Creating Integration Tests for PHP APIs

Exercise HTTP request parsing, validation, routing and response output together. The examples separate the essential operation from the conditions a production implementation must enforce.

What It Does

Exercise HTTP request parsing, validation, routing and response output together.

Prerequisites

Use a dedicated development environment with test accounts and records. Separate authorization, validation and error handling from response formatting; never copy demonstration-only secrets into production.

Example 1: Core Behavior

The first example isolates the core operation so its result is easy to understand.

<?php
function respond(string $method): array {return $method==='GET'?[200,['items'=>[]]]:[405,['error'=>'Method Not Allowed']];}
[$code,$body]=respond('GET'); if ($code!==200||!isset($body['items'])) throw new LogicException('Integration failure'); echo 'OK';

Example 2: Alternative or Failure Case

The second example demonstrates an alternative outcome, rule or failure condition.

<?php
function parsePayload(string $raw): array {return json_decode($raw,true,512,JSON_THROW_ON_ERROR);}
try { parsePayload('{invalid'); echo 'Failed'; } catch (JsonException $e) { echo 'Invalid JSON rejected'; }

Practical Example: Applying the Rule

The practical example shows how to carry the same constraint into application code.

<?php
function policy(int $tenant,int $actor): int { return $tenant===$actor?200:404; }
foreach ([[2,2,200],[2,3,404]] as [$t,$a,$want]) {if (policy($t,$a)!==$want) throw new LogicException('Policy regression');} echo 'Passed';

Important Behavior and Edge Cases

Tests should isolate persistent state and use a separate database or an in-memory fake.

Comparison with Related Functions or Patterns

Common Beginner Mistakes

Key Takeaways

• Exercise HTTP request parsing, validation, routing and response output together.
• Tests should isolate persistent state and use a separate database or an in-memory fake.
• Unit tests of a controller do not verify the HTTP transport boundary.

Select this API or pattern based on its documented behavior and the trust boundaries in your own application, and test all external integrations against their actual deployments.