Carry sources into exported code blocks

app/Tests/Chat/IContentExtensionsTests.cs

@@ -162,16 +162,85 @@ public sealed class IContentExtensionsTests
             "|---|---|",
             "| Q1 | 100 |"), TOOL_SOURCE);
 
-        content.TryGetMarkdownText(out var markdown);
-        var tables = PlainFileExport.ExtractFiles(markdown, ',');
+        var tables = FilesOf(content);
 
         Assert.Multiple(() =>
         {
             Assert.That(tables, Has.Count.EqualTo(1), "One table in the message, one table offered for it.");
-            Assert.That(tables[0].Content, Does.Not.Contain("example.org"), "A data table has no column a link list would fit into.");
+            Assert.That(content.ToExportContent(tables[0]), Is.EqualTo(tables[0].Content), "A data table has no column a link list would fit into.");
         });
     }
 
+    [Test]
+    public void AMarkdownBlockCarriesTheSourcesVisibly()
+    {
+        var content = TextWith(Lines(
+            "Here are your notes:",
+            string.Empty,
+            "```markdown",
+            "# Notes",
+            string.Empty,
+            "The notes.",
+            "```"), TOOL_SOURCE);
+
+        var exported = content.ToExportContent(FilesOf(content).Single());
+
+        Assert.That(TopLevelBlocksOf(exported), Is.EqualTo(new[] { "h1", "ParagraphBlock", "h1", "h2", "ListBlock" }), "The notes without the text around them, followed by the source list just as the entire answer carries it.");
+    }
+
+    [Test]
+    public void AWebPageCarriesTheSourcesInAComment()
+    {
+        var content = TextWith(Lines(
+            "```html",
+            "<!DOCTYPE html>",
+            "<html><body><p>Hello</p></body></html>",
+            "```"), TOOL_SOURCE);
+
+        var file = FilesOf(content).Single();
+        var exported = content.ToExportContent(file);
+        var appended = exported[file.Content.Length..].Trim();
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(exported, Does.StartWith(file.Content), "The page stays as the model wrote it.");
+            Assert.That(appended, Does.StartWith("<!--").And.EndWith("-->"), "Below the page stands one comment and nothing a browser would show.");
+            Assert.That(appended, Does.Contain(TOOL_SOURCE.URL));
+        });
+    }
+
+    [Test]
+    public void ALatexBlockCarriesTheSourcesInComments()
+    {
+        var content = TextWith(Lines(
+            "```latex",
+            @"\section{Results}",
+            "```"), TOOL_SOURCE);
+
+        var file = FilesOf(content).Single();
+        var exported = content.ToExportContent(file);
+        var appended = exported[file.Content.Length..].Trim();
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(exported, Does.StartWith(file.Content), "The document stays as the model wrote it.");
+            Assert.That(appended.Split(Environment.NewLine), Has.All.StartWith("%"), "A line LaTeX would read could stop the whole run.");
+            Assert.That(appended, Does.Contain(TOOL_SOURCE.URL));
+        });
+    }
+
+    [TestCase("markdown")]
+    [TestCase("html")]
+    [TestCase("latex")]
+    public void WithoutSourcesACodeBlockStaysAsTheModelWroteIt(string language)
+    {
+        var content = TextWith(Lines($"```{language}", "The content.", "```"));
+
+        var file = FilesOf(content).Single();
+
+        Assert.That(content.ToExportContent(file), Is.EqualTo(file.Content), "No comment, no heading, no empty line.");
+    }
+
     /// <summary>
     /// A text message with the given sources hanging on it.
     /// </summary>
@@ -184,6 +253,17 @@ public sealed class IContentExtensionsTests
         Sources = [..sources],
     };
 
+    /// <summary>
+    /// Reads the files of a message the way the export menu does.
+    /// </summary>
+    /// <param name="content">The content to read.</param>
+    /// <returns>The files the export menu offers for it.</returns>
+    private static IReadOnlyList<MessageFile> FilesOf(IContent content)
+    {
+        content.TryGetMarkdownText(out var markdown);
+        return PlainFileExport.ExtractFiles(markdown, ',');
+    }
+
     /// <summary>
     /// Names the blocks a Markdown text is made of, headings by their level.
     /// </summary>

app/Tests/Tools/FileExportFormatTests.cs

@@ -69,4 +69,54 @@ public sealed class FileExportFormatTests
             Assert.That(format, Is.EqualTo(FileExportFormat.NONE));
         });
     }
+
+    [TestCase(FileExportFormat.HTML)]
+    [TestCase(FileExportFormat.MARKDOWN)]
+    public void AnHtmlCommentEndsWhereItShouldAndNowhereElse(FileExportFormat format)
+    {
+        var found = format.TryToComment("A page titled --> Start, and one titled --!> Next", out var comment);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(found, Is.True);
+            Assert.That(comment, Does.StartWith("<!--"));
+            Assert.That(comment.IndexOf("-->", StringComparison.Ordinal), Is.EqualTo(comment.Length - 3), "Only the end of the comment may end it; the title would spill onto the page otherwise.");
+            Assert.That(comment, Does.Not.Contain("--!>"), "A browser ends a comment there as well.");
+            Assert.That(comment, Does.Contain("Start").And.Contain("Next"), "The title stays readable.");
+        });
+    }
+
+    [Test]
+    public void AnHtmlCommentKeepsTheDashesOfAnAddress()
+    {
+        FileExportFormat.HTML.TryToComment("https://xn--mnchen-3ya.de/", out var comment);
+
+        Assert.That(comment, Does.Contain("https://xn--mnchen-3ya.de/"), "A domain with an umlaut is written with two dashes, and the link has to keep working.");
+    }
+
+    [Test]
+    public void EveryLineOfALatexCommentIsOne()
+    {
+        var found = FileExportFormat.LATEX.TryToComment(Lines("# Sources", string.Empty, "- [1] A title with 100 % and a_b"), out var comment);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(found, Is.True);
+            Assert.That(comment.Split(Environment.NewLine), Is.EqualTo(new[] { "% # Sources", "%", "% - [1] A title with 100 % and a_b" }), "LaTeX has no end of a comment, only the end of a line.");
+        });
+    }
+
+    [TestCase(FileExportFormat.CSV)]
+    [TestCase(FileExportFormat.TSV)]
+    [TestCase(FileExportFormat.MICROSOFT_WORD)]
+    public void AFormatWithoutCommentsSaysSo(FileExportFormat format)
+    {
+        Assert.Multiple(() =>
+        {
+            Assert.That(format.TryToComment("A text.", out var comment), Is.False);
+            Assert.That(comment, Is.Empty);
+        });
+    }
+
+    private static string Lines(params string[] lines) => string.Join(Environment.NewLine, lines);
 }