Parallel Execution Best Practices

To accelerate CI feedback loops, Gherkio supports multi-threaded, parallel test executions. However, running integration tests concurrently requires careful state separation.

⚡ Running Parallel Tests from the CLI

Run a directory of tests with custom concurrency levels using the --parallel (or -p) flag:

# Run tests with 4 parallel execution threads
gherkio run .gherkio/tests/ -p 4

⚠️ The Concurrent Mutation Problem

If multiple tests manipulate the exact same shared DB entity, race conditions will occur:

sequenceDiagram
    participant T1 as Test 1 (Edit Laptop Price)
    participant DB as Shared Database
    participant T2 as Test 2 (Assert Laptop Details)

    T1->>DB: UPDATE laptop WHERE id = 1 SET price = 10.00
    T2->>DB: GET laptop WHERE id = 1
    Note over T2: Asserts price == 12.00 (expected original)
    DB-->>T2: returns price = 10.00
    Note over T2: ❌ Test Failed!

🛡️ Key Safety Strategies

1. Isolated Dynamic Data

Avoid hardcoding entity identifiers or emails. Utilize Gherkio's dynamic generators to create unique resources per test thread:

steps:
  - request:
      method: POST
      url: /v1/users
      body:
        email: $randomEmail         # Unique email per thread!
        name: "Test User"

2. Microservice Routing Isolation

If your microservices support multi-tenant isolation, inject tenancy headers: