GSOC2026 TestDemoApp

Demo app for the GSoC 2026 project Globally Scoped Traits for Swift Testing via Runtime Configuration Schema.

This app references a modified swift-testing fork as a local dependency to validate the global traits feature.

Requirements

• Swift 6.3+
• swift-testing fork cloned locally (demian/gsoc-global-traits branch)

Project Structure

GSOC2026_TestDemoApp/
├── Package.swift
├── Sources/
├── Tests/
│   └── TestDemoAppTests/
│       ├── TimeoutTest.swift        — global timeout
│       ├── OverrideTest.swift       — local wins over global
│       ├── SerializedTest.swift     — global serialization
│       ├── RetryTest.swift          — global retry
│       └── TagTest.swift            — global tags
└── config.json

config.json

{
  "globalTraits": {
    "defaultTimeLimit": { "seconds": 5 },
    "maximumTimeLimit": { "seconds": 30 },
    "tags": ["ci"],
    "serialized": true,
    "retryCount": 3,
    "timeLimitGranularity": { "seconds": 1 }
  }
}

Setting	What it does
defaultTimeLimit	5s fallback for tests without a time limit
maximumTimeLimit	30s hard cap on all tests
tags	Adds "ci" tag to every test
serialized	Runs all tests sequentially
retryCount	Retries 3 times on failure (4 total)
timeLimitGranularity	1s precision (default is 60s)

How to Run

Before (no global traits)

swift test

All tests pass without limits. Tests run in parallel.

After with JSON config

swift test --configuration-path config.json

Same test code. Global traits applied through config.json.

After with CLI Flags

CLI flags require the modified SwiftPM.

# timeout only
~/Documents/GitHub/swift-package-manager/.build/debug/swift-test \
    --experimental-global-timeout 5 --experimental-global-granularity 1

# serialized only
~/Documents/GitHub/swift-package-manager/.build/debug/swift-test \
    --experimental-global-serialized

# all flags
~/Documents/GitHub/swift-package-manager/.build/debug/swift-test \
    --experimental-global-timeout 5 \
    --experimental-global-granularity 1 \
    --experimental-global-serialized \
    --experimental-global-retry-count 3 \
    --experimental-global-tags ci \
    --experimental-global-max-timeout 30

Only specified flags apply. Unspecified settings use defaults.

Before / After (JSON config or CLI flags)

	Before	After
Slow test (10s)	Pass (no limit)	TIMEOUT (5s limit)
Local wins (8s)	Pass	Pass (local 1min wins)
Execution order	Parallel (1s)	Sequential (3s)
Failed test	Done	4 iterations
Config change	Code change + recompile	JSON or CLI only

Links

• swift-testing Fork
• SwiftPM Fork
• Forum Discussion