path: root/cmd/geth/run_test.go

// Copyright 2016 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package main

import (
    "bufio"
    "bytes"
    "fmt"
    "html/template"
    "io"
    "io/ioutil"
    "os"
    "os/exec"
    "regexp"
    "sync"
    "testing"
    "time"
)

func tmpdir(t *testing.T) string {
    dir, err := ioutil.TempDir("", "geth-test")
    if err != nil {
        t.Fatal(err)
    }
    return dir
}

type testgeth struct {
    // For total convenience, all testing methods are available.
    *testing.T
    // template variables for expect
    Datadir    string
    Executable string

    removeDatadir bool
    cmd           *exec.Cmd
    stdout        *bufio.Reader
    stdin         io.WriteCloser
    stderr        *testlogger
}

func init() {
    // Run the app if we're the child process for runGeth.
    if os.Getenv("GETH_TEST_CHILD") != "" {
        app.RunAndExitOnError()
        os.Exit(0)
    }
}

// spawns geth with the given command line args. If the args don't set --datadir, the
// child g gets a temporary data directory.
func runGeth(t *testing.T, args ...string) *testgeth {
    tt := &testgeth{T: t, Executable: os.Args[0]}
    for i, arg := range args {
        if arg == "-datadir" || arg == "--datadir" {
            if i < len(args)-1 {
                tt.Datadir = args[i+1]
            }
            break
        }
    }
    if tt.Datadir == "" {
        tt.Datadir = tmpdir(t)
        tt.removeDatadir = true
        args = append([]string{"-datadir", tt.Datadir}, args...)
        // Remove the temporary datadir if something fails below.
        defer func() {
            if t.Failed() {
                os.RemoveAll(tt.Datadir)
            }
        }()
    }

    // Boot "geth". This actually runs the test binary but the init function
    // will prevent any tests from running.
    tt.stderr = &testlogger{t: t}
    tt.cmd = exec.Command(os.Args[0], args...)
    tt.cmd.Env = append(os.Environ(), "GETH_TEST_CHILD=1")
    tt.cmd.Stderr = tt.stderr
    stdout, err := tt.cmd.StdoutPipe()
    if err != nil {
        t.Fatal(err)
    }
    tt.stdout = bufio.NewReader(stdout)
    if tt.stdin, err = tt.cmd.StdinPipe(); err != nil {
        t.Fatal(err)
    }
    if err := tt.cmd.Start(); err != nil {
        t.Fatal(err)
    }
    return tt
}

// InputLine writes the given text to the childs stdin.
// This method can also be called from an expect template, e.g.:
//
//     geth.expect(`Passphrase: {{.InputLine "password"}}`)
func (tt *testgeth) InputLine(s string) string {
    io.WriteString(tt.stdin, s+"\n")
    return ""
}

// expect runs its argument as a template, then expects the
// child process to output the result of the template within 5s.
//
// If the template starts with a newline, the newline is removed
// before matching.
func (tt *testgeth) expect(tplsource string) {
    // Generate the expected output by running the template.
    tpl := template.Must(template.New("").Parse(tplsource))
    wantbuf := new(bytes.Buffer)
    if err := tpl.Execute(wantbuf, tt); err != nil {
        panic(err)
    }
    // Trim exactly one newline at the beginning. This makes tests look
    // much nicer because all expect strings are at column 0.
    want := bytes.TrimPrefix(wantbuf.Bytes(), []byte("\n"))
    if err := tt.matchExactOutput(want); err != nil {
        tt.Fatal(err)
    }
    tt.Logf("Matched stdout text:\n%s", want)
}

func (tt *testgeth) matchExactOutput(want []byte) error {
    buf := make([]byte, len(want))
    n := 0
    tt.withKillTimeout(func() { n, _ = io.ReadFull(tt.stdout, buf) })
    buf = buf[:n]
    if n < len(want) || !bytes.Equal(buf, want) {
        // Grab any additional buffered output in case of mismatch
        // because it might help with debugging.
        buf = append(buf, make([]byte, tt.stdout.Buffered())...)
        tt.stdout.Read(buf[n:])
        // Find the mismatch position.
        for i := 0; i < n; i++ {
            if want[i] != buf[i] {
                return fmt.Errorf("Output mismatch at ◊:\n---------------- (stdout text)\n%s◊%s\n---------------- (expected text)\n%s",
                    buf[:i], buf[i:n], want)
            }
        }
        if n < len(want) {
            return fmt.Errorf("Not enough output, got until ◊:\n---------------- (stdout text)\n%s\n---------------- (expected text)\n%s◊%s",
                buf, want[:n], want[n:])
        }
    }
    return nil
}

