Fix Review Coverage when the PR has no files

[gonzaM]

Fix Review Coverage when the PR has no files

Problem

When a pull request has no files changed, the review coverage calculation was causing a division by zero error, resulting in an undefined coverage percentage.

Solution

Return 0 when total_files is zero, preventing the division by zero error.

Changes

• File: app/services/builders/review_coverage.rb
  • Added early return with 0 when total_files.zero? in the coverage_percentage method

Testing

• File: spec/services/builders/review_coverage_spec.rb
  • Added test case for when pull request has no files
  • Verifies that coverage percentage returns 0 and total files changed is 0

Impact

• Prevents application errors when processing pull requests with no file changes
• Ensures consistent behavior for edge cases in review coverage calculations
• Maintains data integrity in metrics reporting