Merge pull request #58 from magento-research/bug/conditional-handle-undefined

Conditional Fall Through

Author: bbatsche

src/DefinitionIterator.php

@@ -42,14 +42,15 @@ public function __clone()
     }
 
     /**
-     * Travserse the Definition for a value, using a resolver if necessary.
+     * Traverse the Definition for a value, using a resolver if necessary.
      *
      * @param string|mixed           $lookup
      * @param Definition|string|null $definition Definition to iterate rather than root definition
      *
-     * @throws RuntimeException if iterator is already attempting to resolve $lookup
-     *                          (ie, definition appears to contain a loop)
-     * @throws RuntimeException if $lookup does not exist in definition
+     * @throws \RuntimeException if iterator is already attempting to resolve $lookup
+     *                           (ie, definition appears to contain a loop)
+     * @throws \RuntimeException if $lookup does not exist in definition
+     * @throws \Exception        if lookup is undefined in the context
      */
     public function get($lookup, $definition = null)
     {

src/Resolver/Conditional.php

@@ -64,9 +64,14 @@ public function resolve($definition)
         }
 
         foreach ($definition->get($this->getIndicator()) as $matcher) {
-            $rawValue = $this->getIterator()->get($matcher->get('matches'));
-            $value    = is_scalar($rawValue) ? (string) $rawValue : json_encode($rawValue);
-            $pattern  = '/' . addcslashes($matcher->get('pattern'), '/') . '/';
+            try {
+                $rawValue = $this->getIterator()->get($matcher->get('matches'));
+            } catch (\Exception $exception) {
+                // exceptions thrown for match value lookups should silently fail and fall through
+                continue;
+            }
+            $value   = is_scalar($rawValue) ? (string) $rawValue : json_encode($rawValue);
+            $pattern = '/' . addcslashes($matcher->get('pattern'), '/') . '/';
 
             if (preg_match($pattern, $value, $matches)) {
                 // preface each key with '$'

test/Resolver/ConditionalTest.php

@@ -134,6 +134,37 @@ public function testIsShorthand(): void
         verify($this->resolver->isShortHand('anything'))->is()->false();
     }
 
+    public function testMatchExceptionFallsThrough(): void
+    {
+        $definition = new Definition([
+            'when' => [[
+                'matches' => 'key for undefined value',
+                'pattern' => '[a-zA-Z]+',
+                'use'     => 'some missing resolver',
+            ], [
+                'matches' => 'key for alpha value',
+                'pattern' => '[0-9]+',
+                'use'     => 'another missing resolver',
+            ]],
+            'default' => 'expected resolver',
+        ]);
+
+        $iterator = Mockery::mock(DefinitionIterator::class);
+        $this->resolver->setIterator($iterator);
+
+        $iterator->shouldReceive('get')
+            ->with('key for undefined value')
+            ->andThrow(new \Exception('Undefined value in context'));
+        $iterator->shouldReceive('get')
+            ->with('key for alpha value')
+            ->andReturn('abcdefgHIJKLMNOP');
+        $iterator->shouldReceive('get')
+            ->with('default', $definition)
+            ->andReturn('value for default resolver');
+
+        verify($this->resolver->resolve($definition))->is()->sameAs('value for default resolver');
+    }
+
     public function testResolveThrowsException(): void
     {
         $this->expectException(\InvalidArgumentException::class);