func TestPipelineDifferentShells(t *testing.T) {
	sh1 := gosh.NewShell(t)
	defer sh1.Cleanup()
	sh2 := gosh.NewShell(t)
	defer sh2.Cleanup()

	setsErr(t, sh1, func() { gosh.NewPipeline(sh1.FuncCmd(echoFunc), sh2.FuncCmd(catFunc)) })
	setsErr(t, sh2, func() { gosh.NewPipeline(sh2.FuncCmd(echoFunc), sh1.FuncCmd(catFunc)) })
	p := gosh.NewPipeline(sh1.FuncCmd(echoFunc))
	setsErr(t, sh1, func() { p.PipeStdout(sh2.FuncCmd(catFunc)) })
	p = gosh.NewPipeline(sh1.FuncCmd(echoFunc))
	setsErr(t, sh1, func() { p.PipeStderr(sh2.FuncCmd(catFunc)) })
	p = gosh.NewPipeline(sh1.FuncCmd(echoFunc))
	setsErr(t, sh1, func() { p.PipeCombinedOutput(sh2.FuncCmd(catFunc)) })
}

func TestStdoutStderr(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	// Write to stdout only.
	c := sh.FuncCmd(writeFunc, true, false)
	stdoutPipe, stderrPipe := c.StdoutPipe(), c.StderrPipe()
	stdout, stderr := c.StdoutStderr()
	eq(t, stdout, "AA")
	eq(t, stderr, "")
	eq(t, toString(t, stdoutPipe), "AA")
	eq(t, toString(t, stderrPipe), "")

	// Write to stderr only.
	c = sh.FuncCmd(writeFunc, false, true)
	stdoutPipe, stderrPipe = c.StdoutPipe(), c.StderrPipe()
	stdout, stderr = c.StdoutStderr()
	eq(t, stdout, "")
	eq(t, stderr, "BB")
	eq(t, toString(t, stdoutPipe), "")
	eq(t, toString(t, stderrPipe), "BB")

	// Write to both stdout and stderr.
	c = sh.FuncCmd(writeFunc, true, true)
	stdoutPipe, stderrPipe = c.StdoutPipe(), c.StderrPipe()
	stdout, stderr = c.StdoutStderr()
	eq(t, stdout, "AA")
	eq(t, stderr, "BB")
	eq(t, toString(t, stdoutPipe), "AA")
	eq(t, toString(t, stderrPipe), "BB")
}

func TestPipelineTerminate(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	for _, d := range []time.Duration{0, time.Hour} {
		for _, s := range []os.Signal{os.Interrupt, os.Kill} {
			fmt.Println(d, s)
			p := gosh.NewPipeline(sh.FuncCmd(sleepFunc, d, 0), sh.FuncCmd(sleepFunc, d, 0))
			p.Start()
			p.Cmds()[0].AwaitVars("ready")
			p.Cmds()[1].AwaitVars("ready")
			// Wait for a bit to allow the zero-sleep commands to exit.
			time.Sleep(100 * time.Millisecond)
			// Terminate should succeed regardless of the exit code, and regardless of
			// whether the signal arrived or the processes had already exited.
			p.Terminate(s)
		}
	}

	// Terminate should fail if Wait has been called.
	z := time.Duration(0)
	p := gosh.NewPipeline(sh.FuncCmd(sleepFunc, z, 0), sh.FuncCmd(sleepFunc, z, 0))
	p.Run()
	setsErr(t, sh, func() { p.Terminate(os.Interrupt) })
}

func TestSignal(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	for _, d := range []time.Duration{0, time.Hour} {
		for _, s := range []os.Signal{os.Interrupt, os.Kill} {
			fmt.Println(d, s)
			c := sh.FuncCmd(sleepFunc, d, 0)
			c.Start()
			c.AwaitVars("ready")
			// Wait for a bit to allow the zero-sleep commands to exit.
			time.Sleep(100 * time.Millisecond)
			c.Signal(s)
			switch {
			case s == os.Interrupt:
				// Wait should succeed as long as the exit code was 0, regardless of
				// whether the signal arrived or the process had already exited.
				c.Wait()
			case d != 0:
				// Note: We don't call Wait in the {d: 0, s: os.Kill} case because doing
				// so makes the test flaky on slow systems.
				setsErr(t, sh, func() { c.Wait() })
			}
		}
	}

	// Signal should fail if Wait has been called.
	c := sh.FuncCmd(sleepFunc, time.Duration(0), 0)
	c.Run()
	setsErr(t, sh, func() { c.Signal(os.Interrupt) })
}

