PhpStan support, consts visibilty and name for tokens (#89)

* Added handler to define not found variables
Added support for string variables
Fixed strings and ints comparison error

* Check if variables have scalar types (int, float, string and bool)
Better $onVarNotFound logic

* Better support for null variables

* Better support for null variables

* Better support for null variables

* Allow null values in `setVar` method

* Support for unary positive operator

* Add PhpStan config file
Fix PhpStan warnings
Set consts visibility
Add name info to variable tokens for easier debugging

Co-authored-by: Javier Marín <contacto@ideatic.net>

7 files changed, 68 insertions, 35 deletions

diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..bed17ae
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,9 @@
+parameters:
+  level: 6
+  paths:
+      - ./
+  excludes_analyse:
+     - vendor/*
+     - tests/*
+  bootstrapFiles:
+     - vendor/autoload.php
\ No newline at end of file
diff --git a/src/NXP/Classes/Calculator.php b/src/NXP/Classes/Calculator.php
index 4785a8f..a8f16af 100644
--- a/src/NXP/Classes/Calculator.php
+++ b/src/NXP/Classes/Calculator.php
@@ -44,7 +44,7 @@ class Calculator
     /**
      * Calculate array of tokens in reverse polish notation
      * @param Token[] $tokens
-     * @param array $variables
+     * @param array<string, float|string> $variables
      * @return mixed
      * @throws IncorrectExpressionException
      * @throws UnknownVariableException
@@ -68,7 +68,7 @@ class Calculator
                     throw new UnknownVariableException($variable);
                 }
 
-                $stack[] = new Token(Token::Literal, $value);
+                $stack[] = new Token(Token::Literal, $value, $variable);
             } elseif ($token->type === Token::Function) {
                 if (!array_key_exists($token->value, $this->functions)) {
                     throw new UnknownFunctionException($token->value);
diff --git a/src/NXP/Classes/CustomFunction.php b/src/NXP/Classes/CustomFunction.php
index f127ad2..6e4fdc5 100644
--- a/src/NXP/Classes/CustomFunction.php
+++ b/src/NXP/Classes/CustomFunction.php
@@ -44,6 +44,11 @@ class CustomFunction
         }
     }
 
+    /**
+     * @param array<Token> $stack
+     *
+     * @throws IncorrectNumberOfFunctionParametersException
+     */
     public function execute(array &$stack) : Token
     {
         if (count($stack) < $this->places) {
diff --git a/src/NXP/Classes/Operator.php b/src/NXP/Classes/Operator.php
index 00485bc..d9a70d7 100644
--- a/src/NXP/Classes/Operator.php
+++ b/src/NXP/Classes/Operator.php
@@ -24,7 +24,7 @@ class Operator
     public $priority;
 
     /**
-     * @var callable<\SplStack>
+     * @var callable(\SplStack)
      */
     public $function;
 
@@ -50,6 +50,11 @@ class Operator
         $this->places = $reflection->getNumberOfParameters();
     }
 
+    /**
+     * @param array<Token> $stack
+     *
+     * @throws IncorrectExpressionException
+     */
     public function execute(array &$stack) : Token
     {
         if (count($stack) < $this->places) {
diff --git a/src/NXP/Classes/Token.php b/src/NXP/Classes/Token.php
index 49bf741..e12315e 100644
--- a/src/NXP/Classes/Token.php
+++ b/src/NXP/Classes/Token.php
@@ -5,31 +5,34 @@ namespace NXP\Classes;
 
 class Token
 {
-    const Literal = "literal";
-    const Variable = "variable";
-    const Operator = "operator";
-    const LeftParenthesis = "LP";
-    const RightParenthesis = "RP";
-    const Function = "function";
-    const ParamSeparator = "separator";
-    const String = "string";
-    const Space = "space";
+    public const Literal = "literal";
+    public const Variable = "variable";
+    public const Operator = "operator";
+    public const LeftParenthesis = "LP";
+    public const RightParenthesis = "RP";
+    public const Function = "function";
+    public const ParamSeparator = "separator";
+    public const String = "string";
+    public const Space = "space";
 
+    /** @var self::* */
     public $type = self::Literal;
 
-    /**
-     * @var float|string
-     */
+    /** @var float|string */
     public $value;
 
