gocheck checker for multiple single-line regexps operating on multiple line output

linesmatch.go

var LinesMatch gc.Checker = &linesMatchChecker{
        &gc.CheckerInfo{Name: "LinesMatch", Params: []string{"obtained", "regexps"}},
}

type linesMatchChecker struct {
        *gc.CheckerInfo
}

func (linesMatchChecker) Check(params []interface{}, names []string) (result bool, error string) {
        obtainedLines := strings.Split(params[0].(string), "\n")
        expectedLines := strings.Split(params[1].(string), "\n")
        if len(obtainedLines) != len(expectedLines) {
                return false, fmt.Sprintf(
                        "obtained value contains %d lines, expected %d",
                        len(obtainedLines), len(expectedLines),
                )
        }
        for i, reStr := range expectedLines {
                obtainedLine := obtainedLines[i]
                matches, err := regexp.MatchString("^"+reStr+"$", obtainedLine)
                if err != nil {
                        return false, "Can't compile regex: " + err.Error()
                }
                if !matches {
                        return false, fmt.Sprintf(
                                "mismatch at line %d: %q does not match %q",
                                i+1, obtainedLine, reStr,
                        )
                }
        }
        return true, ""
}