chore: add more tests for core and filter

[dhmlau]

AI (IBM Bob)generated test cases for core and filter packages.

Checklist

• DCO (Developer Certificate of Origin) signed in all commits
• npm test passes on your machine
• New tests added or existing tests modified to cover all changes
• Code conforms with the style guide
• API Documentation in code was updated
• Documentation in /docs/site was updated
• Affected artifact templates in packages/cli were updated
• Affected example projects in examples/* were updated

👉 Check out how to submit a PR 👈

[coveralls]

Pull Request Test Coverage Report for Build 21519960393

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 54.847%

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Totals
Change from base Build 21489675365:	0.0%
Covered Lines:	9572
Relevant Lines:	12457

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💛 - Coveralls