[FIX] component: render in delayed willUpdateProps

Have a child component on which a render is triggered.
This component delays its willUpdateProps and makes a rendering during the willUpdateProps

Before this commit, renderings of the child were inconsistent across
its parent's renderings.

After this commit, it works as expected.

src/component/component_node.ts

@@ -203,12 +203,6 @@ export class ComponentNode<T extends typeof Component = typeof Component>
     // update
     const fiber = makeChildFiber(this, parentFiber);
     this.fiber = fiber;
-    if (this.willPatch.length) {
-      parentFiber.root.willPatch.push(fiber);
-    }
-    if (this.patched.length) {
-      parentFiber.root.patched.push(fiber);
-    }
     const component = this.component;
     applyDefaultProps(props, component.constructor as any);
     const prom = Promise.all(this.willUpdateProps.map((f) => f.call(component, props)));
@@ -216,8 +210,15 @@ export class ComponentNode<T extends typeof Component = typeof Component>
     if (fiber !== this.fiber) {
       return;
     }
-    this.component.props = props;
+    component.props = props;
     this._render(fiber);
+    const parentRoot = parentFiber.root;
+    if (this.willPatch.length) {
+      parentRoot.willPatch.push(fiber);
+    }
+    if (this.patched.length) {
+      parentRoot.patched.push(fiber);
+    }
   }
 
   /**

src/component/fibers.ts

@@ -3,15 +3,44 @@ import type { ComponentNode } from "./component_node";
 import { fibersInError, handleError } from "./error_handling";
 import { STATUS } from "./status";
 
+/**
+ * Cleans on the root fiber the patch and willPatch fiber lists
+ * It is typically needed when the same root fiber needs to recycle on
+ * of its children or grandchildren's fiber.
+ */
+function cleanPatchableFiber(child: Fiber, root: RootFiber) {
+  const { willPatch, patched } = root;
+  let i = willPatch.indexOf(child);
+  if (i > -1) {
+    willPatch.splice(i, 1);
+  }
+  i = patched.indexOf(child);
+  if (i > -1) {
+    patched.splice(i, 1);
+  }
+}
+
 export function makeChildFiber(node: ComponentNode, parent: Fiber): Fiber {
   let current = node.fiber;
   if (current) {
     // current is necessarily a rootfiber here
     let root = parent.root;
+    const isSameRoot = current.root === root;
     cancelFibers(root, current.children);
     current.children = [];
     current.parent = parent;
-    root.counter++;
+    // only increment our rendering if we were not
+    // already accounted for, or that we have been rendered
+    // already (in which case our fiber was removed from the root rendering)
+    if (!isSameRoot || current.bdom) {
+      root.counter++;
+    }
+
+    if (isSameRoot) {
+      cleanPatchableFiber(current, root);
+    }
+
+    current.bdom = null;
     current.root = root;
     return current;
   }