change how Blob and File initialized

src/browser/webapi/Blob.zig

@@ -34,7 +34,7 @@ slice: []const u8,
 /// MIME attached to blob. Can be an empty string.
 mime: []const u8,
 
-const Type = union(enum) {
+pub const Type = union(enum) {
     generic,
     file: *@import("File.zig"),
 };
@@ -76,7 +76,11 @@ pub fn init(
         break :blk "";
     };
 
-    return page._factory.create(Blob{ .slice = slice, .mime = mime });
+    return page._factory.create(Blob{
+        ._type = .generic,
+        .slice = slice,
+        .mime = mime,
+    });
 }
 
 const largest_vector = @max(std.simd.suggestVectorLength(u8) orelse 1, 8);

src/browser/webapi/File.zig

@@ -28,8 +28,8 @@ const File = @This();
 _proto: *Blob,
 
 // TODO: Implement File API.
-pub fn init() File {
-    return .{ ._proto = undefined };
+pub fn init(page: *Page) !*File {
+    return page._factory.blob(File{ ._proto = undefined });
 }
 
 pub const JsApi = struct {