Rewrite DeleteClause

Author: marijnvanwezel

src/Clauses/DeleteClause.php

@@ -1,37 +1,31 @@
-<?php
-
+<?php declare(strict_types=1);
 /*
- * Cypher DSL
- * Copyright (C) 2021  Wikibase Solutions
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version 2
- * of the License, or (at your option) any later version.
+ * This file is part of php-cypher-dsl.
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * Copyright (C) 2021-  Wikibase Solutions
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
  */
-
 namespace WikibaseSolutions\CypherDSL\Clauses;
 
-use WikibaseSolutions\CypherDSL\Traits\ErrorTrait;
+use WikibaseSolutions\CypherDSL\Patterns\Pattern;
+use WikibaseSolutions\CypherDSL\Query;
+use WikibaseSolutions\CypherDSL\Traits\CastTrait;
 use WikibaseSolutions\CypherDSL\Types\StructuralTypes\StructuralType;
 
 /**
  * This class represents a DELETE clause.
  *
+ * The DELETE clause is used to delete graph element — nodes, relationships and paths.
+ *
  * @see https://neo4j.com/docs/cypher-manual/current/clauses/delete/
+ * @see https://s3.amazonaws.com/artifacts.opencypher.org/openCypher9.pdf (page 105)
+ * @see Query::delete() for a more convenient method to construct this class
  */
-class DeleteClause extends Clause
+final class DeleteClause extends Clause
 {
-    use ErrorTrait;
+    use CastTrait;
 
     /**
      * Whether the DETACH modifier is needed.
@@ -60,31 +54,20 @@ public function setDetach(bool $detach = true): self
     }
 
     /**
-     * Sets the structures to be deleted. This overwrites previous structures if they exist.
+     * Add one or more structures to delete.
      *
-     * @param StructuralType[] $structures The structures to delete
+     * @param StructuralType|Pattern $structures The structures to delete
      * @return $this
      */
-    public function setStructures(array $structures): self
+    public function addStructure(...$structures): self
     {
+        $res = [];
+
         foreach ($structures as $structure) {
-            $this->assertClass('structure', StructuralType::class, $structure);
+            $res[] = self::toStructuralType($structure);
         }
 
-        $this->structures = $structures;
-
-        return $this;
-    }
-
-    /**
-     * Add a structure to be deleted.
-     *
-     * @param StructuralType $structure The structure that should be deleted
-     * @return $this
-     */
-    public function addStructure(StructuralType $structure): self
-    {
-        $this->structures[] = $structure;
+        $this->structures = array_merge($this->structures, $res);
 
         return $this;
     }
@@ -104,7 +87,7 @@ public function detachesDeletion(): bool
      *
      * @return StructuralType[]
      */
-    public function getStructures(): array
+    public function getStructural(): array
     {
         return $this->structures;
     }

src/Query.php

@@ -65,6 +65,7 @@
 use WikibaseSolutions\CypherDSL\Types\StructuralTypes\NodeType;
 use WikibaseSolutions\CypherDSL\Types\StructuralTypes\PathType;
 use WikibaseSolutions\CypherDSL\Types\StructuralTypes\RelationshipType;
+use WikibaseSolutions\CypherDSL\Types\StructuralTypes\StructuralType;
 
 /**
  * Builder class for building complex Cypher queries.
@@ -475,34 +476,23 @@ public function create($patterns): self
     /**
      * Creates the DELETE clause.
      *
-     * @param string|Variable|HasVariable|(string|Variable|HasVariable)[] $variables The nodes to delete
+     * @param StructuralType|Pattern|StructuralType[]|Pattern[] $structures The structures to delete
      * @param bool $detach Whether to DETACH DELETE
      *
      * @return $this
      * @see https://neo4j.com/docs/cypher-manual/current/clauses/delete/
-     *
+     * @see https://s3.amazonaws.com/artifacts.opencypher.org/openCypher9.pdf (page 105)
      */
-    public function delete($variables, bool $detach = false): self
+    public function delete($structures, bool $detach = false): self
     {
-        $deleteClause = new DeleteClause();
-        $deleteClause->setDetach($detach);
-
-        if (!is_array($variables)) {
-            $variables = [$variables];
-        }
-
-        foreach ($variables as $variable) {
-            $this->assertClass('variable', ['string', Variable::class, HasVariable::class], $variable);
-
-            if (is_string($variable)) {
-                $variable = Query::variable($variable);
-            } elseif ($variable instanceof HasVariable) {
-                $variable = $variable->getVariable();
-            }
-
-            $deleteClause->addVariable($variable);
+        if (!is_array($structures)) {
+            $structures = [$structures];
         }
 
