(refactor): not null when attribute implementation

src/MaksIT.Core/Culture.cs

@@ -1,6 +1,6 @@
-using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
-using System.Threading;
+
 
 namespace MaksIT.Core;
 
@@ -15,7 +15,7 @@ public static class Culture {
   /// <param name="culture">The culture to set. If null or empty, the invariant culture is used.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the operation was successful; otherwise, false.</returns>
-  public static bool TrySet(string? culture, out string? errorMessage) {
+  public static bool TrySet(string? culture, [NotNullWhen(false)] out string? errorMessage) {
     try {
       var threadCulture = CultureInfo.InvariantCulture;
 

src/MaksIT.Core/EnvVar.cs

@@ -1,6 +1,7 @@
-using System;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
 
+
 namespace MaksIT.Core;
 
 /// <summary>
@@ -15,7 +16,7 @@ public static class EnvVar {
   /// <param name="newPath">The new path to add.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the operation was successful; otherwise, false.</returns>
-  public static bool TryAddToPath(string newPath, out string? errorMessage) {
+  public static bool TryAddToPath(string newPath, [NotNullWhen(false)] out string? errorMessage) {
     try {
       var pathEnvVar = Environment.GetEnvironmentVariable("PATH") ?? string.Empty;
       char separator = IsWindows ? ';' : ':';
@@ -42,7 +43,7 @@ public static class EnvVar {
   /// <param name="envTarget">The target of the environment variable (machine, user, process).</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the operation was successful; otherwise, false.</returns>
-  public static bool TrySet(string envName, string envValue, string envTarget, out string? errorMessage) {
+  public static bool TrySet(string envName, string envValue, string envTarget, [NotNullWhen(false)] out string? errorMessage) {
     try {
       EnvironmentVariableTarget target = GetEnvironmentVariableTarget(envTarget);
       if (target == EnvironmentVariableTarget.Machine && !IsWindows) {
@@ -66,7 +67,7 @@ public static class EnvVar {
   /// <param name="envTarget">The target of the environment variable (machine, user, process).</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the operation was successful; otherwise, false.</returns>
-  public static bool TryUnSet(string envName, string envTarget, out string? errorMessage) {
+  public static bool TryUnSet(string envName, string envTarget, [NotNullWhen(false)] out string? errorMessage) {
     try {
       EnvironmentVariableTarget target = GetEnvironmentVariableTarget(envTarget);
       if (target == EnvironmentVariableTarget.Machine && !IsWindows) {

src/MaksIT.Core/FileSystem.cs

@@ -1,6 +1,8 @@
-using System.Runtime.InteropServices;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.InteropServices;
 using MaksIT.Core.Extensions;
 
+
 namespace MaksIT.Core;
 
 /// <summary>
@@ -18,7 +20,7 @@ public static class FileSystem {
   /// <param name="overwrite">Whether to overwrite existing files.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the copy operation was successful; otherwise, false.</returns>
-  public static bool TryCopyToFolder(string sourcePath, string destDirPath, bool overwrite, out string? errorMessage) {
+  public static bool TryCopyToFolder(string sourcePath, string destDirPath, bool overwrite, [NotNullWhen(false)] out string? errorMessage) {
     try {
       if (!Directory.Exists(destDirPath)) {
         Directory.CreateDirectory(destDirPath);
@@ -58,7 +60,7 @@ public static class FileSystem {
   /// <param name="itemPath">File or directory path.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the delete operation was successful; otherwise, false.</returns>
-  public static bool TryDeleteFileOrDirectory(string itemPath, out string? errorMessage) {
+  public static bool TryDeleteFileOrDirectory(string itemPath, [NotNullWhen(false)] out string? errorMessage) {
     try {
       if (File.Exists(itemPath)) {
         File.Delete(itemPath);
@@ -169,7 +171,7 @@ public static class FileSystem {
     var count = 1;
     while (File.Exists(newFullPath)) {
       var tempFileName = $"{fileNameOnly}({count++})";
-      newFullPath = Path.Combine(path, tempFileName + extension);
+      newFullPath = Path.Combine(path, $"{tempFileName}{extension}");
     }
 
