Add support for operator chaining

Author: marijnvanwezel

CHANGELOG.md

@@ -8,12 +8,16 @@ The format is based on [Keep a Changelog], and this project adheres to
 
 ## 7.0.0 - T.B.D.
 
+### Added
+
+- Added support for operator chaining (e.g. `a > b > c`).
+
 ### Changed
 
 - Changed the minimum required PHP version to 8.1.
 - Changed the signature of many functions to use PHP 8 union types.
 - Changed the `Relationship::DIR_*` to the `Direction` enum.
-- Remove `$insertParentheses` from all methods, and automatically insert them based on precedence.
+- Remove `$insertParentheses` from all methods, and automatically insert them based on precedence. - No longer insert parentheses when chaining comparison operators.
 
 ### Removed
 

src/Expressions/Operators/ComparisonBinaryOperator.php

@@ -45,4 +45,16 @@ public function __construct(AnyType $left, AnyType $right)
     {
         parent::__construct($left, $right);
     }
+
+    /**
+     * @inheritDoc
+     */
+    protected function shouldInsertParentheses(AnyType $expression): bool
+    {
+        if ($expression instanceof ComparisonBinaryOperator) {
+            return false;
+        }
+
+        return parent::shouldInsertParentheses($expression);
+    }
 }

src/Expressions/Operators/Operator.php

@@ -38,7 +38,7 @@ abstract protected function getPrecedence(): Precedence;
     /**
      * Whether to insert parentheses around the given expression, given the precedence of this operator.
      */
-    final protected function shouldInsertParentheses(AnyType $expression): bool
+    protected function shouldInsertParentheses(AnyType $expression): bool
     {
         if (!$expression instanceof self) {
             return false;

tests/unit/Expressions/Operators/EqualityTest.php

@@ -28,7 +28,7 @@ public function testToQuery(): void
 
         $equality = new Equality($equality, $equality);
 
-        $this->assertSame("(10 = 15) = (10 = 15)", $equality->toQuery());
+        $this->assertSame("10 = 15 = 10 = 15", $equality->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/GreaterThanOrEqualTest.php

@@ -27,7 +27,7 @@ public function testToQuery(): void
 
         $greaterThanOrEqual = new GreaterThanOrEqual($greaterThanOrEqual, $greaterThanOrEqual);
 
-        $this->assertSame("(10 >= 15) >= (10 >= 15)", $greaterThanOrEqual->toQuery());
+        $this->assertSame("10 >= 15 >= 10 >= 15", $greaterThanOrEqual->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/GreaterThanTest.php

@@ -27,7 +27,18 @@ public function testToQuery(): void
 
         $greaterThan = new GreaterThan($greaterThan, $greaterThan, false);
 
-        $this->assertSame("(10 > 15) > (10 > 15)", $greaterThan->toQuery());
+        $this->assertSame("10 > 15 > 10 > 15", $greaterThan->toQuery());
+    }
+
+    public function testChainedComparisons(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(1);
+
+        $expr = $a->gt($b)->gt($c);
+
+        $this->assertSame("10 > 5 > 1", $expr->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/InequalityTest.php

@@ -28,7 +28,7 @@ public function testToQuery(): void
 
         $inequality = new Inequality($inequality, $inequality);
 
-        $this->assertSame("(v.a <> v.b) <> (v.a <> v.b)", $inequality->toQuery());
+        $this->assertSame("v.a <> v.b <> v.a <> v.b", $inequality->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/LessThanOrEqualTest.php

@@ -27,7 +27,7 @@ public function testToQuery(): void
 
         $lessThanOrEqual = new LessThanOrEqual($lessThanOrEqual, $lessThanOrEqual, false);
 
-        $this->assertSame("(10 <= 15) <= (10 <= 15)", $lessThanOrEqual->toQuery());
+        $this->assertSame("10 <= 15 <= 10 <= 15", $lessThanOrEqual->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/LessThanTest.php

@@ -27,7 +27,7 @@ public function testToQuery(): void
 
         $lessThan = new LessThan($lessThan, $lessThan, false);
 
