fix(vue): replacing routes across nested outlets preserves previous route info

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

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• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue URL: resolves #25017

When going across nested outlets, we were accidentally wiping the previous route. Given the following scenario:

/top-level-outlet --> /nested-outlet/1 --> (replace) /nested-outlet/2.

When replacing to /nested-outlet/2 we first removed location history starting with /nested-outlet/1 (because it is getting replaced): https://github.com/ionic-team/ionic-framework/blob/main/packages/vue-router/src/router.ts#L374
This is the correct behavior.

However, the routerAction is replace here which means that locationHistory.add also performed another replace operation: https://github.com/ionic-team/ionic-framework/blob/main/packages/vue-router/src/locationHistory.ts#L9-L11

This means that the /top-level-outlet info was wiped before /nested-outlet/2 was added. Since /top-level-outlet was wiped, pressing the ion-back-button in the nested outlet component would not go back to /top-level-outlet.

What is the new behavior?

• When replacing we ensure that the replace operation only happens once.
• When adding a test I noticed that the should show first page test is made redundant by the beforeEach hook in nested.js, so I removed it.
• I also removed a redundant ionPageVisible('nestedchild') call in should go navigate across nested outlet contexts. This check is already done in the beforeEach hook.

Does this introduce a breaking change?

• Yes
• No

Other information

We can likely clean up this behavior even further. The logic I removed dates back pretty far in Ionic React: #21693 I'm not really sure it's even needed anymore.

Dev build: 6.1.3-dev.11650490791.156717e3