Allow JSON5 in JSONDecoder

.github/scripts/validate_docs.sh

@@ -3,11 +3,17 @@
 set -e
 set -x
 
-cat <<EOF >> Package.swift
+DEPENDENCY='.package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.0.0")'
+
+if grep -q "$DEPENDENCY" Package.swift; then
+  echo "Package.swift already contains 'swift-docc-plugin"
+else
+  cat <<EOF >> Package.swift
 
 package.dependencies.append(
-  .package(url: "https://github.com/swiftlang/swift-docc-plugin", from: "1.0.0")
+  $DEPENDENCY
 )
 EOF
+fi
 
 swift package --disable-sandbox plugin generate-documentation --target "SwiftJavaDocumentation" --warnings-as-errors --analyze

Plugins/JavaCompilerPlugin/JavaCompilerPlugin.swift

@@ -38,7 +38,9 @@ struct JavaCompilerBuildToolPlugin: BuildToolPlugin {
     let config: Configuration?
 
     if let configData = try? Data(contentsOf: configFile) {
-      config = try? JSONDecoder().decode(Configuration.self, from: configData)
+      let decoder = JSONDecoder()
+      decoder.allowsJSON5 = true
+      config = try? decoder.decode(Configuration.self, from: configData)
     } else {
       config = nil
     }

Sources/SwiftJavaConfigurationShared/Configuration.swift

@@ -174,18 +174,14 @@ public func readConfiguration(configPath: URL, file: String = #fileID, line: UIn
 }
 
 public func readConfiguration(string: String, configPath: URL?, file: String = #fileID, line: UInt = #line) throws -> Configuration? {
-  let cleanedConfigString = string
-    .split(separator: "\n")
-    .filter { line in 
-      !line.trimmingCharacters(in: .whitespaces).starts(with: "//")
-    }.joined(separator: "\n")
-
-  guard let configData = cleanedConfigString.data(using: .utf8) else {
+  guard let configData = string.data(using: .utf8) else {
     return nil
   }
 
   do {
-    return try JSONDecoder().decode(Configuration.self, from: configData)
+    let decoder = JSONDecoder()
+    decoder.allowsJSON5 = true
+    return try decoder.decode(Configuration.self, from: configData)
   } catch {
     throw ConfigurationError(message: "Failed to parse SwiftJava configuration at '\(configPath.map({ $0.absoluteURL.description }) ?? "<no-path>")'! \(#fileID):\(#line)", error: error,
       file: file, line: line)

Sources/SwiftJavaDocumentation/Documentation.docc/SwiftJavaCommandLineTool.md

@@ -254,3 +254,14 @@ public final class SomeModule ... {
     public static void globalFunction() { ... }
 }
 ```
+
+### The swift-java.config file
+
+Many of the tools–as well as SwiftPM plugin's–behaviors can be configured using the `swift-java.config` file.
+
+You can refer to the `SwiftJavaConfigurationShared/Configuration` struct to learn about the supported options.
+
+Configuration from the config files may be overriden or augmented by explicit command line parameters,
+please refer to the options documentation for details on their behavior.
+
+> Note: **Comments in configuration**: The configuration is a JSON 5 file, which among other things allows `//` and `/* */` comments, so feel free to add line comments explaining rationale for some of the settings in youf configuration.