Allow amphp/postgres to provide an existing connection

phpunit.xml

@@ -1,26 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.0/phpunit.xsd"
-         bootstrap="vendor/autoload.php"
-         cacheDirectory=".phpunit.cache"
-         executionOrder="depends,defects"
-         requireCoverageMetadata="true"
-         beStrictAboutCoverageMetadata="true"
-         beStrictAboutOutputDuringTests="true"
-         failOnRisky="true"
-         failOnWarning="true">
-    <testsuites>
-        <testsuite name="unit">
-            <directory>tests/Unit</directory>
-        </testsuite>
-        <testsuite name="integration">
-            <directory>tests/Integration</directory>
-        </testsuite>
-    </testsuites>
-
-    <coverage>
-        <include>
-            <directory suffix=".php">src</directory>
-        </include>
-    </coverage>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.1/phpunit.xsd" bootstrap="vendor/autoload.php" cacheDirectory=".phpunit.cache" executionOrder="depends,defects" requireCoverageMetadata="true" beStrictAboutCoverageMetadata="true" beStrictAboutOutputDuringTests="true" failOnRisky="true" failOnWarning="true">
+  <testsuites>
+    <testsuite name="unit">
+      <directory>tests/Unit</directory>
+    </testsuite>
+    <testsuite name="integration">
+      <directory>tests/Integration</directory>
+    </testsuite>
+  </testsuites>
+  <coverage/>
+  <source>
+    <include>
+      <directory suffix=".php">src</directory>
+    </include>
+  </source>
 </phpunit>

src/AmpPostgresConnectionAdapter.php

@@ -4,6 +4,7 @@
 
 use Amp\Postgres\PostgresConfig;
 use Amp\Postgres\PostgresLink;
+use Closure;
 use Cspray\DatabaseTestCase\Exception\MissingRequiredComposerPackage;
 use function Amp\Postgres\connect;
 
@@ -15,21 +16,29 @@ class AmpPostgresConnectionAdapter extends AbstractConnectionAdapter {
 
     private ?PostgresLink $connection = null;
 
-    public function __construct(
-        private readonly ConnectionAdapterConfig $adapterConfig
+    private function __construct(
+        private readonly Closure $connectionFactory
     ) {}
 
-    public function establishConnection() : void {
-        $this->connection = connect(
+    public static function newConnectionFromConfig(ConnectionAdapterConfig $config) : self {
+        return new self(fn() => connect(
             PostgresConfig::fromString(sprintf(
                 'db=%s host=%s port=%d user=%s pass=%s',
-                $this->adapterConfig->database,
-                $this->adapterConfig->host,
-                $this->adapterConfig->port,
-                $this->adapterConfig->user,
-                $this->adapterConfig->password
+                $config->database,
+                $config->host,
+                $config->port,
+                $config->user,
+                $config->password
             ))
-        );
+        ));
+    }
+
+    public static function existingConnection(PostgresLink $link) : self {
+        return new self(fn() => $link);
+    }
+
+    public function establishConnection() : void {
+        $this->connection = ($this->connectionFactory)();
     }
 
     public function onTestStart() : void {

tests/Integration/AmpPostgresConnectionAdapterTest.php

@@ -22,8 +22,6 @@ protected function executeCountSql(string $table) : int {
     }
 
     protected static function getConnectionAdapter() : ConnectionAdapter {
-        return new AmpPostgresConnectionAdapter(
-            new PostgresConnectionConfig()
-        );
+        return AmpPostgresConnectionAdapter::newConnectionFromConfig(new PostgresConnectionConfig());
     }
 }

tests/Unit/Helper/StubDatabaseTestCase.php

@@ -6,7 +6,9 @@
 use Cspray\DatabaseTestCase\DatabaseTestCase;
 use Cspray\DatabaseTestCase\LoadFixture;
 use Cspray\DatabaseTestCase\SingleRecordFixture;
+use PHPUnit\Framework\Attributes\CoversClass;
 
+#[CoversClass(DatabaseTestCase::class)]
 class StubDatabaseTestCase extends DatabaseTestCase {
 
     private static ConnectionAdapter $connectionAdapter;