Merge remote-tracking branch 'origin/main' into fix/api-without-googlefix/api-without-google

1 files changed, 118 insertions, 0 deletions

diff --git a/docs/api/CheckDocumentation.cs b/docs/api/CheckDocumentation.cs
new file mode 100644
index 0000000..f359661
--- /dev/null
+++ b/docs/api/CheckDocumentation.cs
@@ -0,0 +1,118 @@
+// SPDX-FileCopyrightText: 2026 Progmasoft <support@progmasoft.com>
+// SPDX-License-Identifier: AGPL-3.0-or-later WITH AdditionRef-Progmasoft-Patent-Grant-1.1
+
+// Documentation coverage gate of the API reference.
+//
+// DocFX builds a reference from whatever comments exist and does not report a declaration that has none. This
+// program reads the metadata DocFX generated and fails when a namespace, type or member is undocumented, so the
+// reference cannot contain an entry without a description.
+//
+// Usage, after `dotnet docfx metadata docs/api/docfx.json`:
+//
+//     dotnet run docs/api/CheckDocumentation.cs -- docs/api
+//
+// The exit code is 0 when everything is documented, 1 when something is not, and 2 when the metadata is missing.
+
+using System.Text.RegularExpressions;
+
+string root = args.Length > 0 ? args[0] : "docs/api";
+string referenceDirectory = Path.Combine(root, "reference");
+string namespaceDirectory = Path.Combine(root, "namespaces");
+
+if (!Directory.Exists(referenceDirectory))
+{
+    Console.Error.WriteLine($"No metadata in '{referenceDirectory}'. Run 'dotnet docfx metadata' first.");
+    return 2;
+}
+
+// A namespace has no declaration that could carry a comment. Its description is an overwrite file named after it.
+HashSet<string> describedNamespaces = Directory.Exists(namespaceDirectory)
+    ? Directory.EnumerateFiles(namespaceDirectory, "*.md")
+        .Where(HasDescription)
+        .Select(path => Path.GetFileNameWithoutExtension(path)!)
+        .ToHashSet(StringComparer.Ordinal)
+    : [];
+
+List<string> undocumented = [];
+int checkedItems = 0;
+
+foreach (string file in Directory.EnumerateFiles(referenceDirectory, "*.yml").Order(StringComparer.Ordinal))
+{
+    if (Path.GetFileName(file) == "toc.yml")
+    {
+        continue;
+    }
+
+    // The items a file defines come first; the `references` section after them repeats names of other files.
+    string text = File.ReadAllText(file).ReplaceLineEndings("\n");
+    int references = text.IndexOf("\nreferences:", StringComparison.Ordinal);
+    string definitions = references < 0 ? text : text[..references];
+
+    foreach (string item in ItemStart().Split(definitions).Skip(1))
+    {
+        string uid = item[..item.IndexOf('\n')].Trim();
+        string type = ItemType().Match(item) is { Success: true } match ? match.Groups[1].Value : "Item";
+        checkedItems++;
+
+        bool documented = type == "Namespace"
+            ? describedNamespaces.Contains(uid)
+            : ItemSummary().IsMatch(item);
+        if (!documented)
+        {
+            undocumented.Add($"{type} {uid}");
+        }
+    }
+}
+
+if (checkedItems == 0)
+{
+    Console.Error.WriteLine($"The metadata in '{referenceDirectory}' defines nothing; the gate would pass vacuously.");
+    return 2;
+}
+
+if (undocumented.Count != 0)
+{
+    Console.Error.WriteLine($"{undocumented.Count} of {checkedItems} API items have no documentation:");
+    foreach (string entry in undocumented)
+    {
+        Console.Error.WriteLine($"  {entry}");
+    }
+
+    Console.Error.WriteLine("Add a <summary> to each declaration, or a file in docs/api/namespaces for a namespace.");
+    return 1;
+}
+
+Console.WriteLine($"All {checkedItems} API items are documented.");
+return 0;
+
+// An overwrite file describes its namespace when it has text after its front matter and comment header.
+static bool HasDescription(string path)
+{
+    string text = File.ReadAllText(path).ReplaceLineEndings("\n");
+    int frontMatterEnd = text.IndexOf("\n---", 3, StringComparison.Ordinal);
+    if (!text.StartsWith("---\n", StringComparison.Ordinal) || frontMatterEnd < 0)
+    {
+        return false;
+    }
+
+    string body = HtmlComment().Replace(text[(frontMatterEnd + 4)..], string.Empty);
+    return text[..frontMatterEnd].Contains($"uid: {Path.GetFileNameWithoutExtension(path)}", StringComparison.Ordinal)
+        && !string.IsNullOrWhiteSpace(body);
+}
+
+internal static partial class Program
+{
+    // Every defined item starts with its identifier at the left margin.
+    [GeneratedRegex(@"^- uid: ", RegexOptions.Multiline)]
+    private static partial Regex ItemStart();
+
+    [GeneratedRegex(@"^  type: (\w+)", RegexOptions.Multiline)]
+    private static partial Regex ItemType();
+
+    // A summary with content: text on the same line, or a block scalar followed by an indented line.
+    [GeneratedRegex(@"^  summary: (?:[^\s>|].*|[>|][-+]?\n    \S)", RegexOptions.Multiline)]
+    private static partial Regex ItemSummary();
+
+    [GeneratedRegex(@"<!--.*?-->", RegexOptions.Singleline)]
+    private static partial Regex HtmlComment();
+}