IPAddress: add toString() method

api/IPAddress.cpp

@@ -94,6 +94,33 @@ IPAddress::IPAddress(const char *address)
     fromString(address);
 }
 
+String IPAddress::toString4() const
+{
+    char szRet[16];
+    sprintf(szRet,"%u.%u.%u.%u", _address.bytes[IPADDRESS_V4_BYTES_INDEX], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 1], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 2], _address.bytes[IPADDRESS_V4_BYTES_INDEX + 3]);
+    return String(szRet);
+}
+
+String IPAddress::toString6() const
+{
+    char szRet[40];
+    sprintf(szRet,"%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x",
+            _address.bytes[0], _address.bytes[1], _address.bytes[2], _address.bytes[3],
+            _address.bytes[4], _address.bytes[5], _address.bytes[6], _address.bytes[7],
+            _address.bytes[8], _address.bytes[9], _address.bytes[10], _address.bytes[11],
+            _address.bytes[12], _address.bytes[13], _address.bytes[14], _address.bytes[15]);
+    return String(szRet);
+}
+
+String IPAddress::toString() const
+{
+    if (_type == IPv4) {
+        return toString4();
+    } else {
+        return toString6();
+    }
+}
+
 bool IPAddress::fromString(const char *address) {
     if (!fromString4(address)) {
         return fromString6(address);

api/IPAddress.h

@@ -96,6 +96,7 @@ class IPAddress : public Printable {
     IPAddress& operator=(const char *address);
 
     virtual size_t printTo(Print& p) const;
+    String toString() const;
 
     IPType type() { return _type; }
 
@@ -110,6 +111,8 @@ class IPAddress : public Printable {
 protected:
     bool fromString4(const char *address);
     bool fromString6(const char *address);
+    String toString4() const;
+    String toString6() const;
 };
 
 extern const IPAddress IN6ADDR_ANY;

test/CMakeLists.txt

@@ -29,6 +29,7 @@ set(TEST_SRCS
   src/Common/test_map.cpp
   src/Common/test_max.cpp
   src/Common/test_min.cpp
+  src/IPAddress/test_toString.cpp
   src/IPAddress/test_fromString.cpp
   src/IPAddress/test_fromString6.cpp
   src/IPAddress/test_IPAddress.cpp

test/src/IPAddress/test_toString.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2020 Arduino.  All rights reserved.
+ */
+
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
+#include <catch.hpp>
+
+#include <String.h>
+#include <IPAddress.h>
+
+/**************************************************************************************
+ * TEST CODE
+ **************************************************************************************/
+
+TEST_CASE ("Extract valid string from IPv4address", "[IPAddress-toString-01]")
+{
+  arduino::IPAddress ip(129,168,1,2);
+
+  REQUIRE(ip.toString().equals("129.168.1.2") == true);
+}
+
+TEST_CASE ("Extract valid ipv6 string from IPv6address", "[IPAddress-toString-02]")
+{
+  arduino::IPAddress ip(0x20,0x01, 0xd,0xb8, 1,2, 3,4, 5,6, 7,8, 9,0xa, 0xb,0xc);
+
+  REQUIRE(ip.toString().equals("2001:0db8:0102:0304:0506:0708:090a:0b0c") == true);
+}
+
+TEST_CASE ("Extract 0.0.0.0 string from uninitialized IP address", "[IPAddress-toString-03]")
+{
+  arduino::IPAddress ip;
+
+  REQUIRE(ip.toString().equals("0.0.0.0") == true);
+}