remove pointers for immutability

main.go

@@ -1,24 +1,24 @@
 package main
 
 import (
+	"flag"
+
 	"github.com/ryanehamil/lookupip/src/ipapi"
 	"github.com/ryanehamil/lookupip/src/utils"
 )
 
-var detail bool
-var ip string
-var properties string
-
 func main() {
-	// Parse command line flags
+	ip := flag.String("ip", "", "IP address to lookup")
-	utils.ParseFlags(&ip, &properties, &detail)
+	properties := flag.String("p", "", "Properties to retrieve")
+	detail := flag.Bool("d", false, "Show Detail")
+	flag.Parse()
 
 	// Use the IP-API to lookup the IP address
-	data, err := ipapi.Lookup(&ip, &properties)
+	data, err := ipapi.Lookup(*ip)
 	utils.HandleError(err)
 
 	// Format the data to a string
-	result := ipapi.GetProperties(data, properties, detail)
+	result := ipapi.GetProperties(data, *properties, *detail)
 
 	// Print result with PrintOut
 	utils.PrintOut(result)

main_test.go

@@ -21,11 +21,10 @@ func TestLookup(t *testing.T) {
 
 	for _, test := range tests {
 		ip := test.input
-		properties := ""
 		// Use the IP-API to lookup anything
-		data, _ := ipapi.Lookup(&ip, &properties)
+		data, _ := ipapi.Lookup(ip)
 
-		got := ipapi.GetProperties(data, properties, detail)
+		got := ipapi.GetProperties(data, "", false)
 
 		if test.want == "Any IPV4" {
 			if !utils.CheckValidIP(data.Query) {

src/ipapi/ip_api.go

@@ -61,15 +61,9 @@ func buildURL(ip string) (string, error) {
 // Get IP-API data about IP
 //
 // https://ip-api.com/docs/api:json
-func Lookup(ip *string, properties *string) (data *IPAPI, err error) {
+func Lookup(ip string) (data IPAPI, err error) {
 
-	if *ip == "" && *properties == "" {
+	url, error := buildURL(ip)
-		*properties = "Query"
-	} else if *properties == "" {
-		*properties = "Country"
-	}
-
-	url, error := buildURL(*ip)
 	if error != nil {
 		return data, error
 	}
@@ -93,9 +87,11 @@ func Lookup(ip *string, properties *string) (data *IPAPI, err error) {
 	return data, nil
 }
 
-func GetProperties(data *IPAPI, properties_string string, detail bool) string {
+func GetProperties(data IPAPI, properties_string string, detail bool) (output string) {
+	if properties_string == "" {
+		properties_string = "Country"
+	}
 	result := ""
-	output := ""
 	properties := strings.Split(properties_string, ",")
 
 	for _, property := range properties {

src/ipapi/ip_api_test.go

@@ -47,8 +47,7 @@ func TestLookup(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		properties := ""
+		data, err := Lookup(test.ip)
-		data, err := Lookup(&test.ip, &properties)
 		got := data.Country
 		if err != nil && err.Error() != test.want {
 			t.Errorf("%q. error-buildURL(%q) = %v, want %v", test.explain, test.ip, got, test.want)
@@ -78,7 +77,7 @@ func TestGetProperties(t *testing.T) {
 		// This test relies on the lookup function
 		ip := "8.8.8.8"
 		// Use the IP-API to lookup anything
-		data, _ := Lookup(&ip, &test.properties)
+		data, _ := Lookup(ip)
 
 		got := GetProperties(data, test.properties, false)
 		if got != test.want {

src/utils/utils.go

@@ -1,22 +1,11 @@
 package utils
 
 import (
-	"flag"
 	"fmt"
 	"os"
 	"regexp"
 )
 
-// Parse command line flags using go's flag package
-//
-// https://golang.org/pkg/flag/
-func ParseFlags(ip *string, properties *string, detail *bool) {
-	flag.StringVar(ip, "ip", "", "IP address to lookup")
-	flag.StringVar(properties, "p", "", "Properties to retrieve")
-	flag.BoolVar(detail, "d", false, "Show Detail")
-	flag.Parse()
-}
-
 // For printing to the console
 //
 // Currently using fmt.Println