Allow iterators to go out of bounds with prev()

Iterators prev() behavior is now consistent with next(), meaning
that it can go out of bounds and it must be validated with valid()
before using it.

Fixes #587
Fixes #627

Author: dkarlovi

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased]
+
+### Fixed
+
+- Allow iterators to go out of bounds with prev - [#587](https://github.com/PHPOffice/PhpSpreadsheet/issues/587)
+
 ## [1.4.0] - 2018-08-06
 
 ### Added

src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php

@@ -153,10 +153,6 @@ public function next()
      */
     public function prev()
     {
-        if ($this->currentRow <= $this->startRow) {
-            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
-        }
-
         do {
             --$this->currentRow;
         } while (($this->onlyExistingCells) &&
@@ -171,7 +167,7 @@ public function prev()
      */
     public function valid()
     {
-        return $this->currentRow <= $this->endRow;
+        return $this->currentRow <= $this->endRow && $this->currentRow >= $this->startRow;
     }
 
     /**

src/PhpSpreadsheet/Worksheet/ColumnIterator.php

@@ -157,14 +157,9 @@ public function next()
 
     /**
      * Set the iterator to its previous value.
-     *
-     * @throws PhpSpreadsheetException
      */
     public function prev()
     {
-        if ($this->currentColumnIndex <= $this->startColumnIndex) {
-            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ' - ' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ')');
-        }
         --$this->currentColumnIndex;
     }
 
@@ -175,6 +170,6 @@ public function prev()
      */
     public function valid()
     {
-        return $this->currentColumnIndex <= $this->endColumnIndex;
+        return $this->currentColumnIndex <= $this->endColumnIndex && $this->currentColumnIndex >= $this->startColumnIndex;
     }
 }

src/PhpSpreadsheet/Worksheet/Iterator.php

@@ -25,7 +25,7 @@ class Iterator implements \Iterator
      *
      * @param Spreadsheet $subject
      */
-    public function __construct(Spreadsheet $subject = null)
+    public function __construct(Spreadsheet $subject)
     {
         // Set subject
         $this->subject = $subject;
@@ -82,6 +82,6 @@ public function next()
      */
     public function valid()
     {
-        return $this->position < $this->subject->getSheetCount();
+        return $this->position < $this->subject->getSheetCount() && $this->position >= 0;
     }
 }

src/PhpSpreadsheet/Worksheet/RowCellIterator.php

@@ -155,9 +155,6 @@ public function next()
      */
     public function prev()
     {
-        if ($this->currentColumnIndex <= $this->startColumnIndex) {
-            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ' - ' . Coordinate::stringFromColumnIndex($this->endColumnIndex) . ')');
-        }
         do {
             --$this->currentColumnIndex;
         } while (($this->onlyExistingCells) && (!$this->worksheet->cellExistsByColumnAndRow($this->currentColumnIndex, $this->rowIndex)) && ($this->currentColumnIndex >= $this->startColumnIndex));
@@ -170,7 +167,7 @@ public function prev()
      */
     public function valid()
     {
-        return $this->currentColumnIndex <= $this->endColumnIndex;
+        return $this->currentColumnIndex <= $this->endColumnIndex && $this->currentColumnIndex >= $this->startColumnIndex;
     }
 
     /**

src/PhpSpreadsheet/Worksheet/RowIterator.php

@@ -152,15 +152,9 @@ public function next()
 
     /**
      * Set the iterator to its previous value.
-     *
-     * @throws PhpSpreadsheetException
      */
     public function prev()
     {
-        if ($this->position <= $this->startRow) {
-            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
-        }
-
         --$this->position;
     }
 
@@ -171,6 +165,6 @@ public function prev()
      */
     public function valid()
     {
-        return $this->position <= $this->endRow;
+        return $this->position <= $this->endRow && $this->position >= $this->startRow;
     }
 }

tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php

@@ -78,9 +78,8 @@ public function testSeekOutOfRange()
 
     public function testPrevOutOfRange()
     {
-        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
         $iterator = new ColumnCellIterator($this->mockWorksheet, 'A', 2, 4);
         $iterator->prev();
+        self::assertFalse($iterator->valid());
     }
 }

tests/PhpSpreadsheetTests/Worksheet/ColumnIteratorTest.php

@@ -77,9 +77,8 @@ public function testSeekOutOfRange()
 
     public function testPrevOutOfRange()
     {
-        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
         $iterator = new ColumnIterator($this->mockWorksheet, 'B', 'D');
         $iterator->prev();
+        self::assertFalse($iterator->valid());
     }
 }

tests/PhpSpreadsheetTests/Worksheet/IteratorTest.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
+
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\Iterator;
+use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
+use PHPUnit\Framework\TestCase;
+
+class IteratorTest extends TestCase
+{
+    public function testIteratorFullRange()
+    {
+        $spreadsheet = new Spreadsheet();
+        $spreadsheet->createSheet();
+        $spreadsheet->createSheet();
+
+        $iterator = new Iterator($spreadsheet);
+        $columnIndexResult = 0;
+        self::assertEquals($columnIndexResult, $iterator->key());
+
+        foreach ($iterator as $key => $column) {
+            self::assertEquals($columnIndexResult++, $key);
+            self::assertInstanceOf(Worksheet::class, $column);
+        }
+        self::assertSame(3, $columnIndexResult);
+    }
+}

tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php

@@ -80,9 +80,8 @@ public function testSeekOutOfRange()
 
     public function testPrevOutOfRange()
     {
-        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
         $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $iterator->prev();
+        self::assertFalse($iterator->valid());
     }
 }