Duplicate Code: filterPackages duplicated in build-cli and build-infrastructure

🔍 Duplicate Code Detected: filterPackages package-filter logic duplicated

Analysis of commit c9659f0d8c6b7a7314eff8e5f0ad29f4c30e2aab

Assignee: @copilot

Summary

The filterPackages implementation (including its scopesToPrefix helper) is effectively identical in both @fluid-tools/build-cli and @fluid-tools/build-infrastructure. This is a >10-line duplication that increases the risk of divergence if filtering semantics need to change (e.g., scope handling, private filtering).

Duplication Details

Pattern: identical filterPackages + scopesToPrefix

• Severity: Medium

• Occurrences: 2

• Locations:

  • build-tools/packages/build-cli/src/filter.ts (lines 290–339; filterPackages at 298–335, helper at 337–339)
  • build-tools/packages/build-infrastructure/src/filter.ts (lines 241–290; filterPackages at 249–286, helper at 288–290)

• Code Sample (from build-tools/packages/build-cli/src/filter.ts):

  export async function filterPackages(T extends FilterablePackage)(
  	packages: T[],
  	filters: PackageFilterOptions,
  ): Promise(T[]) {
  	const filtered = packages.filter((pkg) => {
  		if (filters === undefined) {
  			return true;
  		}
  
  		const isPrivate: boolean = pkg.private ?? false;
  		if (filters.private !== undefined && filters.private !== isPrivate) {
  			return false;
  		}
  
  		const scopeIn = scopesToPrefix(filters?.scope);
  		const scopeOut = scopesToPrefix(filters?.skipScope);
  
  		if (scopeIn !== undefined) {
  			let found = false;
  			for (const scope of scopeIn) {
  				found ||= pkg.name.startsWith(scope);
  			}
  			if (!found) {
  				return false;
  			}
  		}
  		if (scopeOut !== undefined) {
  			for (const scope of scopeOut) {
  				if (pkg.name.startsWith(scope) === true) {
  					return false;
  				}
  			}
  		}
  		return true;
  	});
  
  	return filtered;
  }
  
  function scopesToPrefix(scopes: string[] | undefined): string[] | undefined {
  	return scopes === undefined ? undefined : scopes.map((s) => `\$\{s}/`);
  }
  

Impact Analysis

• Maintainability: Changes to package filtering semantics must be made in two places.
• Bug Risk: High chance of inconsistency if one copy is updated without the other.
• Code Bloat: Small but avoidable; the larger cost is duplicated ownership and review surface.

Refactoring Recommendations

1. Make build-cli reuse build-infrastructure’s implementation

   • @fluid-tools/build-cli already depends on @fluid-tools/build-infrastructure.
   • Replace the local filterPackages/scopesToPrefix in build-cli/src/filter.ts with imports from @fluid-tools/build-infrastructure (likely from its filter.ts module, or a new exported helper if needed).
   • Estimated effort: Low (≤1 hour) + test validation.

2. (Optional) Extract to a small shared helper module

   • If filter.ts exports are not intended for consumption, move filterPackages + helper into a dedicated shared module under build-infrastructure (or another shared build-tools package) and re-export from both.

Implementation Checklist

• Confirm desired ownership for package-filtering semantics (build-infrastructure vs build-cli)
• Refactor build-cli to import shared implementation
• Remove duplicate implementation from build-cli
• Update any affected types (ensure FilterablePackage remains compatible)
• Run build-cli/build-infrastructure unit tests (or relevant build validation)

Analysis Metadata

• Analyzed Files: 135 (scoped to build-cli, build-infrastructure, and azure-service-utils TypeScript sources; excluding tests)
• Detection Method: Serena symbol overview + semantic/structural duplicate-block scan
• Commit: c9659f0d8c6b7a7314eff8e5f0ad29f4c30e2aab
• Analysis Date: 2026-03-16T21:51:01.514Z

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Read build-tools/packages/build-cli/src/filter.ts and build-tools/packages/build-infrastructure/src/filter.ts, comparing the duplicated filterPackages and scopesToPrefix implementations and their exports and types. Confirm the shared ownership choice, then remove the duplicate and run the relevant build-cli and build-infrastructure unit tests or build validation; done means both packages use one compatible implementation.