Added option to customize SymbolDecorator prefixes.

Author: Bilge

.travis.yml

@@ -1,11 +1,15 @@
-sudo: false
+notifications:
+  email: false
 
 language: php
 
 php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
+  - 7.3
+  - 7.4
 
 env:
   matrix:
@@ -17,19 +21,17 @@ matrix:
 
 cache:
   directories:
-    - .composer/cache
+    - vendor
 
 install:
   - alias composer=composer\ -n && composer selfupdate
   - composer validate
-  - composer update $DEPENDENCIES
+  - composer update --no-progress --no-suggest $DEPENDENCIES
 
 script:
   - composer test -- --coverage-clover=build/logs/clover.xml
 
 after_success:
-  - composer require satooshi/php-coveralls
-  - vendor/bin/coveralls -v
+  - composer require php-coveralls/php-coveralls:^2
+  - vendor/bin/php-coveralls -v
 
-notifications:
-  email: false

src/Byte/Unit/SymbolDecorator.php

@@ -13,6 +13,7 @@ class SymbolDecorator implements UnitDecorator
     const SUFFIX_METRIC = 'B';
     const SUFFIX_IEC = 'iB';
 
+    private $prefixes = self::PREFIXES;
     private $suffix;
     private $alwaysShowUnit;
 
@@ -39,7 +40,19 @@ public function decorate($exponent, $base, $value)
             return $suffix !== static::SUFFIX_NONE || $this->alwaysShowUnit ? 'B' : '';
         }
 
-        return substr(static::PREFIXES, min($exponent, strlen(static::PREFIXES)) - 1, 1) . $suffix;
+        return $this->prefixes[min($exponent, strlen($this->prefixes)) - 1] . $suffix;
+    }
+
+    public function getPrefixes()
+    {
+        return $this->prefixes;
+    }
+
+    public function setPrefixes($prefixes)
+    {
+        $this->prefixes = (string)$prefixes;
+
+        return $this;
     }
 
     public function getSuffix()

test/Unit/Byte/Unit/SymbolDecoratorTest.php

@@ -54,4 +54,13 @@ public function testSuffix()
     {
         self::assertSame($suffix = 'foo', (new SymbolDecorator)->setSuffix($suffix)->getSuffix());
     }
+
+    public function testCustomPrefixes()
+    {
+        $decorator = (new SymbolDecorator())->setPrefixes('XYZ');
+
+        foreach (['B', 'X', 'Y', 'Z', 'Z', 'Z'] as $exponent => $symbol) {
+            self::assertSame($symbol, $decorator->decorate($exponent, 0, 0));
+        }
+    }
 }