env GO111MODULE=off

# Test that cached test results are invalidated in response to
# changes to the external inputs to the test.

[short] skip
[GODEBUG:gocacheverify=1] skip

# We're testing cache behavior, so start with a clean GOCACHE.
env GOCACHE=$WORK/cache

# Build a helper binary to invoke os.Chtimes.
go build -o mkold$GOEXE mkold.go

# Make test input files appear to be a minute old.
exec ./mkold$GOEXE 1m testcache/file.txt
exec ./mkold$GOEXE 1m testcache/script.sh

# If the test reads an environment variable, changes to that variable
# should invalidate cached test results.
env TESTKEY=x
go test testcache -run=TestLookupEnv
go test testcache -run=TestLookupEnv
stdout '\(cached\)'

env TESTKEY=y
go test testcache -run=TestLookupEnv
! stdout '\(cached\)'
go test testcache -run=TestLookupEnv
stdout '\(cached\)'

# If the test stats a file, changes to the file should invalidate the cache.
go test testcache -run=FileSize
go test testcache -run=FileSize
stdout '\(cached\)'

cp 4x.txt testcache/file.txt
go test testcache -run=FileSize
! stdout '\(cached\)'
go test testcache -run=FileSize
stdout '\(cached\)'

# Files should be tracked even if the test changes its working directory.
go test testcache -run=Chdir
go test testcache -run=Chdir
stdout '\(cached\)'
cp 6x.txt testcache/file.txt
go test testcache -run=Chdir
! stdout '\(cached\)'
go test testcache -run=Chdir
stdout '\(cached\)'

# The content of files should affect caching, provided that the mtime also changes.
exec ./mkold$GOEXE 1m testcache/file.txt
go test testcache -run=FileContent
go test testcache -run=FileContent
stdout '\(cached\)'
cp 2y.txt testcache/file.txt
exec ./mkold$GOEXE 50s testcache/file.txt
go test testcache -run=FileContent
! stdout '\(cached\)'
go test testcache -run=FileContent
stdout '\(cached\)'

# Directory contents read via os.ReadDirNames should affect caching.
go test testcache -run=DirList
go test testcache -run=DirList
stdout '\(cached\)'
rm testcache/file.txt
go test testcache -run=DirList
! stdout '\(cached\)'
go test testcache -run=DirList
stdout '\(cached\)'

# Files outside GOROOT and GOPATH should not affect caching.
env TEST_EXTERNAL_FILE=$WORK/external.txt
go test testcache -run=ExternalFile
go test testcache -run=ExternalFile
stdout '\(cached\)'

rm $WORK/external.txt
go test testcache -run=ExternalFile
stdout '\(cached\)'

# Executables within GOROOT and GOPATH should affect caching,
# even if the test does not stat them explicitly.

[!exec:/bin/sh] skip
chmod 0755 ./testcache/script.sh

exec ./mkold$GOEXEC 1m testcache/script.sh
go test testcache -run=Exec
go test testcache -run=Exec
stdout '\(cached\)'

exec ./mkold$GOEXE 50s testcache/script.sh
go test testcache -run=Exec
! stdout '\(cached\)'
go test testcache -run=Exec
stdout '\(cached\)'

-- testcache/file.txt --
xx
-- 4x.txt --
xxxx
-- 6x.txt --
xxxxxx
-- 2y.txt --
yy
-- $WORK/external.txt --
This file is outside of GOPATH.
-- testcache/script.sh --
#!/bin/sh
exit 0
-- testcache/testcache_test.go --
// Copyright 2017 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 testcache

import (
	"io/ioutil"
	"os"
	"testing"
)

func TestChdir(t *testing.T) {
	os.Chdir("..")
	defer os.Chdir("testcache")
	info, err := os.Stat("testcache/file.txt")
	if err != nil {
		t.Fatal(err)
	}
	if info.Size()%2 != 1 {
		t.Fatal("even file")
	}
}

func TestOddFileContent(t *testing.T) {
	f, err := os.Open("file.txt")
	if err != nil {
		t.Fatal(err)
	}
	data, err := ioutil.ReadAll(f)
	f.Close()
	if err != nil {
		t.Fatal(err)
	}
	if len(data)%2 != 1 {
		t.Fatal("even file")
	}
}

func TestOddFileSize(t *testing.T) {
	info, err := os.Stat("file.txt")
	if err != nil {
		t.Fatal(err)
	}
	if info.Size()%2 != 1 {
		t.Fatal("even file")
	}
}

func TestOddGetenv(t *testing.T) {
	val := os.Getenv("TESTKEY")
	if len(val)%2 != 1 {
		t.Fatal("even env value")
	}
}

func TestLookupEnv(t *testing.T) {
	_, ok := os.LookupEnv("TESTKEY")
	if !ok {
		t.Fatal("env missing")
	}
}

func TestDirList(t *testing.T) {
	f, err := os.Open(".")
	if err != nil {
		t.Fatal(err)
	}
	f.Readdirnames(-1)
	f.Close()
}

func TestExec(t *testing.T) {
	// Note: not using os/exec to make sure there is no unexpected stat.
	p, err := os.StartProcess("./script.sh", []string{"script"}, new(os.ProcAttr))
	if err != nil {
		t.Fatal(err)
	}
	ps, err := p.Wait()
	if err != nil {
		t.Fatal(err)
	}
	if !ps.Success() {
		t.Fatalf("script failed: %v", err)
	}
}

func TestExternalFile(t *testing.T) {
	os.Open(os.Getenv("TEST_EXTERNAL_FILE"))
	_, err := os.Stat(os.Getenv("TEST_EXTERNAL_FILE"))
	if err != nil {
		t.Fatal(err)
	}
}
-- mkold.go --
package main

import (
	"log"
	"os"
	"time"
)

func main() {
	d, err := time.ParseDuration(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	path := os.Args[2]
	old := time.Now().Add(-d)
	err = os.Chtimes(path, old, old)
	if err != nil {
		log.Fatal(err)
	}
}