Variable default values

Tests/Parser/VariableTest.php

@@ -29,6 +29,48 @@ public function testGetNullValueException()
         $var->getValue();
     }
 
+    public function testGetValueReturnsDefaultValueIfNoValueSet()
+    {
+        $var = new Variable('foo', 'bar', false, false, new Location(1,1));
+        $var->setDefaultValue('default-value');
+
+        $this->assertEquals(
+            'default-value',
+            $var->getValue()
+        );
+    }
+
+    public function testGetValueReturnsSetValueEvenWithDefaultValue()
+    {
+        $var = new Variable('foo', 'bar', false, false, new Location(1,1));
+        $var->setValue('real-value');
+        $var->setDefaultValue('default-value');
+
+        $this->assertEquals(
+            'real-value',
+            $var->getValue()
+        );
+    }
+
+    public function testIndicatesDefaultValuePresent()
+    {
+        $var = new Variable('foo', 'bar', false, false, new Location(1,1));
+        $var->setDefaultValue('default-value');
+
+        $this->assertTrue(
+            $var->hasDefaultValue()
+        );
+    }
+
+    public function testHasNoDefaultValue()
+    {
+        $var = new Variable('foo', 'bar', false, false, new Location(1,1));
+
+        $this->assertFalse(
+            $var->hasDefaultValue()
+        );
+    }
+
     /**
      * @return array Array of <mixed: value to set, mixed: expected value>
      */
@@ -41,4 +83,4 @@ public static function variableProvider()
             ]
         ];
     }
-}
+}

src/Execution/Request.php

@@ -66,6 +66,12 @@ public function __construct($data = [], $variables = [])
         if (array_key_exists('variableReferences', $data)) {
             foreach ($data['variableReferences'] as $ref) {
                 if (!array_key_exists($ref->getName(), $variables)) {
+                    /** @var Variable $variable */
+                    $variable = $ref->getVariable();
+                    if ($variable->hasDefaultValue()) {
+                        $variables[$variable->getName()] = $variable->getDefaultValue()->getValue();
+                        continue;
+                    }
                     throw new InvalidRequestException(sprintf("Variable %s hasn't been submitted", $ref->getName()), $ref->getLocation());
                 }
             }

src/Parser/Ast/ArgumentValue/Variable.php

@@ -35,6 +35,12 @@ class Variable extends AbstractAst implements ValueInterface
     /** @var bool */
     private $arrayElementNullable = true;
 
+    /** @var bool */
+    private $hasDefaultValue = false;
+
+    /** @var mixed */
+    private $defaultValue = null;
+
     /**
      * @param string   $name
      * @param string   $type
@@ -62,6 +68,9 @@ public function __construct($name, $type, $nullable, $isArray, Location $locatio
     public function getValue()
     {
         if (null === $this->value) {
+            if ($this->hasDefaultValue()) {
+                return $this->defaultValue;
+            }
             throw new \LogicException('Value is not set for variable "' . $this->name . '"');
         }
 
@@ -140,6 +149,32 @@ public function setNullable($nullable)
         $this->nullable = $nullable;
     }
 
+    /**
+     * @return bool
+     */
+    public function hasDefaultValue()
+    {
+        return $this->hasDefaultValue;
+    }
+
+    /**
+     * @return mixed
+     */
+    public function getDefaultValue()
+    {
+        return $this->defaultValue;
+    }
+
+    /**
+     * @param mixed $defaultValue
+     */
+    public function setDefaultValue($defaultValue)
+    {
+        $this->hasDefaultValue = true;
+
+        $this->defaultValue = $defaultValue;
+    }
+
     /**
      * @return boolean
      */

src/Parser/Parser.php

@@ -147,14 +147,21 @@ protected function parseVariables()
                 $this->eat(Token::TYPE_REQUIRED);
             }
 
-            $this->data['variables'][] = new Variable(
+             $variable = new Variable(
                 $nameToken->getData(),
                 $type,
                 $required,
                 $isArray,
                 new Location($variableToken->getLine(), $variableToken->getColumn()),
                 $arrayElementNullable
             );
+
+            if ($this->match(Token::TYPE_EQUAL)) {
+                $this->eat(Token::TYPE_EQUAL);
+                $variable->setDefaultValue($this->parseValue());
+            }
+
+            $this->data['variables'][] = $variable;
         }
 
         $this->expect(Token::TYPE_RPAREN);

src/Parser/Token.php

@@ -33,6 +33,7 @@ class Token
     const TYPE_VARIABLE      = '$';
     const TYPE_POINT         = '.';
     const TYPE_REQUIRED      = '!';
+    const TYPE_EQUAL         = '=';
 
     const TYPE_NULL  = 'null';
     const TYPE_TRUE  = 'true';

src/Parser/Tokenizer.php

@@ -117,6 +117,11 @@ protected function scan()
 
                 return new Token(Token::TYPE_COLON, $this->getLine(), $this->getColumn());
 
+            case Token::TYPE_EQUAL:
+                ++$this->pos;
+
+                return new Token(Token::TYPE_EQUAL, $this->getLine(), $this->getColumn());
+
             case Token::TYPE_POINT:
                 if ($this->checkFragment()) {
                     return new Token(Token::TYPE_FRAGMENT_REFERENCE, $this->getLine(), $this->getColumn());