#169 Fix JsonStreamFile empty line at the end issue, even if SKIP_EMPTY is set. Add JsonStreamReaderTask doc.

Author: njoubert-cleverage

docs/index.md

@@ -46,7 +46,7 @@
         - [CSVSplitterTask]
         - [InputCsvReaderTask](reference/tasks/input_csv_reader_task.md)
     - File/JsonStream
-        - [JsonStreamReaderTask]
+        - [JsonStreamReaderTask](reference/tasks/json_stream_reader_task.md)
         - [JsonStreamWriterTask](reference/tasks/json_stream_writer_task.md)
     - File/XML
         - [XmlReaderTask](reference/tasks/xml_reader_task.md)

docs/reference/tasks/json_stream_reader_task.md

@@ -0,0 +1,43 @@
+JsonStreamReaderTask
+=============
+
+Reads a json file and iterate on each line, returning decoded content as array. Skips empty lines.
+
+Task reference
+--------------
+
+* **Service**: `CleverAge\ProcessBundle\Task\File\JsonStream\JsonStreamReaderTask`
+* **Iterable task**
+
+Accepted inputs
+---------------
+
+`string`: Path of the file to read from (absolute)
+
+Possible outputs
+----------------
+
+`array`: foreach line, it will return content as array.
+Underlying method are [SplFileObject::fgets](https://www.php.net/manual/fr/splfileobject.fgets.php) and [json_decode](https://www.php.net/manual/en/function.json-decode.php).
+
+Options
+-------
+
+none
+
+Example
+-------
+
+```yaml
+# Task configuration level
+entry:
+  service: '@CleverAge\ProcessBundle\Task\ConstantIterableOutputTask'
+  outputs: read
+  options:
+    output:
+      file_path: '%kernel.project_dir%/var/data/json_stream_reader.json'
+read:
+  service: '@CleverAge\ProcessBundle\Task\File\JsonStream\JsonStreamReaderTask'
+```
+
+

src/Filesystem/JsonStreamFile.php

@@ -28,8 +28,8 @@ public function __construct(string $filename, string $mode = 'rb')
     {
         $this->file = new \SplFileObject($filename, $mode);
 
-        // Useful to skip empty trailing lines
-        $this->file->setFlags(\SplFileObject::READ_AHEAD | \SplFileObject::SKIP_EMPTY);
+        // Useful to skip empty trailing lines (doesn't work well on PHP 8, see readLine() code)
+        $this->file->setFlags(\SplFileObject::DROP_NEW_LINE | \SplFileObject::READ_AHEAD | \SplFileObject::SKIP_EMPTY );
     }
 
     /**
@@ -72,6 +72,10 @@ public function readLine(?int $length = null): ?array
         }
 
         $rawLine = $this->file->fgets();
+        // Fix issue on PHP 8 with empty line at the end, even if SKIP_EMPTY is set
+        if ('' === $rawLine) {
+            return null;
+        }
         ++$this->lineNumber;
 
         return json_decode($rawLine, true, 512, \JSON_THROW_ON_ERROR);