Stream readers and writers for NdJson input

messages/php/src/Streams/NdJsonStreamReader.php

@@ -0,0 +1,21 @@
+<?php declare(strict_types=1);
+
+namespace Cucumber\Messages\Streams;
+
+use Cucumber\Messages\Envelope;
+use Generator;
+
+final class NdJsonStreamReader implements StreamReader
+{
+    use WithFileHandleTrait;
+
+    /**
+     * @return Generator<int, Envelope>
+     */
+    public function envelopes() : Generator
+    {
+        while (!feof($this->fileHandle) && ($line = fgets($this->fileHandle))) {
+            yield Envelope::fromJson($line);
+        }
+    }
+}

messages/php/src/Streams/NdJsonStreamWriter.php

@@ -0,0 +1,20 @@
+<?php declare(strict_types=1);
+
+namespace Cucumber\Messages\Streams;
+
+use Cucumber\Messages\Envelope;
+
+final class NdJsonStreamWriter implements StreamWriter
+{
+    use WithFileHandleTrait;
+
+    /**
+     * @param iterable<Envelope> $envelopes
+     */
+    public function writeEnvelopes(iterable $envelopes) : void
+    {
+        foreach($envelopes as $envelope) {
+            fputs($this->fileHandle, $envelope->asJson() . "\n");
+        }
+    }
+}

messages/php/src/Streams/StreamReader.php

@@ -0,0 +1,13 @@
+<?php declare(strict_types=1);
+
+namespace Cucumber\Messages\Streams;
+
+use Cucumber\Messages\Envelope;
+
+interface StreamReader
+{
+    /**
+     * @return iterable<Envelope>
+     */
+    public function envelopes(): iterable;
+}

messages/php/src/Streams/StreamWriter.php

@@ -0,0 +1,13 @@
+<?php declare(strict_types=1);
+
+namespace Cucumber\Messages\Streams;
+
+use Cucumber\Messages\Envelope;
+
+interface StreamWriter
+{
+    /**
+     * @param iterable<Envelope> $envelopes
+     */
+    public function writeEnvelopes(iterable $envelopes): void;
+}

messages/php/src/Streams/WithFileHandleTrait.php

@@ -0,0 +1,24 @@
+<?php declare(strict_types=1);
+
+namespace Cucumber\Messages\Streams;
+
+/**
+ * @internal
+ */
+trait WithFileHandleTrait
+{
+    /**
+     * @param resource $fileHandle
+     */
+    private function __construct(
+        private mixed $fileHandle,
+    ){}
+
+    /**
+     * @param resource $fileHandle
+     */
+    public static function fromFileHandle($fileHandle): self
+    {
+        return new self($fileHandle);
+    }
+}

messages/php/tests/AcceptanceTest.php

@@ -1,11 +1,13 @@
 <?php
 
 use Cucumber\Messages\Envelope;
+use Cucumber\Messages\Streams\NdJsonStreamReader;
+use Cucumber\Messages\Streams\NdJsonStreamWriter;
 use PHPUnit\Framework\TestCase;
 
 class AcceptanceTest extends TestCase
 {
-    /** @dataProvider provideJson */
+    /** @dataProvider provideJsonLines */
     public function testAllNdJsonSurvivesDecodingThenEncoding(string $json) : void
     {
        $envelope = Envelope::fromJson($json);
@@ -14,18 +16,65 @@ public function testAllNdJsonSurvivesDecodingThenEncoding(string $json) : void
        self::assertJsonStringEqualsJsonString($json, $newJson);
     }
 
+    /** @dataProvider provideNdJsonFilenames */
+    public function testAllFileStreamsSurviveDecodingThenEncoding(string $filename) : void
+    {
+        $sourceHandle = fopen($filename, 'r');
+        $destHandle = fopen('php://memory', 'w');
+
+        $reader = NdJsonStreamReader::fromFileHandle($sourceHandle);
+        $writer = NdJsonStreamWriter::fromFileHandle($destHandle);
+
+        $writer->writeEnvelopes($reader->envelopes());
+
+        rewind($sourceHandle);
+        rewind($destHandle);
+
+        while (!feof($sourceHandle)) {
+            $sourceLine = fgets($sourceHandle);
+            $destLine = fgets($destHandle);
+
+            if (!$sourceLine && !$destLine) {
+                break;
+            }
+
+            self::assertJsonStringEqualsJsonString($sourceLine, $destLine);
+        }
+
+        // we exhausted source so dest should also be at end
+        self::assertTrue(feof($destHandle));
+    }
+
     /**
-     * @return Generator<string, list<string>>
+     * @return Generator<string, array{0: string}>
      */
-    public function provideJson() : Generator
+    public function provideJsonLines() : Generator
     {
-        $filePattern = __DIR__ . '/../../../compatibility-kit/javascript/features/**/*.ndjson';
-        foreach (glob($filePattern) as $filename) {
+        foreach ($this->getSampleFiles() as $filename) {
             foreach(file($filename) ?: [] as $lineNumber => $line) {
                 // key is provided for better error messages
                 $key = realpath($filename) . ':' . $lineNumber;
                 yield $key => [$line];
             }
         }
     }
+
+    /**
+     * @return Generator<string, array{0: string}>
+     */
+    public function provideNdJsonFilenames() : Generator
+    {
+        foreach($this->getSampleFiles() as $filename)
+        {
+            yield $filename => [$filename];
+        }
+    }
+
+    /**
+     * @return list<string>
+     */
+    private function getSampleFiles(): array
+    {
+        return glob(__DIR__ . '/../../../compatibility-kit/javascript/features/**/*.ndjson') ?: [];
+    }
 }