First stab at #135 - Add borders (#200)

Fixes #135

Added border support for ODS and XLSX files.
Updated README.

README.md

@@ -125,7 +125,7 @@ The writer always generate CSV files encoded in UTF-8, with a BOM.
 
 #### Row styling
 
-It is possible to apply some formatting options to a row. Spout supports fonts as well as alignment styles.
+It is possible to apply some formatting options to a row. Spout supports fonts, borders as well as alignment styles.
 
 ```php
 use Box\Spout\Common\Type;
@@ -150,6 +150,33 @@ $writer->addRowsWithStyle($multipleRows, $style); // style will be applied to al
 $writer->close();
 ```
 
+Adding borders to a row requires a ```Border``` object.
+
+```php
+use Box\Spout\Common\Type;
+use Box\Spout\Writer\Style\Border;
+use Box\Spout\Writer\Style\BorderBuilder;
+use Box\Spout\Writer\Style\Color;
+use Box\Spout\Writer\Style\StyleBuilder;
+use Box\Spout\Writer\WriterFactory;
+
+$border = (new BorderBuilder())
+    ->setBorderBottom(Color::GREEN, Border::WIDTH_THIN, Border::STYLE_DASHED)
+    ->build();
+
+$style = (new StyleBuilder())
+    ->setBorder($border)
+    ->build();
+
+$writer = WriterFactory::create(Type::ODS);
+$writer->openToFile(__DIR__ . '/borders.xlsx');
+
+$writer->addRowWithStyle(['Border Bottom Green Thin Dashed'], $style)
+
+$writer->close();
+
+```
+
 Unfortunately, Spout does not support all the possible formatting options yet. But you can find the most important ones:
 
 Category  | Property      | API

src/Spout/Writer/Exception/Border/InvalidNameException.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Box\Spout\Writer\Exception\Border;
+
+use Box\Spout\Writer\Exception\WriterException;
+use Box\Spout\Writer\Style\BorderPart;
+
+class InvalidNameException extends WriterException
+{
+    public function __construct($name)
+    {
+        $msg = '%s is not a valid name identifier for a border. Valid identifiers are: %s.';
+
+        parent::__construct(sprintf($msg, $name, implode(',', BorderPart::getAllowedNames())));
+    }
+}

src/Spout/Writer/Exception/Border/InvalidStyleException.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Box\Spout\Writer\Exception\Border;
+
+use Box\Spout\Writer\Exception\WriterException;
+use Box\Spout\Writer\Style\BorderPart;
+
+class InvalidStyleException extends WriterException
+{
+    public function __construct($name)
+    {
+        $msg = '%s is not a valid style identifier for a border. Valid identifiers are: %s.';
+
+        parent::__construct(sprintf($msg, $name, implode(',', BorderPart::getAllowedStyles())));
+    }
+}

src/Spout/Writer/Exception/Border/InvalidWidthException.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Box\Spout\Writer\Exception\Border;
+
+use Box\Spout\Writer\Exception\WriterException;
+use Box\Spout\Writer\Style\BorderPart;
+
+class InvalidWidthException extends WriterException
+{
+    public function __construct($name)
+    {
+        $msg = '%s is not a valid width identifier for a border. Valid identifiers are: %s.';
+
+        parent::__construct(sprintf($msg, $name, implode(',', BorderPart::getAllowedWidths())));
+    }
+}

