Prevent empty id attribute (#143)

src/Html/FormBuilder.php

@@ -285,6 +285,10 @@ public function input(string $type, ?string $name = null, ?string $value = null,
             // when creating the HTML element. Then, we will return the entire input.
             $merge = compact('type', 'value', 'id');
 
+            if ($id === "") {
+                unset($merge['id']);
+            }
+
             $options = array_filter(array_merge($options, $merge), function ($item) {
                 return !is_null($item);
             });

tests/Html/FormBuilderTest.php

@@ -0,0 +1,58 @@
+<?php
+
+use Winter\Storm\Html\HtmlBuilder;
+use Winter\Storm\Html\FormBuilder;
+use Winter\Storm\Router\UrlGenerator;
+
+use Illuminate\Http\Request;
+use Illuminate\Routing\RouteCollection;
+
+class FormBuilderTest extends TestCase
+{
+    public function setUp() : void
+    {
+        $htmlBuilder = new HtmlBuilder;
+        $generator = new UrlGenerator(
+            new RouteCollection,
+            Request::create('https://www.example.com/path/?query=arg#fragment')
+        );
+        $this->formBuilder = new FormBuilder($htmlBuilder, $generator);
+    }
+
+    public function testInputIdMissing()
+    {
+        $result = $this->formBuilder->input(type:"text", name:"my-name", value:"my value");
+        $this->assertEquals('<input name="my-name" type="text" value="my value">', $result);
+    }
+
+    public function testInputIdEmpty()
+    {
+        $result = $this->formBuilder->input(type:"text", name:"my-name", value:"my value", options:["id"=>""]);
+        $this->assertEquals('<input id="" name="my-name" type="text" value="my value">', $result);
+    }
+
+    public function testInputIdNull()
+    {
+        $result = $this->formBuilder->input(type:"text", name:"my-name", value:"my value", options:["id"=>null]);
+        $this->assertEquals('<input name="my-name" type="text" value="my value">', $result);
+    }
+
+    public function testInputIdFalse()
+    {
+        $result = $this->formBuilder->input(type:"text", name:"my-name", value:"my value", options:["id"=>false]);
+        $this->assertEquals('<input id="" name="my-name" type="text" value="my value">', $result);
+    }
+
+    public function testInputIdZero()
+    {
+        $result = $this->formBuilder->input(type:"text", name:"my-name", value:"my value", options:["id"=>0]);
+        $this->assertEquals('<input id="0" name="my-name" type="text" value="my value">', $result);
+    }
+
+    public function testInputIdMissingWithAssociatedLabel()
+    {
+        $result = $this->formBuilder->label(name:"my-input", value:"my input label");
+        $result = $this->formBuilder->input(type:"text", name:"my-input", value:"my value");
+        $this->assertEquals('<input name="my-input" type="text" value="my value" id="my-input">', $result);
+    }
+}