Add lbToKg pp action to the scraper (#1337)

pkg/scraper/mapped.go

@@ -462,12 +462,25 @@ func (p *postProcessFeetToCm) Apply(value string, q mappedQuery) string {
 	return strconv.Itoa(int(math.Round(centimeters)))
 }
 
+type postProcessLbToKg bool
+
+func (p *postProcessLbToKg) Apply(value string, q mappedQuery) string {
+	const lb_in_kg = 0.45359237
+	w, err := strconv.ParseFloat(value, 64)
+	if err == nil {
+		w = w * lb_in_kg
+		value = strconv.Itoa(int(math.Round(w)))
+	}
+	return value
+}
+
 type mappedPostProcessAction struct {
 	ParseDate  string                   `yaml:"parseDate"`
 	Replace    mappedRegexConfigs       `yaml:"replace"`
 	SubScraper *mappedScraperAttrConfig `yaml:"subScraper"`
 	Map        map[string]string        `yaml:"map"`
 	FeetToCm   bool                     `yaml:"feetToCm"`
+	LbToKg     bool                     `yaml:"lbToKg"`
 }
 
 func (a mappedPostProcessAction) ToPostProcessAction() (postProcessAction, error) {
@@ -511,6 +524,14 @@ func (a mappedPostProcessAction) ToPostProcessAction() (postProcessAction, error
 		action := postProcessFeetToCm(a.FeetToCm)
 		ret = &action
 	}
+	if a.LbToKg {
+		if found != "" {
+			return nil, fmt.Errorf("post-process actions must have a single field, found %s and %s", found, "lbToKg")
+		}
+		found = "lbToKg"
+		action := postProcessLbToKg(a.LbToKg)
+		ret = &action
+	}
 
 	if ret == nil {
 		return nil, errors.New("invalid post-process action")