Fix confusing error when files have same name but different case

[sanki92]

Fix confusing error when files have same name but different case

Problem

When two files exist in the same directory with identical names but different case (e.g., fooBar.tests.js and FooBar.tests.js), Meteor would crash with a confusing source-map error instead of providing a clear message about the filename collision.

Original Error:

Error: "version" is a required argument.
    at Object.getArg (/home/user/.meteor/packages/meteor-tool/...source-map/lib/util.js:24:11)
    at ImportScanner.combineFiles (/tools/isobuild/import-scanner.ts:719:7)

Solution

Added case-sensitive filename collision detection in the addFile method of import-scanner.ts. Now when files differ only in case, the build process throws a clear, actionable error message:

Filename collision detected: "fooBar.tests.js" and "FooBar.tests.js" resolve to the same path when case is ignored. Please ensure file names have consistent casing to avoid conflicts.

Changes Made

• File Modified: tools/isobuild/import-scanner.ts
• Method: addFile()
• Change: Added validation to detect when old.absPath !== absPath but they resolve to the same case-insensitive path
• Error Message: Clear, user-friendly message explaining the case sensitivity issue

Root Cause

The import scanner uses absPath.toLowerCase() to check for duplicate files, making it case-insensitive. However, when two files have the same lowercase path but different actual paths, the system tries to combine them using combineFiles(), which fails because the source maps cannot be properly merged.

Testing

The fix has been tested to ensure:

• ✅ Clear error message appears for case-sensitive collisions
• ✅ Normal file processing continues to work unchanged
• ✅ No breaking changes to existing functionality

Fixes #13785

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[nachocodoner]

I'll take some time to test this locally. Not sure if logging an error is the best approach, instead of just resolving it properly. Though it may be seem fine this solution according to your report details.

Marking it for 3.4, so I can review it later for contributions.

Thank you for your contribution 🚀

[sanki92]

Hey @nachocodoner! Thanks for reviewing this. Since this PR won’t be merged right away, could you please add the hacktoberfest-accepted label so it counts for the event? Appreciate it!

[nachocodoner]

This properly shows the expected message on described case.

Merging for its inclusion in last Meteor 3.4-beta.13.