+    /** @var string */
+    public $name;
+
     /**
      * Token constructor.
-     * @param string $type
+     * @param self::* $type
      * @param float|string $value
      */
-    public function __construct(string $type, $value)
+    public function __construct(string $type, $value, string $name = null)
     {
         $this->type = $type;
         $this->value = $value;
+        $this->name = $name;
     }
 }
diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index a774561..5584d1a 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -1,5 +1,4 @@
 <?php
-
 /**
  * This file is part of the MathExecutor package
  *
@@ -14,6 +13,7 @@ namespace NXP;
 use NXP\Classes\Calculator;
 use NXP\Classes\CustomFunction;
 use NXP\Classes\Operator;
+use NXP\Classes\Token;
 use NXP\Classes\Tokenizer;
 use NXP\Exception\DivisionByZeroException;
 use NXP\Exception\MathExecutorException;
@@ -29,12 +29,12 @@ class MathExecutor
     /**
      * Available variables
      *
-     * @var array
+     * @var array<string, float|string>
      */
     private $variables = [];
 
     /**
-     * @var callable
+     * @var callable|null
      */
     private $onVarNotFound = null;
 
@@ -44,12 +44,12 @@ class MathExecutor
     private $operators = [];
 
     /**
-     * @var CustomFunction[]
+     * @var array<string, CustomFunction>
      */
     private $functions = [];
 
     /**
-     * @var array
+     * @var array<string, Token[]>
      */
     private $cache = [];
 
@@ -80,7 +80,7 @@ class MathExecutor
     /**
      * Get the default operators
      *
-     * @return array of class names
+     * @return array<string, array{callable, int, bool}>
      */
     protected function defaultOperators() : array
     {
@@ -220,7 +220,7 @@ class MathExecutor
      * Gets the default functions as an array.  Key is function name
      * and value is the function as a closure.
      *
-     * @return array
+     * @return array<callable>
      */
     protected function defaultFunctions() : array
     {
@@ -436,14 +436,14 @@ class MathExecutor
      */
     public function execute(string $expression, bool $cache = true)
     {
-        $cachekey = $expression;
-        if (!array_key_exists($cachekey, $this->cache)) {
+        $cacheKey = $expression;
+        if (!array_key_exists($cacheKey, $this->cache)) {
             $tokens = (new Tokenizer($expression, $this->operators))->tokenize()->buildReversePolishNotation();
             if ($cache) {
-                $this->cache[$cachekey] = $tokens;
+                $this->cache[$cacheKey] = $tokens;
             }
         } else {
-            $tokens = $this->cache[$cachekey];
+            $tokens = $this->cache[$cacheKey];
         }
 
         $calculator = new Calculator($this->functions, $this->operators);
@@ -468,7 +468,7 @@ class MathExecutor
     /**
      * Returns the default variables names as key/value pairs
      *
-     * @return array
+     * @return array<string, float>
      */
     protected function defaultVars() : array
     {
@@ -481,7 +481,7 @@ class MathExecutor
     /**
      * Get all vars
      *
-     * @return array
+     * @return array<string, float|string>
      */
     public function getVars() : array
     {
@@ -507,7 +507,7 @@ class MathExecutor
      * Add variable to executor
      *
      * @param  string $variable
-     * @param  integer|float $value
+     * @param  int|float $value
      * @return MathExecutor
      */
     public function setVar(string $variable, $value) : self
@@ -524,7 +524,7 @@ class MathExecutor
     /**
      * Add variables to executor
      *
-     * @param  array $variables
+     * @param  array<string, float|int|string> $variables
      * @param  bool $clear Clear previous variables
      * @return MathExecutor
      * @throws \Exception
@@ -580,7 +580,7 @@ class MathExecutor
     /**
      * Get all registered operators to executor
      *
-     * @return array of operator class names
+     * @return array<Operator> of operator class names
      */
     public function getOperators()
     {
@@ -590,7 +590,7 @@ class MathExecutor
     /**
      * Get all registered functions
      *
-     * @return array containing callback and places indexed by
+     * @return array<string, CustomFunction> containing callback and places indexed by
      *         function name
      */
     public function getFunctions() : array
@@ -616,7 +616,7 @@ class MathExecutor
 
     /**
      * Get cache array with tokens
-     * @return array
+     * @return array<string, Token[]>
      */
     public function getCache() : array
     {
diff --git a/tests/MathTest.php b/tests/MathTest.php
index f37d0ec..d086acb 100644
--- a/tests/MathTest.php
+++ b/tests/MathTest.php
@@ -266,6 +266,17 @@ class MathTest extends TestCase
         $this->assertEquals(0, $calculator->execute('10 / 0'));
     }
 
+    public function testUnaryOperators()
+    {
+        $calculator = new MathExecutor();
+        $this->assertEquals(5, $calculator->execute('+5'));
+        $this->assertEquals(5, $calculator->execute('+(3+2)'));
+        $this->assertEquals(-5, $calculator->execute('-5'));
+        $this->assertEquals(5, $calculator->execute('-(-5)'));
+        $this->assertEquals(-5, $calculator->execute('+(-5)'));
+        $this->assertEquals(-5, $calculator->execute('-(3+2)'));
+    }
+
     public function testZeroDivisionException()
     {
         $calculator = new MathExecutor();