fix: dashboard conversion crashes and needless element cache fetch

[xvalovic]

Dashboard conversion crashes

Two Legacy dashboard shapes made CloudDashboard raise, so the dashboard was not migrated at all (24 dashboards across 18 workspaces):

• Empty dashboards (21×): a dashboard with no widgets has no layout key in Legacy. The [] fallback was then indexed with "fluidLayout" → TypeError: list indices must be integers or slices, not str. A missing layout now produces an empty Cloud layout (sections: []).
• Attribute filters without localIdentifier (3×, KPI dashboards from 2020): older Legacy filter contexts don't store it → KeyError: 'localIdentifier'. A stable {idx}_attributeFilter id is generated, mirroring the existing {n}_dateFilter handling; it is used both in the filter and in attributeFilterConfigs.

Skip element cache when nothing is migrated

migrate_metrics/insights/dashboards called legacy_client.initialize_attribute_elements_cache() even when the filtered object list was empty. With --client-prefix (default --without-mapped-objects default_only) most client workspaces have nothing custom to migrate, so this slow fetch was pure overhead. It now runs only when there are objects to process.

Tests

• tests/test_dashboards.py: two new cases, empty_dashboard and dashboard_with_attribute_filter_without_local_identifier, derived from existing sanitized fixtures.
• tests/test_migrate_metrics_element_cache.py: the cache is not loaded for an empty metric list and is loaded otherwise.

All new tests fail on master with the original errors and pass with the fix.

Validation

• make check on a clean checkout: format, lint, 111 tests, type-check pass.
• Real data: both fixes ran in the RingCentral migration (1405 workspaces). The 24 failing dashboards were re-migrated with --overwrite-existing --only-object-ids and verified in Cloud (original title, filter context, widgets).

risk: low

[coderabbitai]

Important

• 🔍 Trigger review

This repository does not receive automatic reviews because it has fewer than 10 stars.

⚙️ Run configuration

• Configuration used: Organization UI
• Review profile: CHILL
• Plan: Advanced
• Run ID: 3ac24a10-3239-4cfc-bab2-c18807214682

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

---

_{Comment @coderabbitai help to get the list of available commands.}

[marmil-cz]

LGTM