allow other XML MIMEs in parseFromString

src/browser/webapi/DOMParser.zig

@@ -19,9 +19,13 @@
 const std = @import("std");
 
 const js = @import("../js/js.zig");
+
 const Page = @import("../Page.zig");
+const Parser = @import("../parser/Parser.zig");
+
 const HTMLDocument = @import("HTMLDocument.zig");
 const XMLDocument = @import("XMLDocument.zig");
+const ProcessingInstruction = @import("../webapi/cdata/ProcessingInstruction.zig");
 
 const DOMParser = @This();
 
@@ -40,7 +44,16 @@ pub fn parseFromString(
     mime_type: []const u8,
     page: *Page,
 ) !HTMLDocumentOrXMLDocument {
-    if (std.mem.eql(u8, mime_type, "text/html")) {
+    const maybe_target_mime = std.meta.stringToEnum(enum {
+        @"text/html",
+        @"text/xml",
+        @"application/xml",
+        @"application/xhtml+xml",
+        @"image/svg+xml",
+    }, mime_type);
+
+    if (maybe_target_mime) |target_mime| switch (target_mime) {
+        .@"text/html" => {
             // Create a new HTMLDocument
             const doc = try page._factory.document(HTMLDocument{
                 ._proto = undefined,
@@ -52,7 +65,6 @@ pub fn parseFromString(
             }
 
             // Parse HTML into the document
-        const Parser = @import("../parser/Parser.zig");
             var parser = Parser.init(page.arena, doc.asNode(), page);
             parser.parse(normalized);
 
@@ -61,26 +73,37 @@ pub fn parseFromString(
             }
 
             return .{ .html_document = doc };
-    }
+        },
-
+        else => {
-    if (std.mem.eql(u8, mime_type, "text/xml")) {
             // Create a new XMLDocument.
             const doc = try page._factory.document(XMLDocument{
                 ._proto = undefined,
             });
 
             // Parse XML into XMLDocument.
-        const Parser = @import("../parser/Parser.zig");
+            const doc_node = doc.asNode();
-        var parser = Parser.init(page.arena, doc.asNode(), page);
+            var parser = Parser.init(page.arena, doc_node, page);
             parser.parseXML(html);
 
             if (parser.err) |pe| {
                 return pe.err;
             }
 
-        return .{ .xml_document = doc };
+            // If first node is a `ProcessingInstruction`, skip it.
+            const first_child = doc_node.firstChild() orelse {
+                // Parsing should fail if there aren't any nodes.
+                unreachable;
+            };
+
+            if (first_child.getNodeType() == 7) {
+                // We're sure that firstChild exist, this cannot fail.
+                _ = doc_node.removeChild(first_child, page) catch unreachable;
             }
 
+            return .{ .xml_document = doc };
+        },
+    };
+
     return error.NotSupported;
 }