C#: Use groups and rename to trap.compression instead. Various changes to description to align with Ruby.

Author: michaelnebel

csharp/codeql-extractor.yml

@@ -17,9 +17,15 @@ file_types:
       - .cs
 legacy_qltest_extraction: true
 options:
-  compression:
-    title: The type of compression.
-    description: >
-      A value indicating, which type of compression that should be used for the TRAP archive.
-      Allowed values are 'brotli', 'gzip' or 'none'. The default is 'brotli'.
-    type: string
+  trap:
+    title: Options pertaining to TRAP.
+    type: object
+    properties:
+      compression:
+        title: Controls compression for the TRAP files written by the extractor.
+        description: >
+          This option is only intended for use in debugging the extractor. Accepted
+          values are 'brotli' (the default, to write brotli-compressed TRAP), 'gzip', and 'none'
+          (to write uncompressed TRAP).
+        type: string
+        pattern: "^(none|gzip|brotli)$"

csharp/extractor/Semmle.Extraction.Tests/Options.cs

@@ -210,19 +210,19 @@ public void ArchiveArguments()
         [Fact]
         public void CompressionTests()
         {
-            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_COMPRESSION", "gzip");
+            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_TRAP_COMPRESSION", "gzip");
             options = CSharp.Options.CreateWithEnvironment(Array.Empty<string>());
             Assert.Equal(TrapWriter.CompressionMode.Gzip, options.TrapCompression);
 
-            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_COMPRESSION", "brotli");
+            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_TRAP_COMPRESSION", "brotli");
             options = CSharp.Options.CreateWithEnvironment(Array.Empty<string>());
             Assert.Equal(TrapWriter.CompressionMode.Brotli, options.TrapCompression);
 
-            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_COMPRESSION", "none");
+            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_TRAP_COMPRESSION", "none");
             options = CSharp.Options.CreateWithEnvironment(Array.Empty<string>());
             Assert.Equal(TrapWriter.CompressionMode.None, options.TrapCompression);
 
-            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_COMPRESSION", null);
+            Environment.SetEnvironmentVariable("CODEQL_EXTRACTOR_CSHARP_OPTION_TRAP_COMPRESSION", null);
             options = CSharp.Options.CreateWithEnvironment(Array.Empty<string>());
             Assert.Equal(TrapWriter.CompressionMode.Brotli, options.TrapCompression);
         }

csharp/extractor/Semmle.Extraction/Options.cs

@@ -66,7 +66,7 @@ public virtual bool HandleOption(string key, string value)
                 case "verbosity":
                     Verbosity = (Verbosity)int.Parse(value);
                     return true;
-                case "compression":
+                case "trap_compression":
                     if (Enum.TryParse<TrapWriter.CompressionMode>(value, true, out var mode))
                     {
                         TrapCompression = mode;

csharp/extractor/Semmle.Util/CommandLineOptions.cs

@@ -47,10 +47,10 @@ private static List<string> GetExtractorOptions()
         {
             var extractorOptions = new List<string>();
 
-            var compressionMode = GetExtractorOption("compression");
-            if (!string.IsNullOrEmpty(compressionMode))
+            var trapCompression = GetExtractorOption("trap_compression");
+            if (!string.IsNullOrEmpty(trapCompression))
             {
-                extractorOptions.Add($"--compression:{compressionMode}");
+                extractorOptions.Add($"--trap_compression:{trapCompression}");
             }
 
             return extractorOptions;

csharp/ql/src/change-notes/2022-02-23-extractor-option-compression.md

@@ -1,5 +1,5 @@
 ---
 category: minorAnalysis
 ---
-* The C# extractor now accepts an extractor option `compression`, which is used to decide the compression format for TRAP files. The legal options are `brotli` (default), `gzip` or `none`.
+* The C# extractor now accepts an extractor option `trap.compression`, which is used to decide the compression format for TRAP files. The legal options are `brotli` (default), `gzip` or `none`.
 * The C# extractor no longer accepts `--no-brotli` or `--brotli` flags to switch between `gzip` and `brotli` as compression method for TRAP files.