Merge pull request #93 from transistive/optional-variables

Make the Variable section in the Pattern optional

src/Patterns/Pattern.php

@@ -35,17 +35,22 @@
  */
 interface Pattern extends QueryConvertible
 {
+    /**
+     * Returns whether a variable has been set for this pattern.
+     */
+    public function hasVariableSet(): bool;
+
     /**
      * Explicitly assign a named variable to this pattern.
      *
-     * @param string|Variable $variable
+     * @param null|string|Variable $variable
      *
      * @return $this
      */
     public function withVariable($variable): self;
 
     /**
-     * Returns the variable of this pattern. This function generates a variable if none has been set.
+     * Returns the variable of this pattern. This function generates a variable if none has been set. It will implicitly set the variable of the pattern as well.
      */
     public function getVariable(): Variable;
 }

src/Traits/PatternTraits/PatternTrait.php

@@ -24,16 +24,24 @@ trait PatternTrait
      */
     protected ?Variable $variable = null;
 
+    /**
+     * Returns whether a variable has been set for this pattern.
+     */
+    public function hasVariableSet(): bool
+    {
+        return $this->variable !== null;
+    }
+
     /**
      * Explicitly assign a named variable to this object.
      *
-     * @param string|Variable $variable
+     * @param null|string|Variable $variable
      *
      * @return $this
      */
     public function withVariable($variable): self
     {
-        $this->variable = self::toName($variable);
+        $this->variable = $variable === null ? null : self::toName($variable);
 
         return $this;
     }

tests/unit/Traits/PatternTraits/PatternTraitTest.php

@@ -72,6 +72,25 @@ public function testDoesNotAcceptAnyType(): void
         $this->stub->withVariable(new stdClass());
     }
 
+    public function testPatternNotSet(): void
+    {
+        $this->assertFalse($this->stub->hasVariableSet());
+    }
+
+    public function testPatternSet(): void
+    {
+        $this->stub->withVariable("hello");
+        $this->assertTrue($this->stub->hasVariableSet());
+    }
+
+    public function testPatternUnSet(): void
+    {
+        $this->stub->withVariable("hello");
+        $this->stub->withVariable(null);
+
+        $this->assertFalse($this->stub->hasVariableSet());
+    }
+
     /**
      * @doesNotPerformAssertions
      */