Improve error message for invalid configuration

Author: GromNaN

src/Connection.php

@@ -261,9 +261,15 @@ protected function getHostDsn(array $config): string
      */
     protected function getDsn(array $config): string
     {
-        return $this->hasDsnString($config)
-            ? $this->getDsnString($config)
-            : $this->getHostDsn($config);
+        if (! empty($config['dsn'])) {
+            return $this->getDsnString($config);
+        }
+
+        if (! empty($config['host'])) {
+            return $this->getHostDsn($config);
+        }
+
+        throw new InvalidArgumentException('MongoDB connection configuration requires "dsn" or "host" key.');
     }
 
     /** @inheritdoc */

tests/ConnectionTest.php

@@ -204,6 +204,14 @@ public function testConnectionWithoutConfiguredDatabase(): void
         new Connection(['dsn' => 'mongodb://some-host']);
     }
 
+    public function testConnectionWithoutConfiguredDsnOrHost(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('MongoDB connection configuration requires "dsn" or "host" key.');
+
+        new Connection(['database' => 'hello']);
+    }
+
     public function testCollection()
     {
         $collection = DB::connection('mongodb')->getCollection('unittest');