Add LazyCsvCollection class

README.md

@@ -24,14 +24,24 @@ composer require bayareawebpro/laravel-simple-csv
 ## Usage:
 
 ```php
-<?php
 use BayAreaWebPro\SimpleCsv\SimpleCsv;
-$lazyCollection = SimpleCsv::import(storage_path('collection.csv'));
+
+$lazyCsvCollection = SimpleCsv::import(storage_path('collection.csv'));
+```
+
+### Empty Keys to Null
+
+PHP's 'putcsv' doesn't support writing `null` to csv files. The LazyCsvCollection returned by the import method 
+exposes a lazy 'emptyToNull' method that will convert empty array keys to null values for convenience. 
+
+```php
+use BayAreaWebPro\SimpleCsv\SimpleCsv;
+
+SimpleCsv::import(storage_path('collection.csv'))->emptyToNull();
 ```
 
 ### Export to File
 ```php
-<?php
 use BayAreaWebPro\SimpleCsv\SimpleCsv;
 
 // Collection
@@ -62,28 +72,31 @@ SimpleCsv::export(
 ### Export Download Stream
 
 ```php
-<?php
 use BayAreaWebPro\SimpleCsv\SimpleCsv;
+
 return SimpleCsv::download([...], 'download.csv');
 ```
 
 #### Override Options
 ```php
-<?php
 use Illuminate\Support\Facades\Config;
-Config::set('simple-csv.delimiter', ...);
-Config::set('simple-csv.enclosure', ...);
-Config::set('simple-csv.escape', ...);
+
+Config::set('simple-csv', [
+    'delimiter' => '?',
+    'enclosure' => '?',
+    'escape'    => '?',
+]);
 ```
 
 ## Or, Create a Config File
+
+`config/simple-csv.php`
+
 ```php
-<?php
-//config/simple-csv.php
 return [
-    'delimiter' => "???",
-    'enclosure' => "???",
-    'escape'    => "???",
+    'delimiter' => '?',
+    'enclosure' => '?',
+    'escape'    => '?',
 ];
 ```
 

src/LazyCsvCollection.php

@@ -0,0 +1,26 @@
+<?php namespace BayAreaWebPro\SimpleCsv;
+
+use Illuminate\Support\Enumerable;
+use Illuminate\Support\LazyCollection;
+
+final class LazyCsvCollection extends LazyCollection
+{
+    /**
+     * Convert empty item array keys to null.
+     */
+    public function emptyToNull()
+    {
+        return new static(function () {
+            foreach ($this as $item){
+                if(is_array($item) || $item instanceof Enumerable){
+                    foreach ($item as $key => $value){
+                        if(empty($value)){
+                            $item[$key] = null;
+                        }
+                    }
+                }
+                yield $item;
+            }
+        });
+    }
+}

src/SimpleCsv.php

@@ -3,12 +3,13 @@
 use Illuminate\Support\Collection;
 use Illuminate\Support\LazyCollection;
 use Illuminate\Support\Facades\Facade as LaravelFacade;
+use Iterator;
 
 /**
  * The SimpleCsv Service Facade
- * @method static \Symfony\Component\HttpFoundation\StreamedResponse download(Collection|LazyCollection|\Iterator|array $collection, string $filename)
- * @method static void export(Collection|LazyCollection|\Iterator|array $collection, string $path)
- * @method static LazyCollection import(string $path)
+ * @method static \Symfony\Component\HttpFoundation\StreamedResponse download(Collection|LazyCollection|Iterator|array $collection, string $filename)
+ * @method static void export(Collection|LazyCollection|Iterator|array $collection, string $path)
+ * @method static LazyCsvCollection import(string $path)
  */
 class SimpleCsv extends LaravelFacade
 {

src/SimpleCsvService.php

@@ -3,7 +3,6 @@
 namespace BayAreaWebPro\SimpleCsv;
 
 use \Iterator;
-use \SplFileObject;
 use \Exception;
 use Illuminate\Support\Collection;
 use Illuminate\Support\LazyCollection;
@@ -32,11 +31,11 @@ public function __construct(
         $this->file = null;
     }
 
-    public function import(string $path): LazyCollection
+    public function import(string $path): LazyCsvCollection
     {
         $this->openFileObject($path);
         $this->headers = array_values($this->getLine());
-        return LazyCollection::make(function () {
+        return LazyCsvCollection::make(function () {
             while ($this->file->valid() && $line = $this->getLine()) {
                 if (!$this->isInValidLine($line)) {
                     yield array_combine($this->headers, $line);

tests/Unit/DefaultTest.php

@@ -2,6 +2,7 @@
 
 namespace BayAreaWebPro\SimpleCsv\Tests\Unit;
 
+use BayAreaWebPro\SimpleCsv\LazyCsvCollection;
 use Symfony\Component\HttpFoundation\StreamedResponse;
 
 use Illuminate\Support\LazyCollection;
@@ -34,6 +35,23 @@ private function getRandomStoragePath()
         return storage_path(Str::random(16) . '.csv');
     }
 
+    public function test_imported_lazy_collection_methods()
+    {
+        $collection = new LazyCsvCollection(LazyGenerator::make(5, function () {
+            return ['null_field_exported_empty' => ''];
+        }));
+        foreach($collection as $row){
+            $this->assertNotNull($row['null_field_exported_empty']);
+        }
+
+        $collection = new LazyCsvCollection(LazyGenerator::make(5, function () {
+            return ['null_field_exported_empty' => ''];
+        }));
+        foreach($collection->emptyToNull() as $row){
+            $this->assertNull($row['null_field_exported_empty']);
+        }
+    }
+
     public function test_export_from_iterables()
     {
         $items = $this->getCollectionData(10)->toArray();
@@ -75,7 +93,8 @@ public function test_export_files_and_restore()
         }
 
         $decoded = SimpleCsv::import($path);
-        $this->assertTrue($decoded instanceof LazyCollection);
+        $this->assertInstanceOf(LazyCollection::class, $decoded);
+
         foreach ($decoded as $decodedItem) {
             $this->assertStringContainsString($decodedItem['email'], $fileData);
         }
@@ -89,7 +108,7 @@ public function test_can_download_streams()
 
         $response = SimpleCsv::download($collectionLazy, 'download.csv');
 
-        $this->assertTrue($response instanceof StreamedResponse);
+        $this->assertInstanceOf(StreamedResponse::class, $response);
 
         //Capture Streamed Output...
         ob_start();