Removed false alarms & the metadata.txt diff from the build script (#1066)

app/Build/Commands/UpdateMetadataCommands.cs

@@ -259,7 +259,7 @@ public sealed partial class UpdateMetadataCommands
         var foundIssue = false;
         foreach (var buildOutputLine in dotnetBuildOutputLines)
         {
-            if(buildOutputLine.Contains(" error ") || buildOutputLine.Contains("#warning"))
+            if(IsDotnetBuildIssue(buildOutputLine))
             {
                 if(!foundIssue)
                 {
@@ -348,7 +348,7 @@ public sealed partial class UpdateMetadataCommands
         var foundRustIssue = false;
         foreach (var buildOutputLine in rustBuildOutputLines)
         {
-            if(buildOutputLine.Contains("error", StringComparison.OrdinalIgnoreCase) || buildOutputLine.Contains("warning"))
+            if(IsRustBuildIssue(buildOutputLine))
             {
                 if(!foundRustIssue)
                 {
@@ -372,6 +372,42 @@ public sealed partial class UpdateMetadataCommands
         }
     }
 
+    /// <summary>
+    /// Whether a line of the .NET build output is an error or the warning of a #warning directive.
+    /// </summary>
+    /// <remarks>
+    /// MSBuild writes its diagnostics as "origin: error CODE: text" and keeps the keyword English in any
+    /// language. Looking for the word alone would also catch messages which merely mention an error.
+    /// </remarks>
+    /// <param name="line">One line of the build output.</param>
+    /// <returns>True, when the line reports an issue.</returns>
+    private static bool IsDotnetBuildIssue(string line) => DotnetErrorRegex().IsMatch(line) || line.Contains("#warning", StringComparison.Ordinal);
+
+    /// <summary>
+    /// Whether a line of the Rust build output is an error or a warning.
+    /// </summary>
+    /// <remarks>
+    /// Cargo and rustc start each diagnostic at the beginning of a line, with "error:", "error[", or "warning:".
+    /// Looking for these words anywhere would also catch the names of crates such as thiserror, which cargo
+    /// prints while compiling them. The note about dependencies which a future Rust version will reject also
+    /// starts with "warning:", yet it says nothing about this build. The Tauri CLI reports its own failures
+    /// with a right-aligned "Error" label.
+    /// </remarks>
+    /// <param name="line">One line of the build output.</param>
+    /// <returns>True, when the line reports an issue.</returns>
+    private static bool IsRustBuildIssue(string line)
+    {
+        const string FUTURE_INCOMPATIBILITY_NOTE = "warning: the following packages contain code that will be rejected by a future version of Rust";
+
+        if (line.StartsWith(FUTURE_INCOMPATIBILITY_NOTE, StringComparison.Ordinal))
+            return false;
+
+        return line.StartsWith("error:", StringComparison.Ordinal)
+            || line.StartsWith("error[", StringComparison.Ordinal)
+            || line.StartsWith("warning:", StringComparison.Ordinal)
+            || TauriErrorRegex().IsMatch(line);
+    }
+
     private async Task CreateNextChangelog(int currentBuildNumber, AppVersion currentAppVersion)
     {
         Console.Write("- Create the next changelog ...");
@@ -525,7 +561,6 @@ public sealed partial class UpdateMetadataCommands
 
         return new(
             metadataPath,
-            metadataContent,
             metadataLines,
             appVersion,
             buildNumber,
@@ -558,8 +593,7 @@ public sealed partial class UpdateMetadataCommands
         releaseState.MetadataLines[BUILD_TIME_INDEX] = buildTimeString;
         releaseState.MetadataLines[BUILD_NUMBER_INDEX] = buildNumber.ToString(CultureInfo.InvariantCulture);
         releaseState.MetadataLines[COMMIT_HASH_INDEX] = $"{releaseState.HeadCommitHash}, release";
-        var updatedMetadata = JoinLines(releaseState.MetadataContent, releaseState.MetadataLines);
-        await File.WriteAllTextAsync(releaseState.MetadataPath, updatedMetadata, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(releaseState.MetadataPath, releaseState.MetadataLines);
 
         var updatedChangelogHeader = FormatChangelogHeader(releaseState.AppVersion, buildNumber, buildTime);
         var updatedChangelog = ReplaceExactlyOnce(releaseState.ChangelogContent, releaseState.ChangelogHeader, updatedChangelogHeader);
@@ -767,10 +801,20 @@ public sealed partial class UpdateMetadataCommands
         return content.Replace("\r\n", "\n", StringComparison.Ordinal).Split('\n');
     }
 
