diff --git a/tests/DbgTest.php b/tests/DbgTest.php
index 03069d0..968a1fb 100644
--- a/tests/DbgTest.php
+++ b/tests/DbgTest.php
@@ -16,66 +16,35 @@
  */
 class DbgTest extends \PHPUnit\Framework\TestCase
 {
-    /**
-     * Test printing number.
-     *
-     * @return void
-     */
     public function testPrintNumber()
     {
-        $var = 123;
-        $this->assertEquals('123', $this->captureOutput($var));
+        $var = TestHelper::randomInt();
+
+        $this->assertEquals($var, $this->captureOutput($var));
     }
 
-    /**
-     * Test printing string.
-     *
-     * @return void
-     */
     public function testPrintString()
     {
-        $var = 'some string';
+        $var = TestHelper::randomString();
+
         $this->assertEquals($var, $this->captureOutput($var));
     }
 
-    /**
-     * Test printing output.
-     *
-     * @return void
-     */
     public function testPrintArray()
     {
-        $var = ['first', 'second', 'third'];
-        $expected = <<<'EOT'
-Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
+        $var = TestHelper::randomArray();
+        $expected = TestHelper::makeArrayOutput($var);
 
-EOT;
         $this->assertEquals($expected, $this->captureOutput($var));
     }
 
-    /**
-     * Test printing output in non-CLI environment.
-     *
-     * @return void
-     */
     public function testPrintArrayNonCli()
     {
         TestDebug::init();
-        $var = ['first', 'second', 'third'];
-        $expected = <<<'EOT'
-<pre>Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
-</pre>
-EOT;
+
+        $var = TestHelper::randomArray();
+        $expected = '<pre>' . TestHelper::makeArrayOutput($var) . '</pre>';
+
         $this->assertEquals($expected, $this->captureOutput($var));
     }
 
diff --git a/tests/DbgThrowTest.php b/tests/DbgThrowTest.php
index c25857a..8e4679c 100644
--- a/tests/DbgThrowTest.php
+++ b/tests/DbgThrowTest.php
@@ -18,45 +18,25 @@
  */
 class DbgThrowTest extends \PHPUnit\Framework\TestCase
 {
-    /**
-     * Test printing number.
-     *
-     * @return void
-     */
     public function testThrowNumber()
     {
-        $var = 123;
+        $var = TestHelper::randomInt();
+
         $this->assertEquals($var, $this->captureException($var));
     }
 
-    /**
-     * Test printing string.
-     *
-     * @return void
-     */
     public function testThrowString()
     {
-        $var = 'some string';
+        $var = TestHelper::randomString();
+
         $this->assertEquals($var, $this->captureException($var));
     }
 
-    /**
-     * Test printing output.
-     *
-     * @return void
-     */
-    public function testPrintArray()
+    public function testThrowArray()
     {
-        $var = ['first', 'second', 'third'];
-        $expected = <<<'EOT'
-Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
+        $var = TestHelper::randomArray();
+        $expected = TestHelper::makeArrayOutput($var);
 
-EOT;
         $this->assertEquals($expected, $this->captureException($var));
     }
 
diff --git a/tests/DbglogTest.php b/tests/DbglogTest.php
index a0f09ec..0e6c710 100644
--- a/tests/DbglogTest.php
+++ b/tests/DbglogTest.php
@@ -19,11 +19,6 @@
  */
 class DbglogTest extends \PHPUnit\Framework\TestCase
 {
-    /**
-     * Test printing number with log file.
-     *
-     * @return void
-     */
     public function testLogNumberWithLogFile()
     {
         $logfile = TestHelper::createTempFile();
@@ -31,7 +26,7 @@ public function testLogNumberWithLogFile()
             'log_file' => $logfile
         ]);
 
-        $var = random_int(PHP_INT_MIN, PHP_INT_MAX);
+        $var = TestHelper::randomInt();
         dbglog($var);
 
         $this->assertRegExp(
@@ -40,11 +35,6 @@ public function testLogNumberWithLogFile()
         );
     }
 
-    /**
-     * Test printing string with log file.
-     *
-     * @return void
-     */
     public function testLogStringWithLogFile()
     {
         $logfile = TestHelper::createTempFile();
@@ -52,7 +42,7 @@ public function testLogStringWithLogFile()
             'log_file' => $logfile
         ]);
 
-        $var = base64_encode(random_bytes(24));
+        $var = TestHelper::randomString();
         dbglog($var);
 
         $this->assertRegExp(
@@ -61,11 +51,6 @@ public function testLogStringWithLogFile()
         );
     }
 
