Preserve all SFSymbol classes

SwiftDraw/Parser.XML.Color.swift

@@ -55,7 +55,8 @@ extension XMLParser {
   }
 
   private func parseColorNone(data: String) -> DOM.Color? {
-    if data.trimmingCharacters(in: .whitespaces) == "none" {
+    let trimmed = data.trimmingCharacters(in: .whitespaces)
+    if trimmed == "none" || trimmed == "transparent" {
       return DOM.Color.none // .none resolves to Optional.none
     }
     return nil

SwiftDraw/Renderer.SFSymbol.swift

@@ -126,7 +126,6 @@ extension SFSymbolRenderer {
         case black
     }
 
-
     func getInsets(for variant: Variant) -> CommandLine.Insets {
         switch variant {
         case .regular:
@@ -177,7 +176,8 @@ extension SFSymbolRenderer {
     static func getSymbolPaths(for layer: LayerTree.Layer,
                                ctm: LayerTree.Transform.Matrix = .identity) -> [SymbolPath] {
 
-        guard layer.opacity > 0 else { return [] }
+        let isSFSymbolLayer = containsAcceptedName(layer.class)
+        guard isSFSymbolLayer || layer.opacity > 0 else { return [] }
         guard layer.clip.isEmpty else {
             print("Warning:", "clip-path unsupported in SF Symbols.", to: &.standardError)
             return []
@@ -190,12 +190,15 @@ extension SFSymbolRenderer {
         let ctm = ctm.concatenated(layer.transform.toMatrix())
         var paths = [SymbolPath]()
 
-        let symbolClass = containsAcceptedName(layer.class) ? layer.class : nil
+        let symbolClass = isSFSymbolLayer ? layer.class : nil
 
         for c in layer.contents {
             switch c {
             case let .shape(shape, stroke, fill):
-                if let path = makePath(for: shape, stoke: stroke, fill: fill)?.applying(matrix: ctm) {
+                if let path = makePath(for: shape, 
+                                       stoke: stroke,
+                                       fill: fill,
+                                       preserve: isSFSymbolLayer)?.applying(matrix: ctm) {
                     if fill.rule == .evenodd {
                         paths.append(SymbolPath(class: symbolClass, path: path.makeNonZero()))
                     } else {
@@ -218,13 +221,14 @@ extension SFSymbolRenderer {
 
     static func makePath(for shape: LayerTree.Shape,
                          stoke: LayerTree.StrokeAttributes,
-                         fill: LayerTree.FillAttributes) -> LayerTree.Path? {
+                         fill: LayerTree.FillAttributes,
+                         preserve: Bool) -> LayerTree.Path? {
 
-        if fill.fill != .none && fill.opacity > 0 {
+        if preserve || (fill.fill != .none && fill.opacity > 0) {
             return shape.path
         }
 
-        if stoke.color != .none && stoke.width > 0 {
+        if preserve || (stoke.color != .none && stoke.width > 0) {
 #if canImport(CoreGraphics)
             return expandOutlines(for: shape.path, stroke: stoke)
 #else

SwiftDrawTests/Parser.XML.ColorTests.swift

@@ -40,6 +40,12 @@ final class ParserColorTests: XCTestCase {
     XCTAssertEqual(try XMLParser().parseColor("\t none \t"), .none)
   }
 
+  func testColorTransparent() {
+    XCTAssertEqual(try XMLParser().parseColor("transparent"), .none)
+    XCTAssertEqual(try XMLParser().parseColor(" transparent"), .none)
+    XCTAssertEqual(try XMLParser().parseColor("\t transparent \t"), .none)
+  }
+
   func testColorCurrent() {
     XCTAssertEqual(try XMLParser().parseColor("currentColor"), .currentColor)
     XCTAssertEqual(try XMLParser().parseColor(" currentColor"), .currentColor)

SwiftDrawTests/Renderer.SFSymbolTests.swift

@@ -72,6 +72,62 @@ final class RendererSFSymbolTests: XCTestCase {
 
     }
 
+    func testTransparentLayers_Are_Removed() throws {
+        let source = try DOM.SVG.parse(#"""
+        <?xml version="1.0" encoding="UTF-8"?>
+        <svg width="64" height="64" version="1.1" xmlns="http://www.w3.org/2000/svg">
+            <rect width="100" height="100" fill="currentColor" />
+            <rect width="100" height="100" fill="transparent" />
+            <rect width="100" height="100" fill="currentColor" opacity="0" />
+        </svg>
+        """#)
+
+        let template = try SFSymbolTemplate.parse(
+            SFSymbolRenderer.render(svg: source)
+        )
+
+        XCTAssertEqual(
+            template.ultralight.contents.paths.count,
+            1
+        )
+        XCTAssertEqual(
+            template.regular.contents.paths.count,
+            1
+        )
+        XCTAssertEqual(
+            template.black.contents.paths.count,
+            1
+        )
+    }
+
+    func testTransparentSFSymboleLayers_AreNot_Removed() throws {
+        let source = try DOM.SVG.parse(#"""
+        <?xml version="1.0" encoding="UTF-8"?>
+        <svg width="64" height="64" version="1.1" xmlns="http://www.w3.org/2000/svg">
+            <rect width="100" height="100" fill="currentColor" />
+            <rect width="100" height="100" fill="transparent" class="multicolor-0:custom" />
+            <rect width="100" height="100" fill="currentColor" opacity="0" class="SFSymbolsPreview" />
+        </svg>
+        """#)
+
+        let template = try SFSymbolTemplate.parse(
+            SFSymbolRenderer.render(svg: source)
+        )
+
+        XCTAssertEqual(
+            template.ultralight.contents.paths.count,
+            3
+        )
+        XCTAssertEqual(
+            template.regular.contents.paths.count,
+            3
+        )
+        XCTAssertEqual(
+            template.black.contents.paths.count,
+            3
+        )
+    }
+
     #if canImport(CoreGraphics)
     func testStrokeSymbol() throws {
         let url = try Bundle.test.url(forResource: "key.svg")