-    private static string JoinLines(string originalContent, string[] lines)
+    /// <summary>
+    /// Writes the metadata file with a line feed after each line, the last one included.
+    /// </summary>
+    /// <remarks>
+    /// This is the form in which the file is committed, and the build script of the Rust runtime writes it
+    /// the same way. File.WriteAllLinesAsync would end the lines with the line break of the current OS, so
+    /// that the file would change with the OS it was last built on.
+    /// </remarks>
+    /// <param name="pathMetadata">The path of the metadata file.</param>
+    /// <param name="lines">The lines to write. An empty element after the final line break, as SplitLines leaves it, adds no empty line.</param>
+    private static async Task WriteMetadataLinesAsync(string pathMetadata, IEnumerable<string> lines)
     {
-        var lineEnding = originalContent.Contains("\r\n", StringComparison.Ordinal) ? "\r\n" : "\n";
-        return string.Join(lineEnding, lines);
+        var metadata = string.Join('\n', lines).TrimEnd('\n') + '\n';
+        await File.WriteAllTextAsync(pathMetadata, metadata, Environment.UTF8_NO_BOM);
     }
     
     private async Task<string> ReadPdfiumVersion()
@@ -794,7 +838,7 @@ public sealed partial class UpdateMetadataCommands
         Console.Write($"- Updating architecture to {rid.ToUserFriendlyName()} ...");
         lines[ARCHITECTURE_INDEX] = rid.AsMicrosoftRid();
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
         Console.WriteLine(" done.");
     }
     
@@ -813,7 +857,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updating commit hash from '{currentCommitHash}' to '{updatedCommitHash}'.");
         lines[COMMIT_HASH_INDEX] = updatedCommitHash;
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
 
     private async Task<AppVersion> UpdateAppVersion(PrepareAction action, string? version = null)
@@ -876,7 +920,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updating app version from '{currentAppVersionLine}' to '{updatedAppVersion}'.");
 
         lines[APP_VERSION_INDEX] = updatedAppVersion;
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
 
         return new(updatedAppVersion, newMajor, newMinor, newPatch);
     }
@@ -935,7 +979,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updated Tauri version from {currentTauriVersion} to {updatedTauriVersion}.");
         lines[TAURI_VERSION_INDEX] = updatedTauriVersion;
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
 
     private async Task UpdateVectorStoreVersion()
@@ -960,7 +1004,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updated vector store version from {currentVectorStoreVersion} to {updatedVectorStoreVersion}.");
         lines[VECTOR_STORE_VERSION_INDEX] = updatedVectorStoreVersion;
 
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
 
     private async Task UpdateMudBlazorVersion()
@@ -985,7 +1029,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updated MudBlazor version from {currentMudBlazorVersion} to {updatedMudBlazorVersion}.");
         lines[MUD_BLAZOR_VERSION_INDEX] = updatedMudBlazorVersion;
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
 
     private async Task UpdateRustVersion()
@@ -1009,7 +1053,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updated Rust version from {currentRustVersion} to {updatedRustVersion}.");
         lines[RUST_VERSION_INDEX] = updatedRustVersion;
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
 
     private async Task UpdateDotnetVersion()
@@ -1040,7 +1084,7 @@ public sealed partial class UpdateMetadataCommands
         lines[DOTNET_VERSION_INDEX] = updatedDotnetVersion;
         lines[DOTNET_SDK_VERSION_INDEX] = updatedDotnetSdkVersion;
         
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
     }
     
     private async Task<IList<Match>> DetermineVersion(string name, string workingDirectory,  Regex regex, string program, string command)
@@ -1126,7 +1170,7 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updating build number from '{lines[BUILD_NUMBER_INDEX]}' to '{buildNumber}'.");
         
         lines[BUILD_NUMBER_INDEX] = buildNumber.ToString();
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
         return buildNumber;
     }
     
@@ -1140,13 +1184,12 @@ public sealed partial class UpdateMetadataCommands
         Console.WriteLine($"- Updating build time from '{lines[BUILD_TIME_INDEX]}' to '{buildTime}'.");
         
         lines[BUILD_TIME_INDEX] = buildTime;
-        await File.WriteAllLinesAsync(pathMetadata, lines, Environment.UTF8_NO_BOM);
+        await WriteMetadataLinesAsync(pathMetadata, lines);
         return buildTime;
     }
 
     private sealed record RebuildReleaseState(
         string MetadataPath,
-        string MetadataContent,
         string[] MetadataLines,
         string AppVersion,
         int BuildNumber,
@@ -1200,6 +1243,14 @@ public sealed partial class UpdateMetadataCommands
     [GeneratedRegex("^[0-9a-fA-F]{40,64}$")]
     private static partial Regex GitCommitHashRegex();
 
+    // Matches the category of an MSBuild error, e.g., "): error CS0103:", "MSBUILD : error MSB1009:", or "): error :":
+    [GeneratedRegex(""":\s*error(?:\s+[A-Z]+[0-9]+)?\s*:""")]
+    private static partial Regex DotnetErrorRegex();
+
+    // Matches the label of a Tauri CLI error, which is right-aligned to twelve characters:
+    [GeneratedRegex("""^\s+Error\s""")]
+    private static partial Regex TauriErrorRegex();
+
     // Matches one Markdown link. The address may hold one level of parentheses, as Wikipedia addresses do:
     [GeneratedRegex("""\[(?<text>[^\[\]]+)\]\((?<address>(?:[^()\s]|\([^()\s]*\))+)\)""")]
     private static partial Regex MarkdownLinkRegex();