Merge pull request #79 from bschaatsbergen/c/document-functions

cmd/count.go

@@ -46,6 +46,6 @@ func init() {
 }
 
 func count(network *net.IPNet) uint64 {
-	count := core.AddressCount(network)
+	count := core.GetAddressCount(network)
 	return count
 }

cmd/root.go

@@ -15,7 +15,7 @@ var (
 	rootCmd = &cobra.Command{
 		Use:     "cidr",
 		Short:   "cidr - CLI to perform various actions on CIDR ranges",
-		Version: version, // The version is set during the build by making using of `go build -ldflags`
+		Version: version, // The version is set during the build by making using of `go build -ldflags`.
 		Run: func(cmd *cobra.Command, args []string) {
 			err := cmd.Help()
 			if err != nil {

pkg/core/core.go

@@ -4,12 +4,14 @@ import (
 	"net"
 )
 
-func AddressCount(network *net.IPNet) uint64 {
+// GetAddressCount returns the number of usable addresses in the given IP network.
+// It considers the network type (IPv4 or IPv6) and handles edge cases for specific prefix lengths.
+// The result excludes the network address and broadcast address.
+func GetAddressCount(network *net.IPNet) uint64 {
 	prefixLen, bits := network.Mask.Size()
 
-	// Check if network is IPv4 or IPv6
-	if network.Mask != nil {
-		// Handle edge cases
+	// Handle edge cases for specific IPv4 prefix lengths.
+	if network.Mask != nil && network.IP.To4() != nil {
 		switch prefixLen {
 		case 32:
 			return 1
@@ -18,10 +20,11 @@ func AddressCount(network *net.IPNet) uint64 {
 		}
 	}
 
-	// Remember to subtract the network address and broadcast address
+	// Subtract the network address and broadcast address (2) from the total number of addresses.
 	return 1<<(uint64(bits)-uint64(prefixLen)) - 2
 }
 
+// ParseCIDR parses the given CIDR notation string and returns the corresponding IP network.
 func ParseCIDR(network string) (*net.IPNet, error) {
 	_, ip, err := net.ParseCIDR(network)
 	if err != nil {
@@ -30,10 +33,14 @@ func ParseCIDR(network string) (*net.IPNet, error) {
 	return ip, err
 }
 
+// ContainsAddress checks if the given IP network contains the specified IP address.
+// It returns true if the address is within the network, otherwise false.
 func ContainsAddress(network *net.IPNet, ip net.IP) bool {
 	return network.Contains(ip)
 }
 
+// Overlaps checks if there is an overlap between two IP networks.
+// It returns true if there is any overlap, otherwise false.
 func Overlaps(network1, network2 *net.IPNet) bool {
 	return network1.Contains(network2.IP) || network2.Contains(network1.IP)
 }

pkg/core/core_test.go

@@ -7,7 +7,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestAddressCount(t *testing.T) {
+func TestGetAddressCount(t *testing.T) {
 	IPv4CIDR, err := ParseCIDR("10.0.0.0/16")
 	if err != nil {
 		t.Log(err)
@@ -60,7 +60,7 @@ func TestAddressCount(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			count := AddressCount(tt.cidr)
+			count := GetAddressCount(tt.cidr)
 			assert.Equal(t, int(tt.expectedCount), int(count), "Both address counts should be equal")
 		})
 	}