Minor tweaks

Author: marijnvanwezel

src/Patterns/Node.php

@@ -128,17 +128,6 @@ public function named($variable): self
         return $this;
     }
 
-    /**
-     * @param string $label
-     * @return Node
-     */
-    public function labeled(string $label): self
-    {
-        $this->labels[] = $label;
-
-        return $this;
-    }
-
     /**
      * Returns the name of this node. This function automatically generates a name if the node does not have a
      * name yet.
@@ -148,7 +137,7 @@ public function labeled(string $label): self
     public function getName(): ?Variable
     {
         if (!isset($this->variable)) {
-            $this->named($this->generateUUID());
+            $this->named(new Variable());
         }
 
         return $this->variable;
@@ -167,20 +156,19 @@ public function setName($variable): self
     }
 
     /**
-     * Returns true if and only if this node has a name.
-     *
-     * @return bool
+     * @param string $label
+     * @return Node
      */
-    public function hasName(): bool
+    public function labeled(string $label): self
     {
-        return isset($this->variable);
+        $this->labels[] = $label;
+
+        return $this;
     }
 
     /**
-     * Returns the property of the given name for this expression. For instance, if this expression is the
-     * variable "foo", a function call like $expression->property("bar") would yield "foo.bar".
-     *
-     * TODO: Maybe move this function to the NodeType trait and add it to the interface?
+     * Returns the property of the given name for this node. For instance, if this node is "(foo:PERSON)", a function call
+     * like $node->property("bar") would yield "foo.bar".
      *
      * @param string $property
      * @return Property
@@ -220,18 +208,4 @@ public function toQuery(): string
 
         return "($nodeInner)";
     }
-
-    /**
-     * Generates a unique random identifier.
-     *
-     * @note It is not entirely guaranteed that this function gives a truly unique identifier. However, because the
-     * number of possible IDs is so huge, it should not be a problem.
-     *
-     * @param int $length
-     * @return string
-     */
-    private function generateUUID(int $length = 32): string
-    {
-        return substr(bin2hex(openssl_random_pseudo_bytes(ceil($length / 2))), 0, $length);
-    }
 }

src/Query.php

@@ -120,10 +120,10 @@ public static function relationship(StructuralType $a, StructuralType $b, array
     /**
      * Creates a variable.
      *
-     * @param string $variable
+     * @param string $variable The name of the variable; leave empty to automatically generate a variable name
      * @return Variable
      */
-    public static function variable(string $variable): Variable
+    public static function variable(?string $variable = null): Variable
     {
         return new Variable($variable);
     }

src/Variable.php

@@ -69,6 +69,8 @@ class Variable implements
     StringType,
     TimeType
 {
+    public const AUTOMATIC_VARIABLE_LENGTH = 32;
+
     use EscapeTrait;
     use DateTrait;
     use DateTimeTrait;
@@ -93,8 +95,12 @@ class Variable implements
      *
      * @param string $variable The variable
      */
-    public function __construct(string $variable)
+    public function __construct(?string $variable = null)
     {
+        if ($variable === null) {
+            $variable = $this->generateUUID(self::AUTOMATIC_VARIABLE_LENGTH);
+        }
+
         $this->variable = $variable;
     }
 
@@ -139,4 +145,18 @@ public function toQuery(): string
     {
         return $this->escape($this->variable);
     }
+
+    /**
+     * Generates a unique random identifier.
+     *
+     * @note It is not entirely guaranteed that this function gives a truly unique identifier. However, because the
+     * number of possible IDs is so huge, it should not be a problem.
+     *
+     * @param int $length
+     * @return string
+     */
+    private static function generateUUID(int $length): string
+    {
+        return substr(bin2hex(openssl_random_pseudo_bytes(ceil($length / 2))), 0, $length);
+    }
 }

tests/Unit/QueryTest.php

@@ -92,6 +92,13 @@ public function testVariable()
         $this->assertInstanceOf(Variable::class, Query::variable("foo"));
     }
 
+    public function testVariableEmpty()
+    {
+        $this->assertInstanceOf(Variable::class, Query::variable());
+
+        $this->assertMatchesRegularExpression('/[0-9a-f]+/', Query::variable()->toQuery());
+    }
+
     public function testParameter()
     {
         $this->assertInstanceOf(Parameter::class, Query::parameter("foo"));
@@ -875,6 +882,26 @@ public function testWikiExamples()
         $this->assertSame("((nineties.released >= 1990) AND (nineties IS NOT NULL))", $expression->toQuery());
     }
 
+    public function testAutomaticIdentifierGeneration()
+    {
+        $node = Query::node();
+
+        $this->assertMatchesRegularExpression('/[0-9a-f]+\.foo/', $node->property('foo')->toQuery());
+
+        $node->named('foo');
+
+        $this->assertSame('foo.bar', $node->property('bar')->toQuery());
+
+        $node = Query::node();
+        $statement = Query::new()->match($node)->returning($node)->build();
+
+        $this->assertMatchesRegularExpression('/MATCH \([0-9a-f]+\) RETURN [0-9a-f]+/', $statement);
+
+        $node = Query::node();
+
+        $this->assertInstanceOf(Variable::class, $node->getName());
+    }
+
     public function provideLiteralData(): array
     {
         return [