src/Spout/Writer/ODS/Helper/BorderHelper.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Box\Spout\Writer\ODS\Helper;
+
+use Box\Spout\Writer\Style\BorderPart;
+use Box\Spout\Writer\Style\Border;
+
+/**
+ * Class BorderHelper
+ *
+ * The fo:border, fo:border-top, fo:border-bottom, fo:border-left and fo:border-right attributes
+ * specify border properties
+ * http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#__RefHeading__1419780_253892949
+ *
+ * Example table-cell-properties
+ *
+ * <style:table-cell-properties
+ * fo:border-bottom="0.74pt solid #ffc000" style:diagonal-bl-tr="none"
+ * style:diagonal-tl-br="none" fo:border-left="none" fo:border-right="none"
+ * style:rotation-align="none" fo:border-top="none"/>
+ */
+class BorderHelper
+{
+    /**
+     * Width mappings
+     *
+     * @var array
+     */
+    protected static $widthMap = [
+        Border::WIDTH_THIN => '0.75pt',
+        Border::WIDTH_MEDIUM => '1.75pt',
+        Border::WIDTH_THICK => '2.5pt',
+    ];
+
+    /**
+     * Style mapping
+     *
+     * @var array
+     */
+    protected static $styleMap = [
+        Border::STYLE_SOLID => 'solid',
+        Border::STYLE_DASHED => 'dashed',
+        Border::STYLE_DOTTED => 'dotted',
+        Border::STYLE_DOUBLE => 'double',
+    ];
+
+    /**
+     * @param BorderPart $borderPart
+     * @return string
+     */
+    public static function serializeBorderPart(BorderPart $borderPart)
+    {
+        $definition = 'fo:border-%s="%s"';
+
+        if ($borderPart->getStyle() === Border::STYLE_NONE) {
+            $borderPartDefinition = sprintf($definition, $borderPart->getName(), 'none');
+        } else {
+            $attributes = [
+                self::$widthMap[$borderPart->getWidth()],
+                self::$styleMap[$borderPart->getStyle()],
+                '#' . $borderPart->getColor(),
+            ];
+            $borderPartDefinition = sprintf($definition, $borderPart->getName(), implode(' ', $attributes));
+        }
+
+        return $borderPartDefinition;
+    }
+}

src/Spout/Writer/ODS/Helper/StyleHelper.php

@@ -3,6 +3,7 @@
 namespace Box\Spout\Writer\ODS\Helper;
 
 use Box\Spout\Writer\Common\Helper\AbstractStyleHelper;
+use Box\Spout\Writer\Style\BorderPart;
 
 /**
  * Class StyleHelper
@@ -256,9 +257,16 @@ EOD;
             $content .= '<style:table-cell-properties fo:wrap-option="wrap" style:vertical-align="automatic"/>';
         }
 
+        if ($style->shouldApplyBorder()) {
+            $borderProperty = '<style:table-cell-properties %s />';
+            $borders = array_map(function (BorderPart $borderPart) {
+                return BorderHelper::serializeBorderPart($borderPart);
+            }, $style->getBorder()->getParts());
+            $content .= sprintf($borderProperty, implode(' ', $borders));
+        }
+
         $content .= '</style:style>';
 
         return $content;
     }
-
 }

src/Spout/Writer/Style/Border.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Box\Spout\Writer\Style;
+
+/**
+ * Class Border
+ */
+class Border
+{
+    const LEFT = 'left';
+    const RIGHT = 'right';
+    const TOP = 'top';
+    const BOTTOM = 'bottom';
+
+    const STYLE_NONE = 'none';
+    const STYLE_SOLID = 'solid';
+    const STYLE_DASHED = 'dashed';
+    const STYLE_DOTTED = 'dotted';
+    const STYLE_DOUBLE = 'double';
+
+    const WIDTH_THIN = 'thin';
+    const WIDTH_MEDIUM = 'medium';
+    const WIDTH_THICK = 'thick';
+
+    /**
+     * @var array A list of BorderPart objects for this border.
+     */
+    protected $parts = [];
+
+    /**
+     * @param array|void $borderParts
+     */
+    public function __construct(array $borderParts = [])
+    {
+        $this->setParts($borderParts);
+    }
+
+    /**
+     * @return array
+     */
+    public function getParts()
+    {
+        return $this->parts;
+    }
+
+    /**
+     * Set BorderParts
+     * @param array $parts
+     */
+    public function setParts($parts)
+    {
+        unset($this->parts);
+        foreach ($parts as $part) {
+            $this->addPart($part);
+        }
+    }
+
+    /**
+     * @param BorderPart $borderPart
+     * @return self
+     */
+    public function addPart(BorderPart $borderPart)
+    {
+        $this->parts[$borderPart->getName()] = $borderPart;
+        return $this;
+    }
+}

