From 2c563ee380e467487df2420232264b2b48d022ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A9ry=20Debongnie?= <ged@odoo.com>
Date: Sat, 26 Oct 2019 10:27:56 +0200
Subject: [PATCH] [REF] component: move error handling into the fiber

---
 src/component/component.ts | 45 +++++---------------------------------
 src/component/fiber.ts     | 29 +++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 40 deletions(-)

diff --git a/src/component/component.ts b/src/component/component.ts
index 99e5a2e8..b1ef1462 100644
--- a/src/component/component.ts
+++ b/src/component/component.ts
@@ -262,8 +262,11 @@ export class Component<T extends Env, Props extends {}> {
   /**
    * catchError is a method called whenever some error happens in the rendering or
    * lifecycle hooks of a child.
+   *
+   * It needs to be implemented by a component that is designed to handle the
+   * error properly.
    */
-  catchError(error: Error): void {}
+  catchError?(error?: Error):void;
 
   //--------------------------------------------------------------------------
   // Public
@@ -561,7 +564,7 @@ export class Component<T extends Env, Props extends {}> {
     try {
       await Promise.all([this.willStart(), this.__owl__.willStartCB && this.__owl__.willStartCB()]);
     } catch (e) {
-      errorHandler(e, fiber);
+      fiber.handleError(e);
       fiber.vnode = h("div"); // -> we render this div at the end
       return Promise.resolve();
     }
@@ -586,7 +589,7 @@ export class Component<T extends Env, Props extends {}> {
       });
     } catch (e) {
       vnode = __owl__.vnode || h("div");
-      errorHandler(e, fiber);
+      fiber.handleError(e);
     }
     fiber.vnode = vnode;
     if (__owl__.observer) {
@@ -650,39 +653,3 @@ export class Component<T extends Env, Props extends {}> {
     return <Props>props;
   }
 }
-
-//------------------------------------------------------------------------------
-// Error handling
-//------------------------------------------------------------------------------
-
-Fiber.prototype.handleError = function(error) {
-  errorHandler(error, this);
-};
-/**
- * This is the global error handler for errors occurring in Owl main lifecycle
- * methods.  Caught errors are triggered on the QWeb instance, and are
- * potentially given to some parent component which implements `catchError`.
- *
- * If there are no such component, we destroy everything. This is better than
- * being in a corrupted state.
- */
-function errorHandler(error: Error, fiber: Fiber) {
-  let canCatch = false;
-  let component = fiber.component;
-  let qweb = component.env.qweb;
-  let root = component;
-  while (component && !(canCatch = component.catchError !== Component.prototype.catchError)) {
-    root = component;
-    component = component.__owl__.parent!;
-  }
-  console.error(error);
-  qweb.trigger("error", error);
-
-  if (canCatch) {
-    setTimeout(() => {
-      component.catchError(error);
-    });
-  } else {
-    root.destroy();
-  }
-}
diff --git a/src/component/fiber.ts b/src/component/fiber.ts
index 157e3b00..182c5dee 100644
--- a/src/component/fiber.ts
+++ b/src/component/fiber.ts
@@ -195,5 +195,32 @@ export class Fiber {
     });
   }
 
-  handleError(e: Error) {}
+  /**
+   * This is the global error handler for errors occurring in Owl main lifecycle
+   * methods.  Caught errors are triggered on the QWeb instance, and are
+   * potentially given to some parent component which implements `catchError`.
+   *
+   * If there are no such component, we destroy everything. This is better than
+   * being in a corrupted state.
+   */
+  handleError(error: Error) {
+    let canCatch = false;
+    let component = this.component;
+    let qweb = component.env.qweb;
+    let root = component;
+    while (component && !(canCatch = !!component.catchError)) {
+      root = component;
+      component = component.__owl__.parent!;
+    }
+    console.error(error);
+    qweb.trigger("error", error);
+
+    if (canCatch) {
+      setTimeout(() => {
+        component.catchError!(error);
+      });
+    } else {
+      root.destroy();
+    }
+  }
 }