-    /**
-     * Test printing output with log file.
-     *
-     * @return void
-     */
     public function testLogArrayWithLogFile()
     {
         $logfile = TestHelper::createTempFile();
@@ -73,29 +58,16 @@ public function testLogArrayWithLogFile()
             'log_file' => $logfile
         ]);
 
-        $var = ['first', 'second', 'third'];
+        $var = TestHelper::randomArray();
         dbglog($var);
 
-        $expected = <<<'EOT'
-Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
-
-EOT;
+        $expected = TestHelper::makeArrayOutput($var);
         $this->assertRegExp(
             TestHelper::makePattern($expected),
             file_get_contents($logfile)
         );
     }
 
-    /**
-     * Test printing data with no log file.
-     *
-     * @return void
-     */
     public function testLogWithNoLogFile()
     {
         $logfile = TestHelper::createTempFile();
@@ -103,26 +75,20 @@ public function testLogWithNoLogFile()
             'log_file' => null
         ]);
 
-        $var = random_int(PHP_INT_MIN, PHP_INT_MAX);
+        $var = TestHelper::randomInt();
         dbglog($var);
 
         $this->assertEmpty(file_get_contents($logfile));
     }
 
-    /**
-     * Test printing number with logger.
-     *
-     * @return void
-     */
     public function testLogNumberWithLogger()
     {
-        $fp = tmpfile();
-        $logfile = stream_get_meta_data($fp)['uri'];
+        $logfile = TestHelper::createTempFile();
         dbginit([
             'logger' => new Logger($logfile)
         ]);
 
-        $var = random_int(PHP_INT_MIN, PHP_INT_MAX);
+        $var = TestHelper::randomInt();
         dbglog($var);
 
         $this->assertRegExp(
@@ -131,20 +97,14 @@ public function testLogNumberWithLogger()
         );
     }
 
-    /**
-     * Test printing string with logger.
-     *
-     * @return void
-     */
     public function testLogStringWithLogger()
     {
-        $fp = tmpfile();
-        $logfile = stream_get_meta_data($fp)['uri'];
+        $logfile = TestHelper::createTempFile();
         dbginit([
             'logger' => new Logger($logfile)
         ]);
 
-        $var = base64_encode(random_bytes(24));
+        $var = TestHelper::randomString();
         dbglog($var);
 
         $this->assertRegExp(
@@ -153,52 +113,33 @@ public function testLogStringWithLogger()
         );
     }
 
-    /**
-     * Test printing output with logger.
-     *
-     * @return void
-     */
     public function testLogArrayWithLogger()
     {
-        $fp = tmpfile();
-        $logfile = stream_get_meta_data($fp)['uri'];
+        $logfile = TestHelper::createTempFile();
         dbginit([
             'logger' => new Logger($logfile)
         ]);
 
-        $var = ['first', 'second', 'third'];
+        $var = TestHelper::randomArray();
         dbglog($var);
 
-        $expected = <<<'EOT'
-Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
+        $expected = TestHelper::makeArrayOutput($var);
 
-EOT;
         $this->assertRegExp(
             TestHelper::makePattern($expected),
             file_get_contents($logfile)
         );
     }
 
-    /**
-     * Test printing data with custom date format.
-     *
-     * @return void
-     */
     public function testLogWithLoggerAndCustomDateFormat()
     {
-        $fp = tmpfile();
-        $logfile = stream_get_meta_data($fp)['uri'];
+        $logfile = TestHelper::createTempFile();
         $dateFormat = 'Y/m/d H/i/s';
         dbginit([
             'logger' => new Logger($logfile, $dateFormat)
         ]);
 
-        $var = random_int(PHP_INT_MIN, PHP_INT_MAX);
+        $var = TestHelper::randomInt();
         dbglog($var);
 
         $this->assertRegExp(
@@ -207,20 +148,14 @@ public function testLogWithLoggerAndCustomDateFormat()
         );
     }
 
-    /**
-     * Test printing data with no logger.
-     *
-     * @return void
-     */
     public function testLogWithNoLogger()
     {
-        $fp = tmpfile();
-        $logfile = stream_get_meta_data($fp)['uri'];
+        $logfile = TestHelper::createTempFile();
         dbginit([
             'logger' => null
         ]);
 
-        $var = random_int(PHP_INT_MIN, PHP_INT_MAX);
+        $var = TestHelper::randomInt();
         dbglog($var);
 
         $this->assertEmpty(file_get_contents($logfile));
diff --git a/tests/DbgrTest.php b/tests/DbgrTest.php
index ebbf2df..ee29f7a 100644
--- a/tests/DbgrTest.php
+++ b/tests/DbgrTest.php
@@ -18,97 +18,63 @@
  */
 class DbgrTest extends \PHPUnit\Framework\TestCase
 {
-    /**
-     * Test number output.
-     *
-     * @return void
-     */
     public function testDebugNumber()
     {
-        $var = 123;
-        $this->assertSame('123', dbgr($var));
+        $var = TestHelper::randomInt();
+
+        $this->assertEquals($var, dbgr($var));
     }
 