src/Spout/Writer/Style/BorderBuilder.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace Box\Spout\Writer\Style;
+
+/**
+ * Class BorderBuilder
+ */
+class BorderBuilder
+{
+    /**
+     * @var Border
+     */
+    protected $border;
+
+    public function __construct()
+    {
+        $this->border = new Border();
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderTop($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::TOP, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderRight($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::RIGHT, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderBottom($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::BOTTOM, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @param string|void $color Border A RGB color code
+     * @param string|void $width Border width @see BorderPart::allowedWidths
+     * @param string|void $style Border style @see BorderPart::allowedStyles
+     * @return BorderBuilder
+     */
+    public function setBorderLeft($color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->border->addPart(new BorderPart(Border::LEFT, $color, $width, $style));
+        return $this;
+    }
+
+    /**
+     * @return Border
+     */
+    public function build()
+    {
+        return $this->border;
+    }
+}

src/Spout/Writer/Style/BorderPart.php

@@ -0,0 +1,184 @@
+<?php
+
+namespace Box\Spout\Writer\Style;
+
+use Box\Spout\Writer\Exception\Border\InvalidNameException;
+use Box\Spout\Writer\Exception\Border\InvalidStyleException;
+use Box\Spout\Writer\Exception\Border\InvalidWidthException;
+
+/**
+ * Class BorderPart
+ */
+class BorderPart
+{
+    /**
+     * @var string The style of this border part.
+     */
+    protected $style;
+
+    /**
+     * @var string The name of this border part.
+     */
+    protected $name;
+
+    /**
+     * @var string The color of this border part.
+     */
+    protected $color;
+
+    /**
+     * @var string The width of this border part.
+     */
+    protected $width;
+
+    /**
+     * @var array Allowed style constants for parts.
+     */
+    protected static $allowedStyles = [
+        'none',
+        'solid',
+        'dashed',
+        'dotted',
+        'double'
+    ];
+
+    /**
+     * @var array Allowed names constants for border parts.
+     */
+    protected static $allowedNames = [
+        'left',
+        'right',
+        'top',
+        'bottom',
+    ];
+
+    /**
+     * @var array Allowed width constants for border parts.
+     */
+    protected static $allowedWidths = [
+        'thin',
+        'medium',
+        'thick',
+    ];
+
+    /**
+     * @param string $name @see  BorderPart::$allowedNames
+     * @param string $color A RGB color code
+     * @param string $width @see BorderPart::$allowedWidths
+     * @param string $style @see BorderPart::$allowedStyles
+     * @throws InvalidNameException
+     * @throws InvalidStyleException
+     * @throws InvalidWidthException
+     */
+    public function __construct($name, $color = Color::BLACK, $width = Border::WIDTH_MEDIUM, $style = Border::STYLE_SOLID)
+    {
+        $this->setName($name);
+        $this->setColor($color);
+        $this->setWidth($width);
+        $this->setStyle($style);
+    }
+
+    /**
+     * @return string
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * @param string $name The name of the border part @see BorderPart::$allowedNames
+     * @throws InvalidNameException
+     * @return void
+     */
+    public function setName($name)
+    {
+        if (!in_array($name, self::$allowedNames)) {
+            throw new InvalidNameException($name);
+        }
+        $this->name = $name;
+    }
+
+    /**
+     * @return string
+     */
+    public function getStyle()
+    {
+        return $this->style;
+    }
+
+    /**
+     * @param string $style The style of the border part @see BorderPart::$allowedStyles
+     * @throws InvalidStyleException
+     * @return void
+     */
+    public function setStyle($style)
+    {
+        if (!in_array($style, self::$allowedStyles)) {
+            throw new InvalidStyleException($style);
+        }
+        $this->style = $style;
+    }
+
+    /**
+     * @return string
+     */
+    public function getColor()
+    {
+        return $this->color;
+    }
+
+    /**
+     * @param string $color The color of the border part @see Color::rgb()
+     * @return void
+     */
+    public function setColor($color)
+    {
+        $this->color = $color;
+    }
+
+    /**
+     * @return string
+     */
+    public function getWidth()
+    {
+        return $this->width;
+    }
+
+    /**
+     * @param string $width The width of the border part @see BorderPart::$allowedWidths
+     * @throws InvalidWidthException
+     * @return void
+     */
+    public function setWidth($width)
+    {
+        if (!in_array($width, self::$allowedWidths)) {
+            throw new InvalidWidthException($width);
+        }
+        $this->width = $width;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedStyles()
+    {
+        return self::$allowedStyles;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedNames()
+    {
+        return self::$allowedNames;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAllowedWidths()
+    {
+        return self::$allowedWidths;
+    }
+}

src/Spout/Writer/Style/Style.php

@@ -61,6 +61,16 @@ class Style
     /** @var bool Whether the wrap text property was set */
     protected $hasSetWrapText = false;
 
