Benchmark fmt.Sprintf %v vs %s

README.MD

go test -bench=. -benchmem                    
goos: darwin
goarch: amd64
pkg: fmt-perf
BenchmarkFmtV-16         6899274               174 ns/op              64 B/op          1 allocs/op
BenchmarkFmtS-16         9181304               129 ns/op              80 B/op          2 allocs/op
PASS
ok      fmt-perf        4.138s

fmt_test.go

package fmtperf

import (
	"errors"
	"fmt"
	"testing"
)

var (
	err    = errors.New("failed to connect to sidecar server")
	output string
)

func BenchmarkFmtV(b *testing.B) {
	for i := 0; i < b.N; i++ {
		msg := fmt.Sprintf("could not get root node: %v", err)
		output = msg
	}
}

func BenchmarkFmtS(b *testing.B) {
	for i := 0; i < b.N; i++ {
		msg := fmt.Sprintf("could not get root node: %s", err.Error())
		output = msg
	}
}