-        $this->assertSame("(10 < 15) < (10 < 15)", $lessThan->toQuery());
+        $this->assertSame("10 < 15 < 10 < 15", $lessThan->toQuery());
     }
 
     public function testInstanceOfBooleanType(): void

tests/unit/Expressions/Operators/PrecedenceTest.php

@@ -106,7 +106,7 @@ public function testComparisonWithAdditive(): void
         $this->assertSame('10 + 5 > 10 - 5', $expr->toQuery());
 
         $expr = new Equality(new Inequality($num1, $num2), new Boolean(true));
-        $this->assertSame('(10 <> 5) = true', $expr->toQuery());
+        $this->assertSame('10 <> 5 = true', $expr->toQuery());
     }
 
     public function testAdditiveWithMultiplicative(): void
@@ -380,7 +380,7 @@ public function testMixedUnaryBinaryNesting(): void
             new LessThan($num, $num),
             $num
         );
-        $this->assertSame('(3.0 < 3.0) < 3.0', $expr->toQuery());
+        $this->assertSame('3.0 < 3.0 < 3.0', $expr->toQuery());
 
         $expr = new Multiplication(
             new UnaryMinus(new Exponentiation($num, $num)),
@@ -452,10 +452,10 @@ public function testAllSamePrecedenceCombinations(): void
         $this->assertSame('NOT (NOT true)', $expr->toQuery());
 
         $expr = new Equality(new LessThan($num, $num), $true);
-        $this->assertSame('(7.0 < 7.0) = true', $expr->toQuery());
+        $this->assertSame('7.0 < 7.0 = true', $expr->toQuery());
 
         $expr = new LessThanOrEqual(new GreaterThanOrEqual($num, $num), $num);
-        $this->assertSame('(7.0 >= 7.0) <= 7.0', $expr->toQuery());
+        $this->assertSame('7.0 >= 7.0 <= 7.0', $expr->toQuery());
 
         $expr = new Addition(new Subtraction($num, $num), $num);
         $this->assertSame('(7.0 - 7.0) + 7.0', $expr->toQuery());
@@ -478,4 +478,68 @@ public function testAllSamePrecedenceCombinations(): void
         $expr = new Equality(new Contains($var, $var), new StartsWith($var, $var));
         $this->assertSame('y CONTAINS y = y STARTS WITH y', $expr->toQuery());
     }
+
+    public function testChainedComparison(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(1);
+
+        $expr = new GreaterThan(new GreaterThan($a, $b), $c);
+        $this->assertSame("10 > 5 > 1", $expr->toQuery());
+    }
+
+    public function testChainedComparisonRhs(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(1);
+
+        $expr = new GreaterThan($a, new GreaterThan($b, $c));
+        $this->assertSame("10 > 5 > 1", $expr->toQuery());
+    }
+
+    public function testChainedComparisonRhsCheck(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(1);
+        $d = new Integer(0);
+
+        $expr = new GreaterThan($a, new GreaterThan($b, new GreaterThan($c, $d)));
+        $this->assertSame("10 > 5 > 1 > 0", $expr->toQuery());
+    }
+
+    public function testChainedMixedComparisons(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(5);
+
+        $expr = new GreaterThanOrEqual(new GreaterThan($a, $b), $c);
+        $this->assertSame("10 > 5 >= 5", $expr->toQuery());
+    }
+
+    public function testChainedInequality(): void
+    {
+        $a = new Integer(10);
+        $b = new Integer(5);
+        $c = new Integer(10);
+
+        $expr = new Inequality(new Inequality($a, $b), $c);
+        $this->assertSame("10 <> 5 <> 10", $expr->toQuery());
+    }
+
+    public function testChainedEquality(): void
+    {
+        $a = new Integer(1);
+        $b = new Integer(1);
+        $c = new Integer(1);
+
+        $expr = new Equality(new Equality($a, $b), $c);
+        $this->assertSame("1 = 1 = 1", $expr->toQuery());
+
+        $expr = new Equality($a, new Equality($b, $c));
+        $this->assertSame("1 = 1 = 1", $expr->toQuery());
+    }
 }