+    /**
+     * @var Border
+     */
+    protected $border = null;
+
+    /**
+     * @var bool Whether border properties should be applied
+     */
+    protected $shouldApplyBorder = false;
+
     /**
      * @return int|null
      */
@@ -79,6 +89,32 @@ class Style
         return $this;
     }
 
+    /**
+     * @return Border
+     */
+    public function getBorder()
+    {
+        return $this->border;
+    }
+
+    /**
+     * @param Border $border
+     */
+    public function setBorder(Border $border)
+    {
+        $this->shouldApplyBorder = true;
+        $this->border = $border;
+        return $this;
+    }
+
+    /**
+     * @return boolean
+     */
+    public function shouldApplyBorder()
+    {
+        return $this->shouldApplyBorder;
+    }
+
     /**
      * @return boolean
      */
@@ -302,6 +338,9 @@ class Style
         if (!$this->hasSetWrapText && $baseStyle->shouldWrapText()) {
             $mergedStyle->setShouldWrapText();
         }
+        if (!$this->getBorder() && $baseStyle->shouldApplyBorder()) {
+            $mergedStyle->setBorder($baseStyle->getBorder());
+        }
 
         return $mergedStyle;
     }

src/Spout/Writer/Style/StyleBuilder.php

@@ -121,6 +121,18 @@ class StyleBuilder
         return $this;
     }
 
+    /**
+     * Set a border
+     *
+     * @param Border $border
+     * @return $this
+     */
+    public function setBorder(Border $border)
+    {
+        $this->style->setBorder($border);
+        return $this;
+    }
+
     /**
      * Returns the configured style. The style is cached and can be reused.
      *

src/Spout/Writer/XLSX/Helper/BorderHelper.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Box\Spout\Writer\XLSX\Helper;
+
+use Box\Spout\Writer\Style\Border;
+use Box\Spout\Writer\Style\BorderPart;
+
+class BorderHelper
+{
+    public static $xlsxStyleMap = [
+        Border::STYLE_SOLID => [
+            Border::WIDTH_THIN => 'thin',
+            Border::WIDTH_MEDIUM => 'medium',
+            Border::WIDTH_THICK => 'thick'
+        ],
+        Border::STYLE_DOTTED => [
+            Border::WIDTH_THIN => 'dotted',
+            Border::WIDTH_MEDIUM => 'dotted',
+            Border::WIDTH_THICK => 'dotted',
+        ],
+        Border::STYLE_DASHED => [
+            Border::WIDTH_THIN => 'dashed',
+            Border::WIDTH_MEDIUM => 'mediumDashed',
+            Border::WIDTH_THICK => 'mediumDashed',
+        ],
+        Border::STYLE_DOUBLE => [
+            Border::WIDTH_THIN => 'double',
+            Border::WIDTH_MEDIUM => 'double',
+            Border::WIDTH_THICK => 'double',
+        ],
+        Border::STYLE_NONE => [
+            Border::WIDTH_THIN => 'none',
+            Border::WIDTH_MEDIUM => 'none',
+            Border::WIDTH_THICK => 'none',
+        ],
+    ];
+
+    /**
+     * @param BorderPart $borderPart
+     * @return string
+     */
+    public static function serializeBorderPart(BorderPart $borderPart)
+    {
+        $borderStyle = self::getBorderStyle($borderPart);
+
+        $colorEl = $borderPart->getColor() ? sprintf('<color rgb="%s"/>', $borderPart->getColor()) : '';
+        $partEl = sprintf(
+            '<%s style="%s">%s</%s>',
+            $borderPart->getName(),
+            $borderStyle,
+            $colorEl,
+            $borderPart->getName()
+        );
+
+        return $partEl . PHP_EOL;
+    }
+
+    /**
+     * Get the style definition from the style map
+     *
+     * @param BorderPart $borderPart
+     * @return string
+     */
+    protected static function getBorderStyle(BorderPart $borderPart)
+    {
+        return self::$xlsxStyleMap[$borderPart->getStyle()][$borderPart->getWidth()];
+    }
+}

