feat: support Next.js 16 within component testing

[AtofStryker]

• Closes Support Next.js 16 for Component Testing #32857

Additional details

Adds component testing support for Next.js 16 (still needs tests). Based on the feedback in #32857, the underlying webpack implementation has changed slightly, where as an init() function no longer exists but invokes what we need on require().

Steps to test

How has the user experience changed?

PR Tasks

• Have tests been added/updated (WIP)?
• Has a PR for user-facing changes been opened in cypress-documentation?
• Have API changes been updated in the type definitions?

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Note

Adds Next.js 16 support for component testing (via webpack) with updates to webpack integration, scaffolding/detection, tests, CI filters, and changelog.

• Features / Integration
  • Add Next.js 16 support in component testing using webpack.
  • Update nextHandler to handle Next 16’s compiled webpack loading (use semver, call init() only for <16) and make hasReactRoot check robust.
• Tests / Fixtures
  • Add system-tests/projects/next-16-tsconfig-tailwind (React 19, Tailwind 4) and wire into CT e2e (next.cy.ts).
  • Adjust error assertions for Next 15/16 (code frame vs. message).
• Scaffold / Detection
  • Allow Next ^16.0.0 in wizard dependencies; update detection specs; expand README supported matrix to "Next.js 14, 15, 16".
• CI
  • Include feat/support_next_16 in CircleCI workflow filters and artifact persistence conditions.
• Docs
  • Update CLI CHANGELOG.md (15.7.0) to announce Next 16 CT support and note Turbopack is not supported.

^{Written by Cursor Bugbot for commit 372cd17. This will update automatically on new commits. Configure here.}

[cypress]

cypress    Run #67421

Run Properties:   Failed #67421  •  372cd17abd: Merge branch 'develop' into feat/support_next_16

Project	cypress
Branch Review	feat/support_next_16
Run status	Failed #67421
Run duration	22m 14s
Commit	372cd17abd: Merge branch 'develop' into feat/support_next_16
Committer	Jennifer Shehane
View all properties for this run ↗︎

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Test results
Failures	7
Flaky	4
Pending	25
Skipped	15
Passing	562
View all changes introduced in this branch ↗︎

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Warning

Partial Report: The results for the Application Quality reports may be incomplete.

UI Coverage  0%
Untested elements	4
Tested elements	0

Accessibility  100%
Failed rules	0 critical   0 serious   0 moderate   0 minor
Failed elements	0

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Tests for review

  cypress\e2e\runner\retries.experimentalRetries.mochaEvents.cy.ts • 1 failed test • app-e2e

View Output

Test		Artifacts
... > does not try to serialize error with err.actual as DOM node		Test Replay Screenshots

  cypress\e2e\runner\runner.ui.cy.ts • 3 failed tests • app-e2e

View Output

Test		Artifacts
src/cypress/runner > tests finish with correct state > no tests		Test Replay Screenshots
src/cypress/runner > other specs > file with empty suites only displays no tests found		Test Replay Screenshots
src/cypress/runner > reporter interaction > user can stop test execution		Test Replay Screenshots

  cypress\e2e\runner\ct-framework-errors.cy.ts • 2 failed tests • app-e2e

View Output

Test		Artifacts
Angular 18 > error conditions		Test Replay Screenshots
Angular 19 > error conditions		Test Replay Screenshots

  cypress\e2e\runner\cloud-debug-filter.cy.ts • 1 failed test • app-e2e

View Output

Test		Artifacts
cloud debug test filtering > filter is maintained across cross-domain reinitialization		Test Replay Screenshots

  cypress\e2e\cypress-in-cypress-run-mode.cy.ts • 0 failed tests • app-e2e

View Output

Test		Artifacts

The first 5 failed specs are shown, see all 22 specs in Cypress Cloud.

  cypress\e2e\runner\runner.experimentalRetries.mochaEvents.cy.ts • 1 flaky test • app-e2e

View Output

Test		Artifacts
... > hook failures > fail in [beforeEach]		Test Replay Screenshots

  cypress\e2e\studio\studio-new-tests.cy.ts • 1 flaky test • app-e2e

View Output

Test		Artifacts
Cypress Studio - New Test Creation > creates a new test from an empty spec		Test Replay Screenshots

  cypress\e2e\cypress-origin-communicator.cy.ts • 2 flaky tests • app-e2e

View Output

Test		Artifacts
Cypress In Cypress Origin Communicator > primary origin memory leak prevention > cleans up the primaryOriginCommunicator events when navigating away from the /specs to /runs		Test Replay Screenshots
Cypress In Cypress Origin Communicator > primary origin memory leak prevention > cleans up the primaryOriginCommunicator events when navigating to run a different spec		Test Replay Screenshots

[MikeMcC399]

• Successfully tested preview. See Support Next.js 16 for Component Testing #32857 (comment)