open-nomad/helper/testlog/testlog.go
Mahmood Ali fc6c3620c4 tests: log to stderr directly
Go 1.14 now streams t.Log output as it happens [1], so we no longer need
to maintain our log STDOUT helper.

I preserved the interface, so `testlog` still takes in a `*testing.T`
though unused. Changing it requires so too many changes that I didn't
want to make quite yet.

[1] https://golang.org/doc/go1.14#go-test
2020-05-27 08:42:29 -04:00

83 lines
2 KiB
Go

// Package testlog creates a *log.Logger backed by *testing.T to ease logging
// in tests. This allows logs from components being tested to only be printed
// if the test fails (or the verbose flag is specified).
package testlog
import (
"bytes"
"io"
"log"
"os"
hclog "github.com/hashicorp/go-hclog"
)
// LogPrinter is the methods of testing.T (or testing.B) needed by the test
// logger.
type LogPrinter interface {
Logf(format string, args ...interface{})
}
// NewWriter creates a new io.Writer backed by a Logger.
func NewWriter(t LogPrinter) io.Writer {
return os.Stderr
}
// NewPrefixWriter creates a new io.Writer backed by a Logger with a custom
// prefix per Write.
func NewPrefixWriter(t LogPrinter, prefix string) io.Writer {
return &prefixStderr{[]byte(prefix)}
}
// New returns a new test logger. See https://golang.org/pkg/log/#New
func New(t LogPrinter, prefix string, flag int) *log.Logger {
return log.New(os.Stderr, prefix, flag)
}
// WithPrefix returns a new test logger with the Lmicroseconds flag set.
func WithPrefix(t LogPrinter, prefix string) *log.Logger {
return New(t, prefix, log.Lmicroseconds)
}
// Logger returns a new test logger with the Lmicroseconds flag set and no
// prefix.
func Logger(t LogPrinter) *log.Logger {
return WithPrefix(t, "")
}
//HCLogger returns a new test hc-logger.
func HCLogger(t LogPrinter) hclog.InterceptLogger {
level := hclog.Trace
envLogLevel := os.Getenv("NOMAD_TEST_LOG_LEVEL")
if envLogLevel != "" {
level = hclog.LevelFromString(envLogLevel)
}
opts := &hclog.LoggerOptions{
Level: level,
Output: os.Stderr,
IncludeLocation: true,
}
return hclog.NewInterceptLogger(opts)
}
type prefixStderr struct {
prefix []byte
}
// Write to stdout with a prefix per call containing non-whitespace characters.
func (w *prefixStderr) Write(p []byte) (int, error) {
if len(p) == 0 {
return 0, nil
}
// Skip prefix if only writing whitespace
if len(bytes.TrimSpace(p)) > 0 {
_, err := os.Stderr.Write(w.prefix)
if err != nil {
return 0, err
}
}
return os.Stderr.Write(p)
}