Introduce trait ipl\Sql\Test\Databases

src/Test/Databases.php

@@ -0,0 +1,142 @@
+<?php
+
+namespace ipl\Sql\Test;
+
+use ipl\Sql\Connection;
+use RuntimeException;
+
+/**
+ * Data provider for database connections. Use this to provide real database connections for your tests.
+ *
+ * To use it, implement {@see Databases::createSchema()} and {@see Databases::dropSchema()}.
+ * The environment also needs to provide the following variables: (Replace * with the name of a supported adapter)
+ *
+ * Name              | Description
+ * ----------------- | ------------------------
+ * *_TESTDB          | The database to use
+ * *_TESTDB_HOST     | The server to connect to
+ * *_TESTDB_PORT     | The port to connect to
+ * *_TESTDB_USER     | The user to connect with
+ * *_TESTDB_PASSWORD | The password of the user
+ *
+ * Each test case will run multiple times, once for each database.
+ * The connection is passed as the first argument to it.
+ *
+ * If you need to implement your own setUp() and tearDown() methods, make sure to call
+ * {@see Databases::setUpDatabases()} and {@see Databases::tearDownDatabases()} respectively.
+ */
+trait Databases
+{
+    /**
+     * Create the schema for the test database
+     *
+     * This is called once for each dataset and test case. (i.e. Twice per test-case)
+     *
+     * @param Connection $db
+     * @param string $driver
+     *
+     * @return void
+     */
+    abstract protected function createSchema(Connection $db, string $driver): void;
+
+    /**
+     * Drop the schema of the test database
+     *
+     *  This is called once for each dataset and test case. (i.e. Twice per test-case)
+     *
+     * @param Connection $db
+     * @param string $driver
+     *
+     * @return void
+     */
+    abstract protected function dropSchema(Connection $db, string $driver): void;
+
+    /**
+     * Provide the database connections
+     *
+     * @return array<string, Connection[]>
+     */
+    public function databases(): array
+    {
+        $supportedAdapters = ['mssql', 'mysql', 'oracle', 'pgsql', 'sqlite'];
+
+        $connections = [];
+        foreach ($supportedAdapters as $driver) {
+            if (isset($_SERVER[strtoupper($driver) . '_TESTDB'])) {
+                $connections[$driver] = [$this->createConnection($driver)];
+            }
+        }
+
+        return $connections;
+    }
+
+    /**
+     * Get the value of an environment variable
+     *
+     * @param string $name
+     *
+     * @return string
+     *
+     * @throws RuntimeException if the environment variable is not set
+     */
+    private function getEnvVariable(string $name): string
+    {
+        $value = getenv($name);
+        if ($value === false) {
+            throw new RuntimeException("Environment variable $name is not set");
+        }
+
+        return $value;
+    }
+
+    /**
+     * Create a database connection
+     *
+     * @param string $driver
+     *
+     * @return Connection
+     */
+    private function createConnection(string $driver): Connection
+    {
+        return new Connection([
+            'db' => $driver,
+            'host' => $this->getEnvVariable(strtoupper($driver) . '_TESTDB_HOST'),
+            'port' => $this->getEnvVariable(strtoupper($driver) . '_TESTDB_PORT'),
+            'username' => $this->getEnvVariable(strtoupper($driver) . '_TESTDB_USER'),
+            'password' => $this->getEnvVariable(strtoupper($driver) . '_TESTDB_PASSWORD'),
+            'dbname' => $this->getEnvVariable(strtoupper($driver) . '_TESTDB'),
+        ]);
+    }
+
+    public function setUp(): void
+    {
+        $this->setUpDatabases();
+    }
+
+    protected function setUpDatabases(): void
+    {
+        if (method_exists($this, 'dataName') && method_exists($this, 'getProvidedData')) {
+            // A small performance improvement. Though, it relies on internal methods, hence the check.
+            $this->createSchema($this->getProvidedData()[0], $this->dataName());
+        } else {
+            $this->createSchema($this->createConnection('mysql'), 'mysql');
+            $this->createSchema($this->createConnection('pgsql'), 'pgsql');
+        }
+    }
+
+    public function tearDown(): void
+    {
+        $this->tearDownDatabases();
+    }
+
+    protected function tearDownDatabases(): void
+    {
+        if (method_exists($this, 'dataName') && method_exists($this, 'getProvidedData')) {
+            // A small performance improvement. Though, it relies on internal methods, hence the check.
+            $this->dropSchema($this->getProvidedData()[0], $this->dataName());
+        } else {
+            $this->dropSchema($this->createConnection('mysql'), 'mysql');
+            $this->dropSchema($this->createConnection('pgsql'), 'pgsql');
+        }
+    }
+}