Only run vd-tool per file if the batch conversion reports an error

Author: maximilian.schubert

Sources/FigmaExport/Output/VectorDrawableConverter.swift

@@ -1,27 +1,71 @@
 import FigmaExportCore
 import Foundation
+import Logging
 
 /// SVG to XML converter
 final class VectorDrawableConverter {
+    private static let notSupportedWarning = "is not supported"
+    private let logger = Logger(label: "com.redmadrobot.figma-export.vector-drawable-converter")
+
     /// Converts SVG files to XML
+    /// In case unsupported XML-Tags are reported, the converting command will be executed for each file for better logging.
     /// - Parameter inputDirectoryUrl: Url to directory with SVG files
     func convert(inputDirectoryUrl: URL) throws {
-        let enumerator = FileManager.default.enumerator(at: inputDirectoryUrl, includingPropertiesForKeys: nil)
-
-        while let file = enumerator?.nextObject() as? URL {
-            guard file.pathExtension == "svg" else { return }
-            let task = Process()
-            task.executableURL = URL(fileURLWithPath: "/usr/local/bin/vd-tool")
-            task.arguments = ["-c", "-in", file.path, "-out", inputDirectoryUrl.path]
-
-            do {
-                try task.run()
-            } catch {
-                task.executableURL = URL(fileURLWithPath: "./vd-tool/bin/vd-tool")
-                try task.run()
+        let errorPipe = Pipe()
+        let outputPipe = Pipe()
+        let directoryTaskArguments = ["-c", "-in", inputDirectoryUrl.path]
+
+        try runVdTool(with: directoryTaskArguments, errorPipe: errorPipe, outputPipe: outputPipe)
+
+        let errorData = errorPipe.fileHandleForReading.readDataToEndOfFile()
+        let error = String(decoding: errorData, as: UTF8.self)
+
+        let outputData = outputPipe.fileHandleForReading.readDataToEndOfFile()
+        let outputString = String(decoding: outputData, as: UTF8.self)
+        // Only log last line out standard output
+        outputString.lastLine.flatMap { logger.info("\($0)") }
+
+        if error.contains(Self.notSupportedWarning) {
+            logger.warning("vd-tool reported unsupported xml tags. Executing vd-tool for each file...")
+            let enumerator = FileManager.default.enumerator(at: inputDirectoryUrl, includingPropertiesForKeys: nil)
+            while let file = enumerator?.nextObject() as? URL {
+                guard file.pathExtension == "svg" else { continue }
+                let fileErrorPipe = Pipe()
+                let fileTaskArguments = ["-c", "-in", file.path, "-out", inputDirectoryUrl.path]
+                logger.info("Converting file: \(file.path)")
+                try runVdTool(with: fileTaskArguments, errorPipe: fileErrorPipe)
+
+                let fileErrorData = fileErrorPipe.fileHandleForReading.readDataToEndOfFile()
+                let fileError = String(decoding: fileErrorData, as: UTF8.self)
+
+                if fileError.contains(Self.notSupportedWarning) {
+                    logger.warning("Error in file: \(file.path)\n\(fileError)")
+                }
             }
+        }
+    }
+
+    private func runVdTool(with arguments: [String], errorPipe: Pipe?, outputPipe: Pipe? = nil) throws {
+        let task = Process()
+        task.executableURL = URL(fileURLWithPath: "/usr/local/bin/vd-tool")
+        task.arguments = arguments
 
-            task.waitUntilExit()
+        task.standardOutput = outputPipe
+        task.standardError = errorPipe
+
+        do {
+            try task.run()
+        } catch {
+            task.executableURL = URL(fileURLWithPath: "./vd-tool/bin/vd-tool")
+            try task.run()
         }
+
+        task.waitUntilExit()
+    }
+}
+
+private extension String {
+    var lastLine: String? {
+        split { $0 == "\n" }.compactMap(String.init).last
     }
 }