[REF] reorganize file structure

in order to separate compiler/ and runtime/ code

src/runtime/error_handling.ts

@@ -0,0 +1,63 @@
+import type { ComponentNode } from "./component_node";
+import type { Fiber } from "./fibers";
+
+// Maps fibers to thrown errors
+export const fibersInError: WeakMap<Fiber, any> = new WeakMap();
+export const nodeErrorHandlers: WeakMap<ComponentNode, ((error: any) => void)[]> = new WeakMap();
+
+function _handleError(node: ComponentNode | null, error: any): boolean {
+  if (!node) {
+    return false;
+  }
+  const fiber = node.fiber;
+  if (fiber) {
+    fibersInError.set(fiber, error);
+  }
+
+  const errorHandlers = nodeErrorHandlers.get(node);
+  if (errorHandlers) {
+    let handled = false;
+    // execute in the opposite order
+    for (let i = errorHandlers.length - 1; i >= 0; i--) {
+      try {
+        errorHandlers[i](error);
+        handled = true;
+        break;
+      } catch (e) {
+        error = e;
+      }
+    }
+
+    if (handled) {
+      return true;
+    }
+  }
+  return _handleError(node.parent, error);
+}
+
+type ErrorParams = { error: any } & ({ node: ComponentNode } | { fiber: Fiber });
+export function handleError(params: ErrorParams) {
+  const error = params.error;
+  const node = "node" in params ? params.node : params.fiber.node;
+  const fiber = "fiber" in params ? params.fiber : node.fiber!;
+
+  // resets the fibers on components if possible. This is important so that
+  // new renderings can be properly included in the initial one, if any.
+  let current: Fiber | null = fiber;
+  do {
+    current.node.fiber = current;
+    current = current.parent;
+  } while (current);
+
+  fibersInError.set(fiber.root!, error);
+
+  const handled = _handleError(node, error);
+  if (!handled) {
+    console.warn(`[Owl] Unhandled error. Destroying the root component`);
+    try {
+      node.app.destroy();
+    } catch (e) {
+      console.error(e);
+    }
+  }
+}