Added mailboxes as local data sources (#1022)

app/Tests/Tools/Mail/MailSummaryReaderTests.cs

@@ -0,0 +1,185 @@
+using AIStudio.Tools.Databases.IndexStore;
+using AIStudio.Tools.Mail;
+
+using MailKit;
+
+using MimeKit;
+
+namespace AIStudio.Tests.Tools.Mail;
+
+/// <summary>
+/// Checks what AI Studio keeps of the summary a server reports about a mail.
+/// </summary>
+/// <remarks>
+/// The summaries are built by hand, with the header blocks of the fixtures: the sync fetches the
+/// whole header block with every mail and reads everything from there.
+/// </remarks>
+[TestFixture]
+public sealed class MailSummaryReaderTests
+{
+    /// <summary>
+    /// Where a part sits in the mail, e.g. "1.2". Nothing here looks at it.
+    /// </summary>
+    private const string PART_SPECIFIER = "1";
+
+    [Test]
+    public void TheIdentityComesFromTheHeaderBlock()
+    {
+        var summary = Summary("header-injection.eml");
+        summary.EmailId = "M6d99ac3275bb4e";
+        summary.Size = 2048;
+
+        var identity = MailSummaryReader.ReadIdentity(summary);
+        Assert.Multiple(() =>
+        {
+            Assert.That(identity.EmailId, Is.EqualTo("M6d99ac3275bb4e"));
+            Assert.That(identity.GmailMessageId, Is.Null);
+            Assert.That(identity.MessageId, Is.EqualTo("<header-injection@example.org>"));
+            Assert.That(identity.Date, Is.EqualTo(new DateTimeOffset(2026, 9, 30, 13, 0, 0, TimeSpan.FromHours(2))));
+            Assert.That(identity.FromAddresses, Is.EqualTo(new[] { "mueller@example.org" }));
+            Assert.That(identity.Subject, Does.StartWith("Hello"));
+            Assert.That(identity.Size, Is.EqualTo(2048));
+        });
+    }
+
+    [Test]
+    public void EveryAddressKeepsItsHeader()
+    {
+        var addresses = MailSummaryReader.ReadAddresses(MailFixtures.Load("header-injection.eml").Headers);
+        Assert.Multiple(() =>
+        {
+            Assert.That(addresses.Count(address => address.Role is MailAddressRole.TO), Is.EqualTo(12), "An address of the second To line is lost.");
+            Assert.That(addresses[0], Is.EqualTo(new MailAddressRecord(MailAddressRole.FROM, "mueller@example.org", "Müller, Jürgen")));
+            Assert.That(addresses[^1], Is.EqualTo(new MailAddressRecord(MailAddressRole.CC, "mueller@example.org", "mueller@example.org")));
+            Assert.That(addresses.Any(address => address.Role is MailAddressRole.SENDER or MailAddressRole.REPLY_TO), Is.False, "A header the mail does not have was made up.");
+        });
+    }
+
+    [Test]
+    public void SenderAndReplyToCountOnlyWhenTheMailSetsThem()
+    {
+        var headers = new HeaderList();
+        headers.Add("From", "Alice <alice@example.org>");
+        headers.Add("Sender", "Assistant <assistant@example.org>");
+        headers.Add("Reply-To", "Team <team@example.org>");
+
+        Assert.That(MailSummaryReader.ReadAddresses(headers), Is.EqualTo(new[]
+        {
+            new MailAddressRecord(MailAddressRole.FROM, "alice@example.org", "Alice"),
+            new MailAddressRecord(MailAddressRole.SENDER, "assistant@example.org", "Assistant"),
+            new MailAddressRecord(MailAddressRole.REPLY_TO, "team@example.org", "Team"),
+        }));
+    }
+
+    [Test]
+    public void TheTextSourceTakesAttachmentsAndEncryptionFromTheStructure()
+    {
+        var attachment = new BodyPartBasic(new ContentType("application", "pdf"), PART_SPECIFIER)
+        {
+            ContentDisposition = new ContentDisposition(ContentDisposition.Attachment) { FileName = "board-report.pdf" },
+        };
+
+        var readable = Summary("priority-with-attachment.eml");
+        readable.Body = Multipart("mixed", new BodyPartText(new ContentType("text", "plain"), PART_SPECIFIER), attachment);
+
+        var encrypted = Summary("smime-enveloped.eml");
+        encrypted.Body = new BodyPartBasic(new ContentType("application", "pkcs7-mime") { Parameters = { { "smime-type", "enveloped-data" } } }, PART_SPECIFIER);
+
+        var readableSource = MailSummaryReader.ReadTextSource(readable, new MailTextParts(null, "Please review the attached report."));
+        var encryptedSource = MailSummaryReader.ReadTextSource(encrypted, null);
+        Assert.Multiple(() =>
+        {
+            Assert.That(readableSource.AttachmentNames, Is.EqualTo(new[] { "board-report.pdf" }));
