c.in)
+			if !reflect.DeepEqual(c.expected, out) {
+				t.Errorf("expected: %#v, got %#v", c.expected, out)
+			}
+		})
+	}
+}
+
+func TestHasTestFiles(t *testing.T) {
+	cases := []struct {
+		input  []string
+		expect bool
+	}{{
+		input:  nil,
+		expect: false,
+	}, {
+		input:  []string{},
+		expect: false,
+	}, {
+		input:  []string{"foo.go"},
+		expect: false,
+	}, {
+		input:  []string{"foo.go", "bar.go"},
+		expect: false,
+	}, {
+		input:  []string{"foo_test.go"},
+		expect: true,
+	}, {
+		input:  []string{"foo.go", "foo_test.go"},
+		expect: true,
+	}, {
+		input:  []string{"foo.go", "foo_test.go", "bar.go", "bar_test.go"},
+		expect: true,
+	}}
+
+	for _, tc := range cases {
+		ret := hasTestFiles(tc.input)
+		if ret != tc.expect {
+			t.Errorf("expected %v, got %v: %q", tc.expect, ret, tc.input)
+		}
+	}
+}
+
+func TestPackageDir(t *testing.T) {
+	cases := []struct {
+		input  *packages.Package
+		expect string
+	}{{
+		input: &packages.Package{
+			PkgPath:      "example.com/foo/bar/qux",
+			GoFiles:      []string{"/src/prj/file.go"},
+			IgnoredFiles: []string{"/otherdir/file.go"},
+		},
+		expect: "/src/prj",
+	}, {
+		input: &packages.Package{
+			PkgPath:      "example.com/foo/bar/qux",
+			IgnoredFiles: []string{"/src/prj/file.go"},
+		},
+		expect: "/src/prj",
+	}, {
+		input: &packages.Package{
+			PkgPath: "example.com/foo/bar/qux",
+		},
+		expect: "",
+	}}
+
+	for i, tc := range cases {
+		ret := packageDir(tc.input)
+		if ret != tc.expect {
+			t.Errorf("[%d] expected %v, got %v: %q", i, tc.expect, ret, tc.input)
+		}
+	}
+}
+
+func TestHasPathPrefix(t *testing.T) {
+	cases := []struct {
+		base   string
+		pfx    string
+		expect bool
+	}{{
+		base:   "",
+		pfx:    "",
+		expect: true,
+	}, {
+		base:   "/foo/bar",
+		pfx:    "",
+		expect: true,
+	}, {
+		base:   "",
+		pfx:    "/foo",
+		expect: false,
+	}, {
+		base:   "/foo",
+		pfx:    "/foo",
+		expect: true,
+	}, {
+		base:   "/foo/bar",
+		pfx:    "/foo",
+		expect: true,
+	}, {
+		base:   "/foobar/qux",
+		pfx:    "/foo",
+		expect: false,
+	}, {
+		base:   "/foo/bar/bat/qux/zrb",
+		pfx:    "/foo/bar/bat",
+		expect: true,
+	}}
+
+	for _, tc := range cases {
+		ret := hasPathPrefix(tc.base, tc.pfx)
+		if ret != tc.expect {
+			t.Errorf("expected %v, got %v: (%q, %q)", tc.expect, ret, tc.base, tc.pfx)
+		}
+	}
+}
+
+func checkAllErrorStrings(t *testing.T, errs []error, expect []string) {
+	t.Helper()
+	if len(errs) != len(expect) {
+		t.Fatalf("expected %d errors, got %d: %q", len(expect), len(errs), errs)
+	}
+
+	for _, str := range expect {
+		found := false
+		for _, err := range errs {
+			if strings.HasPrefix(err.Error(), str) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Errorf("did not find error %q", str)
+			t.Logf("\tseek: %s\n\t  in:", str)
+			for _, err := range errs {
+				t.Logf("\t      %s", err.Error())
+			}
+		}
+	}
+}
+
+func TestSimpleForward(t *testing.T) {
+	pkgs, err := loadPkgs("./testdata/simple-fwd/aaa")
+	if err != nil {
+		t.Fatalf("unexpected failure: %v", err)
+	}
+	if len(pkgs) != 1 {
+		t.Fatalf("expected 1 pkg result, got %d", len(pkgs))
+	}
+	if pkgs[0].PkgPath != "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa" {
+		t.Fatalf("wrong PkgPath: %q", pkgs[0].PkgPath)
+	}
+
+	boss := newBoss(pkgs)
+	errs := boss.Verify(pkgs[0])
+
+	expect := []string{
+		`"k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/f1" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither" did not match any rule`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/n1" did not match any rule`,
+	}
+
+	checkAllErrorStrings(t, errs, expect)
+}
+
+func TestNestedForward(t *testing.T) {
+	pkgs, err := loadPkgs("./testdata/nested-fwd/aaa")
+	if err != nil {
+		t.Fatalf("unexpected failure: %v", err)
+	}
+	if len(pkgs) != 1 {
+		t.Fatalf("expected 1 pkg result, got %d", len(pkgs))
+	}
+	if pkgs[0].PkgPath != "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa" {
+		t.Fatalf("wrong PkgPath: %q", pkgs[0].PkgPath)
+	}
+
+	boss := newBoss(pkgs)
+	errs := boss.Verify(pkgs[0])
+
+	expect := []string{
+		`"k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-root" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-sub" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa" -> "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/neither/n1" did not match any rule`,
+	}
+
+	checkAllErrorStrings(t, errs, expect)
+}
+
+func TestInverse(t *testing.T) {
+	pkgs, err := loadPkgs("./testdata/inverse/...")
+	if err != nil {
+		t.Fatalf("unexpected failure: %v", err)
+	}
+	if len(pkgs) != 10 {
+		t.Fatalf("expected 10 pkg results, got %d", len(pkgs))
+	}
+
+	boss := newBoss(pkgs)
+
+	var errs []error
+	for _, pkg := range pkgs {
+		errs = append(errs, boss.Verify(pkg)...)
+	}
+
+	expect := []string{
+		`"k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden" <- "k8s.io/code-generator/cmd/import-boss/testdata/inverse/aaa" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f1" <- "k8s.io/code-generator/cmd/import-boss/testdata/inverse/aaa" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/a2" <- "k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed" did not match any rule`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f2" <- "k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed" did not match any rule`,
+	}
+
+	checkAllErrorStrings(t, errs, expect)
+}
+
+func TestTransitive(t *testing.T) {
+	pkgs, err := loadPkgs("./testdata/transitive/...")
+	if err != nil {
+		t.Fatalf("unexpected failure: %v", err)
+	}
+	if len(pkgs) != 10 {
+		t.Fatalf("expected 10 pkg results, got %d", len(pkgs))
+	}
+
+	boss := newBoss(pkgs)
+
+	var errs []error
+	for _, pkg := range pkgs {
+		errs = append(errs, boss.Verify(pkg)...)
+	}
+
+	expect := []string{
+		`"k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden" <- "k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f1" <- "k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f2" <-- "k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa" is forbidden`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/a2" <- "k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed" did not match any rule`,
+		`"k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f2" <- "k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed" did not match any rule`,
+	}
+
+	checkAllErrorStrings(t, errs, expect)
+}