src/Spout/Writer/XLSX/Helper/StyleHelper.php

@@ -100,17 +100,29 @@ EOD;
      */
     protected function getBordersSectionContent()
     {
-        return <<<EOD
-<borders count="1">
-    <border>
-        <left/>
-        <right/>
-        <top/>
-        <bottom/>
-        <diagonal/>
-    </border>
-</borders>
-EOD;
+        $registeredStyles = $this->getRegisteredStyles();
+        $registeredStylesCount = count($registeredStyles);
+
+        $content = '<borders count="' . $registeredStylesCount . '">';
+
+        /** @var \Box\Spout\Writer\Style\Style $style */
+        foreach ($registeredStyles as $style) {
+            $border = $style->getBorder();
+            if ($border) {
+                $content .= '<border>';
+                foreach ($border->getParts() as $part) {
+                    /** @var $part \Box\Spout\Writer\Style\BorderPart */
+                    $content .= BorderHelper::serializeBorderPart($part);
+                }
+                $content .= '</border>';
+            } else {
+                $content .= '<border><left/><right/><top/><bottom/><diagonal/></border>';
+            }
+        }
+
+        $content .= '</borders>';
+
+        return $content;
     }
 
     /**
@@ -139,12 +151,16 @@ EOD;
         $content = '<cellXfs count="' . count($registeredStyles) . '">';
 
         foreach ($registeredStyles as $style) {
-            $content .= '<xf numFmtId="0" fontId="' . $style->getId() . '" fillId="0" borderId="0" xfId="0"';
+            $content .= '<xf numFmtId="0" fontId="' . $style->getId() . '" fillId="0" borderId="' . $style->getId() . '" xfId="0"';
 
             if ($style->shouldApplyFont()) {
                 $content .= ' applyFont="1"';
             }
 
+            if ($style->shouldApplyBorder()) {
+                $content .= ' applyBorder="1"';
+            }
+
             if ($style->shouldWrapText()) {
                 $content .= ' applyAlignment="1">';
                 $content .= '<alignment wrapText="1"/>';

tests/Spout/Writer/ODS/WriterWithStyleTest.php

@@ -5,6 +5,9 @@ namespace Box\Spout\Writer\ODS;
 use Box\Spout\Common\Type;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\TestUsingResource;
+use Box\Spout\Writer\ODS\Helper\BorderHelper;
+use Box\Spout\Writer\Style\Border;
+use Box\Spout\Writer\Style\BorderBuilder;
 use Box\Spout\Writer\Style\Color;
 use Box\Spout\Writer\Style\Style;
 use Box\Spout\Writer\Style\StyleBuilder;
@@ -236,6 +239,72 @@ class WriterWithStyleTest extends \PHPUnit_Framework_TestCase
         $this->assertFirstChildHasAttributeEquals('wrap', $customStyleElement, 'table-cell-properties', 'fo:wrap-option');
     }
 
+    /**
+     * @return void
+     */
+    public function testBorders()
+    {
+        $fileName = 'test_borders.ods';
+
+        $dataRows = [
+            ['row-with-border-bottom-green-thick-solid'],
+            ['row-without-border'],
+            ['row-with-border-top-red-thin-dashed'],
+        ];
+
+        $borderBottomGreenThickSolid = (new BorderBuilder())
+            ->setBorderBottom(Color::GREEN, Border::WIDTH_THICK, Border::STYLE_SOLID)->build();
+
+
+        $borderTopRedThinDashed = (new BorderBuilder())
+            ->setBorderTop(Color::RED, Border::WIDTH_THIN, Border::STYLE_DASHED)->build();
+
+        $styles =  [
+            (new StyleBuilder())->setBorder($borderBottomGreenThickSolid)->build(),
+            (new StyleBuilder())->build(),
+            (new StyleBuilder())->setBorder($borderTopRedThinDashed)->build(),
+        ];
+
+        $this->writeToODSFileWithMultipleStyles($dataRows, $fileName, $styles);
+
+        $styleElements = $this->getCellStyleElementsFromContentXmlFile($fileName);
+
+        $this->assertEquals(3, count($styleElements), 'There should be 3 styles)');
+
+        // Use reflection for protected members here
+        $widthMap = \ReflectionHelper::getStaticValue('Box\Spout\Writer\ODS\Helper\BorderHelper', 'widthMap');
+        $styleMap = \ReflectionHelper::getStaticValue('Box\Spout\Writer\ODS\Helper\BorderHelper', 'styleMap');
+
+        $expectedFirst = sprintf(
+            '%s %s #%s',
+            $widthMap[Border::WIDTH_THICK],
+            $styleMap[Border::STYLE_SOLID],
+            Color::GREEN
+        );
+
+        $actualFirst = $styleElements[1]
+            ->getElementsByTagName('table-cell-properties')
+            ->item(0)
+            ->getAttribute('fo:border-bottom');
+
+        $this->assertEquals($expectedFirst, $actualFirst);
+
+        $expectedThird = sprintf(
+            '%s %s #%s',
+            $widthMap[Border::WIDTH_THIN],
+            $styleMap[Border::STYLE_DASHED],
+            Color::RED
+        );
+
+        $actualThird = $styleElements[2]
+            ->getElementsByTagName('table-cell-properties')
+            ->item(0)
+            ->getAttribute('fo:border-top');
+
+        $this->assertEquals($expectedThird, $actualThird);
+    }
+
+
     /**
      * @param array $allRows
      * @param string $fileName

