add test for linear congruential generator

.travis.yml

@@ -3,6 +3,7 @@ language: php
 php:
   - '5.6'
   - '7.0'
+  - '7.1'
 
 services:
   - mysql
@@ -27,5 +28,7 @@ before_install:
 script:
 - cd client
 - npm test
+- cd ../server
+- ./run-tests.sh
 - cd ../tests
 - bacon init.rb

server/libs/Hashing.php

@@ -30,6 +30,8 @@ class Hashing {
         $sqrt = sqrt($number);
         $prime = true;
 
+        if($number <= 1) return false;
+
         for($i = 2; $i <= $sqrt; $i++) {
             if($number % $i === 0) {
                 $prime = false;

server/tests/libs/HashingTest.php

@@ -0,0 +1,73 @@
+<?php
+include_once 'libs/Hashing.php';
+
+use PHPUnit\Framework\TestCase;
+
+class HashingTest extends TestCase {
+
+    public function testShouldGenerateRandomToken() {
+        $token1 = Hashing::generateRandomToken();
+        $token2 = Hashing::generateRandomToken();
+
+        $this->assertNotEquals($token1, $token2);
+    }
+
+    public function testShouldHashAndVerifyPassword() {
+        $TEST_TIMES = 5;
+
+        for ($i = 0; $i < $TEST_TIMES; $i++) {
+            $password = Hashing::generateRandomToken();
+            $passwordHash = Hashing::hashPassword($password);
+
+            $this->assertTrue(Hashing::verifyPassword($password, $passwordHash));
+            $this->assertFalse(Hashing::verifyPassword('', $passwordHash));
+            $this->assertFalse(Hashing::verifyPassword($password, ''));
+            $this->assertFalse(Hashing::verifyPassword('', ''));
+            $this->assertFalse(Hashing::verifyPassword($password . 'a', $passwordHash));
+            $this->assertFalse(Hashing::verifyPassword($password, $passwordHash . 'a'));
+        }
+
+    }
+
+    public function testShouldGenerateNumber() {
+        $TEST_TIMES = 10;
+
+        for ($i = 0; $i < $TEST_TIMES; $i++) {
+            $min = $i*1000;
+            $max = $TEST_TIMES*6000;
+
+            $number1 = Hashing::generateRandomNumber($min, $max);
+            $number2 = Hashing::generateRandomNumber($min, $max);
+
+            $this->assertTrue($min < $number1 && $number1 < $max);
+            $this->assertTrue($min < $number2 && $number2 < $max);
+            $this->assertNotEquals($number1, $number2);
+        }
+    }
+
+    public function testShouldRecognizePrime() {
+        $primes = [2, 3, 5, 7, 11, 17, 53, 163, 379, 401, 443, 449, 701];
+        $nonPrimes = [0, 1, 4, 27, 40, 51, 155, 363, 381, 511, 703, 928];
+
+        foreach($primes as $number) $this->assertTrue(Hashing::isPrime($number));
+        foreach($nonPrimes as $number) $this->assertFalse(Hashing::isPrime($number));
+    }
+
+    public function testShouldGenerateRandsomPrime() {
+        $TEST_TIMES = 10;
+
+        for ($i = 0; $i < $TEST_TIMES; $i++) {
+            $min = $i*1000;
+            $max = $TEST_TIMES*6000;
+
+            $number1 = Hashing::generateRandomPrime($min, $max);
+            $number2 = Hashing::generateRandomPrime($min, $max);
+
+            $this->assertTrue($min < $number1 && $number1 < $max);
+            $this->assertTrue($min < $number2 && $number2 < $max);
+            $this->assertNotEquals($number1, $number2);
+            $this->assertTrue(Hashing::isPrime($number1));
+            $this->assertTrue(Hashing::isPrime($number2));
+        }
+    }
+}

server/tests/libs/LinearCongruentialGeneratorTest.php

@@ -0,0 +1,30 @@
+<?php
+include_once 'libs/Hashing.php';
+include_once 'libs/LinearCongruentialGenerator.php';
+
+use PHPUnit\Framework\TestCase;
+
+class LinearCongruentialGeneratorTest extends TestCase {
+
+    public function testAvoidCollisions() {
+        $TEST_TIMES = 10;
+        $GENERATE_TIMES = 500000;
+        $min = 100000;
+        $max = 999999;
+
+        for($i = 0; $i < $TEST_TIMES; $i++) {
+            $linearCongruentialGenerator = new LinearCongruentialGenerator();
+            $linearCongruentialGenerator->setRange($min, $max);
+            $linearCongruentialGenerator->setGap(Hashing::generateRandomPrime($min, $max));
+            $linearCongruentialGenerator->setFirst($linearCongruentialGenerator->generateFirst());
+
+            $used = [];
+
+            for($j = 0; $j < $GENERATE_TIMES; $j++) {
+                $generatedNumber = $linearCongruentialGenerator->generate($j);
+                $this->assertFalse(array_key_exists($generatedNumber, $used));
+                $used[$generatedNumber] = true;
+            }
+        }
+    }
+}