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/aaa/file.go

@@ -0,0 +1,12 @@
+package aaa
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/a1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither/n1"
+)
+
+var X = "aaa"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/.import-restrictions

@@ -0,0 +1,4 @@
+inverseRules:
+  - selectorRegexp: k8s[.]io
+    allowedPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/inverse/aaa

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/a1/file.go

@@ -0,0 +1,3 @@
+package a1
+
+var X = "a1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/a2/file.go

@@ -0,0 +1,3 @@
+package a2
+
+var X = "a2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/file.go

@@ -0,0 +1,9 @@
+package allowed
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/allowed/a2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither/n2"
+)
+
+var X = "allowed"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/.import-restrictions

@@ -0,0 +1,4 @@
+inverseRules:
+  - selectorRegexp: k8s[.]io
+    forbiddenPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/inverse/aaa

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f1/file.go

@@ -0,0 +1,3 @@
+package f1
+
+var X = "f1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/f2/file.go

@@ -0,0 +1,3 @@
+package f2
+
+var X = "f2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/forbidden/file.go

@@ -0,0 +1,3 @@
+package forbidden
+
+var X = "forbidden"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither/file.go

@@ -0,0 +1,3 @@
+package neither
+
+var X = "neither"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither/n1/file.go

@@ -0,0 +1,3 @@
+package n1
+
+var X = "n1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/inverse/neither/n2/file.go

@@ -0,0 +1,3 @@
+package n2
+
+var X = "n2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/.import-restrictions

@@ -0,0 +1,8 @@
+rules:
+  - selectorRegexp: k8s[.]io
+    allowedPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-root
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-both
+    forbiddenPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-root
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa/.import-restrictions

