Files
Sean Perkins beb46bf9de fix(react): nav will remove components from the DOM (#25763)
Issue #: resolves #25753

----------

<!-- Please refer to our contributing documentation for any questions on
submitting a pull request, or let us know here if you need any help:
https://ionicframework.com/docs/building/contributing -->

## Pull request checklist

Please check if your PR fulfills the following requirements:
- [x] Tests for the changes have been added (for bug fixes / features)
- [ ] Docs have been reviewed and added / updated if needed (for bug
fixes / features)
- Some docs updates need to be made in the `ionic-docs` repo, in a
separate PR. See the [contributing
guide](https://github.com/ionic-team/ionic-framework/blob/main/.github/CONTRIBUTING.md#modifying-documentation)
for details.
- [x] Build (`npm run build`) was run locally and any changes were
pushed
- [x] Lint (`npm run lint`) has passed locally and any fixes were made
for failures


## Pull request type

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

<!-- Please try to limit your pull request to one type, submit multiple
pull requests if needed. -->

Please check the type of change your PR introduces:
- [x] 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?
<!-- Please describe the current behavior that you are modifying. -->

When `IonNav` performs a pop operation (navigating to root, back, etc.)
the views are not removed from the DOM.

<!-- Issues are required for both bug fixes and features. -->


## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- `IonNav` removes pages from the DOM when they are popped (navigate
back, navigate to root, etc.)
- Memoized constructing React delegate (was reconstructing on each
render)

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!-- If this introduces a breaking change, please describe the impact
and migration path for existing applications below. -->


## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

---------

Co-authored-by: Liam DeBeasi <liamdebeasi@users.noreply.github.com>
2023-04-19 17:03:24 +00:00
..

React E2E Test Apps

Ionic Framework supports multiple versions of React. As a result, we need to verify that Ionic works correctly with each of these React versions.

Syncing Local Changes

The React test app supports syncing your locally built changes for validation.

  1. Build the core, packages/react, and packages/react-router directories using npm run build.
  2. Build the React test app.
  3. Navigate to the built test app.
  4. Install dependencies using npm install.
  5. Sync your local changes using npm run sync.

From here you can either build the application or start a local dev server. When re-syncing changes, you will need to wipe the build cache in node_modules/.cache and restart the dev server/re-build.

Test App Build Structure

Unlike other test applications, these test apps are broken up into multiple directories. These directories are then combined to create a single application. This allows us to share common application code, tests, etc so that each app is being tested the same way. Below details the different pieces that help create a single test application.

apps - This directory contains partial applications for each version of React we want to test. Typically these directories contain new package.json files, cypress.config.ts files, and more. If you have code that is specific to a particular version of React, put it in this directory.

base - This directory contains the base application that each test app will use. This is where tests, application logic, and more live. If you have code that needs to be run on every test app, put it in this directory.

build - When the apps and base directories are merged, the final result is put in this directory. The build directory should never be committed to git.

build.sh - This is the script that merges the apps and base directories and places the built application in the build directory.

Usage:

# Build a test app using apps/react17 as a reference
./build.sh react17

How to modify test apps

To add new tests, components, or pages, modify the base project. This ensures that tests are run for every tested version.

If you want to add a version-specific change, add the change inside of the appropriate projects in apps. Be sure to replicate the directory structure. For example, if you are adding a new E2E test file called test.e2e.ts in apps/react17, make sure you place the file in apps/react17/tests/e2e/test.e2e.ts.

Version-specific tests

If you need to add E2E tests that are only run on a specific version of the JS Framework, replicate the VersionTest component on each partial application. This ensures that tests for framework version X do not get run for framework version Y.

Adding New Test Apps

As we add support for new versions of React, we will also need to update this directory to test against new applications. The following steps can serve as a guide for adding new apps:

  1. Navigate to the built app for the most recent version of React that Ionic tests.
  2. Update the application to the latest version of React.
  3. Make note of any files that changed during the upgrade (package.json, package-lock.json, etc).
  4. Copy the changed files to a new directory in apps.
  5. Add a new entry to the matrix for test-react-e2e in ./github/workflows/build.yml. This will allow the new test app to run against all PRs.
  6. Commit these changes and push.