chore: add unit tests for file click on codeblock

[uinstinct]

Description

Add test to check if file click on codeblock is functional

closes CON-2832

Checklist

• [] I've read the contributing guide
• [] The relevant docs, if any, have been updated or created
• [] The relevant tests, if any, have been updated or created

Screenshots

[ For visual changes, include screenshots. Screen recordings are particularly helpful, and appreciated! ]

Tests

[ What tests were added or updated to ensure the changes work as expected? ]

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Summary by cubic

Added a unit test to check that clicking a file name in the code block preview opens the correct file.

• Tests
• Verifies that the "showFile" action is called with the expected file path when the file title is clicked.