     return newFullPath;

src/MaksIT.Core/MaksIT.Core.csproj

@@ -8,7 +8,7 @@
 
     <!-- NuGet package metadata -->
     <PackageId>MaksIT.Core</PackageId>
-    <Version>1.1.7</Version>
+    <Version>1.1.8</Version>
     <Authors>Maksym Sadovnychyy</Authors>
     <Company>MAKS-IT</Company>
     <Product>MaksIT.Core</Product>

src/MaksIT.Core/Networking/PingPort.cs

@@ -1,6 +1,8 @@
 using System.Net;
 using System.Net.Sockets;
 using System.Text;
+using System.Diagnostics.CodeAnalysis;
+
 
 namespace MaksIT.Core.Networking;
 
@@ -15,7 +17,11 @@ public static class PingPort {
   /// <param name="portNumber">The port number.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the host is reachable on the specified port; otherwise, false.</returns>
-  public static bool TryHostPort(string hostUri, int portNumber, out string? errorMessage) {
+  public static bool TryHostPort(
+    string hostUri,
+    int portNumber,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     if (string.IsNullOrEmpty(hostUri)) {
       errorMessage = "Host URI cannot be null or empty.";
       return false;
@@ -53,7 +59,11 @@ public static class PingPort {
   /// <param name="portNumber">The port number.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the host is reachable on the specified port; otherwise, false.</returns>
-  public static bool TryUDPPort(string hostUri, int portNumber, out string? errorMessage) {
+  public static bool TryUDPPort(
+    string hostUri,
+    int portNumber,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     if (string.IsNullOrEmpty(hostUri)) {
       errorMessage = "Host URI cannot be null or empty.";
       return false;

src/MaksIT.Core/Networking/Windows/NetworkConnection.cs

@@ -1,7 +1,8 @@
-using Microsoft.Extensions.Logging;
+using System.Diagnostics.CodeAnalysis;
-using System;
 using System.Net;
 using System.Runtime.InteropServices;
+using Microsoft.Extensions.Logging;
+
 
 namespace MaksIT.Core.Networking.Windows;
 
@@ -15,11 +16,12 @@ public class NetworkConnection : IDisposable {
   }
 
   public static bool TryCreate(
-      ILogger<NetworkConnection> logger,
+    ILogger<NetworkConnection> logger,
-      string networkName,
+    string networkName,
-      NetworkCredential credentials,
+    NetworkCredential credentials,
-      out NetworkConnection? networkConnection,
+    [NotNullWhen(true)] out NetworkConnection? networkConnection,
-      out string? errorMessage) {
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       if (!OperatingSystem.IsWindows()) {
         throw new PlatformNotSupportedException("NetworkConnection is only supported on Windows.");
@@ -81,7 +83,7 @@ public class NetworkConnection : IDisposable {
     public ResourceDisplayType DisplayType;
     public int Usage;
     public string? LocalName;
-    public string RemoteName;
+    public string? RemoteName;
     public string? Comment;
     public string? Provider;
   }

src/MaksIT.Core/Processes.cs

@@ -1,5 +1,7 @@
 using MaksIT.Core.Extensions;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
+
 
 namespace MaksIT.Core;
 
