Missing test coverage for handleChangelogAutocomplete function. This function handles cache updates, filtering, and Discord response construction but has no tests. Consider adding tests for:

• Cache update behavior
• Filtering releases by user input
• Limiting to 25 choices
• Empty cache handling
• Error handling when cache update fails

Inconsistent error handling compared to other methods in this file. The CreateIssue method (lines 77-82) checks the response object for status codes to provide more detailed error messages, but CompareCommits doesn't follow this pattern. Consider updating to match:

comparison, resp, err := c.client.Repositories.CompareCommits(c.ctx, owner, repo, base, head, nil)
if err != nil {
    if resp != nil {
        return nil, fmt.Errorf("github API returned %d: failed to compare commits: %w", resp.StatusCode, err)
    }
    return nil, fmt.Errorf("failed to compare commits: %w", err)
}

Missing test coverage for handleChangelog function. The handler orchestrates validation, deferred response, GitHub API calls, and error handling, but none of these behaviors are tested. Consider adding tests for:

• Missing base/head version validation
• Successful changelog retrieval and formatting
• Error handling when GitHub API fails
• Interaction response behavior

Missing test coverage for updateReleaseCache function. This function implements double-checked locking pattern for cache management, which is complex and error-prone. The concurrency behavior, cache expiration, and error handling should be tested to ensure correctness. Consider adding tests for:

• Cache expiration after duration
• Concurrent access patterns
• Error handling when GitHub API fails
• Cache initialization from empty state

Missing edge case handling in tests for formatChangelogMessage. The test should verify behavior when:

• comparison.Commits is nil (potential panic)
• commit.SHA is nil or shorter than 7 characters (would panic on line 94)
• commit.Author is nil (handled but not tested)
• commit.Commit.Author is nil (potential panic when falling back)

Consider adding test cases for these nil/edge case scenarios to ensure robustness.

Inconsistent error handling compared to other methods in this file. The CreateIssue method (lines 77-82) checks the response object for status codes to provide more detailed error messages, but GetReleases doesn't follow this pattern. Consider updating to match:

releases, resp, err := c.client.Repositories.ListReleases(c.ctx, owner, repo, opts)
if err != nil {
    if resp != nil {
        return nil, fmt.Errorf("github API returned %d: failed to list releases: %w", resp.StatusCode, err)
    }
    return nil, fmt.Errorf("failed to list releases: %w", err)
}

Consider adding a test case with a SHA shorter than 7 characters to ensure the code handles this edge case gracefully (currently it would panic at line 95 of changelog_handler.go).

Potential panic if commit.GetSHA() returns an empty string or a string with fewer than 7 characters. Add a length check before slicing:

sha := commit.GetSHA()
shortSHA := sha
if len(sha) > 7 {
    shortSHA = sha[:7]
}

[nitpick] Consider adding a comment explaining the cache invalidation strategy. The double-checked locking pattern is correctly implemented, but it would be helpful to document why a 5-minute cache duration was chosen and what tradeoffs it represents (freshness vs. API rate limits).

Consider adding a test case that covers the scenario where commit.GetAuthor() returns nil or where commit.GetCommit().GetAuthor() returns nil. This would help catch the nil pointer dereference issue at line 91 and ensure the fallback to "Unknown" works correctly.

The cache update logic with double-checked locking lacks test coverage. Consider adding tests to verify: 1) concurrent access doesn't cause race conditions, 2) cache expiration works correctly, and 3) the double-check mechanism prevents redundant API calls.

The autocomplete handler handleChangelogAutocomplete lacks test coverage. Consider adding tests to verify: 1) filtering releases based on user input, 2) limiting results to 25 choices, and 3) handling empty or failed cache updates.