From e112882fe0a2602a7ffe7ab7760b6071bf84114e Mon Sep 17 00:00:00 2001
From: Lucas Teles <lucas.teles@outlook.com>
Date: Wed, 28 Dec 2022 15:27:06 -0300
Subject: [PATCH] add simple email model

---
 src/BrazilModels.csproj                |  2 +-
 src/Email.cs                           | 95 ++++++++++++++++++++++++++
 tests/BrazilModels.Tests/EmailTests.cs | 81 ++++++++++++++++++++++
 3 files changed, 177 insertions(+), 1 deletion(-)
 create mode 100644 src/Email.cs
 create mode 100644 tests/BrazilModels.Tests/EmailTests.cs

diff --git a/src/BrazilModels.csproj b/src/BrazilModels.csproj
index 47b37ca..66d35ba 100644
--- a/src/BrazilModels.csproj
+++ b/src/BrazilModels.csproj
@@ -24,7 +24,7 @@
     <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
   <ItemGroup>
-    <None Include="..\README.md" Pack="true" PackagePath="\"/>
+    <None Include="..\README.md" Pack="true" PackagePath="\" />
   </ItemGroup>
 
   <PropertyGroup Condition="'$(GITHUB_ACTIONS)' == 'true'">
diff --git a/src/Email.cs b/src/Email.cs
new file mode 100644
index 0000000..dd508ee
--- /dev/null
+++ b/src/Email.cs
@@ -0,0 +1,95 @@
+namespace BrazilModels;
+
+using System;
+using System.ComponentModel;
+using System.Diagnostics;
+
+/// <summary>
+/// Basic strongly typed E-mail representation
+/// </summary>
+[System.Text.Json.Serialization.JsonConverter(typeof(StringSystemTextJsonConverter<Email>))]
+[TypeConverter(typeof(StringTypeConverter<Email>))]
+[DebuggerDisplay("{DebuggerDisplay(),nq}")]
+[Swashbuckle.AspNetCore.Annotations.SwaggerSchemaFilter(typeof(StringSchemaFilter))]
+public readonly record struct Email : IComparable<Email>
+{
+    /// <summary>
+    /// String representation of the Email
+    /// </summary>
+    public string Value { get; }
+
+    /// <summary>
+    /// Create a new email instance
+    /// </summary>
+    /// <exception cref="InvalidOperationException"></exception>
+    /// <exception cref="ArgumentNullException"></exception>
+    public Email(string email)
+    {
+        ArgumentNullException.ThrowIfNull(email);
+        this.Value = email.ToLowerInvariant();
+    }
+
+    /// <inheritdoc />
+    public override string ToString() => Value;
+
+    /// <summary>
+    /// Get Email instance of an Value string
+    /// </summary>
+    /// <exception cref="InvalidOperationException"></exception>
+    /// <exception cref="ArgumentNullException"></exception>
+    public static explicit operator Email(string value)
+        => Parse(value);
+
+    /// <summary>
+    /// Return string representation of Email
+    /// </summary>
+    public static implicit operator string(Email email)
+        => email.Value;
+
+    /// <summary>
+    /// Try parse an Value string to an Email instance
+    /// </summary>
+    public static bool TryParse(string? value, out Email email)
+    {
+        email = default;
+        if (value is null || !IsValid(value))
+            return false;
+
+        email = new(value);
+        return true;
+    }
+
+    /// <summary>
+    /// Parse an Value string to an Email instance
+    /// </summary>
+    /// <exception cref="InvalidOperationException"></exception>
+    /// <exception cref="ArgumentNullException"></exception>
+    public static Email Parse(string value) =>
+        TryParse(value, out var valid)
+            ? valid
+            : throw new InvalidOperationException($"Invalid E-mail {value}");
+
+    /// <summary>
+    /// Validate Email string
+    /// </summary>
+    /// <param name="value"></param>
+    /// <returns></returns>
+    public static bool IsValid(string? value)
+    {
+        const string at = "@";
+        if (value is null)
+            return false;
+
+        var index = value.IndexOf(at, StringComparison.OrdinalIgnoreCase);
+
+        return index > 0 &&
+               index != value.Length - 1 &&
+               index == value.LastIndexOf(at, StringComparison.OrdinalIgnoreCase);
+    }
+
+    /// <inheritdoc />
+    public int CompareTo(Email other) =>
+        string.Compare(Value, other.Value, StringComparison.OrdinalIgnoreCase);
+
+    string DebuggerDisplay() => $"EMAIL{{{Value}}}";
+}
diff --git a/tests/BrazilModels.Tests/EmailTests.cs b/tests/BrazilModels.Tests/EmailTests.cs
new file mode 100644
index 0000000..ef465f2
--- /dev/null
+++ b/tests/BrazilModels.Tests/EmailTests.cs
@@ -0,0 +1,81 @@
+namespace BrazilModels.Tests;
+
+using System.Text.Json;
+
+public class EmailTests : BaseTest
+{
+    [Test]
+    public void ShouldReturnValidForValidEmail()
+    {
+        var emailStr = faker.Person.Email;
+        Email.IsValid(emailStr).Should().BeTrue();
+    }
+
+    [Test]
+    public void ShouldReturnFalseForInvalid()
+    {
+        var emailStr = faker.Person.FirstName;
+        Email.IsValid(emailStr).Should().BeFalse();
+    }
+
+    [Test]
+    public void ShouldParseEmail()
+    {
+        var emailStr = "teste@email.com";
+        var sut = Email.Parse(emailStr);
+        sut.Value.Should().Be(emailStr);
+    }
+
+    [Test]
+    public void ShouldThrowInvalidEmail()
+    {
+        var emailStr = faker.Person.FirstName;
+        var action = () => Email.Parse(emailStr);
+        action.Should().Throw<InvalidOperationException>();
+    }
+
+    [Test]
+    public void ShouldTryParseSuccessfully()
+    {
+        var emailStr = faker.Person.Email;
+        Email.TryParse(emailStr, out var email).Should().BeTrue();
+        email.Value.Should().Be(emailStr.ToLower());
+    }
+
+    [Test]
+    public void ShouldTryParseReturnFalse()
+    {
+        var emailStr = faker.Person.FirstName;
+        Email.TryParse(emailStr, out _).Should().BeFalse();
+    }
+
+    [Test]
+    public void ShouldCompareEmail()
+    {
+        var emailStr = faker.Person.Email;
+        Email emailLower = Email.Parse(emailStr.ToLowerInvariant());
+        Email emailUpper = Email.Parse(emailStr.ToUpperInvariant());
+        emailLower.Should().Be(emailUpper);
+    }
+
+
+    record Sut(Email Value);
+
+    [Test]
+    public void ShouldSerializeEmail()
+    {
+        var data = faker.Person.Email;
+        var json = JsonSerializer.Serialize(new Sut(Email.Parse(data)));
+        json.Should().Be(@$"{{""Value"":""{data.ToLowerInvariant()}""}}");
+    }
+
+    [Test]
+    public void ShouldDeserializeEmail()
+    {
+        var value = Email.Parse(faker.Person.Email);
+        var body = @$"{{""Value"":""{value.Value}""}}";
+        var parsed = JsonSerializer.Deserialize<Sut>(body)!;
+        var expected = Email.Parse(value);
+        parsed.Value.Should().Be(expected);
+    }
+}