@@ -27,7 +29,7 @@ public static class Processes {
   /// <param name="silent">If true, the process will be started without creating a window.</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if the process started successfully; otherwise, false.</returns>
-  public static bool TryStart(string fileName, string arguments, int timeout, bool silent, out string? errorMessage) {
+  public static bool TryStart(string fileName, string arguments, int timeout, bool silent, [NotNullWhen(false)] out string? errorMessage) {
     try {
       var processInfo = new ProcessStartInfo(fileName) {
         Arguments = arguments,
@@ -60,7 +62,7 @@ public static class Processes {
   /// <param name="process">Process name. Accepts wildcards '*' or '?'</param>
   /// <param name="errorMessage">The error message if the operation fails.</param>
   /// <returns>True if at least one process was killed successfully; otherwise, false.</returns>
-  public static bool TryKill(string process, out string? errorMessage) {
+  public static bool TryKill(string process, [NotNullWhen(false)] out string? errorMessage) {
     bool success = false;
     errorMessage = null;
     foreach (var proc in System.Diagnostics.Process.GetProcesses()) {

src/MaksIT.Core/Security/AESGCMUtility.cs

@@ -1,4 +1,6 @@
 using System.Security.Cryptography;
+using System.Diagnostics.CodeAnalysis;
+
 
 namespace MaksIT.Core.Security;
 
@@ -9,7 +11,12 @@ public static class AESGCMUtility {
   private const int IvLength = 12; // 12 bytes for AES-GCM IV
   private const int TagLength = 16; // 16 bytes for AES-GCM Tag
 
-  public static bool TryEncryptData(byte[] data, string base64Key, out byte[]? result, out string? errorMessage) {
+  public static bool TryEncryptData(
+    byte[] data,
+    string base64Key,
+    [NotNullWhen(true)] out byte[]? result,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var key = Convert.FromBase64String(base64Key);
       using (AesGcm aesGcm = new AesGcm(key, AesGcm.TagByteSizes.MaxSize)) {
@@ -38,7 +45,12 @@ public static class AESGCMUtility {
     }
   }
 
-  public static bool TryDecryptData(byte[] data, string base64Key, out byte[]? decryptedData, out string? errorMessage) {
+  public static bool TryDecryptData(
+    byte[] data,
+    string base64Key,
+    [NotNullWhen(true)] out byte[]? decryptedData,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var key = Convert.FromBase64String(base64Key);
 

src/MaksIT.Core/Security/Base32Encoder.cs

@@ -1,7 +1,6 @@
-using System;
+using System.Text;
-using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
-using System.Linq;
+
-using System.Text;
 
 namespace MaksIT.Core.Security;
 
@@ -9,7 +8,11 @@ public static class Base32Encoder {
   private static readonly char[] Base32Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567".ToCharArray();
   private const string PaddingChar = "=";
 
-  public static bool TryEncode(byte[] data, out string? encoded, out string? errorMessage) {
+  public static bool TryEncode(
+    byte[] data,
+    [NotNullWhen(true)] out string? encoded,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       if (data == null || data.Length == 0) {
         throw new ArgumentNullException(nameof(data));
@@ -57,7 +60,11 @@ public static class Base32Encoder {
     }
   }
 
-  public static bool TryDecode(string base32, out byte[]? decoded, out string? errorMessage) {
+  public static bool TryDecode(
+    string base32,
+    [NotNullWhen(true)] out byte[]? decoded,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       if (string.IsNullOrEmpty(base32)) {
         throw new ArgumentNullException(nameof(base32));

src/MaksIT.Core/Security/ChecksumUtility.cs

@@ -1,7 +1,14 @@
-namespace MaksIT.Core.Security;
+using System.Diagnostics.CodeAnalysis;
+
+namespace MaksIT.Core.Security;
+
 
 public static class ChecksumUtility {
-  public static bool TryCalculateCRC32Checksum(byte[] data, out string? checksum, out string? errorMessage) {
+  public static bool TryCalculateCRC32Checksum(
+    byte[] data,
+    [NotNullWhen(true)] out string? checksum,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     if (Crc32.TryCompute(data, out var result, out errorMessage)) {
       checksum = BitConverter.ToString(BitConverter.GetBytes(result)).Replace("-", "").ToLower();
       return true;
@@ -26,7 +33,12 @@ public static class ChecksumUtility {
     }
   }
 
