test: Add tests to EnvValidationResult

tests/Common/EnvValidationResultTests.cs

@@ -0,0 +1,98 @@
+namespace DotEnv.Core.Tests.Common;
+
+[TestClass]
+public class EnvValidationResultTests
+{
+    [TestMethod]
+    public void HasError_WhenThereAreErrors_ShouldReturnsTrue()
+    {
+        // Arrange
+        var validationResult = new EnvValidationResult
+        {
+            "Error!"
+        };
+
+        // Act
+        bool actual = validationResult.HasError();
+
+        // Assert
+        actual.Should().BeTrue();
+    }
+
+    [TestMethod]
+    public void HasError_WhenThereAreNoErrors_ShouldReturnsFalse()
+    {
+        // Arrange
+        var validationResult = new EnvValidationResult();
+
+        // Act
+        bool actual = validationResult.HasError();
+
+        // Assert
+        actual.Should().BeFalse();
+    }
+
+    [TestMethod]
+    public void ErrorMessages_WhenThereAreNoErrors_ShouldReturnsEmptyString()
+    {
+        // Arrange
+        var validationResult = new EnvValidationResult();
+
+        // Act
+        string actual = validationResult.ErrorMessages;
+
+        // Assert
+        actual.Should().BeEmpty();
+    }
+
+    [TestMethod]
+    public void ErrorMessages_WhenThereAreErrors_ShouldReturnsSetOfErrors()
+    {
+        // Arrange
+        var validationResult = new EnvValidationResult
+        {
+            "Error1",
+            "Error2",
+            "Error3"
+        };
+        // Add new line at the beginning and end.
+        var expectedMessages =
+        """
+
+        Error1
+        Error2
+        Error3
+
+        """;
+
+        // Act
+        string actual = validationResult.ErrorMessages;
+
+        // Assert
+        actual.Should().Be(expectedMessages);
+    }
+
+    [TestMethod]
+    public void GetEnumerator_WhenThereAreErrors_ShouldAllowIteratingOverThem()
+    {
+        // Arrange
+        var validationResult = new EnvValidationResult
+        {
+            "Error1",
+            "Error2",
+            "Error3"
+        };
+        var expected = new[]
+        {
+            "Error1",
+            "Error2",
+            "Error3"
+        };
+
+        // Act
+        IEnumerable<string> actual = validationResult.AsEnumerable();
+
+        // Assert
+        actual.Should().BeEquivalentTo(expected);
+    }
+}