Phase 2.5: Properties Methods

[Sam-Bolling]

Task

Implement all 6 Properties methods in url_builder.ts and add Properties method tests to url_builder.spec.ts. Properties is the fifth Phase 2 resource type and follows the pattern established by Systems (Issue #5). Properties is unique among Part 1 resources: it is read-only (no create/update/delete) and is the only Part 1 resource that is not a GeoJSON Feature.

ROADMAP Reference: Phase 2, Task 5 — Properties Methods (~1–1.5 hours implementation + ~0.5 hour testing, Medium complexity)

---

Files to Create or Modify

File	Action	Est. Lines	Purpose
src/ogc-api/csapi/url_builder.ts	Modify	~35–50 added	Add 6 Properties methods with resource validation
src/ogc-api/csapi/url_builder.spec.ts	Modify	~25–30 added	Add Properties method tests

Blueprint Reference

Follow the Systems methods pattern established in Issue #5 (same file). Also reference the EDR pattern in src/ogc-api/edr/url_builder.ts (562 lines) for resource validation, URL construction, and query parameter appending.

Scope — What to Implement

6 Properties Methods

Each method validates resource availability (~2 lines), builds a URL using buildResourceUrl(), appends query parameters using buildQueryString(), and returns the constructed URL string. Properties is read-only — no create/update/delete methods.

Collection query:

• getProperties(options?: PropertyQueryOptions): string — GET /properties with pagination, filtering, sorting

Single resource:

• getProperty(id: string, options?): string — GET /properties/{id}

Association links:

• getPropertySystems(id: string, options?): string — GET /properties/{id}/systems (systems capable of observing this property)
• getPropertyDataStreams(id: string, options?): string — GET /properties/{id}/datastreams (Part 2 cross-reference)
• getPropertyControlStreams(id: string, options?): string — GET /properties/{id}/controlstreams (Part 2 cross-reference)

History:

• getPropertyHistory(id: string, options?): string — GET /properties/{id}/history

Properties Query Parameters

Properties support: system, baseProperty, id, uid, q, property filters, limit, offset, f, sortBy, sortOrder.

All parameters are serialised by the shared buildQueryString() helper (Issue #3). Note: Properties do not support bbox, datetime, or any Part 2 temporal parameters (see Guide §6 temporal applicability matrix).

JSDoc Requirements

• Document each method with @param for all parameters, @returns description, and usage example
• Add @see links to OGC CSAPI Part 1 specification sections for Properties endpoints
• Note in JSDoc that Properties is the only Part 1 resource that is not a GeoJSON Feature
• Follow the JSDoc style in src/ogc-api/edr/url_builder.ts and the Systems methods from Issue Phase 2.1: Systems Methods #5

Testing Requirements

• Extend src/ogc-api/csapi/url_builder.spec.ts (~25–30 lines)
• Test getProperties collection query and getProperty individual retrieval
• Test system, datastream, and control stream association methods (getPropertySystems, getPropertyDataStreams, getPropertyControlStreams)
• Test resource validation — calling any Properties method when properties is not in availableResources throws an error
• Follow test patterns from Systems tests (Issue Phase 2.1: Systems Methods #5) and src/ogc-api/edr/url_builder.spec.ts

Scope — What NOT to Touch

• ❌ Do NOT implement Systems, Deployments, Procedures, Sampling Features, DataStreams, Observations, Control Streams, or Commands methods — those belong to Issues Phase 2.1: Systems Methods #5–Phase 2.4: Sampling Features Methods #8 and Phase 2.6: DataStreams Methods #10–Phase 2.9: Commands Methods #13
• ❌ Do NOT modify model.ts — type definitions belong to Issue Phase 1.1: Create Type System (csapi/model.ts) #1
• ❌ Do NOT modify helpers.ts — helper utilities belong to Issue Phase 1.2: Create Helper Utilities (csapi/helpers.ts) #2
• ❌ Do NOT modify the constructor, buildResourceUrl(), buildQueryString(), extractAvailableResources(), or availableResources — those belong to Issue Phase 1.3: Create Stub QueryBuilder (csapi/url_builder.ts) #3
• ❌ Do NOT modify endpoint.ts, info.ts, or src/index.ts — integration belongs to Issue Phase 1.4: Integrate with OgcApiEndpoint #4
• ❌ Do NOT modify Systems, Deployments, Procedures, or Sampling Features methods — those belong to Issues Phase 2.1: Systems Methods #5–Phase 2.4: Sampling Features Methods #8
• ❌ Do NOT modify files outside the "Files to Create or Modify" table above
• ❌ Do NOT refactor existing code unless required to complete this task

Acceptance Criteria

• url_builder.ts contains all 6 Properties methods listed above
• Each method validates resource availability before constructing a URL
• Each method uses buildResourceUrl() and buildQueryString() helpers
• All new methods have complete JSDoc documentation with @param, @returns, @see
• url_builder.spec.ts contains Properties tests covering property retrieval, system/datastream/controlstream associations, and resource validation (~25–30 lines)
• Existing tests still pass (npm test)
• No lint errors

Dependencies

Blocked by: Issue #1 (Type System — provides PropertyQueryOptions and resource types), Issue #2 (Helper Utilities — provides encoding helpers), Issue #3 (Stub QueryBuilder — provides constructor, buildResourceUrl, buildQueryString, availableResources), Issue #5 (Systems Methods — establishes the pattern)
Blocks: Issues #10–#13 (subsequent resource type methods)

---

Operational Constraints

⚠️ MANDATORY: Before starting work on this issue, review docs/governance/AI_OPERATIONAL_CONSTRAINTS.md.

