#patch: improve error testing

geofence.go

@@ -1,6 +1,7 @@
 package geofence
 
 import (
+	"fmt"
 	"net"
 	"time"
 
@@ -11,7 +12,6 @@ import (
 
 const (
 	freeGeoIPBaseURL                = "https://api.freegeoip.app/json"
-	invalidIPAddressString          = "invalid IP address provided"
 	deleteExpiredCacheItemsInternal = 10 * time.Minute
 )
 
@@ -57,21 +57,12 @@ func (e *FreeGeoIPError) Error() string {
 }
 
 // ErrInvalidIPAddress is the error raised when an invalid IP address is provided
-type ErrInvalidIPAddress struct {
-	msg string
-}
-
-func (e *ErrInvalidIPAddress) Error() string {
-	return e.msg
-}
+var ErrInvalidIPAddress = fmt.Errorf("invalid IP address provided")
 
 // validateIPAddress ensures valid ip address
 func validateIPAddress(ipAddress string) error {
-	ipAddressErr := &ErrInvalidIPAddress{
-		msg: invalidIPAddressString,
-	}
 	if net.ParseIP(ipAddress) == nil {
-		return ipAddressErr
+		return ErrInvalidIPAddress
 	}
 	return nil
 }

geofence_test.go

@@ -12,34 +12,33 @@ import (
 )
 
 func TestValidateIPAddress(t *testing.T) {
-	type test struct {
-		Expected error
-		Input    string
-	}
-	tests := []test{
+	tests := []struct {
+		expected error
+		input    string
+	}{
 		{
-			Input:    "8.8.8.8",
-			Expected: nil,
+			input:    "8.8.8.8",
+			expected: nil,
 		},
 		{
-			Input:    "8.8.88",
-			Expected: &ErrInvalidIPAddress{},
+			input:    "8.8.88",
+			expected: ErrInvalidIPAddress,
 		},
 		{
-			Input:    "2001:db8:3333:4444:5555:6666:7777:8888",
-			Expected: nil,
+			input:    "2001:db8:3333:4444:5555:6666:7777:8888",
+			expected: nil,
 		},
 		{
-			Input:    "2001:db8:3333:4444:5555:6666:7777:88888",
-			Expected: &ErrInvalidIPAddress{},
+			input:    "2001:db8:3333:4444:5555:6666:7777:88888",
+			expected: ErrInvalidIPAddress,
 		},
 	}
 	for _, test := range tests {
-		actual := validateIPAddress(test.Input)
-		if test.Expected != nil {
-			assert.EqualErrorf(t, actual, invalidIPAddressString, "Error should be: %v, got: %v", invalidIPAddressString, actual)
+		actual := validateIPAddress(test.input)
+		if test.expected != nil {
+			assert.ErrorIs(t, actual, test.expected)
 		} else {
-			if !errors.Is(actual, test.Expected) {
+			if !errors.Is(actual, test.expected) {
 				t.Fail()
 			}
 		}