Methods and validator

Web3 allowed methods:
* clientVersion
* sha3

Validator:
* HexValidator

src/Validators/HexValidator.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace Web3\Validators;
+
+use Web3\Validators\IValidator;
+
+class HexValidator
+{
+    /**
+     * validate
+     *
+     * @param string $value
+     * @return bool
+     */
+    public static function validate($value)
+    {
+        if (!is_string($value)) {
+            return false;
+        }
+        return (preg_match('/^0x[a-fA-F0-9]+$/', $value) >= 1);
+    }
+}

src/Validators/IValidators.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Web3\Validators;
+
+interface IValidators
+{
+    /**
+     * validate
+     *
+     * @param mixed $value
+     * @return bool
+     */
+     public static function validate($value);
+}

src/Web3.php

@@ -7,6 +7,7 @@ use Web3\Providers\Provider;
 use Web3\Providers\HttpProvider;
 use Web3\RequestManagers\RequestManager;
 use Web3\RequestManagers\HttpRequestManager;
+use Web3\Validators\HexValidator;
 
 class Web3
 {
@@ -24,6 +25,20 @@ class Web3
      */
     protected $eth;
 
+    /**
+     * methods
+     * 
+     * @var array
+     */
+    private $methods = [
+        'web3_clientVersion' => [],
+        'web3_sha3' => [
+            'params' => [
+                HexValidator::class
+            ]
+        ]
+    ];
+
     /**
      * construct
      *
@@ -62,6 +77,19 @@ class Web3
         if (strtolower($class[0]) === 'web3' && preg_match('/^[a-zA-Z0-9]+$/', $name) === 1) {
             $method = strtolower($class[1]) . '_' . $name;
 
+            if (!array_key_exists($method, $this->methods)) {
+                throw new \RuntimeException('Unallowed rpc method: ' . $method);
+            }
+            $allowedMethod = $this->methods[$method];
+
+            if (isset($allowedMethod['params'])) {
+                // validate params
+                foreach ($allowedMethod['params'] as $key => $rule) {
+                    if (call_user_func([$rule, 'validate'], $arguments[$key]) === false) {
+                        throw new \RuntimeException('Wrong type of ' . $name . ' method argument ' . $key . '.');
+                    }
+                }
+            }
             if ($this->provider->isBatch) {
                 $this->provider->send($method, $arguments, null);
             } else {

test/unit/Web3Test.php

@@ -2,6 +2,7 @@
 
 namespace Test\Unit;
 
+use RuntimeException;
 use Test\TestCase;
 use Web3\Web3;
 use Web3\Eth;
@@ -111,4 +112,50 @@ class Web3Test extends TestCase
             $this->assertEquals($data[1]->result, $this->testHash);
         });
     }
+
+    /**
+     * testUnallowedMethod
+     * 
+     * @return void
+     */
+    public function testUnallowedMethod()
+    {
+        $this->expectException(RuntimeException::class);
+
+        $web3 = $this->web3;
+
+        $web3->hello(function ($err, $hello) {
+            if ($err !== null) {
+                return $this->fail($err->getMessage());
+            }
+            if (isset($hello->result)) {
+                $this->assertTrue(true);
+            } else {
+                $this->fail($hello->error->message);
+            }
+        });
+    }
+
+    /**
+     * testWrongParam
+     * 
+     * @return void
+     */
+    public function testWrongParam()
+    {
+        $this->expectException(RuntimeException::class);
+
+        $web3 = $this->web3;
+
+        $web3->sha3('hello world', function ($err, $hash) {
+            if ($err !== null) {
+                return $this->fail($err->getMessage());
+            }
+            if (isset($hash->result)) {
+                $this->assertTrue(true);
+            } else {
+                $this->fail($hash->error->message);
+            }
+        });
+    }
 }