Improve Agreement Router reliability, validation consistency, and template handling

[muralimadhava96-ui]

Overview
This PR refactors the Agreement router to improve code structure, validation robustness, and execution safety. It also introduces comprehensive test coverage for agreement execution, template handling, and error scenarios.

The goal is to align the implementation with production-grade backend practices while ensuring reliability and maintainability.

---

Key Improvements

-->Architecture & Maintainability

• Introduced service-level abstractions (e.g., resolveAgreement, template resolution)
• Reduced duplication in template lookup logic
• Simplified control flow and improved readability

--> Validation Enhancements

• Combined schema validation with domain-level validation (Concerto)
• Added strict ID parsing to prevent invalid database queries
• Improved validation for trigger request types

--> Safer Execution

• Avoided full object mutation during database updates (partial state updates only)
• Ensured agreement state is initialized safely before trigger execution
• Improved error handling with consistent response structure

--> Template Handling

• Simplified template URI normalization
• Added hash-based template caching to avoid duplicate inserts
• Improved external template fetching and storage flow

--> Logging

• Replaced console logs with structured logging for better debugging and observability

---

Test Coverage

-->Added comprehensive tests covering:

• ✅ Successful agreement trigger execution
• ✅ State persistence across multiple triggers
• ✅ Validation failures (invalid request types and malformed payloads)
• ✅ Error scenarios (missing agreement, missing template, DB failures)
• ✅ External template fetching and database insertion
• ✅ Request parsing edge cases (invalid JSON)

-->Test improvements:

• Removed duplicate test definitions
• Introduced structured test organization (Trigger, Errors, Creation)
• Replaced unsafe mocks with partial mocks
• Improved type safety for mocked database layer

---

--> Behavior Changes

• More consistent HTTP responses (clear distinction between 400 and 500 errors)
• Safer handling of invalid IDs and malformed inputs
• More predictable and reliable trigger execution flow

---

--> Performance

• Reduced redundant database queries via centralized template resolution
• Improved caching efficiency using template hash lookup

---

--> Compatibility

• No breaking API changes introduced
• Existing routes and response formats remain unchanged

---

--> Future Work

• Add authentication and authorization middleware
• Introduce rate limiting for trigger endpoints
• Replace remaining any types with strict typings
• Expand test coverage (edge cases, performance scenarios)
• Support additional template retrievers (e.g., IPFS, GitHub)

---

--> Motivation
This refactor improves reliability, maintainability, and developer experience while preparing the codebase for future scalability and extensibility. The addition of strong test coverage ensures confidence in agreement execution and template processing workflows.

[muralimadhava96-ui]

Hi maintainers 👋

This PR focuses on improving Agreement API reliability by:

• reducing over-mocking in tests
• improving error visibility
• making validation responses consistent

I’d really appreciate your feedback on whether this direction aligns with the project’s testing and API design approach.

Especially curious about:
👉 preferred balance between mocking vs real template execution in tests

Thanks!

[github-actions]

This PR is stale because it has been open 15 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[github-actions]

This PR is stale because it has been open with no activity. Remove the stale label or comment to keep it active. Only items with maintainer engagement are auto-closed.

[github-actions]

This PR is stale because it has been open with no activity. Remove the stale label or comment to keep it active. Only items with maintainer engagement are auto-closed.

[JayDS22]

Wanted to flag before you invest in a rebase. server/handlers/agreements.ts has been through a service extraction since this PR opened: the CRUD half moved into services/agreementService.ts (#211), then convertAgreement (#213), then triggerAgreement (#214). Typed errors and centralized Express error handling landed alongside (#184, ab46121). A lot of the reliability and validation improvements this PR targets have since been addressed in that redesign.

A rebase now will surface heavy conflicts, and the diff shape will change substantially. Worth reassessing which of the improvements are still relevant against current main and re-scoping into a smaller focused PR if so.

[JayDS22]

Thanks @muralimadhava96-ui for the original direction here. Closing this out because the reliability, validation, and template-handling intent has landed on main via a different code path: the router logic was extracted into a transport-agnostic service layer, and each concern from this PR shipped as a focused change on top of that.

Coverage on main:

• feat(services): port templateService + rewire mcp.ts template loops (slice 1) #211: templateService port (template handling extracted from the router)
• feat(services): port agreementService CRUD half + rewire mcp.ts agreement lookups (slice 2) #213: agreementService CRUD half (validation + persistence consolidated)
• feat(services): port convertAgreement to agreementService, rewire REST + MCP (slice 2b) #214: convertAgreement service extraction
• feat(services): port triggerAgreement, unify REST + MCP trigger path (slice 2c) #216: triggerAgreement service + state-only persist tightening
• feat(server): introduce typed ServiceError hierarchy, wire agreements handler #184: typed ServiceError hierarchy + centralized Express error handling (the validation-consistency piece)
• feat(server): typed errors in mcp.ts (slice 3) #200: typed errors wired through mcp.ts
• feat(crud): slice 3 REST list delegates to service via listService #225: slice 3 REST list unification (in review, closes the workstream)

Closing rather than rebasing because the underlying router shape this PR targets no longer exists on main, so a rebase would be a rewrite rather than a merge. If you see specific gaps the service extraction missed (a validation case, a template edge case, a router response shape), a focused follow-up PR against current main is welcome and will be much easier to review than reconstructing this one.

Credit for surfacing the original set of concerns stays with you.