tests/Spout/Writer/Style/BorderTest.php

@@ -0,0 +1,110 @@
+<?php
+
+namespace Box\Spout\Writer\Style;
+
+class BorderTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * @return void
+     */
+    public function testValidInstance()
+    {
+        $noConstructorParams = new Border();
+        $withConstructorParams = new Border([
+            new BorderPart(Border::LEFT)
+        ]);
+    }
+
+    /**
+     * @expectedException \Box\Spout\Writer\Exception\Border\InvalidNameException
+     */
+    public function testInvalidBorderPart()
+    {
+        $invalidBorderPart = new BorderPart('invalid');
+    }
+
+    /**
+     * @expectedException \Box\Spout\Writer\Exception\Border\InvalidStyleException
+     */
+    public function testInvalidBorderPartStyle()
+    {
+        $invalidBorderPartStyle = new BorderPart(Border::LEFT, Color::BLACK, Border::WIDTH_THIN, 'invalid');
+    }
+
+    /**
+     * @expectedException \Box\Spout\Writer\Exception\Border\InvalidWidthException
+     */
+    public function testInvalidBorderPartWidth()
+    {
+        $invalidBorderPartStyle = new BorderPart(Border::LEFT, Color::BLACK, 'invalid', Border::STYLE_DASHED);
+    }
+
+    /**
+     * @return void
+     */
+    public function testNotMoreThanFourPartsPossible()
+    {
+        $border = new Border();
+        $border
+            ->addPart(new BorderPart(Border::LEFT))
+            ->addPart(new BorderPart(Border::RIGHT))
+            ->addPart(new BorderPart(Border::TOP))
+            ->addPart(new BorderPart(Border::BOTTOM))
+            ->addPart(new BorderPart(Border::LEFT));
+
+        $this->assertEquals(4, count($border->getParts()), 'There should never be more than 4 border parts');
+    }
+
+    /**
+     * @return void
+     */
+    public function testSetParts()
+    {
+        $border = new Border();
+        $border->setParts([
+            new BorderPart(Border::LEFT)
+        ]);
+
+        $this->assertEquals(1, count($border->getParts()), 'It should be possible to set the border parts');
+    }
+
+    /**
+     * @return void
+     */
+    public function testBorderBuilderFluent()
+    {
+        $border = (new BorderBuilder())
+            ->setBorderBottom()
+            ->setBorderTop()
+            ->setBorderLeft()
+            ->setBorderRight()
+            ->build();
+        $this->assertEquals(4, count($border->getParts()), 'The border builder exposes a fluent interface');
+    }
+
+    /**
+     * :D :S
+     * @return void
+     */
+    public function testAnyCombinationOfAllowedBorderPartsParams()
+    {
+        $color = Color::BLACK;
+        foreach (BorderPart::getAllowedNames() as $allowedName) {
+            foreach (BorderPart::getAllowedStyles() as $allowedStyle) {
+                foreach (BorderPart::getAllowedWidths() as $allowedWidth) {
+                    $borderPart = new BorderPart($allowedName, $color, $allowedWidth, $allowedStyle);
+                    $border = new Border();
+                    $border->addPart($borderPart);
+                    $this->assertEquals(1, count($border->getParts()));
+
+                    /** @var $part BorderPart */
+                    $part = $border->getParts()[$allowedName];
+
+                    $this->assertEquals($allowedStyle, $part->getStyle());
+                    $this->assertEquals($allowedWidth, $part->getWidth());
+                    $this->assertEquals($color, $part->getColor());
+                }
+            }
+        }
+    }
+}

