fix: stderr tokens are no longer injected when in development mode

[cacieprins]

• Closes webpack info logs less readable with CYPRESS.STDERR annotations #32569

Additional details

Most notably in CT, when running Cypress in development mode, the STDERR marking tokens were appearing in the final cli output. This:

• Ensures that we are not adding tokens when we shouldn't (e.g., debugging electron, internal development mode for Cypress)
• Ensures that we are not stripping tokens when we aren't adding them
• Refactors to make this distinction easier to determine

Steps to test

Check out and build; run cypress:run --component --project ./packages/driver, ensure no tokens exist in the output

How has the user experience changed?

PR Tasks

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

---

Note

Disables stderr tag injection in development/ELECTRON_ENABLE_LOGGING modes, refactors filtering/tagging logic accordingly, and updates tests and changelog.

• stderr-filtering:
  • Conditional Tagging: Introduce tagsDisabled() to skip tags when CYPRESS_INTERNAL_ENV=development or ELECTRON_ENABLE_LOGGING=1.
  • Refactor filter: Remove disableTags arg and DISABLE_TAGS; only construct FilterTaggedContent when tags are enabled.
  • TagStream updates: Add conditional tag() application, use buffers consistently for empty output, and add verbose debug namespace.
  • logError: Use tagsDisabled() to omit START_TAG/END_TAG when disabled.
• Tests:
  • Update specs to use env stubbing; add cases for development/Electron logging; assert no tag stream when disabled; adjust buffer expectations.
• Changelog:
  • Add note that verbose tag bracketing is suppressed in Cypress dev environments or when Electron logging is enabled.

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[cypress]

cypress    Run #66435

Run Properties:   Failed #66435  •  9f65f37b47: Merge branch 'develop' into fix/stderr-tokens-dev-mode

Project	cypress
Branch Review	fix/stderr-tokens-dev-mode
Run status	Failed #66435
Run duration	20m 29s
Commit	9f65f37b47: Merge branch 'develop' into fix/stderr-tokens-dev-mode
Committer	Cacie Prins
View all properties for this run ↗︎

---

Test results
Failures	1
Flaky	11
Pending	1102
Skipped	4
Passing	26730
View all changes introduced in this branch ↗︎

---

Warning

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

UI Coverage  45.4%
Untested elements	185
Tested elements	158

Accessibility  97.97%
Failed rules	4 critical   8 serious   2 moderate   2 minor
Failed elements	101

---

Tests for review

  cypress/e2e/studio/studio.cy.ts • 1 failed test • app-e2e

View Output

Test		Artifacts
Cypress Studio > updates an existing test with assertions		Test Replay Screenshots

  e2e/origin/config_env.cy.ts • 1 flaky test • 5x-driver-inject-document-domain-chrome:beta

View Output

Test		Artifacts
cy.origin- Cypress.config() > serializable > overwrites different values in secondary if one exists in the primary		Test Replay

  e2e/origin/config_env.cy.ts • 1 flaky test • 5x-driver-inject-document-domain-chrome

View Output

Test		Artifacts
cy.origin- Cypress.config() > serializable > overwrites different values in secondary if one exists in the primary		Test Replay

  issues/28527.cy.ts • 1 flaky test • 5x-driver-electron

View Output

Test		Artifacts
issue 28527 > fails and then retries and verifies about:blank is not displayed		Test Replay Screenshots

  issues/28527.cy.ts • 1 flaky test • 5x-driver-chrome

View Output

Test		Artifacts
issue 28527 > fails and then retries and verifies about:blank is not displayed		Test Replay Screenshots

  commands/net_stubbing.cy.ts • 1 flaky test • 5x-driver-firefox

View Output

Test		Artifacts
... > stops waiting when an xhr request is canceled		</td> </tr></table> The first 5 flaky specs are shown, see all 11 specs in Cypress Cloud.

[cypress-bot]

Released in 15.5.0.

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