Ionic Framework supports multiple versions of React. As a result, we need to verify that Ionic works correctly with each of these React versions.
The React test app supports syncing your locally built changes for validation.
- Build the
core
,packages/react
, andpackages/react-router
directories usingnpm run build
. - Build the React test app.
- Navigate to the built test app.
- Install dependencies using
npm install
. - 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.
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
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
.
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.
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:
- Navigate to the built app for the most recent version of React that Ionic tests.
- Update the application to the latest version of React.
- Make note of any files that changed during the upgrade (
package.json
,package-lock.json
, etc). - Copy the changed files to a new directory in
apps
. - 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. - Commit these changes and push.