// expectRegexp expects the child process to output text matching the
// given regular expression within 5s.
//
// Note that an arbitrary amount of output may be consumed by the
// regular expression. This usually means that expect cannot be used
// after expectRegexp.
func (tt *testgeth) expectRegexp(resource string) (*regexp.Regexp, []string) {
    var (
        re      = regexp.MustCompile(resource)
        rtee    = &runeTee{in: tt.stdout}
        matches []int
    )
    tt.withKillTimeout(func() { matches = re.FindReaderSubmatchIndex(rtee) })
    output := rtee.buf.Bytes()
    if matches == nil {
        tt.Fatalf("Output did not match:\n---------------- (stdout text)\n%s\n---------------- (regular expression)\n%s",
            output, resource)
        return re, nil
    }
    tt.Logf("Matched stdout text:\n%s", output)
    var submatch []string
    for i := 0; i < len(matches); i += 2 {
        submatch = append(submatch, string(output[i:i+1]))
    }
    return re, submatch
}

// expectExit expects the child process to exit within 5s without
// printing any additional text on stdout.
func (tt *testgeth) expectExit() {
    var output []byte
    tt.withKillTimeout(func() {
        output, _ = ioutil.ReadAll(tt.stdout)
    })
    tt.cmd.Wait()
    if tt.removeDatadir {
        os.RemoveAll(tt.Datadir)
    }
    if len(output) > 0 {
        tt.Errorf("Unmatched stdout text:\n%s", output)
    }
}

func (tt *testgeth) interrupt() {
    tt.cmd.Process.Signal(os.Interrupt)
}

// stderrText returns any stderr output written so far.
// The returned text holds all log lines after expectExit has
// returned.
func (tt *testgeth) stderrText() string {
    tt.stderr.mu.Lock()
    defer tt.stderr.mu.Unlock()
    return tt.stderr.buf.String()
}

func (tt *testgeth) withKillTimeout(fn func()) {
    timeout := time.AfterFunc(5*time.Second, func() {
        tt.Log("killing the child process (timeout)")
        tt.cmd.Process.Kill()
        if tt.removeDatadir {
            os.RemoveAll(tt.Datadir)
        }
    })
    defer timeout.Stop()
    fn()
}

// testlogger logs all written lines via t.Log and also
// collects them for later inspection.
type testlogger struct {
    t   *testing.T
    mu  sync.Mutex
    buf bytes.Buffer
}

func (tl *testlogger) Write(b []byte) (n int, err error) {
    lines := bytes.Split(b, []byte("\n"))
    for _, line := range lines {
        if len(line) > 0 {
            tl.t.Logf("(stderr) %s", line)
        }
    }
    tl.mu.Lock()
    tl.buf.Write(b)
    tl.mu.Unlock()
    return len(b), err
}

// runeTee collects text read through it into buf.
type runeTee struct {
    in interface {
        io.Reader
        io.ByteReader
        io.RuneReader
    }
    buf bytes.Buffer
}

func (rtee *runeTee) Read(b []byte) (n int, err error) {
    n, err = rtee.in.Read(b)
    rtee.buf.Write(b[:n])
    return n, err
}

func (rtee *runeTee) ReadRune() (r rune, size int, err error) {
    r, size, err = rtee.in.ReadRune()
    if err == nil {
        rtee.buf.WriteRune(r)
    }
    return r, size, err
}

func (rtee *runeTee) ReadByte() (b byte, err error) {
    b, err = rtee.in.ReadByte()
    if err == nil {
        rtee.buf.WriteByte(b)
    }
    return b, err
}