Duplicate Code Detected: Protocol type definitions duplicated across protocol-definitions and driver-definitions

🔍 Duplicate Code Detected: Protocol type definitions duplicated across protocol-definitions and driver-definitions

Analysis of commit 456709ace7f54858b3f94e8487eba71a5421ac32

Assignee: @copilot

Summary

Multiple protocol-type definition files appear to be copied verbatim between common/lib/protocol-definitions and packages/common/driver-definitions, creating a high risk of divergence and duplicated maintenance effort.

Duplication Details

Pattern: Identical exported protocol interfaces/types in two packages

• Severity: High

• Occurrences: 6 identical files (verbatim) + 6 additional overlapping files with strong similarity but non-identical content.

• Locations (verbatim duplicates):

  • common/lib/protocol-definitions/src/clients.ts (lines 1-152)
  • packages/common/driver-definitions/src/protocol/clients.ts (lines 1-152)
  • common/lib/protocol-definitions/src/config.ts (lines 1-38)
  • packages/common/driver-definitions/src/protocol/config.ts (lines 1-38)
  • common/lib/protocol-definitions/src/sockets.ts (lines 1-178)
  • packages/common/driver-definitions/src/protocol/sockets.ts (lines 1-178)
  • common/lib/protocol-definitions/src/date.ts (lines 1-55)
  • packages/common/driver-definitions/src/protocol/date.ts (lines 1-55)
  • common/lib/protocol-definitions/src/scopes.ts (lines 1-32)
  • packages/common/driver-definitions/src/protocol/scopes.ts (lines 1-32)
  • common/lib/protocol-definitions/src/users.ts (lines 1-15)
  • packages/common/driver-definitions/src/protocol/users.ts (lines 1-15)

• Overlapping but non-identical (likely drift risk / partial copy):

  • consensus.ts, index.ts, protocol.ts, storage.ts, summary.ts, tokens.ts in both directories.

• Code Sample (excerpt from clients.ts, identical in both locations):

export type ConnectionMode = "write" | "read";

export interface ICapabilities {
	interactive: boolean;
}

export interface IClientDetails {
	capabilities: ICapabilities;
	type?: string;
	environment?: string;
	device?: string;
}

export interface IClient {
	mode: ConnectionMode;
	details: IClientDetails;
	permission: string[];
	user: IUser;
	scopes: string[];
	timestamp?: number;
}

Impact Analysis

• Maintainability: Changes to protocol shapes must be duplicated and kept consistent across two packages; this is easy to miss during refactors.
• Bug Risk: High risk of subtle type mismatches when one copy changes and the other does not (especially for non-identical-but-overlapping files like protocol.ts / tokens.ts).
• Code Bloat: Multiple files duplicated across packages, increasing review surface and build artifacts.

Refactoring Recommendations

1. Single source of truth via dependency/re-export

   • Make @fluidframework/driver-definitions depend on @fluidframework/protocol-definitions (or the reverse, whichever layering constraints allow), and re-export the shared types from one package.
   • Estimated effort: Medium
   • Benefits: Eliminates drift risk and reduces maintenance overhead.

2. Generate one copy from the other (build step)

   • If layering constraints prevent direct dependency, consider generating the second set from the first during build (and fail CI if the generated output is modified).
   • Estimated effort: Medium/High
   • Benefits: Maintains separation while ensuring consistency.

3. Enforce synchronization with a policy check

   • Add/extend an existing policy check to ensure the overlapping directory trees remain identical where intended.
   • Estimated effort: Low/Medium
   • Benefits: Prevents future divergence even if duplication remains temporarily.

Implementation Checklist

• Confirm whether duplication is intentional for packaging/layering reasons
• Decide ownership for the canonical protocol type definitions
• Implement re-export or codegen strategy
• Update any downstream imports
• Ensure API docs / type tests still pass

Analysis Metadata

• Analyzed Files: HEAD diff scan for .ts/.cjs/.mjs (non-test, non-workflow) + file-level comparison
• Detection Method: Serena semantic overview + diff-based duplicate block detection
• Commit: 456709ace7f54858b3f94e8487eba71a5421ac32
• Analysis Date: 2026-02-23

AI generated by Duplicate Code Detector

To add this workflow in your repository, run gh aw add github/gh-aw/.github/workflows/duplicate-code-detector.md@94662b1dee8ce96c876ba9f33b3ab8be32de82a4. See usage guide.

Start by comparing the six listed duplicate file pairs under common/lib/protocol-definitions and packages/common/driver-definitions/src/protocol, then inspect the overlapping consensus.ts, index.ts, protocol.ts, storage.ts, summary.ts, and tokens.ts files. Confirm the intended package layering and canonical ownership before choosing a re-export, generation, or synchronization approach; done means downstream imports and API documentation/type tests still pass without unmanaged duplication.