Sharepoint-Toolbox/.planning/phases/17-group-expansion-html-reports/17-01-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech_stack, key_files, decisions, metrics

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
17-group-expansion-html-reports	01	services	group-resolution csom graph-api tdd di	requires provides affects ISharePointGroupResolver SharePointGroupResolver ResolvedMember App.xaml.cs DI container	added patterns CSOM SiteGroups.GetByName Graph transitiveMembers PageIterator OrdinalIgnoreCase dict lazy Graph client init	created modified SharepointToolbox/Core/Models/ResolvedMember.cs SharepointToolbox/Services/ISharePointGroupResolver.cs SharepointToolbox/Services/SharePointGroupResolver.cs SharepointToolbox.Tests/Services/SharePointGroupResolverTests.cs SharepointToolbox/App.xaml.cs	Static helpers IsAadGroup/ExtractAadGroupId/StripClaims declared internal to enable unit testing via InternalsVisibleTo without polluting public API Graph client created lazily on first AAD group encountered to avoid unnecessary auth overhead for groups with no nested AAD members GraphUser/GraphUserCollectionResponse aliased to resolve ambiguity between Microsoft.SharePoint.Client.User and Microsoft.Graph.Models.User	duration_minutes tasks_completed files_created files_modified completed_date 3 2 4 1 2026-04-09

Phase 17 Plan 01: SharePoint Group Resolver Service Summary

One-liner: CSOM + Graph transitive member resolver with OrdinalIgnoreCase dictionary, graceful error fallback, and internal static helpers for unit testing.

What Was Built

Created the ISharePointGroupResolver service that pre-resolves SharePoint group members before HTML export. The service uses CSOM to enumerate direct group users, then calls Microsoft Graph groups/{id}/transitiveMembers/microsoft.graph.user for any nested AAD groups — satisfying the RPT-02 transitive membership requirement.

Files Created

• SharepointToolbox/Core/Models/ResolvedMember.cs — Simple record ResolvedMember(string DisplayName, string Login) value type.
• SharepointToolbox/Services/ISharePointGroupResolver.cs — Interface with single ResolveGroupsAsync(ctx, clientId, groupNames, ct) method returning IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>.
• SharepointToolbox/Services/SharePointGroupResolver.cs — Implementation: CSOM group user loading, AAD group detection via IsAadGroup(), Graph TransitiveMembers.GraphUser.GetAsync() with PageIterator pagination, per-group try/catch for graceful fallback.
• SharepointToolbox.Tests/Services/SharePointGroupResolverTests.cs — 14 tests (12 passing unit tests + 2 live-tenant skip-marked): covers IsAadGroup, ExtractAadGroupId, StripClaims, empty-list behavior, and OrdinalIgnoreCase comparer verification.

Files Modified

• SharepointToolbox/App.xaml.cs — Added services.AddTransient<ISharePointGroupResolver, SharePointGroupResolver>() under Phase 17 comment.

Decisions Made

1. Internal static helpers for testability: IsAadGroup, ExtractAadGroupId, StripClaims are internal static — accessible to the test project via the existing InternalsVisibleTo("SharepointToolbox.Tests") assembly attribute without exposing them as public API.

2. Lazy Graph client creation: graphClient is created on-demand only when the first AAD group is encountered in the loop. This avoids a Graph auth round-trip for sites with no nested AAD groups (common case).

3. Type alias for ambiguous User: GraphUser = Microsoft.Graph.Models.User and GraphUserCollectionResponse aliased to resolve CS0104 ambiguity — both CSOM (Microsoft.SharePoint.Client.User) and Graph SDK (Microsoft.Graph.Models.User) are referenced in the same file.

Deviations from Plan

Auto-fixed Issues

1. [Rule 1 - Bug] CS0104 ambiguous User reference

• Found during: Task 1 GREEN phase (first build)
• Issue: PageIterator<User, UserCollectionResponse> was ambiguous between Microsoft.SharePoint.Client.User and Microsoft.Graph.Models.User — both namespaces imported.
• Fix: Added using GraphUser = Microsoft.Graph.Models.User and using GraphUserCollectionResponse = Microsoft.Graph.Models.UserCollectionResponse aliases.
• Files modified: SharepointToolbox/Services/SharePointGroupResolver.cs

2. [Rule 1 - Bug] IReadOnlyDictionary.Comparer not accessible

• Found during: Task 1 GREEN phase (test compile)
• Issue: Test cast result.Comparer fails because IReadOnlyDictionary<,> does not expose .Comparer. The concrete Dictionary<,> does.
• Fix: Updated test to cast the result to Dictionary<string, IReadOnlyList<ResolvedMember>> before accessing comparer behavior — works because SharePointGroupResolver.ResolveGroupsAsync returns a Dictionary<> via IReadOnlyDictionary<>.
• Files modified: SharepointToolbox.Tests/Services/SharePointGroupResolverTests.cs

Test Results

dotnet test --filter "FullyQualifiedName~SharePointGroupResolverTests"
Passed: 12, Skipped: 2 (live tenant), Failed: 0

dotnet test (full suite)
Passed: 314, Skipped: 28, Failed: 0

Self-Check

Files created: verified. Commits verified below.