xhr: fix getter/setter for callbacks

src/xhr/xhr.zig

@@ -35,32 +35,69 @@ pub const XMLHttpRequestEventTarget = struct {
     // Extend libdom event target for pure zig struct.
     base: parser.EventTargetTBase = parser.EventTargetTBase{},
 
+    onloadstart_cbk: ?Callback = null,
+    onprogress_cbk: ?Callback = null,
+    onabort_cbk: ?Callback = null,
+    onload_cbk: ?Callback = null,
+    ontimeout_cbk: ?Callback = null,
+    onloadend_cbk: ?Callback = null,
+
     fn register(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, typ: []const u8, cbk: Callback) !void {
         try parser.eventTargetAddEventListener(@as(*parser.EventTarget, @ptrCast(self)), alloc, typ, cbk, false);
     }
+    fn unregister(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, typ: []const u8, cbk: Callback) !void {
+        const et = @as(*parser.EventTarget, @ptrCast(self));
+        // check if event target has already this listener
+        const lst = try parser.eventTargetHasListener(et, typ, false, cbk.id());
+        if (lst == null) {
+            return;
+        }
+
+        // remove listener
+        try parser.eventTargetRemoveEventListener(et, alloc, typ, lst.?, false);
+    }
+
+    pub fn get_onloadstart(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.onloadstart_cbk;
+    }
+    pub fn get_onprogress(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.onprogress_cbk;
+    }
+    pub fn get_onabort(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.onabort_cbk;
+    }
+    pub fn get_onload(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.onload_cbk;
+    }
+    pub fn get_ontimeout(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.ontimeout_cbk;
+    }
+    pub fn get_onloadend(self: *XMLHttpRequestEventTarget) ?Callback {
+        return self.onloadend_cbk;
+    }
 
     pub fn set_onloadstart(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.onloadstart_cbk) |cbk| try self.unregister(alloc, "loadstart", cbk);
         try self.register(alloc, "loadstart", handler);
     }
     pub fn set_onprogress(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.onprogress_cbk) |cbk| try self.unregister(alloc, "progress", cbk);
         try self.register(alloc, "progress", handler);
     }
     pub fn set_onabort(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.onabort_cbk) |cbk| try self.unregister(alloc, "abort", cbk);
         try self.register(alloc, "abort", handler);
     }
-    // TODO remove-me, test func du to an issue w/ the setter.
-    // see https://lightpanda.slack.com/archives/C05TRU6RBM1/p1706708213838989
-    pub fn _setOnload(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
-        try self.set_onload(alloc, handler);
-    }
-
     pub fn set_onload(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.onload_cbk) |cbk| try self.unregister(alloc, "load", cbk);
         try self.register(alloc, "load", handler);
     }
     pub fn set_ontimeout(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.ontimeout_cbk) |cbk| try self.unregister(alloc, "timeout", cbk);
         try self.register(alloc, "timeout", handler);
     }
     pub fn set_onloadend(self: *XMLHttpRequestEventTarget, alloc: std.mem.Allocator, handler: Callback) !void {
+        if (self.onloadend_cbk) |cbk| try self.unregister(alloc, "loadend", cbk);
         try self.register(alloc, "loadend", handler);
     }
 
@@ -438,9 +475,8 @@ pub fn testExecFn(
         .{ .src = "var nb = 0; function cbk(event) { nb ++; }", .ex = "undefined" },
         .{ .src = "const req = new XMLHttpRequest()", .ex = "undefined" },
 
-        // TODO remove-me, test func du to an issue w/ the setter.
+        .{ .src = "req.onload = cbk", .ex = "function cbk(event) { nb ++; }" },
-        // see https://lightpanda.slack.com/archives/C05TRU6RBM1/p1706708213838989
+        // .{ .src = "req.onload", .ex = "function cbk(event) { nb ++; }" },
-        .{ .src = "req.setOnload(cbk)", .ex = "undefined" },
         // .{ .src = "req.onload = cbk", .ex = "function cbk(event) { nb ++; }" },
 
         .{ .src = "req.open('GET', 'https://w3.org')", .ex = "undefined" },