add tests

ChatBot.Tests/Configuration/Validators/TelegramBotSettingsValidatorTests.cs

@@ -0,0 +1,76 @@
+using ChatBot.Models.Configuration;
+using ChatBot.Models.Configuration.Validators;
+using FluentAssertions;
+
+namespace ChatBot.Tests.Configuration.Validators;
+
+public class TelegramBotSettingsValidatorTests
+{
+    private readonly TelegramBotSettingsValidator _validator = new();
+
+    [Fact]
+    public void Validate_ShouldReturnSuccess_WhenSettingsAreValid()
+    {
+        // Arrange
+        var settings = new TelegramBotSettings
+        {
+            BotToken = "1234567890:ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijk",
+        };
+
+        // Act
+        var result = _validator.Validate(null, settings);
+
+        // Assert
+        result.Succeeded.Should().BeTrue();
+    }
+
+    [Fact]
+    public void Validate_ShouldReturnFailure_WhenBotTokenIsEmpty()
+    {
+        // Arrange
+        var settings = new TelegramBotSettings { BotToken = "" };
+
+        // Act
+        var result = _validator.Validate(null, settings);
+
+        // Assert
+        result.Succeeded.Should().BeFalse();
+        result.Failures.Should().Contain(f => f.Contains("Telegram bot token is required"));
+    }
+
+    [Fact]
+    public void Validate_ShouldReturnFailure_WhenBotTokenIsTooShort()
+    {
+        // Arrange
+        var settings = new TelegramBotSettings
+        {
+            BotToken = "1234567890:ABC", // 15 chars, too short
+        };
+
+        // Act
+        var result = _validator.Validate(null, settings);
+
+        // Assert
+        result.Succeeded.Should().BeFalse();
+        result
+            .Failures.Should()
+            .Contain(f => f.Contains("Telegram bot token must be at least 40 characters"));
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void Validate_ShouldReturnFailure_WhenBotTokenIsNullOrWhitespace(string? botToken)
+    {
+        // Arrange
+        var settings = new TelegramBotSettings { BotToken = botToken! };
+
+        // Act
+        var result = _validator.Validate(null, settings);
+
+        // Assert
+        result.Succeeded.Should().BeFalse();
+        result.Failures.Should().Contain(f => f.Contains("Telegram bot token is required"));
+    }
+}