README

Database-backed experiment provider for Yii3 A/B testing. Implements the ExperimentProvider interface from rasuvaeff/yii3-ab-testing and reads experiment configuration from a database table in a single query, so experiments can be toggled and reweighted at runtime without a deploy.

Using an AI coding assistant? llms.txt contains a compact API reference you can ingest in your prompt context.

Requirements

• PHP 8.3+
• rasuvaeff/yii3-ab-testing ^1.0
• yiisoft/db ^2.0
• yiisoft/db-migration ^2.0 (ships the table migration)
• a PSR-16 cache implementation — required transitively by yiisoft/db 2.0 (e.g. yiisoft/cache)

Installation

composer require rasuvaeff/yii3-ab-testing-db

With Yii3 config-plugin this package binds ExperimentProvider automatically — do not also bind ExperimentProvider in your application or another backend, or yiisoft/config reports a Duplicate key error.

Database schema

Create the ab_experiments table (adjust types for your RDBMS):

CREATE TABLE ab_experiments (
    name             VARCHAR(190) PRIMARY KEY,
    enabled          BOOLEAN      NOT NULL DEFAULT TRUE,
    salt             VARCHAR(190) NOT NULL DEFAULT '',
    fallback_variant VARCHAR(190) NOT NULL DEFAULT '',
    variants         TEXT         NOT NULL DEFAULT '{}'
);

A row's variants looks like {"control":50,"green":50}. The total weight must be greater than zero and fallback_variant must match one of the keys, or the row is rejected with InvalidExperimentRowException.

Migration

The package ships a migration (migrations/) for yiisoft/db-migration. Register the source path in your app's config/params.php:

'yiisoft/db-migration' => [
    'sourcePaths' => [
        dirname(__DIR__) . '/vendor/rasuvaeff/yii3-ab-testing-db/migrations',
    ],
],

Then apply and revert it with Yii Console:

./yii migrate:up
./yii migrate:down --limit=1

The table name defaults to ab_experiments and must match the table argument of DbExperimentProvider. To use a custom name, bind the migration constructor argument:

M260610000000CreateAbExperimentsTable::class => [
    '__construct()' => ['table' => 'my_ab_experiments'],
],

Usage

Basic DB provider

use Rasuvaeff\Yii3AbTesting\AbTesting;
use Rasuvaeff\Yii3AbTesting\WeightedHashAssignmentStrategy;
use Rasuvaeff\Yii3AbTestingDb\DbExperimentProvider;

$provider = new DbExperimentProvider(
    db: $connection,            // yiisoft/db ConnectionInterface
    table: 'ab_experiments',    // optional, default is 'ab_experiments'
);

$ab = new AbTesting(provider: $provider, strategy: new WeightedHashAssignmentStrategy());

if ($ab->is(experiment: 'checkout-button', variant: 'green', subjectId: (string) $userId)) {
    // green variant
}

With PSR-16 caching

getExperiments() runs on every registry build (per request). Without caching that is a DB query per request — wrap the provider in CachedExperimentProvider:

use Rasuvaeff\Yii3AbTestingDb\CachedExperimentProvider;

$cached = new CachedExperimentProvider(
    inner: $provider,
    cache: $psr16Cache,         // PSR-16 CacheInterface
    ttl: 60,                    // seconds
);

$ab = new AbTesting(provider: $cached, strategy: new WeightedHashAssignmentStrategy());

Clear cache

$cached->clear();               // removes cached experiments, next call reloads from DB

API reference

Security

• Assignment hashing, fallback handling, forced/disabled logic remain in the core package — the DB adapter is only a configuration source.
• Invalid row data (missing columns, malformed variants JSON, wrong types, negative weights, invalid experiment name, unknown fallback, zero total weight) throws InvalidExperimentRowException instead of silently mis-assigning. Core validation errors are wrapped, so callers only need to catch one exception type.
• No SQL injection risk: the table name is quoted via the yiisoft/db quoter.
• Reweighting shifts buckets. Safe to flip enabled (kill switch). Changing weights or the variant set shifts bucket boundaries and reshuffles subjects — use yii3-ab-testing-web sticky assignment to pin subjects across such changes.

Examples

See examples/ for runnable scripts.

Development

composer build          # full gate: validate + normalize + cs + psalm + test
composer cs:fix         # auto-fix code style
composer psalm          # static analysis
composer test           # run tests

License

BSD-3-Clause. See LICENSE.md.