[Bug] RouteInfo.find() produces undefined items

[nelstrom]

🐞 Describe the Bug

The documentation for the RouteInfo.find() method says:

Allows you to traverse through the linked list of RouteInfos from the topmost to leafmost. Returns the first RouteInfo in the linked list for which the callback returns true.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, array);

Up until v4.2 of Ember, this callback function worked as expected. Since v4.3 of Ember, the callback sometimes produces an undefined value for the item.

🔬 Minimal Reproduction

I've created a minimal reproduction.

The beforeModel hook in the 'accounts.account' route demonstrates the bug:

  beforeModel({ to }) {
    to.find(function (item, index, array) {
      console.log('accounts.account#beforeModel:', {
        item,
        index,
        array,
        parent: item?.parent,
      });
    });
  }

To exercise this code, check out the repository and run the tests.

😕 Actual Behavior

The RouteInfo.find() callback produces an undefined value for the item.

This screenshot was created while running the minimal reproduction against Ember 4.5.

🤔 Expected Behavior

The RouteInfo.find() callback should always provide a value for the item:

This screenshot was created while running the minimal reproduction against Ember 4.2.

🌍 Environment

• Ember: -4.3
• Node.js/npm: v16.13.0/8.1.0
• OS: Mac OS 12.1
• Browser: Chrome v103

➕ Additional Context

We used git bisect to find the commit that introduced this problem. Here's the output from our bisect session:

Git bisect output

a47efb0356441c151c4c9a985059659975d4caf1 is the first bad commit
commit a47efb0356441c151c4c9a985059659975d4caf1
Date:   Thu Jan 27 15:29:23 2022 -0800
Future public @ember/routing types

package.json                                       |   2 +-

.../-internals/glimmer/lib/components/link-to.ts   |  12 +-

packages/@ember/-internals/routing/index.ts        |   8 +-

.../-internals/routing/lib/ext/controller.ts       |  10 +-

.../-internals/routing/lib/services/router.ts      | 222 ++++----

.../-internals/routing/lib/services/routing.ts     |  24 +-

.../-internals/routing/lib/system/route-info.ts    |   4 +-

.../@ember/-internals/routing/lib/system/route.ts  | 605 +++++++++++----------

.../@ember/-internals/routing/lib/system/router.ts | 141 ++---

.../-internals/routing/lib/system/router_state.ts  |  22 +-

packages/@ember/-internals/routing/lib/utils.ts    |  54 +-

.../@ember/controller/lib/controller_mixin.d.ts    |   5 +-

packages/@ember/routing/auto-location.js           |   1 -

packages/@ember/routing/auto-location.ts           |   1 +

packages/@ember/routing/hash-location.js           |   1 -

packages/@ember/routing/hash-location.ts           |   1 +

packages/@ember/routing/location.js                |   1 -

packages/@ember/routing/location.ts                |   1 +

packages/@ember/routing/none-location.js           |   1 -

packages/@ember/routing/none-location.ts           |   1 +

packages/@ember/routing/route.js                   |   1 -

packages/@ember/routing/route.ts                   |   1 +

packages/@ember/routing/router-service.ts          |   5 +

packages/@ember/routing/router.js                  |   1 -

packages/@ember/routing/router.ts                  |   1 +

.../routing/type-tests/auto-location.test.ts       |  10 +

.../routing/type-tests/hash-location.test.ts       |  10 +

.../routing/type-tests/history-location.test.ts    |  10 +

packages/@ember/routing/type-tests/link-to.test.ts |   6 +

.../@ember/routing/type-tests/location.test.ts     |  40 ++

.../routing/type-tests/none-location.test.ts       |  10 +

.../@ember/routing/type-tests/route/index.test.ts  |  72 +++

.../routing/type-tests/route/overrides.test.ts     |  47 ++

.../routing/type-tests/route/query-params.test.ts  |  34 ++

.../@ember/routing/type-tests/route/send.test.ts   |  30 +

.../routing/type-tests/router-service.test.ts      |  94 ++++

.../@ember/routing/type-tests/router/index.test.ts |  44 ++

.../@ember/routing/type-tests/router/map.test.ts   |  26 +

yarn.lock                                          |   8 +-

39 files changed, 1023 insertions(+), 544 deletions(-)

