plugeth/internal/utesting/utesting.go
Felix Lange 5d20fbbb6f
cmd/devp2p, internal/utesting: implement TAP output (#21760)
TAP is a text format for test results. Parsers for it are available in many languages,
making it easy to consume. I want TAP output from our protocol tests because the
Hive wrapper around them needs to know about the test names and their individual
results and logs. It would also be possible to just write this info as JSON, but I don't
want to invent a new format.

This also improves the normal console output for tests (when running without --tap).
It now prints -- RUN lines before any output from the test, and indents the log output
by one space.
2020-11-04 15:02:58 +01:00

340 lines
8.0 KiB
Go

// Copyright 2020 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// Package utesting provides a standalone replacement for package testing.
//
// This package exists because package testing cannot easily be embedded into a
// standalone go program. It provides an API that mirrors the standard library
// testing API.
package utesting
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"regexp"
"runtime"
"sync"
"time"
)
// Test represents a single test.
type Test struct {
Name string
Fn func(*T)
}
// Result is the result of a test execution.
type Result struct {
Name string
Failed bool
Output string
Duration time.Duration
}
// MatchTests returns the tests whose name matches a regular expression.
func MatchTests(tests []Test, expr string) []Test {
var results []Test
re, err := regexp.Compile(expr)
if err != nil {
return nil
}
for _, test := range tests {
if re.MatchString(test.Name) {
results = append(results, test)
}
}
return results
}
// RunTests executes all given tests in order and returns their results.
// If the report writer is non-nil, a test report is written to it in real time.
func RunTests(tests []Test, report io.Writer) []Result {
if report == nil {
report = ioutil.Discard
}
results := run(tests, newConsoleOutput(report))
fails := CountFailures(results)
fmt.Fprintf(report, "%v/%v tests passed.\n", len(tests)-fails, len(tests))
return results
}
// RunTAP runs the given tests and writes Test Anything Protocol output
// to the report writer.
func RunTAP(tests []Test, report io.Writer) []Result {
return run(tests, newTAP(report, len(tests)))
}
func run(tests []Test, output testOutput) []Result {
var results = make([]Result, len(tests))
for i, test := range tests {
buffer := new(bytes.Buffer)
logOutput := io.MultiWriter(buffer, output)
output.testStart(test.Name)
start := time.Now()
results[i].Name = test.Name
results[i].Failed = runTest(test, logOutput)
results[i].Duration = time.Since(start)
results[i].Output = buffer.String()
output.testResult(results[i])
}
return results
}
// testOutput is implemented by output formats.
type testOutput interface {
testStart(name string)
Write([]byte) (int, error)
testResult(Result)
}
// consoleOutput prints test results similarly to go test.
type consoleOutput struct {
out io.Writer
indented *indentWriter
curTest string
wroteHeader bool
}
func newConsoleOutput(w io.Writer) *consoleOutput {
return &consoleOutput{
out: w,
indented: newIndentWriter(" ", w),
}
}
// testStart signals the start of a new test.
func (c *consoleOutput) testStart(name string) {
c.curTest = name
c.wroteHeader = false
}
// Write handles test log output.
func (c *consoleOutput) Write(b []byte) (int, error) {
if !c.wroteHeader {
// This is the first output line from the test. Print a "-- RUN" header.
fmt.Fprintln(c.out, "-- RUN", c.curTest)
c.wroteHeader = true
}
return c.indented.Write(b)
}
// testResult prints the final test result line.
func (c *consoleOutput) testResult(r Result) {
c.indented.flush()
pd := r.Duration.Truncate(100 * time.Microsecond)
if r.Failed {
fmt.Fprintf(c.out, "-- FAIL %s (%v)\n", r.Name, pd)
} else {
fmt.Fprintf(c.out, "-- OK %s (%v)\n", r.Name, pd)
}
}
// tapOutput produces Test Anything Protocol v13 output.
