viewBox now accepts comma delimited values

DOM/Sources/Parser.XML.SVG.swift

@@ -29,6 +29,8 @@
 //  3. This notice may not be removed or altered from any source distribution.
 //
 
+import Foundation
+
 package extension XMLParser {
 
     func parseSVG(_ e: XML.Element) throws -> DOM.SVG {
@@ -72,9 +74,9 @@ package extension XMLParser {
         guard let data = data else { return nil }
         var scanner = XMLParser.Scanner(text: data)
 
-        let x = try scanner.scanCoordinate()
-        let y = try scanner.scanCoordinate()
-        let width = try scanner.scanCoordinate()
+        let x = try scanner.scanViewBoxCoordinate()
+        let y = try scanner.scanViewBoxCoordinate()
+        let width = try scanner.scanViewBoxCoordinate()
         let height = try scanner.scanCoordinate()
 
         guard scanner.isEOF else {
@@ -247,3 +249,17 @@ package extension XMLParser {
         return pattern
     }
 }
+
+private extension XMLParser.Scanner {
+
+    mutating func scanViewBoxCoordinate() throws -> DOM.Coordinate {
+        let coordinate = try scanCoordinate()
+        _ = try? scanCharacter(matchingAny: .viewBoxSeparator)
+        return coordinate
+    }
+}
+
+private extension Foundation.CharacterSet {
+
+    static let viewBoxSeparator = Foundation.CharacterSet(charactersIn: ",")
+}

DOM/Tests/Parser.SVGTests.swift

@@ -199,6 +199,25 @@ struct ParserSVGTests {
         }
     }
 
+    @Test
+    func viewBoxWithCommaDelimiters() throws {
+        let parsed = try #require(try XMLParser().parseViewBox("0,0,150,50"))
+        #expect(parsed.x == 0)
+        #expect(parsed.y == 0)
+        #expect(parsed.width == 150)
+        #expect(parsed.height == 50)
+    }
+
+    @Test
+    func invalidViewBoxWithCommaDelimiters() {
+        #expect(throws: (any Error).self) {
+            try XMLParser().parseViewBox("10,,,10,10,10")
+        }
+        #expect(throws: (any Error).self) {
+            try XMLParser().parseViewBox("10,10,10")
+        }
+    }
+
     @Test
     func clipPath() throws {
         let node = XML.Element(name: "clipPath", attributes: ["id": "hello"])