change to use a typed map per code review

common/env.go

@@ -1,11 +1,19 @@
 package common
 
-type envKey string
+type EnvKeyType string
 
-// Env is a context key that can be used to set programmatically the environment
+// EnvKey is a context key that can be used to set programmatically the environment
 // gopsutil relies on to perform calls against the OS.
 // Example of use:
 //
-//	ctx := context.WithValue(context.Background(), Env, map[string]string{"HOST_PROC": "/myproc"})
+//	ctx := context.WithValue(context.Background(), common.EnvKey, EnvMap{"HOST_PROC": "/myproc"})
 //	avg, err := load.AvgWithContext(ctx)
-var Env = envKey("env")
+var EnvKey = EnvKeyType("env")
+
+const (
+	HostProcEnvKey EnvKeyType = "HOST_PROC"
+	HostSysEnvKey  EnvKeyType = "HOST_SYS"
+	HostEtcEnvKey  EnvKeyType = "HOST_ETC"
+)
+
+type EnvMap map[EnvKeyType]string

internal/common/common.go

@@ -324,11 +324,11 @@ func PathExistsWithContents(filename string) bool {
 }
 
 // GetEnvWithContext retrieves the environment variable key. If it does not exist it returns the default.
-// The context may optionally contain a map superseding os.Env.
+// The context may optionally contain a map superseding os.EnvKey.
 func GetEnvWithContext(ctx context.Context, key string, dfault string, combineWith ...string) string {
 	var value string
-	if env, ok := ctx.Value(common.Env).(map[string]string); ok {
+	if env, ok := ctx.Value(common.EnvKey).(common.EnvMap); ok {
-		value = env[key]
+		value = env[common.EnvKeyType(key)]
 	}
 	if value == "" {
 		value = os.Getenv(key)

internal/common/common_test.go

@@ -8,6 +8,8 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+
+	"github.com/shirou/gopsutil/v3/common"
 )
 
 func TestReadlines(t *testing.T) {
@@ -196,7 +198,7 @@ func TestGetEnvWithContextOverride(t *testing.T) {
 	defer func() {
 		os.Setenv("HOST_ETC", old)
 	}()
-	ctx := context.WithValue(context.Background(), Env, map[string]string{"HOST_ETC": "/foo"})
+	ctx := context.WithValue(context.Background(), common.EnvKey, common.EnvMap{common.HostEtcEnvKey: "/foo"})
 	p := HostEtcWithContext(ctx, "mtab")
 	if p != "/foo/mtab" {
 		t.Errorf("invalid HostEtc, %s", p)