// Copyright 2010 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package os_test

import (
	. "os"
	"reflect"
	"testing"
)

func TestConsistentEnviron(t *testing.T) {
	e0 := Environ()
	for i := 0; i < 10; i++ {
		e1 := Environ()
		if !reflect.DeepEqual(e0, e1) {
			t.Fatalf("environment changed")
		}
	}
}

func TestLookupEnv(t *testing.T) {
	const smallpox = "SMALLPOX"      // No one has smallpox.
	value, ok := LookupEnv(smallpox) // Should not exist.
	if ok || value != "" {
		t.Fatalf("%s=%q", smallpox, value)
	}
	defer Unsetenv(smallpox)
	err := Setenv(smallpox, "virus")
	if err != nil {
		t.Fatalf("failed to release smallpox virus")
	}
	_, ok = LookupEnv(smallpox)
	if !ok {
		t.Errorf("smallpox release failed; world remains safe but LookupEnv is broken")
	}
}