Improve the API diff (#15020)

tools/apidiff/.gitignore

@@ -1,5 +1,5 @@
 temp/
-diff/
+output/
 links/
 references/
 updated-references/

tools/apidiff/merger.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Security.Cryptography;
 using System.Text;
 
@@ -20,16 +21,15 @@ public static void Process (string platform, string path, string os, string? des
 		if (!Directory.Exists (path))
 			throw new DirectoryNotFoundException (path);
 
-		if (destinationPath is not null && !Directory.Exists (destinationPath))
-			throw new DirectoryNotFoundException (destinationPath);
-
 		var content = new StringWriter ();
 		var files = Directory.GetFileSystemEntries (path, "*.md");
 		Array.Sort (files);
 		string from = "unknown";
 		string to = "unknown";
 		bool lookForVersion = false;
 		foreach (var file in files) {
+			if (new FileInfo (file).Length == 0)
+				continue;
 			// skip everything before and including title (single #) from each file, we already have one
 			string? foundTitle = null;
 			foreach (var line in File.ReadAllLines (file)) {
@@ -55,6 +55,7 @@ public static void Process (string platform, string path, string os, string? des
 				}
 			}
 		}
+		var hasVersions = from != "unknown" && to != "unknown";
 
 		// https://github.com/MicrosoftDocs/xamarin-docs/blob/live/contributing-guidelines/template.md#file-name
 		var filename = $"{os}-{from}-{to}".Replace ('.', '-').ToLowerInvariant () + ".md";
@@ -65,11 +66,18 @@ public static void Process (string platform, string path, string os, string? des
 		var guid = new Guid (digest[0..16]);
 
 		var headers = new StringWriter ();
-		var title = $"{platform} SDK API diff: {from} vs {to}";
+		var title = $"{platform} SDK API diff";
+		if (hasVersions) {
+			title += $": {from} vs {to}";
+		}
 		// https://github.com/MicrosoftDocs/xamarin-docs/blob/live/contributing-guidelines/template.md#metadata
 		headers.WriteLine ("---");
 		headers.WriteLine ($"title: \"{title}\"");
-		headers.WriteLine ($"description: List of API changes between {platform} versions {from} and {to}.");
+		if (hasVersions) {
+			headers.WriteLine ($"description: List of API changes between {platform} versions {from} and {to}.");
+		} else {
+			headers.WriteLine ($"description: List of API changes for {platform}.");
+		}
 		headers.WriteLine ($"author: spouliot");
 		headers.WriteLine ($"ms.author: sepoulio");
 		headers.WriteLine ($"ms.date: {DateTime.Now.ToString ("d", new CultureInfo ("en-US"))}");
@@ -81,17 +89,13 @@ public static void Process (string platform, string path, string os, string? des
 		headers.WriteLine ($"# {title}");
 		headers.WriteLine ();
 
-		var filePath = destinationPath is not null ? Path.Combine (destinationPath, filename) : filename;
+		var filePath = destinationPath;
 		File.WriteAllText (filePath, headers.ToString ());
 
 		var alldiffs = content.ToString ();
 		if (alldiffs.Length == 0)
 			alldiffs = "No changes were found between both versions."; // should not happen for releases (versions change)
 		File.AppendAllText (filePath, alldiffs);
-		Console.WriteLine ($"@MonkeyWrench: AddFile: {Path.GetFullPath (filePath)}");
-
-		if (File.Exists ("api-diff.html"))
-			File.AppendAllText ("api-diff.html", $"\n<h2><a href=\"{filePath}\">{platform} API diff (markdown)</a></h2>");
 	}
 
 	public static int Main (string [] args)

tools/apidiff/report-status.sh

@@ -0,0 +1,53 @@
+#!/bin/bash -e
+
+PLATFORM=$1
+OUTPUT_DIR=$2
+FORMAT=$3
+HTML=$4
+MARKDOWN=$5
+OUTPUT=$6
+
+if test -n "$7"; then
+	shift 6
+	echo "Too many arguments: $*"
+	exit 1
+fi
+
+if [[ $FORMAT == html ]]; then
+	echo -n "<li>" >> "$OUTPUT"
+
+	if ! test -f "$OUTPUT_DIR/$HTML"; then
+		echo -n "<s>$PLATFORM</s> (no diff detected)" >> "$OUTPUT"
+	elif ! test -s "$OUTPUT_DIR/$HTML"; then
+		echo -n "<s>$PLATFORM</s> (empty diff detected)" >> "$OUTPUT"
+	elif grep "BreakingChangesDetected" "$OUTPUT_DIR/$HTML" >/dev/null 2>&1; then
+		echo -n "$PLATFORM: <a href='$HTML'>html</a> <a href='$MARKDOWN'>markdown</a> ($HTML_BREAKING_CHANGES_MESSAGE)" >> "$OUTPUT"
+	elif ! grep "No change detected" "$OUTPUT_DIR/$HTML" >/dev/null 2>&1; then
+		echo -n "$PLATFORM: <a href='$HTML'>html</a> <a href='$MARKDOWN'>markdown</a> ($HTML_NO_BREAKING_CHANGES_MESSAGE)" >> "$OUTPUT"
+	else
+		echo -n "<s>$PLATFORM</s> (no change detected)" >> "$OUTPUT"
+	fi
+
+	echo "</li>" >> "$OUTPUT"
+
+elif [[ $FORMAT == markdown ]]; then
+	echo -n "* " >> "$OUTPUT"
+
+	if ! test -f "$OUTPUT_DIR/$HTML"; then
+		echo -n "~$PLATFORM~: (no diff detected)" >> "$OUTPUT"
+	elif ! test -s "$OUTPUT_DIR/$HTML"; then
+		echo -n "~$PLATFORM~: (empty diff detected)" >> "$OUTPUT"
+	elif grep "BreakingChangesDetected" "$OUTPUT_DIR/$HTML" >/dev/null 2>&1; then
+		echo -n "$PLATFORM: [vsdrops]($HTML) [gist]($MARKDOWN) ($MARKDOWN_BREAKING_CHANGES_MESSAGE)" >> "$OUTPUT"
+	elif ! grep "No change detected" "$OUTPUT_DIR/$HTML" >/dev/null 2>&1; then
+		echo -n "$PLATFORM: [vsdrops]($HTML) [gist]($MARKDOWN) ($MARKDOWN_NO_BREAKING_CHANGES_MESSAGE)" >> "$OUTPUT"
+	else
+		echo -n "~$PLATFORM~ (no change detected)" >> "$OUTPUT"
+	fi
+
+	echo "" >> "$OUTPUT"
+else
+	echo "Unknown output format: $FORMAT"
+	exit 1
+fi
+