Adding support for expanding array placeholders.

src/Expander.php

@@ -247,8 +247,8 @@ public static function expandProperty($property_name, $unexpanded_value, $data)
         } else {
             $expanded_value = $data->get($property_name);
             if (is_array($expanded_value)) {
-                self::log("\${'$property_name'} is an array and cannot be expanded.");
-                return $unexpanded_value;
+                $expanded_value = Yaml::dump($expanded_value, 0);
+                return $expanded_value;
             }
             self::log("Expanding property \${'$property_name'} => $expanded_value.");
             return $expanded_value;

tests/phpunit/ExpanderTest.php

@@ -27,14 +27,11 @@ public function testExpandArrayProperties($filename, $reference_array)
         $this->assertEquals('Dune by Frank Herbert', $expanded['summary']);
         $this->assertEquals('${book.media.1}, hardcover', $expanded['available-products']);
         $this->assertEquals('Dune', $expanded['product-name']);
-        $this->assertEquals('${book}', $expanded['expand-array']);
+        $this->assertEquals(Yaml::dump($array['inline-array'], 0), $expanded['expand-array']);
 
         $expanded = Expander::expandArrayProperties($array, $reference_array);
         $this->assertEquals('Dune Messiah, and others.', $expanded['sequels']);
         $this->assertEquals('Dune Messiah', $expanded['book']['nested-reference']);
-
-        // Attempt to expand an entire array. This should not work.
-        $this->assertEquals('${book}', $expanded['expand-array']);
     }
 
     /**

tests/resources/valid.yml

@@ -31,5 +31,4 @@ product-name: ${${type}.title}
 boolean-value: true
 null-value: null
 inline-array: [ one, two, three ]
-# Attempt to reference an entire array rather than a string. This is invalid.
-expand-array: ${book}
+expand-array: ${inline-array}