Add extensions to Roslyn primitive analyser config options & dir helper

Author: Lamparter

src/roslyn/Riverside.CompilerPlatform.Extensions/Extensions/AnalyzerConfigOptionsExtensions.cs

@@ -0,0 +1,92 @@
+using System;
+using System.Linq;
+
+namespace Riverside.CompilerPlatform.Extensions;
+
+/// <summary>
+/// Provides extension methods for reading typed values from <see cref="AnalyzerConfigOptions"/>.
+/// </summary>
+public static class AnalyzerConfigOptionsExtensions
+{
+	/// <summary>
+	/// Returns the string value for <paramref name="key"/>, or <see langword="null"/> if the key is absent or whitespace.
+	/// </summary>
+	/// <param name="options">The analyser config options to read from.</param>
+	/// <param name="key">The property key, typically prefixed with <c>build_property.</c>.</param>
+	/// <returns>The trimmed string value, or <see langword="null"/>.</returns>
+	public static string? GetString(this AnalyzerConfigOptions options, string key)
+	{
+		options.TryGetValue(key, out var value);
+		return string.IsNullOrWhiteSpace(value) ? null : value;
+	}
+
+	/// <summary>
+	/// Returns a nullable <see cref="bool"/> for <paramref name="key"/>.
+	/// Returns <see langword="null"/> when the key is absent, empty, or not a valid boolean string.
+	/// </summary>
+	/// <param name="options">The analyzer config options to read from.</param>
+	/// <param name="key">The property key.</param>
+	/// <returns>The parsed boolean, or <see langword="null"/>.</returns>
+	public static bool? GetNullableBool(this AnalyzerConfigOptions options, string key)
+	{
+		var value = options.GetString(key);
+		return value is not null && bool.TryParse(value, out var result) ? result : null;
+	}
+
+	/// <summary>
+	/// Returns a nullable <typeparamref name="TEnum"/> for <paramref name="key"/>, parsed case-insensitively.
+	/// Returns <see langword="null"/> when the key is absent, empty, or does not map to a valid enum member.
+	/// </summary>
+	/// <typeparam name="TEnum">The enum type to parse into.</typeparam>
+	/// <param name="options">The analyser config options to read from.</param>
+	/// <param name="key">The property key.</param>
+	/// <returns>The parsed enum value, or <see langword="null"/>.</returns>
+	public static TEnum? GetNullableEnum<TEnum>(this AnalyzerConfigOptions options, string key)
+		where TEnum : struct, Enum
+	{
+		var value = options.GetString(key);
+		return value is not null && Enum.TryParse<TEnum>(value, ignoreCase: true, out var result) ? result : null;
+	}
+
+	/// <summary>
+	/// Returns a <see cref="string"/>[] by splitting <paramref name="key"/>'s value on the <c>|</c> character.
+	/// Empty or whitespace-only segments are discarded.
+	/// Returns <see langword="null"/> when the key is absent, empty, or yields no usable segments.
+	/// </summary>
+	/// <param name="options">The analyser config options to read from.</param>
+	/// <param name="key">The property key.</param>
+	/// <returns>A non-empty trimmed array of segments, or <see langword="null"/>.</returns>
+	public static string[]? GetPipeSeparatedArray(this AnalyzerConfigOptions options, string key)
+	{
+		var value = options.GetString(key);
+		if (value is null)
+			return null;
+		var parts = value.Split('|')
+			.Select(p => p.Trim())
+			.Where(p => p.Length > 0)
+			.ToArray();
+		return parts.Length > 0 ? parts : null;
+	}
+
+	/// <summary>
+	/// Returns a <typeparamref name="TEnum"/>[] by splitting <paramref name="key"/>'s value on <c>|</c> and parsing each segment case-insensitively.
+	/// Segments that do not match a valid enum member are silently skipped.
+	/// </summary>
+	/// <typeparam name="TEnum">The enum type to parse each segment into.</typeparam>
+	/// <param name="options">The analyser config options to read from.</param>
+	/// <param name="key">The property key.</param>
+	/// <returns>A non-empty array of parsed enum values, or <see langword="null"/> when the <paramref name="key"/> is absent, empty, or yields no valid members.</returns>
+	public static TEnum[]? GetPipeSeparatedEnumArray<TEnum>(this AnalyzerConfigOptions options, string key)
+		where TEnum : struct, Enum
+	{
+		var raw = options.GetPipeSeparatedArray(key);
+		if (raw is null)
+			return null;
+		var parsed = raw
+			.Select(s => (ok: Enum.TryParse<TEnum>(s, ignoreCase: true, out var v), val: v))
+			.Where(t => t.ok)
+			.Select(t => t.val)
+			.ToArray();
+		return parsed.Length > 0 ? parsed : null;
+	}
+}

src/roslyn/Riverside.CompilerPlatform.Extensions/Helpers/DirectoryHelpers.cs

@@ -0,0 +1,33 @@
+using System;
+using System.IO;
+
+namespace Riverside.CompilerPlatform.Helpers;
+
+/// <summary>
+/// Provides utility methods for common directory operations.
+/// </summary>
+public static class DirectoryHelpers
+{
+    /// <summary>
+    /// Deletes <paramref name="path"/> and all of its contents recursively, suppressing any exception that occurs.
+    /// </summary>
+    /// <param name="path">The directory to delete.</param>
+    public static void TryDelete(string path)
+    {
+        try { if (Directory.Exists(path)) Directory.Delete(path, recursive: true); }
+        catch { }
+    }
+
+    /// <summary>
+    /// Creates a uniquely named subdirectory under <paramref name="basePath"/> and returns its full path.
+    /// The subdirectory name is a compact <see cref="Guid"/> with no formatting characters.
+    /// </summary>
+    /// <param name="basePath">The parent directory. Created if it does not already exist.</param>
+    /// <returns>The full path of the newly created temporary directory.</returns>
+    public static string CreateTemporary(string basePath)
+    {
+        var path = Path.Combine(basePath, Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(path);
+        return path;
+    }
+}