1 files changed, 168 insertions, 0 deletions
diff --git a/src/os/env_test.go b/src/os/env_test.go
new file mode 100644
index 0000000..4b86015
--- /dev/null
+++ b/src/os/env_test.go
@@ -0,0 +1,168 @@
+// 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"
+	"strings"
+	"testing"
+)
+
+// testGetenv gives us a controlled set of variables for testing Expand.
+func testGetenv(s string) string {
+	switch s {
+	case "*":
+		return "all the args"
+	case "#":
+		return "NARGS"
+	case "$":
+		return "PID"
+	case "1":
+		return "ARGUMENT1"
+	case "HOME":
+		return "/usr/gopher"
+	case "H":
+		return "(Value of H)"
+	case "home_1":
+		return "/usr/foo"
+	case "_":
+		return "underscore"
+	}
+	return ""
+}
+
+var expandTests = []struct {
+	in, out string
+}{
+	{"", ""},
+	{"$*", "all the args"},
+	{"$$", "PID"},
+	{"${*}", "all the args"},
+	{"$1", "ARGUMENT1"},
+	{"${1}", "ARGUMENT1"},
+	{"now is the time", "now is the time"},
+	{"$HOME", "/usr/gopher"},
+	{"$home_1", "/usr/foo"},
+	{"${HOME}", "/usr/gopher"},
+	{"${H}OME", "(Value of H)OME"},
+	{"A$$$#$1$H$home_1*B", "APIDNARGSARGUMENT1(Value of H)/usr/foo*B"},
+	{"start$+middle$^end$", "start$+middle$^end$"},
+	{"mixed$|bag$$$", "mixed$|bagPID$"},
+	{"$", "$"},
+	{"$}", "$}"},
+	{"${", ""},  // invalid syntax; eat up the characters
+	{"${}", ""}, // invalid syntax; eat up the characters
+}
+
+func TestExpand(t *testing.T) {
+	for _, test := range expandTests {
+		result := Expand(test.in, testGetenv)
+		if result != test.out {
+			t.Errorf("Expand(%q)=%q; expected %q", test.in, result, test.out)
+		}
+	}
+}
+
+var global interface{}
+
+func BenchmarkExpand(b *testing.B) {
+	b.Run("noop", func(b *testing.B) {
+		var s string
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			s = Expand("tick tick tick tick", func(string) string { return "" })
+		}
+		global = s
+	})
+	b.Run("multiple", func(b *testing.B) {
+		var s string
+		b.ReportAllocs()
+		for i := 0; i < b.N; i++ {
+			s = Expand("$a $a $a $a", func(string) string { return "boom" })
+		}
+		global = s
+	})
+}
+
+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 TestUnsetenv(t *testing.T) {
+	const testKey = "GO_TEST_UNSETENV"
+	set := func() bool {
+		prefix := testKey + "="
+		for _, key := range Environ() {
+			if strings.HasPrefix(key, prefix) {
+				return true
+			}
+		}
+		return false
+	}
+	if err := Setenv(testKey, "1"); err != nil {
+		t.Fatalf("Setenv: %v", err)
+	}
+	if !set() {
+		t.Error("Setenv didn't set TestUnsetenv")
+	}
+	if err := Unsetenv(testKey); err != nil {
+		t.Fatalf("Unsetenv: %v", err)
+	}
+	if set() {
+		t.Fatal("Unsetenv didn't clear TestUnsetenv")
+	}
+}
+
+func TestClearenv(t *testing.T) {
+	const testKey = "GO_TEST_CLEARENV"
+	const testValue = "1"
+
+	// reset env
+	defer func(origEnv []string) {
+		for _, pair := range origEnv {
+			// Environment variables on Windows can begin with =
+			// https://blogs.msdn.com/b/oldnewthing/archive/2010/05/06/10008132.aspx
+			i := strings.Index(pair[1:], "=") + 1
+			if err := Setenv(pair[:i], pair[i+1:]); err != nil {
+				t.Errorf("Setenv(%q, %q) failed during reset: %v", pair[:i], pair[i+1:], err)
+			}
+		}
+	}(Environ())
+
+	if err := Setenv(testKey, testValue); err != nil {
+		t.Fatalf("Setenv(%q, %q) failed: %v", testKey, testValue, err)
+	}
+	if _, ok := LookupEnv(testKey); !ok {
+		t.Errorf("Setenv(%q, %q) didn't set $%s", testKey, testValue, testKey)
+	}
+	Clearenv()
+	if val, ok := LookupEnv(testKey); ok {
+		t.Errorf("Clearenv() didn't clear $%s, remained with value %q", testKey, val)
+	}
+}
+
+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")
+	}
+}