Added Joins strategy and accompanying tests and documentation.

Removed support for PHP 5.6.

.travis.yml

@@ -6,7 +6,6 @@ sudo: false
 language: php
 
 php:
-  - 5.5
   - 5.6
   - 7.0
   - 7.1

composer.json

@@ -9,7 +9,7 @@
   ],
   "license": "LGPL-3.0",
   "require": {
-    "php": ">=5.5",
+    "php": "^5.6|^7",
     "scriptfusion/array-walker": "^1",
     "eloquent/enumeration": "^5"
   },

src/Strategy/Join.php

@@ -0,0 +1,28 @@
+<?php
+namespace ScriptFUSION\Mapper\Strategy;
+
+/**
+ * Joins sub-string expressions together with a glue string.
+ */
+class Join extends Delegate
+{
+    private $glue;
+
+    /**
+     * Initializes this instance with the specified glue to join the specified sub-strings together.
+     *
+     * @param string $glue Glue.
+     * @param array ...$expressions Sub-string expressions.
+     */
+    public function __construct($glue, ...$expressions)
+    {
+        parent::__construct($expressions);
+
+        $this->glue = "$glue";
+    }
+
+    public function __invoke($data, $context = null)
+    {
+        return implode($this->glue, parent::__invoke($data, $context));
+    }
+}

test/Functional/DocumentationTest.php

@@ -13,6 +13,7 @@
 use ScriptFUSION\Mapper\Strategy\Filter;
 use ScriptFUSION\Mapper\Strategy\Flatten;
 use ScriptFUSION\Mapper\Strategy\IfExists;
+use ScriptFUSION\Mapper\Strategy\Join;
 use ScriptFUSION\Mapper\Strategy\Merge;
 use ScriptFUSION\Mapper\Strategy\TakeFirst;
 use ScriptFUSION\Mapper\Strategy\ToList;
@@ -228,6 +229,17 @@ public function testIfExists()
         self::assertFalse((new Mapper)->map($data, new IfExists(new Copy('bar'), true, false)));
     }
 
+    public function testJoin()
+    {
+        self::assertSame(
+            'foo-bar',
+            (new Mapper)->map(
+                ['foo' => 'foo'],
+                new Join('-', new Copy('foo'), 'bar')
+            )
+        );
+    }
+
     public function testMerge()
     {
         self::assertSame(

test/Integration/Mapper/Strategy/JoinTest.php

@@ -0,0 +1,20 @@
+<?php
+namespace ScriptFUSIONTest\Integration\Mapper\Strategy;
+
+use ScriptFUSION\Mapper\Mapper;
+use ScriptFUSION\Mapper\Strategy\Join;
+use ScriptFUSION\Mapper\Strategy\Strategy;
+
+final class JoinTest extends \PHPUnit_Framework_TestCase
+{
+    public function testJoin()
+    {
+        $join = (new Join(
+            '-',
+            'foo',
+            \Mockery::mock(Strategy::class)->shouldReceive('__invoke')->andReturn('bar')->once()->getMock()
+        ))->setMapper(new Mapper);
+
+        self::assertSame('foo-bar', $join([]));
+    }
+}