// Tests that we don't log command failures when ExitErrorIsOk or
// ContinueOnError is set.
func TestCmdFailureLoggingDisabled(t *testing.T) {
	tb := &customTB{t: t, buf: &bytes.Buffer{}}
	sh := gosh.NewShell(tb)
	defer sh.Cleanup()

	// If ExitErrorIsOk is set and the command fails, we shouldn't log anything.
	tb.Reset()
	c := sh.FuncCmd(exitFunc, 1)
	c.ExitErrorIsOk = true
	c.Run()
	eq(t, tb.calledFailNow, false)
	eq(t, tb.buf.String(), "")

	// If ContinueOnError is set and the command fails, we should log the exit
	// status but not the command stderr.
	tb.Reset()
	c = sh.FuncCmd(exitFunc, 1)
	sh.ContinueOnError = true
	c.Run()
	eq(t, tb.calledFailNow, false)
	got := tb.buf.String()
	if !strings.Contains(got, "exit status 1") {
		t.Fatalf("missing error: %s", got)
	}
	if strings.Contains(got, "STDERR") {
		t.Fatalf("should not log stderr: %s", got)
	}
}

func TestPushdPopd(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	startDir, err := os.Getwd()
	ok(t, err)
	parentDir := filepath.Dir(startDir)
	neq(t, startDir, parentDir)
	sh.Pushd(parentDir)
	cwd, err := os.Getwd()
	ok(t, err)
	eq(t, cwd, parentDir)
	sh.Pushd(startDir)
	cwd, err = os.Getwd()
	ok(t, err)
	eq(t, cwd, startDir)
	sh.Popd()
	cwd, err = os.Getwd()
	ok(t, err)
	eq(t, cwd, parentDir)
	sh.Popd()
	cwd, err = os.Getwd()
	ok(t, err)
	eq(t, cwd, startDir)
	// The next sh.Popd() will fail.
	setsErr(t, sh, func() { sh.Popd() })
}

// Tests that it's safe to add os.Stdout and os.Stderr as writers.
func TestAddStdoutStderrWriter(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	stdout, stderr := sh.FuncCmd(writeMoreFunc).StdoutStderr()
	eq(t, stdout, "AA stdout done")
	eq(t, stderr, "BB stderr done")
}

// Tests that AwaitVars returns immediately when the process exits.
func TestAwaitVarsProcessExit(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	c := sh.FuncCmd(exitFunc, 0)
	c.Start()
	setsErr(t, sh, func() { c.AwaitVars("foo") })
}

func TestMakeTempFile(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	file := sh.MakeTempFile()
	fi, err := file.Stat()
	ok(t, err)
	eq(t, fi.Mode().IsRegular(), true)
}

func TestMakeTempDir(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	name := sh.MakeTempDir()
	fi, err := os.Stat(name)
	ok(t, err)
	eq(t, fi.Mode().IsDir(), true)
}

func TestCustomTB(t *testing.T) {
	tb := &customTB{t: t}
	sh := gosh.NewShell(tb)
	defer sh.Cleanup()

	sh.HandleError(fakeError)
	// Note, our deferred sh.Cleanup() should succeed despite this error.
	nok(t, sh.Err)
	eq(t, tb.calledFailNow, true)
}

func TestPushdNoPopdCleanup(t *testing.T) {
	startDir := getwdEvalSymlinks(t)
	sh := gosh.NewShell(t)
	tmpDir := sh.MakeTempDir()
	sh.Pushd(tmpDir)
	eq(t, getwdEvalSymlinks(t), evalSymlinks(t, tmpDir))
	// There is no matching popd; the cwd is tmpDir, which is deleted by Cleanup.
	// Cleanup needs to put us back in startDir, otherwise all subsequent Pushd
	// calls will fail.
	sh.Cleanup()
	eq(t, getwdEvalSymlinks(t), startDir)
}

// Tests that Shell.HandleError panics under various conditions.
func TestHandleErrorPanics(t *testing.T) {
	func() { // errDidNotCallNewShell
		sh := gosh.Shell{}
		defer func() { neq(t, recover(), nil) }()
		sh.HandleError(fakeError)
	}()
	func() { // errShellErrIsNotNil
		sh := gosh.NewShell(t)
		sh.ContinueOnError = true
		defer sh.Cleanup()
		sh.Err = fakeError
		defer func() { neq(t, recover(), nil) }()
		sh.HandleError(fakeError)
	}()
	func() { // errAlreadyCalledCleanup
		sh := gosh.NewShell(t)
		sh.ContinueOnError = true
		sh.Cleanup()
		defer func() { neq(t, recover(), nil) }()
		sh.HandleError(fakeError)
	}()
}

