Bug: Incorrect encoding of complex numbers

[hemantjadon]

zap.Complex128 and zap.Complex64 field types incorrectly formats complex numbers with negative imaginary component. Extra + sign is added before the actual - sign
Eg. 2-3i is formatted as 2+-3i

package main

import (
	"go.uber.org/zap"
)

func main() {
    l, _ := zap.NewProduction()

    l.Info("test", zap.Complex128("key", complex(2, -3)))
}

Got output

{"level":"info","ts":1257894000,"caller":"sandbox516008598/prog.go:10","msg":"test","key":"2+-3i"}

Expected output

{"level":"info","ts":1257894000,"caller":"sandbox516008598/prog.go:10","msg":"test","key":"2-3i"}

Reference

https://play.golang.org/p/xz9b8kz_hCR

[abhinav]

Thanks for reporting @hemantjadon. This appears to be a legitimate bug.
We'll fix it shortly unless you already have a fix inbound.

(Internal issue: GO-857)