Add compiler utils test.

api/internal/plugins/compiler/utils.go

@@ -0,0 +1,102 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package compiler
+
+import (
+	"os"
+	"path/filepath"
+	"runtime"
+	"time"
+
+	"sigs.k8s.io/kustomize/api/filesys"
+	"sigs.k8s.io/kustomize/api/konfig"
+)
+
+func goBin() string {
+	return filepath.Join(runtime.GOROOT(), "bin", "go")
+}
+
+// DeterminePluginSrcRoot guesses where the user
+// has her ${g}/${v}/$lower(${k})/${k}.go files.
+func DeterminePluginSrcRoot(fSys filesys.FileSystem) (string, error) {
+	return konfig.FirstDirThatExistsElseError(
+		"source directory", fSys, []konfig.NotedFunc{
+			{
+				Note: "relative to unit test",
+				F: func() string {
+					return filepath.Clean(
+						filepath.Join(
+							os.Getenv("PWD"),
+							"..", "..",
+							konfig.RelPluginHome))
+				},
+			},
+			{
+				Note: "relative to unit test (internal pkg)",
+				F: func() string {
+					return filepath.Clean(
+						filepath.Join(
+							os.Getenv("PWD"),
+							"..", "..", "..", "..",
+							konfig.RelPluginHome))
+				},
+			},
+			{
+				Note: "relative to api package",
+				F: func() string {
+					return filepath.Clean(
+						filepath.Join(
+							os.Getenv("PWD"),
+							"..", "..", "..",
+							konfig.RelPluginHome))
+				},
+			},
+			{
+				Note: "old style $GOPATH",
+				F: func() string {
+					return filepath.Join(
+						os.Getenv("GOPATH"),
+						"src", konfig.DomainName,
+						konfig.ProgramName, konfig.RelPluginHome)
+				},
+			},
+			{
+				Note: "HOME with literal 'gopath'",
+				F: func() string {
+					return filepath.Join(
+						konfig.HomeDir(), "gopath",
+						"src", konfig.DomainName,
+						konfig.ProgramName, konfig.RelPluginHome)
+				},
+			},
+			{
+				Note: "home directory",
+				F: func() string {
+					return filepath.Join(
+						konfig.HomeDir(), konfig.DomainName,
+						konfig.ProgramName, konfig.RelPluginHome)
+				},
+			},
+		})
+}
+
+// FileYoungerThan returns true if the file age is <= the Duration argument.
+func FileYoungerThan(path string, d time.Duration) bool {
+	fi, err := os.Stat(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return time.Since(fi.ModTime()) <= d
+}
+
+func FileExists(name string) bool {
+	if _, err := os.Stat(name); err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return true
+}