delete mode 100644 packages/@ember/routing/auto-location.js

create mode 100644 packages/@ember/routing/auto-location.ts

delete mode 100644 packages/@ember/routing/hash-location.js

create mode 100644 packages/@ember/routing/hash-location.ts

delete mode 100644 packages/@ember/routing/location.js

create mode 100644 packages/@ember/routing/location.ts

delete mode 100644 packages/@ember/routing/none-location.js

create mode 100644 packages/@ember/routing/none-location.ts

delete mode 100644 packages/@ember/routing/route.js

create mode 100644 packages/@ember/routing/route.ts

create mode 100644 packages/@ember/routing/router-service.ts

delete mode 100644 packages/@ember/routing/router.js

create mode 100644 packages/@ember/routing/router.ts

create mode 100644 packages/@ember/routing/type-tests/auto-location.test.ts

create mode 100644 packages/@ember/routing/type-tests/hash-location.test.ts

create mode 100644 packages/@ember/routing/type-tests/history-location.test.ts

create mode 100644 packages/@ember/routing/type-tests/link-to.test.ts

create mode 100644 packages/@ember/routing/type-tests/location.test.ts

create mode 100644 packages/@ember/routing/type-tests/none-location.test.ts

create mode 100644 packages/@ember/routing/type-tests/route/index.test.ts

create mode 100644 packages/@ember/routing/type-tests/route/overrides.test.ts

create mode 100644 packages/@ember/routing/type-tests/route/query-params.test.ts

create mode 100644 packages/@ember/routing/type-tests/route/send.test.ts

create mode 100644 packages/@ember/routing/type-tests/router-service.test.ts

create mode 100644 packages/@ember/routing/type-tests/router/index.test.ts

create mode 100644 packages/@ember/routing/type-tests/router/map.test.ts

We came across this bug while upgrading our Ember app from 4.2 to 4.3. Here's a (simplified) sample of the code that drew our attention to the issue:

import Route from '@ember/routing/route';
import { assert } from '@ember/debug';

export default class AccountsAccountRoute extends Route {

  beforeModel({ to }) {
    let routeInfo = to.find(({ name }) => name === 'accounts.account');
    let { account_id } = routeInfo?.params;
    assert("Couldn't find account_id parameter", account_id);
    // ...etc...
  }
}

As a work around, we've rewritten the call to find() as follows:

let routeInfo = to.find((item) => item?.name === 'accounts.account');

[chriskrycho]

Looks like a duplicate of #20056?

[m3l1x]

Looks like a duplicate of #20056?

Yes, it is, but a more detailed one. I could close mine if it's desired.

[chriskrycho]

Yeah, if you could pull your comment over onto that thread, that would be helpful from a maintenance POV! Thank you!

[sly7-7]

@chriskrycho 🤔 I think this is still an issue, maybe you wanted to close the other one ?

Thank you @nelstrom for the detail, I was just bitten by this. I can't see what changes in the router lib could have caused this, but eventually the work done by @wagenet around better types. tildeio/router.js@c83aeed#r82130596,

or maybe https://github.com/emberjs/ember.js/pull/19971/files could also have side effects ?

It seems like the underlyning weak map does not have the correct keys to retrieve the route infos. But I don't think the changes in the types could have an impact.

But other than that, for now I can't see what change in the commit could lead to this issue

[chriskrycho]

It is still an issue, yes; but it's the same issue as the other one. 😄

[sly7-7]

Yes, sorry, so that mean you close this one on purpose, right ? Even if it has more details than the other. In that case, should I put my comments in #20056 ?