Added mailboxes as local data sources (#1022)

app/Tests/Tools/Mail/MailImportanceDetectionTests.cs

@@ -0,0 +1,51 @@
+using AIStudio.Tools.Mail;
+
+using MimeKit;
+
+namespace AIStudio.Tests.Tools.Mail;
+
+/// <summary>
+/// Checks how the three headers for the importance of a mail are read.
+/// </summary>
+[TestFixture]
+public sealed class MailImportanceDetectionTests
+{
+    [TestCase("Importance", "High", ExpectedResult = MailImportance.HIGH)]
+    [TestCase("Importance", "low", ExpectedResult = MailImportance.LOW)]
+    [TestCase("Importance", "normal", ExpectedResult = MailImportance.NORMAL)]
+    [TestCase("X-Priority", "1 (Highest)", ExpectedResult = MailImportance.HIGH)]
+    [TestCase("X-Priority", "2", ExpectedResult = MailImportance.HIGH)]
+    [TestCase("X-Priority", "3 (Normal)", ExpectedResult = MailImportance.NORMAL)]
+    [TestCase("X-Priority", "4 (Low)", ExpectedResult = MailImportance.LOW)]
+    [TestCase("X-Priority", "5", ExpectedResult = MailImportance.LOW)]
+    [TestCase("X-Priority", "10", ExpectedResult = MailImportance.NORMAL)]
+    [TestCase("Priority", "urgent", ExpectedResult = MailImportance.HIGH)]
+    [TestCase("Priority", "Non-Urgent", ExpectedResult = MailImportance.LOW)]
+    public MailImportance EachHeaderIsRead(string field, string value)
+    {
+        var headers = new HeaderList();
+        headers.Add(field, value);
+        return MailImportanceDetection.Detect(headers);
+    }
+
+    [Test]
+    public void TheImportanceHeaderComesFirst()
+    {
+        var headers = new HeaderList();
+        headers.Add("X-Priority", "1 (Highest)");
+        headers.Add("Importance", "low");
+        Assert.That(MailImportanceDetection.Detect(headers), Is.EqualTo(MailImportance.LOW));
+    }
+
+    [Test]
+    public void AValueNobodyDefinedLeavesTheDecisionToTheNextHeader()
+    {
+        var headers = new HeaderList();
+        headers.Add("Importance", "whenever");
+        headers.Add("X-Priority", "1 (Highest)");
+        Assert.That(MailImportanceDetection.Detect(headers), Is.EqualTo(MailImportance.HIGH));
+    }
+
+    [Test]
+    public void AMailWithoutAnyOfTheHeadersIsNormal() => Assert.That(MailImportanceDetection.Detect(new HeaderList()), Is.EqualTo(MailImportance.NORMAL));
+}