claude sonnet 4 refactor run

[harbu]

Testing how backend refactor worked with claude sonnet 4

[Copilot]

Pull Request Overview

This PR refactors the backend into a layered architecture, adds type-safe validation utilities, and centralizes Express app creation with graceful shutdown handling.

• Introduces ValidationError and stream/partition validation in src/utils/validation.ts
• Extracts services (StreamrService, TopologyService), a controller, and routes for /topology
• Implements an app factory, config object, and updates crawlTopology to accept maxConcurrent

Reviewed Changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/utils/validation.ts	Adds ValidationError, validateStreamId, validatePartition, and createStreamPartId utilities
src/types/index.ts	Defines shared interfaces (LocationData, Node, etc.)
src/services/TopologyService.ts	Encapsulates topology crawling logic and formatting
src/services/StreamrService.ts	Wraps the Streamr client lifecycle
src/routes/index.ts	Extracts route definitions for /topology
src/index.ts	Refactors entry point to use createApp, initialize services, and handle graceful shutdown
src/app.ts	Centralizes Express middleware, routes, health, and error handling
src/fetchLocationData.ts	Imports LocationData from shared types instead of redeclaring
src/crawlTopology.ts	Adds maxConcurrent parameter and removes hardcoded constant
src/controllers/TopologyController.ts	Implements the HTTP handler with input validation and error handling
src/config/index.ts	Introduces a type-safe config object
src/Topology.ts	Removes local Node interface in favor of shared type
src/README.md	Documents the new layered architecture and endpoints

Comments suppressed due to low confidence (1)

src/utils/validation.ts:11

• Add unit tests for validateStreamId, validatePartition, and createStreamPartId to ensure all validation branches (missing, invalid, and valid inputs) are covered.

export function validateStreamId(streamIdParam: string): StreamID {

[Copilot]

Include the radix parameter when parsing integers to avoid unexpected bases: parseInt(partitionParam, 10).

Suggested change

	const partition = parseInt(partitionParam)
	const partition = parseInt(partitionParam, 10)

[Copilot]

Avoid casting req to any; instead, properly type the handler: e.g., router.get<{}, any, any, TopologyQueryParams>('/topology', topologyController.getTopology).

Suggested change

	router.get('/topology', (req, res) => topologyController.getTopology(req as any, res))
	interface TopologyQueryParams {
	// Define the expected query parameters here, e.g.:
	// param1: string;
	}
	router.get<{}, any, any, TopologyQueryParams>('/topology', (req, res) => topologyController.getTopology(req, res))

[Copilot]

[nitpick] The double getNode() call and unknown cast reduces clarity; consider updating the SDK types or wrapping the result in a properly typed method to eliminate the unknown cast.

Suggested change

	async getNetworkNode(): Promise<NetworkNode> {
	return (this.client.getNode()).getNode() as unknown as NetworkNode
	private getTypedNetworkNode(): NetworkNode {
	return this.client.getNode() as NetworkNode
	}
	async getNetworkNode(): Promise<NetworkNode> {
	return this.getTypedNetworkNode()