-  public static bool TryCalculateCRC32ChecksumFromFileInChunks(string filePath, out string? checksum, out string? errorMessage, int chunkSize = 8192) {
+  public static bool TryCalculateCRC32ChecksumFromFileInChunks(
+    string filePath,
+    [NotNullWhen(true)] out string? checksum,
+    [NotNullWhen(false)] out string? errorMessage,
+    int chunkSize = 8192
+  ) {
     try {
       using var crc32 = new Crc32();
       using var stream = File.OpenRead(filePath);

src/MaksIT.Core/Security/Crc32.cs

@@ -1,4 +1,5 @@
-using System.Security.Cryptography;
+using System.Diagnostics.CodeAnalysis;
+using System.Security.Cryptography;
 
 namespace MaksIT.Core.Security;
 
@@ -37,7 +38,11 @@ public class Crc32 : HashAlgorithm {
 
   public override int HashSize => 32;
 
-  public static bool TryCompute(byte[] buffer, out uint result, out string? errorMessage) {
+  public static bool TryCompute(
+    byte[] buffer,
+    out uint result,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       result = Compute(DefaultPolynomial, DefaultSeed, buffer);
       errorMessage = null;
@@ -50,7 +55,12 @@ public class Crc32 : HashAlgorithm {
     }
   }
 
-  public static bool TryCompute(uint seed, byte[] buffer, out uint result, out string? errorMessage) {
+  public static bool TryCompute(
+    uint seed,
+    byte[] buffer,
+    out uint result,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       result = Compute(DefaultPolynomial, seed, buffer);
       errorMessage = null;
@@ -63,7 +73,13 @@ public class Crc32 : HashAlgorithm {
     }
   }
 
-  public static bool TryCompute(uint polynomial, uint seed, byte[] buffer, out uint result, out string? errorMessage) {
+  public static bool TryCompute(
+    uint polynomial,
+    uint seed,
+    byte[] buffer,
+    out uint result,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       result = Compute(polynomial, seed, buffer);
       errorMessage = null;

src/MaksIT.Core/Security/JwtGenerator.cs

@@ -3,6 +3,7 @@ using System.Security.Claims;
 using System.Security.Cryptography;
 using System.IdentityModel.Tokens.Jwt;
 using Microsoft.IdentityModel.Tokens;
+using System.Diagnostics.CodeAnalysis;
 
 namespace MaksIT.Core.Security;
 
@@ -14,7 +15,16 @@ public class JWTTokenClaims {
 }
 
 public static class JwtGenerator {
-  public static bool TryGenerateToken(string secret, string issuer, string audience, double expiration, string username, List<string> roles, out (string, JWTTokenClaims)? tokenData, out string? errorMessage) {
+  public static bool TryGenerateToken(
+    string secret,
+    string issuer,
+    string audience,
+    double expiration,
+    string username,
+    List<string> roles,
+    [NotNullWhen(true)] out (string, JWTTokenClaims)? tokenData,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var secretKey = GetSymmetricSecurityKey(secret);
       var credentials = new SigningCredentials(secretKey, SecurityAlgorithms.HmacSha256);
@@ -62,7 +72,14 @@ public static class JwtGenerator {
 
   public static string GenerateSecret(int keySize = 32) => Convert.ToBase64String(GetRandomBytes(keySize));
 
-  public static bool TryValidateToken(string secret, string issuer, string audience, string token, out JWTTokenClaims? tokenClaims, out string? errorMessage) {
+  public static bool TryValidateToken(
+    string secret,
+    string issuer,
+    string audience,
+    string token,
+    out JWTTokenClaims? tokenClaims,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var key = Encoding.UTF8.GetBytes(secret);
       var tokenHandler = new JwtSecurityTokenHandler();

src/MaksIT.Core/Security/PasswordHasher.cs

@@ -1,4 +1,5 @@
-using System.Security.Cryptography;
+using System.Diagnostics.CodeAnalysis;
+using System.Security.Cryptography;
 using Microsoft.AspNetCore.Cryptography.KeyDerivation;
 
 namespace MaksIT.Core.Security;
@@ -23,7 +24,11 @@ public static class PasswordHasher {
     return Convert.ToBase64String(valueBytes);
   }
 
