fix: ensure that absolute paths can be found via source maps

[ryanthemanuel]

• Closes Open in IDE does not work when preprocessor uses a different root directory than the project root #32809

Additional details

Current Cypress code that determines absolute paths assumes that source maps are relative to the project root. This is not true. Users can have a webpack configuration that specifies a new root via the context property. To allow for this, we determine the new root. We do this by treating the spec file as an anchor point since we know it's absolute path. We can then look at the source maps and determine what "relative" is for that spec file. From this, we then calculate what the root is.

Steps to test

How has the user experience changed?

PR Tasks

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

---

Note

Determine and propagate a source map project root to resolve correct absolute file paths and IDE opening, and add targeted sourcemap tests and configs across runners.

• Core/Driver (sourcemaps):
  • Add source_map_utils APIs to extract source maps, set/get projectRoot via spec anchor, and compute getBaseDirectory.
  • Use source map project root in cypress.ts, script_utils, stack_utils, mocha, origin and sessions commands to enhance stacks, invocation details, and file resolution.
  • Expose Cypress.areSourceMapsAvailable and Cypress.sourceMapProjectRoot.
  • Move custom protocol stripping to utils.stripCustomProtocol and update callers.
• Reporter/Verification:
  • Pass filePath through createVerify and verifyIdeOpen to assert correct absolute path and IDE open behavior.
• Tests:
  • Add/expand sourcemap E2E/CT tests (Vite and Webpack dev servers) to verify file path display and open:file events; scaffold specs under src/.
  • Add system tests with new .mjs configs (enabled/disabled and updated sourcemap root) and a new fixture project runner-e2e-specs-new-sourcemap-root.
• Misc:
  • Update changelog with bugfix entry; tweak CI workflow branch filter.

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[cypress]

cypress    Run #66974

Run Properties:   Failed #66974  •  69f79b0c96: fix build

Project	cypress
Branch Review	ryanm/fix/issue-with-sourcemaps
Run status	Failed #66974
Run duration	21m 23s
Commit	69f79b0c96: fix build
Committer	Ryan Manuel
View all properties for this run ↗︎

---

Test results
Failures	2
Flaky	1
Pending	28
Skipped	1
Passing	792
View all changes introduced in this branch ↗︎

UI Coverage  61.84%
Untested elements	27
Tested elements	47

Accessibility  99%
Failed rules	0 critical   3 serious   1 moderate   0 minor
Failed elements	18

---

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\runs.cy.ts • 1 failed test • app-e2e

View Output

Test		Artifacts
... > displays each run with correct information		Test Replay Screenshots

  cypress\e2e\choose-a-browser.cy.ts • 1 flaky test • launchpad-e2e

View Output

Test		Artifacts
Choose a browser page > System Browsers Detected > launches when --browser is passed alone through the command line		Test Replay Screenshots

[ryanthemanuel]

Bug: Bug

The source map project root is set too late. The mocha patches (in patchSuiteAddTest, patchSuiteAddSuite, and patchSuiteHooks) call getInvocationDetails() which depends on sourceMapProjectRoot being set. However, sourceMapProjectRoot is only set after runScripts() completes, which happens after the spec file is evaluated. During spec file evaluation, when describe() and it() are called, they trigger the patched mocha functions before sourceMapProjectRoot is initialized.

The correct order should be:

1. Set sourceMapProjectRoot before evaluating the spec
2. Then evaluate the spec (which calls describe/it)

Currently the order is:

1. Apply mocha patches (with empty sourceMapProjectRoot)
2. Load scripts and extract source maps
3. Evaluate spec file (describe/it calls use empty sourceMapProjectRoot)
4. Set sourceMapProjectRoot in .then() callback (too late)

packages/driver/src/cypress.ts#L435-L454

cypress/packages/driver/src/cypress.ts

Lines 435 to 454 in c7539c5

	}))
	})
	.then(() => {
	this.cy.initialize(this.$autIframe)
	this.onSpecReady()
	})
	}
	if (this.waitForStudio) {
	// when running studio, wait until it's initialized before running
	this.waitForStudio(run)
	} else {
	run()
	}
	}
	maybeEmitCypressInCypress (...args: unknown[]) {
	// emit an event if we are running a Cypress in Cypress E2E Test.
	// used to assert the runner (mocha) is emitting the expected
	// events/payload.

 

This took a surgical approach. We:

1. Patch mocha. This reads the source map root at execution time not at patch time
2. Load the scripts and their corresponding sourcemaps
3. Update the source map root path
4. Run the scripts which then reads the root as described in step 1