log

Example of a very common case of chained tests in go:

package main

import (
	"errors"

	"github.com/sqp/godock/libs/cdtype"
	"github.com/sqp/godock/libs/log"
)

func NewTestLogger(hist cdtype.LogOut) *log.Log {
	logger := log.NewLog(hist)
	logger.SetName("test")

	logger.SetTimeFormat("")
	logger.SetColorName(nocolor)
	logger.SetColorInfo(nocolor)
	logger.SetColorDebug(nocolor)
	logger.SetColorDEV(nocolor)
	logger.SetColorWarn(nocolor)
	logger.SetColorError(nocolor)
	return logger
}

func nocolor(str string) string { return str }

func main() {
	logger := NewTestLogger(log.Logs) // The logger with its common history.

	testChain := func(isErrGet, isErrParse, isErrUse bool) error {
		data, e := GetSomeData(isErrGet)
		if logger.Err(e, "Get data") { // when we need to keep or forward the error.
			return e
		}

		parsed, e := ParseMyData(data, isErrParse)
		logger.Err(e, "Parse data", "(don't block)") // when we just want to output it.

		result, e := UseData(parsed, isErrParse, isErrUse)
		if logger.Err(e, "Use data") { // used as a simple test.
			return e
		}
		logger.Info("Data used", result)
		return nil
	}

	for _, test := range []struct {
		isErrGet, isErrParse, isErrUse bool
	}{
		{true, false, false},
		{false, true, false},
		{false, false, true},
		{false, false, false},
	} {
		testChain(test.isErrGet, test.isErrParse, test.isErrUse)
	}

}

func GetSomeData(isErrGet bool) (string, error) {
	if isErrGet {
		return "", errors.New("get fail")
	}
	return "get success", nil
}

func ParseMyData(data string, isErrParse bool) (string, error) {
	if isErrParse {
		return "", errors.New("parse fail")
	}
	return "parse success", nil
}

func UseData(parsed string, isErrParse, isErrUse bool) (string, error) {
	if isErrUse {
		return "", errors.New("use fail")
	}
	if isErrParse {
		return "have half data", nil
	}
	return "everything is fine", nil
}

Output:

test [error] Get data : get fail
test [error] Parse data (don't block) : parse fail
test [Data used] have half data
test [error] Use data : use fail
test [Data used] everything is fine