---
id: TST-COM-FUL-051
title: Change events contract
kind: unit
product_area: commerce
module: fulfillment
revision: 1
status: draft
source_sha:
  services-commerce: c8b66a98e2490617aec38ba5c8165dd9bd0a8f9b
  react-console: baf6dae382d6f41dce976c7f848667ccc37e076f
repository: services-commerce
files:
  - modules/fulfillment/tests/unit/facts/change-events-contract.spec.js
implements: []
environment: mock
implementation_state: implemented
latest_result: not-run
latest_run_at: null
latest_run_ref: null
conformance: not-verified
estimated_minutes: 1
isolation: 'In-memory inputs, recorded calls and test-owned doubles; no shared customer records.'
evidence:
  - repository: services-commerce
    path: modules/fulfillment/tests/unit/facts/change-events-contract.spec.js
    test_titles:
      - accepts a batch of the stream at version 1 and keeps a row column it does not name
      - 'accepts an empty batch and one of a hundred events, and refuses a hundred and one'
      - >-
        refuses another version, another stream, a batch with a field it does not know, and an event
        of another stream or operation
      - 'refuses an event with no id, no tenant, a negative sequence or no event type'
      - names a reversal by its event type and nothing else
      - >-
        names the cause each reversal type stands for, the money coming back first, and none for a
        fact that reverses nothing
    scenario_anchors: []
---

# Change events contract

## Verification Boundary

This suite checks change events contract with controlled inputs and recorded dependencies. Its entry points remain within the process.

## What This Suite Proves

The suite’s source cases exercise the registered boundary, but this back-fill does not map them to a complete capability or feature scenario. The executable record remains useful without an invented scenario binding.

## What It Does Not Prove

Controlled inputs do not establish database enforcement, deployed integration or browser behavior. A recorded call is evidence about the adapter contract rather than a remote operation.

## Real Dependencies and Test Doubles

The imported logic is real; test inputs and dependency responses are controlled.

## Must Not Be Doubled

Keep the imported production logic and its request construction real. Record dependency calls and refusals rather than replacing the behavior being asserted.