Fix for Issue #222: handle EOF and offset correctly on read

src/OpenedFile.php

@@ -261,7 +261,7 @@ public function getGroup(): int
 
     private function restorePosition(): void
     {
-        $this->base->getContentObject()->seek($this->position, SEEK_SET);
+        $this->base->getContentObject()->seek($this->position, SEEK_SET, false);
     }
 
     private function savePosition(): void

src/content/FileContent.php

@@ -38,7 +38,7 @@ public function read(int $count): string;
     /**
      * seeks to the given offset
      */
-    public function seek(int $offset, int $whence): bool;
+    public function seek(int $offset, int $whence, bool $resetEof = true): bool;
 
     /**
      * checks whether pointer is at end of file

src/content/SeekableFileContent.php

@@ -32,13 +32,26 @@ abstract class SeekableFileContent implements FileContent
      */
     private $offset = 0;
 
-    /**
+	/**
+	 * has the stream reached EOF; this happens on the first read *after* seeking to the end of the file
+	 *
+	 * @var bool
+	 */
+	private $eof=false;
+
+	/**
      * reads the given amount of bytes from content
      */
     public function read(int $count): string
     {
+        // If offset is already at or past end of file, set EOF flag
+        if ( $this->offset >= $this->size() ) {
+            $this->eof = true;
+            return '';
+	    }
+
         $data = $this->doRead($this->offset, $count);
-        $this->offset += $count;
+        $this->offset += strlen($data);
 
         return $data;
     }
@@ -51,7 +64,7 @@ abstract protected function doRead(int $offset, int $count): string;
     /**
      * seeks to the given offset
      */
-    public function seek(int $offset, int $whence): bool
+    public function seek(int $offset, int $whence, bool $resetEof = true): bool
     {
         $newOffset = $this->offset;
         switch ($whence) {
@@ -76,6 +89,10 @@ public function seek(int $offset, int $whence): bool
         }
 
         $this->offset = $newOffset;
+        // EOF is always false after a manual seek
+        if ( $resetEof ) {
+            $this->eof = false;
+        }
 
         return true;
     }
@@ -85,7 +102,7 @@ public function seek(int $offset, int $whence): bool
      */
     public function eof(): bool
     {
-        return $this->size() <= $this->offset;
+        return $this->eof;
     }
 
     /**

tests/phpunit/content/StringBasedFileContentTestCase.php

@@ -125,18 +125,38 @@ public function readLessThenSizeDoesNotReachEof(): void
     /**
      * @test
      */
-    public function readSizeReachesEof(): void
+    public function readSizeReachesDoesNotReachEof(): void
     {
         $this->stringBasedFileContent->read(9);
+        assertFalse($this->stringBasedFileContent->eof());
+    }
+
+    /**
+     * @test
+     */
+    public function readSizeReachesEofOnNextRead(): void
+    {
+        $this->stringBasedFileContent->read(9);
+        $this->stringBasedFileContent->read(1);
         assertTrue($this->stringBasedFileContent->eof());
     }
 
     /**
      * @test
      */
-    public function readMoreThanSizeReachesEof(): void
+    public function readMoreThanSizeDoesNotReachEof(): void
+    {
+        $this->stringBasedFileContent->read(10);
+        assertFalse($this->stringBasedFileContent->eof());
+    }
+
+    /**
+     * @test
+     */
+    public function readMoreThanSizeReachesEofOnNextRead(): void
     {
         $this->stringBasedFileContent->read(10);
+        $this->stringBasedFileContent->read(1);
         assertTrue($this->stringBasedFileContent->eof());
     }
 

tests/phpunit/vfsStreamFileTestCase.php

@@ -145,9 +145,9 @@ public function contentCanBeChanged(): void
     /**
      * @test
      */
-    public function isAtEofWhenEmpty(): void
+    public function isNotAtEofWhenEmpty(): void
     {
-        assertTrue($this->file->eof());
+        assertFalse($this->file->eof());
     }
 
