Make FnType accept params and content

Signed-off-by: davidarendsen <davidarendsen@hey.com>

README.md

@@ -1,7 +1,7 @@
 # InfluxDB 2.x Flux Query Builder
 
 With this query builder you can build queries for Flux.
-See https://docs.influxdata.com/influxdb/v2.3/query-data/flux/
+See https://docs.influxdata.com/influxdb/v2.4/query-data/flux/
 
 ## Installation
 

src/Type/FnType.php

@@ -4,13 +4,28 @@ namespace Arendsen\FluxQueryBuilder\Type;
 
 class FnType implements TypeInterface
 {
-    public function __construct(string $value)
+    /**
+     * @var mixed $value
+     */
+    protected $value;
+
+    /**
+     * @var string $content
+     */
+    protected $content;
+
+    public function __construct($value, string $content = '')
     {
         $this->value = $value;
+        $this->content = $content;
     }
 
     public function __toString(): string
     {
-        return $this->value;
+        if(is_string($this->value)) {
+            return $this->value;
+        }
+
+        return '(' . implode(', ', $this->value) . ') => ' . $this->content;
     }
 }

tests/Type/FactoryTypeTest.php

@@ -8,6 +8,7 @@ use DateTime;
 use Arendsen\FluxQueryBuilder\Type;
 use Arendsen\FluxQueryBuilder\Type\CustomType;
 use Arendsen\FluxQueryBuilder\Type\DurationType;
+use Arendsen\FluxQueryBuilder\Type\FnType;
 use Arendsen\FluxQueryBuilder\Type\MathType;
 use Arendsen\FluxQueryBuilder\Type\RecordType;
 use PHPUnit\Framework\TestCase;
@@ -79,6 +80,14 @@ final class FactoryTypeTest extends TestCase
                 new CustomType('this can be anything'),
                 'this can be anything'
             ],
+            'FnType with only content' => [
+                new FnType('(r) => ({ r with _value: r._value * r._value })'),
+                '(r) => ({ r with _value: r._value * r._value })'
+            ],
+            'FnType with params and content' => [
+                new FnType(['r', 'a'], '({ r with _value: r._value * r._value })'),
+                '(r, a) => ({ r with _value: r._value * r._value })'
+            ],
         ];
     }
 }