Moved BindingGenerator from gen html project. It makes more sense here.

Plugins/BindingPlugin/source.swift

@@ -0,0 +1,173 @@
+//
+//  source.swift
+//  gen_html
+//
+//  Created by Isaac Paul on 9/30/25.
+//
+
+import Foundation
+import PackagePlugin
+
+final class AppError: LocalizedError, Sendable {
+    
+    let message: String
+    
+    init(_ message: String) {
+        self.message = message
+    }
+    init(_ message: String, _ error:Error) {
+        self.message = "\(message) : \(error.localizedDescription)"
+    }
+    
+    static func failure<T>(_ message: String) -> Result<T, AppError> {
+        return .failure(AppError(message))
+    }
+    
+    var errorDescription: String? {
+        get {
+            return message
+        }
+    }
+    
+    var failureReason: String? { get { return message } }
+}
+
+let toolName = "BindingGenerator"
+
+extension BindingPlugin: BuildToolPlugin {
+    func createBuildCommands(context: PluginContext, target: Target) async throws -> [Command] {
+        guard let swiftTarget = target as? SwiftSourceModuleTarget else {
+            print("Unexpected target: \(type(of: target)). Needs SwiftSourceModuleTarget")
+            throw AppError("Unexpected target: \(type(of: target)). Needs SwiftSourceModuleTarget")
+        }
+        let toolUrl = try context.tool(named: toolName).url
+        
+        return try createBuildCommands(
+            outputDir: context.pluginWorkDirectoryURL,
+            inputDir: swiftTarget.directoryURL,
+            inputFiles: swiftTarget.sourceFiles,
+            toolExe: toolUrl
+        )
+    }
+}
+
+#if canImport(XcodeProjectPlugin)
+
+    import XcodeProjectPlugin
+import System
+
+    // The entry point for Xcode project builds.
+    extension BindingPlugin: XcodeBuildToolPlugin {
+        func createBuildCommands(context: XcodePluginContext, target: XcodeTarget) throws -> [Command] {
+            let toolUrl = try context.tool(named: toolName).url
+            return try createBuildCommands(
+                outputDir: context.pluginWorkDirectoryURL,
+                inputDir: context.xcodeProject.directoryURL,
+                inputFiles: target.inputFiles,
+                toolExe: toolUrl
+            )
+        }
+    }
+
+#endif
+
+struct Config: Codable {
+    var root_path: String?
+}
+
+extension URL {
+    func isHtml() -> Bool {
+        return self.pathExtension == "html" || self.pathExtension == "htm"
+    }
+}
+
+extension String {
+    func uppercaseFirstLetter() -> String {
+        guard let firstLetter = self.first else { return self }
+        return firstLetter.uppercased() + self.dropFirst()
+    }
+}
+
+@main
+struct BindingPlugin {
+
+    private static let configFile = "binding_generator_plugin.json"
+
+    private func createBuildCommands(
+        outputDir: URL,
+        inputDir: URL,
+        inputFiles: FileList,
+        toolExe: URL
+    ) throws -> [Command] {
+
+        let configFilePath = inputFiles.first(where: { $0.url.lastPathComponent == BindingPlugin.configFile })
+        let configFileURL = configFilePath?.url
+
+        //let listSearchDir: [String]
+        let htmlFiles = inputFiles.filter { $0.url.isHtml() }.map { $0.url }
+        let rootPath:URL
+
+        if let configFileURL = configFileURL {
+            
+            let configData = try Data(contentsOf: configFileURL)
+            let config = try JSONDecoder().decode(Config.self, from: configData)
+
+            let baseDirectory:URL = configFileURL.deletingLastPathComponent()
+            if let configRootPath = config.root_path {
+                rootPath = baseDirectory.appending(path: configRootPath)
+            } else {
+                rootPath = inputDir
+            }
+            /*
+            for source in config.sources ?? [] {
+                let sourceFileOrDirectory = baseDirectory.appendingPathComponent(source)
+                if sourceFileOrDirectory.isHtml()  {
+                    htmlFiles.append(sourceFileOrDirectory)
+                } else {
+                    let files = try FileManager.default.contentsOfDirectory(
+                        at: sourceFileOrDirectory,
+                        includingPropertiesForKeys: nil
+                    )
+                    let filteredFiles = files.filter { $0.isHtml() }
+                    htmlFiles.append(contentsOf: filteredFiles)
+                }
+            }*/
+            
+        } else {
+            rootPath = inputDir
+        }
+/*
+ /Users/isaacpaul/Projects/swift-projects/HRW/Plugins/BindingPlugin/source.swift:146:13: error: 'let' cannot appear nested inside another 'var' or 'let' pattern
+ <unknown>:0: error: error opening input file '/Users/isaacpaul/Library/Developer/Xcode/DerivedData/HRW-bicwrilrmihgqogjvxyqtcosfaro/Build/Intermediates.noindex/BuildToolPluginIntermediates/hrw.output/HRWTests/BindingPlugin/Example.swift' (No such file or directory)
+ //
+ Showing All Messages
+ Error opening input file '/Users/isaacpaul/Library/Developer/Xcode/DerivedData/HRW-bicwrilrmihgqogjvxyqtcosfaro/Build/Intermediates.noindex/BuildToolPluginIntermediates/hrw.output/HRWTests/BindingPlugin/ExampleBinding.swift' (No such file or directory)
+ */
+        return htmlFiles.map { eachFile in
+            let fileName = eachFile.lastPathComponent
+            let ext = eachFile.pathExtension
+            let extIndex = fileName.index(fileName.startIndex, offsetBy: fileName.count - (ext.count + 1))
+            let withoutExt = String(fileName[fileName.startIndex..<extIndex])
+            let targetFileName = "\(withoutExt.uppercaseFirstLetter()).swift"
+            
+            let rootFP = FilePath(rootPath.path)
+            var inputFP = FilePath(eachFile.path)
+            let outputDirFP = FilePath(outputDir.path)
+            
+            let _ = inputFP.removePrefix(rootFP)
+            inputFP.removeLastComponent()
+            //let idk = outputDirFP.pushing(inputFP)
+            let outputFileA = outputDir.appendingPathComponent(inputFP.string)
+            let outputFile = outputFileA.appendingPathComponent(targetFileName)
+            print("Expected path: \(outputFile.path)")
+
+            return .buildCommand(
+                displayName: "Generating binding to \(outputFile.path)",
+                executable: toolExe,
+                arguments: ["-o", outputDir.path, "-i", eachFile.path, "-b", rootPath.path],
+                inputFiles: [eachFile],
+                outputFiles: [URL(fileURLWithPath: outputFile.path)]
+            )
+        }
+    }
+}