type tapOutput struct {
out io.Writer
indented *indentWriter
counter int
}
func newTAP(out io.Writer, numTests int) *tapOutput {
fmt.Fprintf(out, "1..%d\n", numTests)
return &tapOutput{
out: out,
indented: newIndentWriter("# ", out),
}
}
func (t *tapOutput) testStart(name string) {
t.counter++
}
// Write does nothing for TAP because there is no real-time output of test logs.
func (t *tapOutput) Write(b []byte) (int, error) {
return len(b), nil
}
func (t *tapOutput) testResult(r Result) {
status := "ok"
if r.Failed {
status = "not ok"
}
fmt.Fprintln(t.out, status, t.counter, r.Name)
t.indented.Write([]byte(r.Output))
t.indented.flush()
}
// indentWriter indents all written text.
type indentWriter struct {
out io.Writer
indent string
inLine bool
}
func newIndentWriter(indent string, out io.Writer) *indentWriter {
return &indentWriter{out: out, indent: indent}
}
func (w *indentWriter) Write(b []byte) (n int, err error) {
for len(b) > 0 {
if !w.inLine {
if _, err = io.WriteString(w.out, w.indent); err != nil {
return n, err
}
w.inLine = true
}
end := bytes.IndexByte(b, '\n')
if end == -1 {
nn, err := w.out.Write(b)
n += nn
return n, err
}
line := b[:end+1]
nn, err := w.out.Write(line)
n += nn
if err != nil {
return n, err
}
b = b[end+1:]
w.inLine = false
}
return n, err
}
// flush ensures the current line is terminated.
func (w *indentWriter) flush() {
if w.inLine {
fmt.Println(w.out)
w.inLine = false
}
}
// CountFailures returns the number of failed tests in the result slice.
func CountFailures(rr []Result) int {
count := 0
for _, r := range rr {
if r.Failed {
count++
}
}
return count
}
// Run executes a single test.
func Run(test Test) (bool, string) {
output := new(bytes.Buffer)
failed := runTest(test, output)
return failed, output.String()
}
func runTest(test Test, output io.Writer) bool {
t := &T{output: output}
done := make(chan struct{})
go func() {
defer close(done)
defer func() {
if err := recover(); err != nil {
buf := make([]byte, 4096)
i := runtime.Stack(buf, false)
t.Logf("panic: %v\n\n%s", err, buf[:i])
t.Fail()
}
}()
test.Fn(t)
}()
<-done
return t.failed
}
// T is the value given to the test function. The test can signal failures
// and log output by calling methods on this object.
type T struct {
mu sync.Mutex
failed bool
output io.Writer
}
// Helper exists for compatibility with testing.T.
func (t *T) Helper() {}
// FailNow marks the test as having failed and stops its execution by calling
// runtime.Goexit (which then runs all deferred calls in the current goroutine).
func (t *T) FailNow() {
t.Fail()
runtime.Goexit()
}
// Fail marks the test as having failed but continues execution.
func (t *T) Fail() {
t.mu.Lock()
defer t.mu.Unlock()
t.failed = true
}
// Failed reports whether the test has failed.
func (t *T) Failed() bool {
t.mu.Lock()
defer t.mu.Unlock()
return t.failed
}
// Log formats its arguments using default formatting, analogous to Println, and records
// the text in the error log.
func (t *T) Log(vs ...interface{}) {
t.mu.Lock()
defer t.mu.Unlock()
fmt.Fprintln(t.output, vs...)
}
// Logf formats its arguments according to the format, analogous to Printf, and records
// the text in the error log. A final newline is added if not provided.
func (t *T) Logf(format string, vs ...interface{}) {
t.mu.Lock()
defer t.mu.Unlock()
if len(format) == 0 || format[len(format)-1] != '\n' {
format += "\n"
}
fmt.Fprintf(t.output, format, vs...)
}
// Error is equivalent to Log followed by Fail.
func (t *T) Error(vs ...interface{}) {
t.Log(vs...)
t.Fail()
}
// Errorf is equivalent to Logf followed by Fail.
func (t *T) Errorf(format string, vs ...interface{}) {
t.Logf(format, vs...)
t.Fail()
}
// Fatal is equivalent to Log followed by FailNow.
func (t *T) Fatal(vs ...interface{}) {
t.Log(vs...)
t.FailNow()
}
// Fatalf is equivalent to Logf followed by FailNow.
func (t *T) Fatalf(format string, vs ...interface{}) {
t.Logf(format, vs...)
t.FailNow()
}