     /**
@@ -169,19 +169,10 @@ public function readFromEmptyFileReturnsEmptyString(): void
     /**
      * @test
      */
-    public function readFromEmptyFileMovesPointer(): void
+    public function readFromEmptyFileDoesNotMovePointer(): void
     {
         $this->file->read(5);
-        assertThat($this->file->getBytesRead(), equals(5));
-    }
-
-    /**
-     * @test
-     */
-    public function reportsAmountOfBytesReadEvenWhenEmpty(): void
-    {
-        $this->file->read(5);
-        assertThat($this->file->getBytesRead(), equals(5));
+        assertThat($this->file->getBytesRead(), equals(0));
     }
 
     /**
@@ -228,6 +219,10 @@ public function partialReads(): void
 
         assertThat($this->file->read(3), equals('baz'));
         assertThat($this->file->getBytesRead(), equals(9));
+        assertFalse($this->file->eof());
+
+        assertThat($this->file->read(1), equals(''));
+        assertThat($this->file->getBytesRead(), equals(9));
         assertTrue($this->file->eof());
     }
 

tests/phpunit/vfsStreamWrapperFileTestCase.php

@@ -172,6 +172,7 @@ public function recognizesEof(): void
     {
         $fp = fopen($this->fileInSubdir->url(), 'r');
         fseek($fp, 1, SEEK_END);
+        fread($fp, 1);
         assertTrue(feof($fp));
         fclose($fp);
     }

tests/phpunit/vfsStreamWrapperTestCase.php

@@ -904,4 +904,98 @@ public function multipleWritesOnSameFileHaveDifferentPointers(): void
 
         assertThat(file_get_contents($url), equals($contentB . $contentA));
     }
+
+    /**
+     * @test
+     */
+    public function readsAndWritesOnSameFileHaveDifferentPointers(): void
+    {
+        $contentA = uniqid('a');
+        $contentB = uniqid('b');
+        $url = $this->fileInSubdir->url();
+
+        $fp1 = fopen($url, 'wb');
+        $fp2 = fopen($url, 'rb');
+
+        fwrite($fp1, $contentA);
+        $contentBeforeWrite = fread($fp2, strlen($contentA));
+
+        fwrite($fp1, $contentB);
+        $contentAfterWrite = fread($fp2, strlen($contentB));
+
+        fclose($fp1);
+        fclose($fp2);
+
+        assertThat($contentBeforeWrite, equals($contentA));
+        assertThat($contentAfterWrite, equals($contentB));
+    }
+
+    /**
+     * @test
+     */
+    public function feofIsFalseWhenEmptyFileOpened(): void
+    {
+        $this->fileInSubdir->setContent('');
+
+        $stream = fopen($this->fileInSubdir->url(), 'r');
+
+        assertFalse(feof($stream));
+    }
+
+    /**
+     * @test
+     */
+    public function feofIsTrueAfterEmptyFileRead(): void
+    {
+        $this->fileInSubdir->setContent('');
+
+        $stream = fopen($this->fileInSubdir->url(), 'r');
+
+        fgets($stream);
+
+        assertTrue(feof($stream));
+    }
+
+    /**
+     * @test
+     */
+    public function feofIsFalseWhenEmptyStreamRewound(): void
+    {
+        $this->fileInSubdir->setContent('');
+
+        $stream = fopen($this->fileInSubdir->url(), 'r');
+
+        fgets($stream);
+        rewind($stream);
+        assertFalse(feof($stream));
+    }
+
+    /**
+     * @test
+     */
+    public function feofIsFalseAfterReadingLastLine(): void
+    {
+        $this->fileInSubdir->setContent("Line 1\n");
+
+        $stream = fopen($this->fileInSubdir->url(), 'r');
+
+        fgets($stream);
+
+        assertFalse(feof($stream));
+    }
+
+    /**
+     * @test
+     */
+    public function feofIsTrueAfterReadingBeyondLastLine(): void
+    {
+        $this->fileInSubdir->setContent("Line 1\n");
+
+        $stream = fopen($this->fileInSubdir->url(), 'r');
+
+        fgets($stream);
+        fgets($stream);
+
+        assertTrue(feof($stream));
+    }
 }