null safety, clean code

CmlLib/Core/Auth/MLogin.cs

@@ -175,7 +175,15 @@ public MLoginResponse Authenticate(string id, string pw, string? clientToken)
 
             HttpWebResponse resHeader = mojangRequest("authenticate", req.ToString());
 
-            using StreamReader res = new StreamReader(resHeader.GetResponseStream());
+            var stream = resHeader.GetResponseStream();
+            if (stream == null)
+                return new MLoginResponse(
+                    MLoginResult.UnknownError, 
+                    null, 
+                    "null response stream", 
+                    null);
+
+            using StreamReader res = new StreamReader(stream);
             string rawResponse = res.ReadToEnd();
             if (resHeader.StatusCode == HttpStatusCode.OK) // ResultCode == 200
                 return parseSession(rawResponse, clientToken);
@@ -207,7 +215,7 @@ public MLoginResponse TryAutoLogin(MSession session)
         public MLoginResponse TryAutoLoginFromMojangLauncher()
         {
             var mojangAccounts = MojangLauncher.MojangLauncherAccounts.FromDefaultPath();
-            var activeAccount = mojangAccounts.GetActiveAccount();
+            var activeAccount = mojangAccounts?.GetActiveAccount();
 
             if (activeAccount == null)
                 return new MLoginResponse(MLoginResult.NeedLogin, null, null, null);
@@ -218,7 +226,7 @@ public MLoginResponse TryAutoLoginFromMojangLauncher()
         public MLoginResponse TryAutoLoginFromMojangLauncher(string accountFilePath)
         {
             var mojangAccounts = MojangLauncher.MojangLauncherAccounts.FromFile(accountFilePath);
-            var activeAccount = mojangAccounts.GetActiveAccount();
+            var activeAccount = mojangAccounts?.GetActiveAccount();
 
             if (activeAccount == null)
                 return new MLoginResponse(MLoginResult.NeedLogin, null, null, null);
@@ -247,7 +255,15 @@ public MLoginResponse Refresh(MSession session)
                 };
 
             HttpWebResponse resHeader = mojangRequest("refresh", req.ToString());
-            using StreamReader res = new StreamReader(resHeader.GetResponseStream());
+            var stream = resHeader.GetResponseStream();
+            if (stream == null)
+                return new MLoginResponse(
+                    MLoginResult.UnknownError,
+                    null,
+                    "null response stream",
+                    null);
+
+            using StreamReader res = new StreamReader(stream);
             string rawResponse = res.ReadToEnd();
 
             if ((int)resHeader.StatusCode / 100 == 2)

CmlLib/Core/Auth/Microsoft/XboxMinecraftLogin.cs

@@ -20,6 +20,8 @@ private void writeReq(WebRequest req, string data)
         private string readRes(WebResponse res)
         {
             using var resStream = res.GetResponseStream();
+            if (resStream == null)
+                return "";
             using var sr = new StreamReader(resStream);
             return sr.ReadToEnd();
         }

CmlLib/Core/Installer/MForge.cs

@@ -73,7 +73,10 @@ public string InstallForge(string mcVersion, string forgeVersion)
             checkLibraries(installerObj["libraries"] as JArray);
 
             // mapping client data
-            var mapData = mapping(installerObj["data"] as JObject, "client", minecraftJar, installerPath);
+            var installerData = installerObj["data"] as JObject;
+            var mapData = (installerData == null) 
+                ? new Dictionary<string, string?>()
+                : mapping(installerData, "client", minecraftJar, installerPath);
 
             // process
             process(installerObj["processors"] as JArray, mapData);

CmlLib/Core/Mapper.cs

@@ -51,7 +51,7 @@ public static string[] MapPathString(string[] arg, string prepath)
 
         public static string Interpolation(string str, Dictionary<string, string?> dicts)
         {
-            str = argBracket.Replace(str, new MatchEvaluator((match =>
+            str = argBracket.Replace(str, (match =>
             {
                 if (match.Groups.Count < 2)
                     return match.Value;
@@ -66,7 +66,7 @@ public static string Interpolation(string str, Dictionary<string, string?> dicts
                 }
 
                 return match.Value;
-            })));
+            }));
 
             return str;
         }

CmlLib/Core/Mojang/MojangAPI.cs

@@ -14,6 +14,8 @@ public static class MojangAPI
         private static string readRes(WebResponse res)
         {
             using var resStream = res.GetResponseStream();
+            if (resStream == null)
+                return "";
             using var sr = new StreamReader(resStream);
             return sr.ReadToEnd();
         }

CmlLib/Core/MojangLauncher/MojangLauncherAccounts.cs

@@ -37,19 +37,19 @@ public void SaveTo(string path)
             File.WriteAllText(path, json);
         }
 
-        public static MojangLauncherAccounts FromDefaultPath()
+        public static MojangLauncherAccounts? FromDefaultPath()
         {
             var path = Path.Combine(MinecraftPath.GetOSDefaultPath(), "launcher_accounts.json");
             return FromFile(path);
         }
 
-        public static MojangLauncherAccounts FromFile(string path)
+        public static MojangLauncherAccounts? FromFile(string path)
         {
             var content = File.ReadAllText(path);
-            return FromJSON(content);
+            return FromJson(content);
         }
 
-        public static MojangLauncherAccounts? FromJSON(string json)
+        public static MojangLauncherAccounts? FromJson(string json)
         {
             return JsonConvert.DeserializeObject<MojangLauncherAccounts>(json);
         }

CmlLib/Core/Version/MVersionCollection.cs

@@ -3,7 +3,6 @@
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.IO;
-using System.Linq;
 using System.Threading.Tasks;
 using CmlLib.Core.VersionMetadata;
 

CmlLib/Core/Version/MVersionSort.cs

@@ -1,9 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Collections.ObjectModel;
-using System.Diagnostics;
 using System.Linq;
-using System.Text;
 using CmlLib.Core.VersionMetadata;
 
 namespace CmlLib.Core.Version

CmlLib/Core/VersionMetadata/MVersionMetadata.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Data.SqlTypes;
 using System.Threading.Tasks;
 using CmlLib.Core.Version;
 using Newtonsoft.Json;

CmlLib/Utils/SemiVersion.cs

@@ -1,6 +1,4 @@
-using System.Linq;
-
-namespace CmlLib.Utils
+namespace CmlLib.Utils
 {
     public class SemiVersion
     {

CmlLib/Utils/WebDownload.cs

@@ -15,9 +15,12 @@ internal class WebDownload
 
         private class TimeoutWebClient : WebClient
         {
-            protected override WebRequest GetWebRequest(Uri uri)
+            protected override WebRequest? GetWebRequest(Uri uri)
             {
-                WebRequest w = base.GetWebRequest(uri);
+                WebRequest? w = base.GetWebRequest(uri);
+                if (w == null)
+                    return null;
+
                 w.Timeout = DefaultWebRequestTimeout;
 
                 if (IgnoreProxy)
@@ -114,11 +117,12 @@ internal void DownloadFileLimit(string url, string path)
             req.ContinueTimeout = 5000;
             var res = req.GetResponse();
 
-            using (var httpStream = res.GetResponseStream())
-            using (var fs = File.OpenWrite(path))
-            {
-                httpStream.CopyTo(fs);
-            }
+            using var httpStream = res.GetResponseStream();
+            if (httpStream == null)
+                return;
+
+            using var fs = File.OpenWrite(path);
+            httpStream.CopyTo(fs);
         }
 
         private void progressChanged(long value, long max)