Replace "PATH" literals with a constant

pkg/edit/highlight_test.go

@@ -77,8 +77,8 @@ func TestMakeHasCommand(t *testing.T) {
 	// Set up environment.
 	testDir, cleanup := util.InTestDir()
 	defer cleanup()
-	oldPath := os.Getenv("PATH")
-	defer os.Setenv("PATH", oldPath)
+	oldPath := os.Getenv(util.EnvPATH)
+	defer os.Setenv(util.EnvPATH, oldPath)
 	if runtime.GOOS == "windows" {
 		oldPathExt := os.Getenv("PATHEXT")
 		defer os.Setenv("PATHEXT", oldPathExt)
@@ -87,7 +87,7 @@ func TestMakeHasCommand(t *testing.T) {
 	}
 
 	// Set up a directory in PATH.
-	os.Setenv("PATH", filepath.Join(testDir, "bin"))
+	os.Setenv(util.EnvPATH, filepath.Join(testDir, "bin"))
 	mustMkdirAll("bin")
 	mustMkExecutable("bin/external")
 	mustMkExecutable("bin/@external")

pkg/eval/builtin_fn_env_test.go

@@ -5,10 +5,11 @@ import (
 	"testing"
 
 	"github.com/elves/elvish/pkg/eval/vals"
+	"github.com/elves/elvish/pkg/util"
 )
 
 func TestBuiltinFnEnv(t *testing.T) {
-	oldpath := os.Getenv("PATH")
+	oldpath := os.Getenv(util.EnvPATH)
 	listSep := string(os.PathListSeparator)
 	Test(t,
 		That(`get-env var`).ThrowsCause(errNonExistentEnvVar),
@@ -29,5 +30,5 @@ func TestBuiltinFnEnv(t *testing.T) {
 		That(`paths = [/test-path2 $@paths]`),
 		That(`get-env PATH`).Puts("/test-path2"+listSep+"/test-path"),
 	)
-	os.Setenv("PATH", oldpath)
+	os.Setenv(util.EnvPATH, oldpath)
 }

pkg/eval/eval.go

@@ -248,7 +248,7 @@ func (ev *Evaler) SetLibDir(libDir string) {
 }
 
 func searchPaths() []string {
-	return strings.Split(os.Getenv("PATH"), ":")
+	return strings.Split(os.Getenv(util.EnvPATH), ":")
 }
 
 // growPorts makes the size of ec.ports at least n, adding nil's if necessary.

pkg/util/util.go

@@ -4,6 +4,7 @@ package util
 // Environment variables with special significance to Elvish.
 const (
 	EnvHOME  = "HOME"
+	EnvPATH  = "PATH"
 	EnvPWD   = "PWD"
 	EnvSHLVL = "SHLVL"
 )