+        $deleteClause = new DeleteClause();
+        $deleteClause->setDetach($detach);
+        $deleteClause->addStructure(...$structures);
+        
         $this->clauses[] = $deleteClause;
 
         return $this;

src/Traits/CastTrait.php

@@ -12,6 +12,7 @@
 use WikibaseSolutions\CypherDSL\Types\PropertyTypes\NumeralType;
 use WikibaseSolutions\CypherDSL\Types\PropertyTypes\PropertyType;
 use WikibaseSolutions\CypherDSL\Types\PropertyTypes\StringType;
+use WikibaseSolutions\CypherDSL\Types\StructuralTypes\StructuralType;
 
 /**
  * Helper trait for casting native PHP types to Cypher-DSL types. Casts are added to this class on an as-needed basis.
@@ -94,6 +95,18 @@ private static function toPropertyType($property): PropertyType
         return $property instanceof PropertyType ? $property : Literal::literal($property);
     }
 
+    /**
+     * Casts the given value to a StructuralType.
+     *
+     * @param StructuralType|Pattern $structure
+     * @return StructuralType
+     */
+    private static function toStructuralType($structure): StructuralType
+    {
+        self::assertClass('structure', [Pattern::class, StructuralType::class], $structure);
+        return $structure instanceof StructuralType ? $structure : $structure->getVariable();
+    }
+
     /**
      * Casts the given value to a Variable.
      *

tests/Unit/Clauses/DeleteClauseTest.php

@@ -40,7 +40,7 @@ public function testEmptyClause(): void
         $delete = new DeleteClause();
 
         $this->assertSame("", $delete->toQuery());
-        $this->assertEquals([], $delete->getStructures());
+        $this->assertEquals([], $delete->getStructural());
         $this->assertFalse($delete->detachesDeletion());
     }
 
@@ -52,7 +52,7 @@ public function testSingleVariable(): void
         $delete->addStructure($variable);
 
         $this->assertSame("DELETE a", $delete->toQuery());
-        $this->assertEquals([$variable], $delete->getStructures());
+        $this->assertEquals([$variable], $delete->getStructural());
         $this->assertFalse($delete->detachesDeletion());
     }
 
@@ -67,7 +67,7 @@ public function testMultipleVariables(): void
         $delete->addStructure($b);
 
         $this->assertSame("DELETE a, b", $delete->toQuery());
-        $this->assertEquals([$a, $b], $delete->getStructures());
+        $this->assertEquals([$a, $b], $delete->getStructural());
         $this->assertFalse($delete->detachesDeletion());
     }
 
@@ -80,7 +80,7 @@ public function testDetachDelete(): void
         $delete->setDetach(true);
 
         $this->assertSame("DETACH DELETE a", $delete->toQuery());
-        $this->assertEquals([$variable], $delete->getStructures());
+        $this->assertEquals([$variable], $delete->getStructural());
         $this->assertTrue($delete->detachesDeletion());
     }
 
@@ -91,7 +91,7 @@ public function testAcceptsVariable(): void
 
         $delete->addStructure($variable);
         $delete->toQuery();
-        $this->assertEquals([$variable], $delete->getStructures());
+        $this->assertEquals([$variable], $delete->getStructural());
         $this->assertFalse($delete->detachesDeletion());
     }
 
@@ -115,10 +115,10 @@ public function testSetVariables(): void
 
         $variables = [$variableA, $variableB];
 
-        $delete->setStructures($variables);
+        $delete->setPatterns($variables);
 
         $this->assertSame("DELETE a, b", $delete->toQuery());
-        $this->assertSame($variables, $delete->getStructures());
+        $this->assertSame($variables, $delete->getStructural());
     }
 
     public function testSetVariablesDoesNotAcceptAnyType(): void
@@ -132,20 +132,20 @@ public function testSetVariablesDoesNotAcceptAnyType(): void
 
         $this->expectException(TypeError::class);
 
-        $delete->setStructures($variables);
+        $delete->setPatterns($variables);
         $delete->toQuery();
     }
 
     public function testGetVariables(): void
     {
         $delete = new DeleteClause();
 
-        $this->assertSame([], $delete->getStructures());
+        $this->assertSame([], $delete->getStructural());
 
         $variables = [new Variable('a')];
-        $delete->setStructures($variables);
+        $delete->setPatterns($variables);
 
-        $this->assertSame($variables, $delete->getStructures());
+        $this->assertSame($variables, $delete->getStructural());
     }
 
     public function testDetachesDeletion(): void