whowas: return all responses from the server

docs/events.md

@@ -596,19 +596,30 @@ Not all of these options will be available. Some will be missing depending on th
 
 **whowas**
 
-If the requested user was not found, error will contain 'no_such_nick'.
+The response root includes the latest data from `whowas[0]` to maintain backwards compatibility.
+The `whowas` array contains all RPL_WHOWASUSER responses with the newest being first.
+
+If the requested user was not found, `error` will contain 'no_such_nick'.
+
+> Note: The available data can vary depending on the network.
+
 ~~~javascript
 {
     nick: 'prawnsalad',
     ident: 'prawn',
     hostname: 'manchester.isp.net',
     actual_ip: 'sometimes set when using webirc, could be the same as actual_hostname',
     actual_hostname: 'sometimes set when using webirc',
+    actual_username: 'prawn',
     real_name: 'A real prawn',
     server: 'irc.server.net',
     server_info: 'Thu Jun 14 09:15:51 2018',
     account: 'logged on account',
     error: ''
+    whowas: [
+        { ... },
+        { ... },
+    ]
 }
 ~~~
 

src/commands/handlers/user.js

@@ -325,12 +325,29 @@ const handlers = {
 
     RPL_WHOWASUSER: function(command, handler) {
         const cache_key = command.params[1].toLowerCase();
-        const cache = handler.cache('whois.' + cache_key);
+        let whois_cache = handler.cache('whois.' + cache_key);
+
+        // multiple RPL_WHOWASUSER replies are received prior to the RPL_ENDOFWHOWAS command
+        // one for each timestamp the server is aware of, from newest to oldest.
+        // They are optionally interleaved with various other numerics such as RPL_WHOISACTUALLY etc.
+        // Hence if we already find something we are receiving older data and need to make sure that we
+        // store anything already in the cache into its own entry
+        const whowas_cache = handler.cache('whowas.' + cache_key);
+        if (!whowas_cache.whowas) {
+            // this will get populated by the next RPL_WHOWASUSER or RPL_ENDOFWHOWAS
+            whowas_cache.whowas = [];
+        } else {
+            // push the previous event prior to modifying anything
+            whowas_cache.whowas.push(whois_cache);
+            // ensure we are starting with a clean cache for the next data
+            whois_cache.destroy();
+            whois_cache = handler.cache('whois.' + cache_key);
+        }
 
-        cache.nick = command.params[1];
-        cache.ident = command.params[2];
-        cache.hostname = command.params[3];
-        cache.real_name = command.params[command.params.length - 1];
+        whois_cache.nick = command.params[1];
+        whois_cache.ident = command.params[2];
+        whois_cache.hostname = command.params[3];
+        whois_cache.real_name = command.params[command.params.length - 1];
     },
 
     RPL_ENDOFWHOWAS: function(command, handler) {
@@ -344,16 +361,22 @@ const handlers = {
         //   server_info, actual_username
         // More optional fields MAY exist, depending on the type of ircd.
         const cache_key = command.params[1].toLowerCase();
-        const cache = handler.cache('whois.' + cache_key);
-
-        // Should, in theory, never happen.
-        if (!cache.nick) {
-            cache.nick = command.params[1];
-            cache.error = 'no_such_nick';
+        const whois_cache = handler.cache('whois.' + cache_key);
+        const whowas_cache = handler.cache('whowas.' + cache_key);
+
+        // after all prior RPL_WHOWASUSER pushed newer events onto the history stack
+        // push the last one to complete the set (server returns from newest to oldest)
+        whowas_cache.whowas = whowas_cache.whowas || [];
+        if (!whois_cache.error) {
+            whowas_cache.whowas.push(whois_cache);
+            Object.assign(whowas_cache, whowas_cache.whowas[0]);
+        } else {
+            Object.assign(whowas_cache, whois_cache);
         }
 
-        handler.emit('whowas', cache);
-        cache.destroy();
+        handler.emit('whowas', whowas_cache);
+        whois_cache.destroy();
+        whowas_cache.destroy();
     },
 
     ERR_WASNOSUCHNICK: function(command, handler) {