// Mirrors ExampleFuncCmd in internal/gosh_example/main.go.
func TestFuncCmd(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	// Start server.
	c := sh.FuncCmd(serveFunc)
	c.Start()
	addr := c.AwaitVars("addr")["addr"]
	neq(t, addr, "")

	// Run client.
	c = sh.FuncCmd(getFunc, addr)
	eq(t, c.Stdout(), helloWorldStr)
}

// Mirrors TestFuncCmd in shell_test.go.
func ExampleFuncCmd() {
	sh := gosh.NewShell(nil)
	defer sh.Cleanup()

	// Start server.
	c := sh.FuncCmd(serveFunc)
	c.Start()
	addr := c.AwaitVars("addr")["addr"]
	fmt.Println(addr)

	// Run client.
	c = sh.FuncCmd(getFunc, addr)
	fmt.Print(c.Stdout())
}

// Tests that Shell.Cmd uses Shell.Vars["PATH"] to locate executables with
// relative names.
func TestLookPath(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	binDir := sh.MakeTempDir()
	sh.Vars["PATH"] = binDir + ":" + sh.Vars["PATH"]
	relName := "hw"
	absName := filepath.Join(binDir, relName)
	gosh.BuildGoPkg(sh, "", helloWorldPkg, "-o", absName)
	c := sh.Cmd(relName)
	eq(t, c.Stdout(), helloWorldStr)

	// Test the case where we cannot find the executable.
	sh.Vars["PATH"] = ""
	setsErr(t, sh, func() { sh.Cmd("yes") })
}

func TestPipelineClosedPipe(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()
	writeLoop, readLine := sh.FuncCmd(writeLoopFunc), sh.FuncCmd(readFunc)

	// WriteLoop finishes because it gets a closed pipe write error after readLine
	// finishes. Note that the closed pipe error is ignored.
	p := gosh.NewPipeline(writeLoop, readLine)
	eq(t, p.Stdout(), "")
	ok(t, p.Cmds()[0].Err)
	ok(t, p.Cmds()[1].Err)
	p = p.Clone()
	eq(t, p.Stdout(), "")
	ok(t, p.Cmds()[0].Err)
	ok(t, p.Cmds()[1].Err)
}

func TestCombinedOutput(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	c := sh.FuncCmd(writeFunc, true, true)
	buf := &bytes.Buffer{}
	c.AddStdoutWriter(buf)
	c.AddStderrWriter(buf)
	output := c.CombinedOutput()
	// Note, we can't assume any particular ordering of stdout and stderr, so we
	// simply check the length of the combined output.
	eq(t, len(output), 4)
	// The ordering must be the same, regardless of how we captured the combined
	// output.
	eq(t, output, buf.String())
}

// Mirrors TestCmd in shell_test.go.
func ExampleCmd() {
	sh := gosh.NewShell(nil)
	defer sh.Cleanup()

	// Start server.
	binDir := sh.MakeTempDir()
	binPath := gosh.BuildGoPkg(sh, binDir, "github.com/asadovsky/gosh/internal/gosh_example_server")
	c := sh.Cmd(binPath)
	c.Start()
	addr := c.AwaitVars("addr")["addr"]
	fmt.Println(addr)

	// Run client.
	binPath = gosh.BuildGoPkg(sh, binDir, "github.com/asadovsky/gosh/internal/gosh_example_client")
	c = sh.Cmd(binPath, "-addr="+addr)
	fmt.Print(c.Stdout())
}

// Mirrors ExampleCmd in internal/gosh_example/main.go.
func TestCmd(t *testing.T) {
	sh := gosh.NewShell(t)
	defer sh.Cleanup()

	// Start server.
	binDir := sh.MakeTempDir()
	binPath := gosh.BuildGoPkg(sh, binDir, "github.com/asadovsky/gosh/internal/gosh_example_server")
	c := sh.Cmd(binPath)
	c.Start()
	addr := c.AwaitVars("addr")["addr"]
	neq(t, addr, "")

	// Run client.
	binPath = gosh.BuildGoPkg(sh, binDir, "github.com/asadovsky/gosh/internal/gosh_example_client")
	c = sh.Cmd(binPath, "-addr="+addr)
	eq(t, c.Stdout(), helloWorldStr)
}