tests/Spout/Writer/Style/StyleTest.php

@@ -129,4 +129,32 @@ class StyleTest extends \PHPUnit_Framework_TestCase
 
         $this->assertTrue($currentStyle->serialize() === $mergedStyle->serialize());
     }
+
+    /**
+     * @return void
+     */
+    public function testStyleBuilderShouldApplyBorders()
+    {
+        $border = (new BorderBuilder())
+            ->setBorderBottom()
+            ->build();
+        $style = (new StyleBuilder())->setBorder($border)->build();
+        $this->assertTrue($style->shouldApplyBorder());
+    }
+
+    /**
+     * @return void
+     */
+    public function testStyleBuilderShouldMergeBorders()
+    {
+        $border = (new BorderBuilder())->setBorderBottom(Color::RED, Border::WIDTH_THIN, Border::STYLE_DASHED)->build();
+
+        $baseStyle = (new StyleBuilder())->setBorder($border)->build();
+        $currentStyle = (new StyleBuilder())->build();
+        $mergedStyle = $currentStyle->mergeWith($baseStyle);
+
+        $this->assertEquals(null, $currentStyle->getBorder(), 'Current style has no border');
+        $this->assertInstanceOf('Box\Spout\Writer\Style\Border', $baseStyle->getBorder(), 'Base style has a border');
+        $this->assertInstanceOf('Box\Spout\Writer\Style\Border', $mergedStyle->getBorder(), 'Merged style has a border');
+    }
 }

tests/Spout/Writer/XLSX/WriterWithStyleTest.php

@@ -5,6 +5,8 @@ namespace Box\Spout\Writer\XLSX;
 use Box\Spout\Common\Type;
 use Box\Spout\Reader\Wrapper\XMLReader;
 use Box\Spout\TestUsingResource;
+use Box\Spout\Writer\Style\Border;
+use Box\Spout\Writer\Style\BorderBuilder;
 use Box\Spout\Writer\Style\Color;
 use Box\Spout\Writer\Style\Style;
 use Box\Spout\Writer\Style\StyleBuilder;
@@ -232,6 +234,40 @@ class WriterWithStyleTest extends \PHPUnit_Framework_TestCase
         $this->assertFirstChildHasAttributeEquals('1', $xfElement, 'alignment', 'wrapText');
     }
 
+    /**
+     * @return void
+     */
+    public function testBorders()
+    {
+        $fileName = 'test_borders.xlsx';
+
+        $dataRows = [
+            ['row-with-border-bottom-green-thick-solid'],
+            ['row-without-border'],
+            ['row-with-border-top-red-thin-dashed'],
+        ];
+
+        $borderBottomGreenThickSolid = (new BorderBuilder())
+            ->setBorderBottom(Color::GREEN, Border::WIDTH_THICK, Border::STYLE_SOLID)->build();
+
+
+        $borderTopRedThinDashed = (new BorderBuilder())
+            ->setBorderTop(Color::RED, Border::WIDTH_THIN, Border::STYLE_DASHED)->build();
+
+        $styles =  [
+            (new StyleBuilder())->setBorder($borderBottomGreenThickSolid)->build(),
+            (new StyleBuilder())->build(),
+            (new StyleBuilder())->setBorder($borderTopRedThinDashed)->build(),
+        ];
+
+        $this->writeToXLSXFileWithMultipleStyles($dataRows, $fileName, $styles);
+        $borderElements = $this->getXmlSectionFromStylesXmlFile($fileName, 'borders');
+        $this->assertEquals(3, $borderElements->getAttribute('count'), '3 borders present');
+
+        $styleXfsElements = $this->getXmlSectionFromStylesXmlFile($fileName, 'cellXfs');
+        $this->assertEquals(3, $styleXfsElements->getAttribute('count'), '3 cell xfs present');
+    }
+
     /**
      * @param array $allRows
      * @param string $fileName