Add unit tests and documentation for DDM connection string authentication fix

[Copilot]

The existing fix for DDM tab visibility during connection string authentication lacks test coverage and inline documentation explaining the authentication scenario.

Changes

• Add unit tests for isDataMaskingEnabled() covering:

  • Capability-based access (AAD authentication)
  • Policy-based access (connection string authentication)
  • Edge cases (null/undefined policies, empty arrays)

• Add inline documentation explaining why policy existence check supports connection string authentication where databaseAccount capabilities are unavailable

Context

When users authenticate via connection string, isCapabilityEnabled() returns false because databaseAccount is unavailable. The function correctly falls back to checking hasDataMaskingPolicyFromCollection, allowing the DDM tab to appear if a policy exists:

export const isDataMaskingEnabled = (dataMaskingPolicy?: DataModels.DataMaskingPolicy): boolean => {
  const hasDataMaskingCapability = isCapabilityEnabled(Constants.CapabilityNames.EnableDynamicDataMasking);
  const hasDataMaskingPolicyFromCollection =
    dataMaskingPolicy?.includedPaths?.length > 0 || dataMaskingPolicy?.excludedPaths?.length > 0;

  return hasDataMaskingCapability || hasDataMaskingPolicyFromCollection;
};

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.