Function partitionWorkspacesBySection

src/browser/utils/ui/workspaceFiltering.ts:829–859

(
  workspaces: FrontendWorkspaceMetadata[],
  sections: WorkspaceGroupConfig[]
)

 * @returns Partitioned workspaces
 */
export function partitionWorkspacesBySection(
  workspaces: FrontendWorkspaceMetadata[],
  sections: WorkspaceGroupConfig[]
): SectionPartitionResult {
  const sectionIds = new Set(sections.map((s) => s.id));
  const unsectioned: FrontendWorkspaceMetadata[] = [];
  const bySectionId = new Map<string, FrontendWorkspaceMetadata[]>();

  // Initialize all sections with empty arrays to ensure consistent ordering
  for (const section of sections) {
    bySectionId.set(section.id, []);
  }

  // Build workspace lookup for parent resolution
  const byId = new Map<string, FrontendWorkspaceMetadata>();
  for (const workspace of workspaces) {
    byId.set(workspace.id, workspace);
  }

  for (const workspace of workspaces) {
    const effectiveSectionId = resolveEffectiveSectionId(workspace, byId, sectionIds);
    if (effectiveSectionId) {
      const list = bySectionId.get(effectiveSectionId)!;
      list.push(workspace);
    } else {
      unsectioned.push(workspace);
    }
  }

  return { unsectioned, bySectionId };
}

/**
 * Resolve the effective sub-project section ID for a workspace, matching how