+            Assert.That(readableSource.StructureEncryption, Is.EqualTo(MailEncryptionKind.NONE));
+            Assert.That(readableSource.TextBody, Is.EqualTo("Please review the attached report."));
+            Assert.That(readableSource.HtmlBody, Is.Null);
+            Assert.That(encryptedSource.StructureEncryption, Is.EqualTo(MailEncryptionKind.SMIME));
+            Assert.That(MailTextBuilder.Build(encryptedSource).Body, Is.Empty);
+        });
+    }
+
+    [Test]
+    public void TheSignatureOfASignedMailIsNoAttachment()
+    {
+        var signature = new BodyPartBasic(new ContentType("application", "pkcs7-signature"), PART_SPECIFIER)
+        {
+            ContentDisposition = new ContentDisposition(ContentDisposition.Attachment) { FileName = "smime.p7s" },
+        };
+
+        var signed = Summary("smime-clear-signed.eml");
+        signed.Body = Multipart("signed", new BodyPartText(new ContentType("text", "plain"), PART_SPECIFIER), signature);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(MailSummaryReader.ReadAttachments(signed), Is.Empty);
+            Assert.That(MailSummaryReader.ReadTextSource(signed, new MailTextParts(null, "Signed, but readable for everybody.")).AttachmentNames, Is.Empty);
+        });
+    }
+
+    [Test]
+    public void TheFlagsAreRead()
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(MailSummaryReader.ReadFlags(MessageFlags.Seen | MessageFlags.Flagged | MessageFlags.Recent), Is.EqualTo(new MailFlags(IsSeen: true, IsFlagged: true, IsAnswered: false)));
+            Assert.That(MailSummaryReader.ReadFlags(MessageFlags.Answered), Is.EqualTo(new MailFlags(IsSeen: false, IsFlagged: false, IsAnswered: true)));
+            Assert.That(MailSummaryReader.ReadFlags(null), Is.EqualTo(new MailFlags(IsSeen: false, IsFlagged: false, IsAnswered: false)));
+        });
+    }
+
+    [Test]
+    public void TheHeaderBlockStaysAsTheServerSentIt() =>
+        Assert.That(MailSummaryReader.ReadHeaderBlock(MailFixtures.Load("header-injection.eml").Headers), Does.Contain("Subject: =?utf-8?b?SGVsbG8NCkZyb206IGNlb0BleGFtcGxlLm9yZw==?="), "The trust check needs the encoded words as they were sent.");
+
+    [Test]
+    public void TheMailHashFollowsTheMail()
+    {
+        var summary = Summary("priority-with-attachment.eml");
+        summary.Size = 2048;
+        var hash = MailSummaryReader.ComputeMailHash(summary);
+
+        var sameMail = Summary("priority-with-attachment.eml");
+        sameMail.Size = 2048;
+
+        var otherSize = Summary("priority-with-attachment.eml");
+        otherSize.Size = 2049;
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(hash, Does.Match("^[0-9a-f]{64}$"));
+            Assert.That(MailSummaryReader.ComputeMailHash(sameMail), Is.EqualTo(hash));
+            Assert.That(MailSummaryReader.ComputeMailHash(otherSize), Is.Not.EqualTo(hash));
+            Assert.That(MailSummaryReader.ComputeMailHash(Summary("smime-enveloped.eml")), Is.Not.EqualTo(hash));
+        });
+    }
+
+    [Test]
+    public void MessageIdsAreReadWithoutTheirBrackets()
+    {
+        var headers = new HeaderList();
+        headers.Add("In-Reply-To", "<second@example.org>");
+        headers.Add("References", "<first@example.org>\r\n <second@example.org>");
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(MailHeaders.ReadMessageIds(headers, HeaderId.References), Is.EqualTo(new[] { "first@example.org", "second@example.org" }));
+            Assert.That(MailHeaders.ReadMessageIds(headers, HeaderId.InReplyTo), Is.EqualTo(new[] { "second@example.org" }));
+            Assert.That(MailHeaders.ReadMessageIds(headers, HeaderId.MessageId), Is.Empty);
+        });
+    }
+
+    [Test]
+    public void AMailFetchedWithoutItsHeaderBlockIsRefused() =>
+        Assert.That(() => MailSummaryReader.ReadIdentity(new MessageSummary(0)), Throws.InvalidOperationException);
+
+    private static MessageSummary Summary(string fixtureName) => new(0) { Headers = MailFixtures.Load(fixtureName).Headers };
+
+    private static BodyPartMultipart Multipart(string mediaSubtype, params BodyPart[] parts)
+    {
+        var multipart = new BodyPartMultipart(new ContentType("multipart", mediaSubtype), PART_SPECIFIER);
+        foreach (var part in parts)
+            multipart.BodyParts.Add(part);
+
+        return multipart;
+    }
+}