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

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 @@ class ColumnCellIterator extends CellIterator
      */
     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 @@ class ColumnCellIterator extends CellIterator
      */
     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 @@ class ColumnIterator implements \Iterator
 
     /**
      * 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 @@ class ColumnIterator implements \Iterator
      */
     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 @@ class Iterator implements \Iterator
      */
     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 @@ class RowCellIterator extends CellIterator
      */
     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 @@ class RowCellIterator extends CellIterator
      */
     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 @@ class RowIterator implements \Iterator
 
     /**
      * 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 @@ class RowIterator implements \Iterator
      */
     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 @@ class ColumnCellIteratorTest extends TestCase
 
     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 @@ class ColumnIteratorTest extends TestCase
 
     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 @@ class RowCellIteratorTest extends TestCase
 
     public function testPrevOutOfRange()
     {
-        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
         $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $iterator->prev();
+        self::assertFalse($iterator->valid());
     }
 }

tests/PhpSpreadsheetTests/Worksheet/RowIteratorTest.php

@@ -75,9 +75,8 @@ class RowIteratorTest extends TestCase
 
     public function testPrevOutOfRange()
     {
-        $this->expectException(\PhpOffice\PhpSpreadsheet\Exception::class);
-
         $iterator = new RowIterator($this->mockWorksheet, 2, 4);
         $iterator->prev();
+        self::assertFalse($iterator->valid());
     }
 }