@@ -0,0 +1,9 @@
+rules:
+  - selectorRegexp: k8s[.]io
+    allowedPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/bbb
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-sub
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-both
+    forbiddenPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-sub
+      - k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/aaa/file.go

@@ -0,0 +1,14 @@
+package aaa
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-both"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-root"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-sub"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/bbb"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-root"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-sub"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/neither/n1"
+)
+
+var X = "aaa"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-both/file.go

@@ -0,0 +1,3 @@
+package allowedbyboth
+
+var X = "allowedbyboth"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-root/file.go

@@ -0,0 +1,3 @@
+package allowedbyroot
+
+var X = "allowedbyroot"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-sub/file.go

@@ -0,0 +1,3 @@
+package allowedbysub
+
+var X = "allowedbysub"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/bbb/file.go

@@ -0,0 +1,13 @@
+package bbb
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-both"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-root"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/allowed-by-sub"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-root"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-sub"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/neither/n2"
+)
+
+var X = "bbb"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-both/file.go

@@ -0,0 +1,3 @@
+package forbiddenbyboth
+
+var X = "forbiddenbyboth"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-root/file.go

@@ -0,0 +1,3 @@
+package forbiddenbyroot
+
+var X = "forbiddenbyroot"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/forbidden-by-sub/file.go

@@ -0,0 +1,3 @@
+package forbiddenbysub
+
+var X = "forbiddenbysub"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/neither/n1/file.go

@@ -0,0 +1,3 @@
+package n1
+
+var X = "n1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/nested-fwd/neither/n2/file.go

@@ -0,0 +1,3 @@
+package n2
+
+var X = "n2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa/.import-restrictions

@@ -0,0 +1,6 @@
+rules:
+  - selectorRegexp: k8s[.]io
+    allowedPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed
+    forbiddenPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/aaa/file.go

@@ -0,0 +1,12 @@
+package aaa
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed/a1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/f1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/n1"
+)
+
+var X = "aaa"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed/a1/file.go

@@ -0,0 +1,3 @@
+package a1
+
+var X = "a1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed/a2/file.go

@@ -0,0 +1,3 @@
+package a2
+
+var X = "a2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed/file.go

@@ -0,0 +1,9 @@
+package allowed
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/allowed/a2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/f2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/n2"
+)
+
+var X = "allowed"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/f1/file.go

@@ -0,0 +1,3 @@
+package f1
+
+var X = "f1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/f2/file.go

@@ -0,0 +1,3 @@
+package f2
+
+var X = "f2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/forbidden/file.go

@@ -0,0 +1,3 @@
+package forbidden
+
+var X = "forbidden"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/file.go

@@ -0,0 +1,3 @@
+package neither
+
+var X = "neither"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/n1/file.go

@@ -0,0 +1,3 @@
+package n1
+
+var X = "n1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/simple-fwd/neither/n2/file.go

@@ -0,0 +1,3 @@
+package n2
+
+var X = "n2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa/file.go

@@ -0,0 +1,12 @@
+package aaa
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/a1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f1"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither/n1"
+)
+
+var X = "aaa"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/.import-restrictions

@@ -0,0 +1,5 @@
+inverseRules:
+  - selectorRegexp: k8s[.]io
+    allowedPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa
+    transitive: true

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/a1/file.go

@@ -0,0 +1,3 @@
+package a1
+
+var X = "a1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/a2/file.go

@@ -0,0 +1,3 @@
+package a2
+
+var X = "a2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/file.go

@@ -0,0 +1,9 @@
+package allowed
+
+import (
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/allowed/a2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f2"
+	_ "k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither/n2"
+)
+
+var X = "allowed"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/.import-restrictions

@@ -0,0 +1,5 @@
+inverseRules:
+  - selectorRegexp: k8s[.]io
+    forbiddenPrefixes:
+      - k8s.io/code-generator/cmd/import-boss/testdata/transitive/aaa
+    transitive: true

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f1/file.go

@@ -0,0 +1,3 @@
+package f1
+
+var X = "f1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/f2/file.go

@@ -0,0 +1,3 @@
+package f2
+
+var X = "f2"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/forbidden/file.go

@@ -0,0 +1,3 @@
+package forbidden
+
+var X = "forbidden"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither/file.go

@@ -0,0 +1,3 @@
+package neither
+
+var X = "neither"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither/n1/file.go

@@ -0,0 +1,3 @@
+package n1
+
+var X = "n1"

staging/src/k8s.io/code-generator/cmd/import-boss/testdata/transitive/neither/n2/file.go

@@ -0,0 +1,3 @@
+package n2
+
+var X = "n2"