Configuration

By default, if no configuration file is provided, Testo will run tests from the tests folder with the default plugin set.

To configure Testo, create a testo.php file in the root of your project. The file must return an ApplicationConfig instance:

<?php

declare(strict_types=1);

use Testo\Application\Config\ApplicationConfig;
use Testo\Application\Config\SuiteConfig;

return new ApplicationConfig(
    suites: [
        new SuiteConfig(
            name: 'Unit',
            location: ['tests/Unit'],
        ),
        new SuiteConfig(
            name: 'Feature',
            location: ['tests/Feature'],
        ),
    ],
);

ApplicationConfig

The root configuration object:

• suites — array of Test Suites. Must contain at least one element — an empty array will cause an error.
• plugins — application-level plugins. Loaded before Test Suites and act globally (see Plugins section).

All parameters and their default values are described in the class itself — your IDE will show hints.

SuiteConfig

Configuration for a single Test Suite: name, test location, and plugin set.

// Simple form — array
new SuiteConfig(
    name: 'Unit',
    location: ['tests/Unit'],
    plugins: [new NamingConventionPlugin()],
),

// With customization — FinderConfig and SuitePlugins
new SuiteConfig(
    name: 'Unit',
    location: new FinderConfig(
        include: ['tests/Unit'],
        exclude: ['tests/Unit/Stubs'],
    ),
    plugins: SuitePlugins::without(BenchmarkPlugin::class),
),

Arrays in location and plugins are shorthands for new FinderConfig(include: ...) and SuitePlugins::with(...). For more flexible configuration, use FinderConfig and SuitePlugins directly.

FinderConfig

Defines the file search scope — which directories and files to include or exclude. Paths are relative to the project root. Glob patterns and regular expressions are not supported.

new FinderConfig(
    include: ['tests'],
    exclude: ['tests/Fixtures', 'tests/Stubs'],
)

Plugins

Testo is built on plugins — they define how tests are discovered, executed, and processed. Plugins are registered at two levels:

• Application level (ApplicationConfig::$plugins) — act globally across all Test Suites
• Test Suite level (SuiteConfig::$plugins) — act only within a specific Test Suite

If the plugins array is not specified, Testo uses the default plugin set.

Managing Plugins

Use the SuitePlugins and ApplicationPlugins facades to configure plugins (identical API):

with()

// Add NamingConventionPlugin to the default plugins
// Other Test Suite plugins are preserved
new SuiteConfig(
    plugins: SuitePlugins::with(
        new NamingConventionPlugin(),
    ),
)

without()

// Remove BenchmarkPlugin from the default set
// Other Test Suite plugins are preserved
new SuiteConfig(
    plugins: SuitePlugins::without(
        BenchmarkPlugin::class,
    ),
)

only()

// Only LifecyclePlugin — all others are disabled
// Completely replaces the default set
new SuiteConfig(
    plugins: SuitePlugins::only(
        new LifecyclePlugin(),
    ),
)

Chaining

// Add one plugin and remove another
// Methods can be chained together
new SuiteConfig(
    plugins: SuitePlugins::with(new NamingConventionPlugin())
        ->without(BenchmarkPlugin::class),
)

Monorepo

Since suites is a regular PHP array, configurations can be assembled from multiple modules. Each module has its own testo.php that works standalone and as a Test Suite source for the root config:

// modules/billing/testo.php — works standalone
return new ApplicationConfig(
    suites: [
        new SuiteConfig(
            name: 'Billing',
            location: ['tests'],
        ),
    ],
);

// testo.php — root config assembles Test Suites from modules
return new ApplicationConfig(
    suites: array_merge(
        (require 'modules/billing/testo.php')->suites,
        (require 'modules/shipping/testo.php')->suites,
    ),
);

Each module manages its own test configuration independently, while the root config runs everything together.

Can I disable application-level plugins for a specific Test Suite?

No, application-level plugins are loaded before Test Suites and act globally.

Which application plugins are enabled by default?

You can check the default plugin list in the ApplicationPlugins class.

Currently:

• Filter
• Terminal and Teamcity depending on the --teamcity flag

Which Test Suite plugins are enabled by default?

You can check the default plugin list in the SuitePlugins class.

Currently:

• Assert
• Bench
• Inline
• Lifecycle
• Test