Key constraints for this task:

• Precedence: OGC specifications → AI Collaboration Agreement → This issue description → Existing code → Conversational context
• No scope expansion: Do not infer unstated requirements or add unrequested features
• No refactoring: Do not rename, restructure, or "improve" code outside this issue's scope
• Minimal diffs: Prefer the smallest change that satisfies the acceptance criteria
• Ask when unclear: If intent is ambiguous, stop and ask for clarification

---

References

Read these documents before starting implementation. They are ordered by priority.

Primary References (must read)

#	Document	Section/Lines	What It Provides
1	docs/planning/csapi-implementation-guide.md	§6 Properties Resource Methods (lines 1545–1590)	Read-only operations, query parameters, relationship management, non-Feature resource note
2	docs/planning/csapi-implementation-guide.md	§6 Complete Query Parameter Support (lines 1921–2000)	All query parameters with types, applicability, encoding rules
3	docs/planning/csapi-implementation-guide.md	§6 Query Parameters and Code Reuse (lines 720–900)	Parameter distribution analysis, temporal applicability matrix showing Properties has no temporal/spatial params
4	src/ogc-api/edr/url_builder.ts	Full file (562 lines)	Blueprint: method structure, resource validation, URL construction pattern
5	src/ogc-api/edr/url_builder.spec.ts	Full file	Blueprint: test patterns for URL builder methods
6	docs/planning/ROADMAP.md	Phase 2, Task 5 (lines 222–234)	Authoritative task definition, method list, test requirements

Upstream Type/Import References (files this task imports from)

#	Document	What to Import
7	src/ogc-api/csapi/model.ts	PropertyQueryOptions, CSAPIResourceType (created by Issue #1)
8	src/ogc-api/csapi/helpers.ts	Encoding helpers: encodeArray (created by Issue #2)

Research References (context, not required reading)

#	Document	What It Provides
9	docs/research/requirements/csapi-part1-requirements.md	Detailed client implementation requirements for Properties navigation
10	docs/research/requirements/csapi-query-parameters.md	Complete catalog of all CSAPI query parameters

Specification References (for @see links and field accuracy)

#	Document	Use
11	OGC API - Connected Systems Part 1 (23-001)	Properties resource definitions, read endpoints, query parameters
12	OGC API - Connected Systems Part 1: OpenAPI Spec	Properties endpoint definitions — normative URL paths
13	SOSA/SSN Ontology	Semantic definitions for observable and actuatable properties (sosa:ObservableProperty, sosa:ActuatableProperty)
14	OGC API - Connected Systems Part 2 (23-002)	Context for property–datastream and property–controlstream associations

Convention Quick Reference

Rule	Example
Use .js extension for relative imports	import { X } from './file.js'
Use import type for interfaces/types	import type { Y } from './model.js'
Three-tier hierarchy: import from lower tiers only	shared → ogc-api → csapi
Named exports for types and utilities	export interface Z { ... }
as const arrays for enum-like values	export const XTypes = [...] as const
HTTP mocking: globalThis.fetch = jest.fn()	Never use nock, msw, or other libraries
Meaningful tests only	Verify behavior, not that code runs without throwing

[Sam-Bolling]

⚠️ Required Pre-Reading: Lessons Learned

MANDATORY: Before starting work on this issue, read docs/governance/phase-2-lessons-learned.md.

This document contains actionable guardrails derived from real mistakes made in Phase 1–2.2. All 7 lessons apply to this issue. Key callouts for Properties:

Lesson	What to Do for This Issue
L1 — Test Checklist	Use the mandatory 8-item test checklist. Properties is read-only (no CRUD tests needed for create/update/delete), but all other checklist items apply.
L2 — Query Parameters	Check the applicability table: Properties has NO bbox, NO datetime, NO parent/recursive, NO foi. It does support system, baseProperty.
L3 — Temporal Keys	Properties does NOT add new temporal keys. No changes needed to buildQueryString.
L4 — Resource String	Every method must call this.assertResourceAvailable('properties') — grep to verify after implementation.
L5 — Files	All work in url_builder.ts + url_builder.spec.ts only. No new files.
L6 — Review Findings	Note any unexpected behavior as a comment on this issue.
L7 — DRY	Do not copy-paste method bodies. Call shared helpers.