-  public static bool TryCreateSaltedHash(string value, out (string Salt, string Hash)? saltedHash, out string? errorMessage) {
+  public static bool TryCreateSaltedHash(
+    string value,
+    [NotNullWhen(true)] out (string Salt, string Hash)? saltedHash,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var saltBytes = CreateSaltBytes();
       var hash = CreateHash(value, saltBytes);
@@ -40,7 +45,13 @@ public static class PasswordHasher {
     }
   }
 
-  public static bool TryValidateHash(string value, string salt, string hash, out bool isValid, out string? errorMessage) {
+  public static bool TryValidateHash(
+    string value,
+    string salt,
+    string hash,
+    [NotNullWhen(true)] out bool isValid,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var saltBytes = Convert.FromBase64String(salt);
       var hashToCompare = CreateHash(value, saltBytes);

src/MaksIT.Core/Security/TotpGenerator.cs

@@ -1,4 +1,5 @@
-using System.Security.Cryptography;
+using System.Diagnostics.CodeAnalysis;
+using System.Security.Cryptography;
 
 namespace MaksIT.Core.Security;
 
@@ -6,7 +7,13 @@ public static class TotpGenerator {
   private const int Timestep = 30; // Time step in seconds (standard is 30 seconds)
   private const int TotpDigits = 6; // Standard TOTP length is 6 digits
 
-  public static bool TryValidate(string totpCode, string base32Secret, int timeTolerance, out bool isValid, out string? errorMessage) {
+  public static bool TryValidate(
+    string totpCode,
+    string base32Secret,
+    int timeTolerance,
+    out bool isValid,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       // Convert the Base32 encoded secret to a byte array
       if (!Base32Encoder.TryDecode(base32Secret, out byte[]? secretBytes, out errorMessage)) {
@@ -38,7 +45,12 @@ public static class TotpGenerator {
     }
   }
 
-  public static bool TryGenerate(string base32Secret, long timestep, out string? totpCode, out string? errorMessage) {
+  public static bool TryGenerate(
+    string base32Secret,
+    long timestep,
+    [NotNullWhen(true)] out string? totpCode,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       // Convert the Base32 encoded secret to a byte array
       if (!Base32Encoder.TryDecode(base32Secret, out byte[]? secretBytes, out errorMessage)) {
@@ -86,7 +98,10 @@ public static class TotpGenerator {
     return unixTimestamp / Timestep;
   }
 
-  public static bool TryGenerateSecret(out string? secret, out string? errorMessage) {
+  public static bool TryGenerateSecret(
+    [NotNullWhen(true)] out string? secret,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       // Example of generating a 32-character base32 secret for TOTP
       var random = new byte[20];
@@ -108,7 +123,11 @@ public static class TotpGenerator {
     }
   }
 
-  public static bool TryGenerateRecoveryCodes(int defaultCodeCount, out List<string>? recoveryCodes, out string? errorMessage) {
+  public static bool TryGenerateRecoveryCodes(
+    int defaultCodeCount,
+    [NotNullWhen(true)] out List<string>? recoveryCodes,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       recoveryCodes = new List<string>();
 
@@ -128,7 +147,17 @@ public static class TotpGenerator {
     }
   }
 
-  public static bool TryGenerateTotpAuthLink(string label, string username, string twoFactoSharedKey, string issuer, string? algorithm, int? digits, int? period, out string? authLink, out string? errorMessage) {
+  public static bool TryGenerateTotpAuthLink(
+    string label,
+    string username,
+    string twoFactoSharedKey,
+    string issuer,
+    string? algorithm,
+    int? digits,
+    int? period,
+    [NotNullWhen(true)] out string? authLink,
+    [NotNullWhen(false)] out string? errorMessage
+  ) {
     try {
       var queryParams = new List<string> {
                 $"secret={Uri.EscapeDataString(twoFactoSharedKey)}",