test: add base TestCase and bootstrap for in-memory SQLite

tests/TestCase.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace Tests;
+
+use Libs\Database;
+use PDO;
+use PHPUnit\Framework\TestCase as FrameworkTestCase;
+
+/**
+ * TestCase - DuckBrain test harness
+ *
+ * Base class for the framework's own tests. Deliberately lightweight: this
+ * repo has no migrations/ nor duckbrain-commands, so each test defines its
+ * schema with raw DDL through createTable(), and tables registered there are
+ * dropped automatically after the class finishes.
+ */
+abstract class TestCase extends FrameworkTestCase
+{
+    /**
+     * @var list<string> Tables created through createTable() for this class.
+     */
+    private static array $tables = [];
+
+    /**
+     * Returns the PDO connection to the in-memory test database.
+     *
+     * @return PDO
+     */
+    protected static function db(): PDO
+    {
+        return Database::getInstance(DB_TYPE, DB_HOST, DB_NAME, DB_USER, DB_PASS);
+    }
+
+    /**
+     * Creates a table in the test database and registers it for cleanup.
+     *
+     * @param string $name
+     *                     Table name.
+     *
+     * @param string $columns
+     *                       Raw column definition, as accepted by the test
+     *                       engine (sqlite): "id INTEGER PRIMARY KEY, x TEXT".
+     */
+    protected static function createTable(string $name, string $columns): void
+    {
+        static::db()->exec("CREATE TABLE IF NOT EXISTS {$name} ({$columns})");
+        static::$tables[] = $name;
+    }
+
+    /**
+     * Drops every table registered through createTable() during this class.
+     */
+    public static function tearDownAfterClass(): void
+    {
+        foreach (array_unique(static::$tables) as $table) {
+            static::db()->exec("DROP TABLE IF EXISTS {$table}");
+        }
+
+        static::$tables = [];
+    }
+}

tests/bootstrap.php

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+<?php
+
+// Test bootstrap for the DuckBrain development harness.
+// Run PHPUnit from the project root (autoload.php resolves config.php via cwd).
+
+require_once __DIR__ . '/../vendor/autoload.php';
+
+// Define DB constants BEFORE config.php so the test database wins over the
+// real configuration (config.php's define() warnings are suppressed by @).
+define('DB_TYPE', 'sqlite');
+define('DB_HOST', 'localhost');
+define('DB_NAME', ':memory:');
+define('DB_USER', '');
+define('DB_PASS', '');
+
+@require_once __DIR__ . '/../autoload.php';