-    /**
-     * Test string output.
-     *
-     * @return void
-     */
     public function testDebugString()
     {
-        $var = 'some string';
+        $var = TestHelper::randomString();
+
         $this->assertSame($var, dbgr($var));
     }
 
-    /**
-     * Test array output.
-     *
-     * @return void
-     */
     public function testDebugArray()
     {
-        $var = ['first', 'second', 'third'];
-        $expected = <<<'EOT'
-Array
-(
-    [0] => first
-    [1] => second
-    [2] => third
-)
-
-EOT;
+        $var = TestHelper::randomArray();
+        $expected = TestHelper::makeArrayOutput($var);
+
         $this->assertEquals($expected, dbgr($var));
     }
 
-    /**
-     * Test string output setting vardump by init.
-     *
-     * @return void
-     */
     public function testDebugStringUsingVardumpByInit()
     {
         dbginit(['use_vardump' => true]);
-        $var = 'another string';
+
+        $var = TestHelper::randomString();
+
         $this->assertSame(
             $this->extractDumped($this->captureVardump($var), 'string'),
             $this->extractDumped(dbgr($var), 'string')
         );
     }
 
-    /**
-     * Test string output setting vardump by argument.
-     *
-     * @return void
-     */
     public function testDebugStringUsingVardumpByArg()
     {
-        $var = 'Some Third String';
+        $var = TestHelper::randomString();
+
         $this->assertSame(
             $this->extractDumped($this->captureVardump($var), 'string'),
             $this->extractDumped(dbgr($var, Debug::USE_VARDUMP), 'string')
         );
     }
 
-    /**
-     * Test string output setting htmlentities by init.
-     *
-     * @return void
-     */
     public function testDebugStringUsingHtmlentitiesByInit()
     {
         dbginit(['use_htmlentities' => true]);
-        $var = '<b>Header<b>';
+
+        $var = '<b>' . TestHelper::randomInt() . '<b>';
+
         $this->assertSame(htmlentities($var), dbgr($var));
     }
 
-    /**
-     * Test string output setting htmlentities by argument.
-     *
-     * @return void
-     */
     public function testDebugStringUsingHtmlentitiesByArg()
     {
-        $var = '<b>Footer<b>';
+        $var = '<b>' . TestHelper::randomInt() . '<b>';
+
         $this->assertSame(htmlentities($var), dbgr($var, Debug::USE_HTMLENTITIES));
     }
 
diff --git a/tests/TestHelper.php b/tests/TestHelper.php
index dfc3204..6ce6ef5 100644
--- a/tests/TestHelper.php
+++ b/tests/TestHelper.php
@@ -25,6 +25,42 @@ class TestHelper
      */
     private static $fp;
 
+    /**
+     * Generate a random int.
+     *
+     * @return int
+     */
+    public static function randomInt(): int
+    {
+        return random_int(PHP_INT_MIN, PHP_INT_MAX);
+    }
+
+    /**
+     * Generate a random string.
+     *
+     * @return string
+     */
+    public static function randomString(): string
+    {
+        $numChars = random_int(1, 340);
+        return substr(base64_encode(random_bytes(256)), 0, $numChars);
+    }
+
+    /**
+     * Generate a random array.
+     *
+     * @return array
+     */
+    public static function randomArray(): array
+    {
+        $entries = [];
+        $numEntries = random_int(5, 25);
+        while ($numEntries-- > 0) {
+            $entries[self::randomInt()] = self::randomString();
+        }
+        return $entries;
+    }
+
     /**
      * Create temporary file.
      *
@@ -38,7 +74,7 @@ public static function createTempFile(): string
     }
 
     /**
-     * Make regexp pattern for variable.
+     * Create regexp pattern for variable.
      *
      * @param mixed  $var  The variable to analyse.
      *
@@ -62,4 +98,31 @@ public static function makePattern($var, string $dateFormat = Logger::DATE_FORMA
         );
         return '/' . $datePattern . ': ' . preg_quote($var, '/') . '/';
     }
+
+    /**
+     * Create expected output for an array.
+     *
+     * @param array  $entries  The array to analyse.
+     *
+     * @return string
+     */
+    public static function makeArrayOutput(array $entries): string
+    {
+        $output = '';
+        foreach ($entries as $key => $value) {
+            $output .= <<<EOT
+    [{$key}] => {$value}
+
+EOT;
+        }
+        $output = rtrim($output);
+
+        return <<<EOT
+Array
+(
+{$output}
+)
+
+EOT;
+    }
 }