diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc2bb83..d69328c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - upgrade docker system
 - [#30](https://github.com/green-code-initiative/ecoCode-php/issues/30) Upgrade dependencies to latest ones - technical incompatibilities for SonarQube before 9.9 version
+- clean unit test files (to have less other issues)
 
 ### Deleted
 
diff --git a/src/test/resources/checks/AvoidDoubleQuote.php b/src/test/resources/checks/AvoidDoubleQuote.php
index 30e0a47..bbde7b1 100644
--- a/src/test/resources/checks/AvoidDoubleQuote.php
+++ b/src/test/resources/checks/AvoidDoubleQuote.php
@@ -6,19 +6,43 @@
 $isStudent = true;
 $cours = array('physique','chimie','informatique','philosophie');
 
-echo $lastName;
-echo $name;
-echo '<br/>';
-echo "<br/>"; // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
-echo $age;
+mc = new MyClass();
+
+mc->display($lastName);
+mc->display($name);
+mc->display('<br/>');
+mc->display("<br/>"); // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
+mc->display($age);
 
 $identite = $lastName .' '. $name;
-echo $identite;
+mc->display($identite);
+
+mc->myFunction($name, $age, $isStudent);
+
+mc->myFunction("name", "age", "isStudent"); // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
+
+mc->myFunction('name', 'age', 'isStudent');
 
-myFunction($name, $age, $isStudent);
+mc->myFunction("name", 'age', "isStudent"); // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
 
-myFunction("name", "age", "isStudent"); // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
 
-myFunction('name', 'age', 'isStudent');
+class MyClass
+{
+    public function myFunction($name, $age, $isStudent)
+    {
+        if ($name == null) {
+            return 'toto' + $age;
+        } else {
+            return 'tata' + $isStudent;
+        }
+    }
 
-myFunction("name", 'age', "isStudent"); // NOK {{Avoid using double quote ("), prefer using simple quote (')}}
+    public function display($msg)
+    {
+        if ($msg != null) {
+            return $msg;
+        } else {
+            return '';
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/test/resources/checks/AvoidFullSQLRequest.php b/src/test/resources/checks/AvoidFullSQLRequest.php
index 4785c1d..9f62f98 100644
--- a/src/test/resources/checks/AvoidFullSQLRequest.php
+++ b/src/test/resources/checks/AvoidFullSQLRequest.php
@@ -1,8 +1,8 @@
 <?php
 
-$sql1 = 'SELECT * FROM'; // NOK {{Don't use the query SELECT * FROM}}
-$sql2 = 'SeLeCt DiStInCt * FrOm'; // NOK {{Don't use the query SELECT * FROM}}
-$sql3 = 'select name from';
+$sql1 = 'SELECT * FROM toto'; // NOK {{Don't use the query SELECT * FROM}}
+$sql2 = 'SeLeCt DiStInCt * FrOm tutu'; // NOK {{Don't use the query SELECT * FROM}}
+$sql3 = 'select name from titi';
 
 class AvoidFullSQLRequest
 {
@@ -10,7 +10,6 @@ public function literalString()
     {
         OtherClass->SqlCall('SELECT * FROM'); // NOK {{Don't use the query SELECT * FROM}}
         OtherClass->SqlCall('SeLeCt DiStInCt * FrOm'); // NOK {{Don't use the query SELECT * FROM}}
-        OtherClass->SqlCall('SeLeCt `table.name`, *, `my_field` FrOm'); // NOK {{Don't use the query SELECT * FROM}}
         OtherClass->SqlCall('select name from');
     }
 
diff --git a/src/test/resources/checks/AvoidGettingSizeCollectionInLoop.php b/src/test/resources/checks/AvoidGettingSizeCollectionInLoop.php
index 543a8b4..8e123cb 100644
--- a/src/test/resources/checks/AvoidGettingSizeCollectionInLoop.php
+++ b/src/test/resources/checks/AvoidGettingSizeCollectionInLoop.php
@@ -5,7 +5,7 @@
 /**
  * FOR STATEMENTS // RIGHT OPERAND
  */
-for ($i = 0; $i < count($array); ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; $i < count($array); ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -14,7 +14,7 @@
     var_dump($array[$i]);
 }
 
-for ($i = 0; $i < sizeof($array); ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; $i < sizeof($array); ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -23,7 +23,7 @@
     var_dump($array[$i]);
 }
 
-for ($i = 0; $i < iterator_count(new ArrayIterator($array)); ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; $i < iterator_count(new ArrayIterator($array)); ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -35,7 +35,7 @@
 /**
  * FOR STATEMENTS // LEFT OPERAND
  */
-for ($i = 0; count($array) > $i; ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; count($array) > $i; ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -44,7 +44,7 @@
     var_dump($array[$i]);
 }
 
-for ($i = 0; sizeof($array) > $i; ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; sizeof($array) > $i; ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -53,7 +53,7 @@
     var_dump($array[$i]);
 }
 
-for ($i = 0; iterator_count(new ArrayIterator($array)) > $i; ++$i) {  // NOK {{Avoid getting the size of the collection in the loop}}
+for ($i = 0; iterator_count(new ArrayIterator($array)) > $i; ++$i) { // NOK {{Avoid getting the size of the collection in the loop}}
     var_dump($array[$i]);
 }
 
@@ -115,7 +115,7 @@
 
 $i = 0;
 $size = count($array);
-while ($size> $i) { // Compliant
+while ($size > $i) { // Compliant
     var_dump($array[$i]);
     ++$i;
 }
diff --git a/src/test/resources/checks/AvoidSQLRequestInLoop.php b/src/test/resources/checks/AvoidSQLRequestInLoop.php
index 5a804bb..41088ab 100644
--- a/src/test/resources/checks/AvoidSQLRequestInLoop.php
+++ b/src/test/resources/checks/AvoidSQLRequestInLoop.php
@@ -6,7 +6,7 @@ class AvoidFullSQLRequest
     private $dbName = 'name';
     private $dbPass = 'pass';
     private $dbHost = 'host';
-    private $query = 'SELECT * FROM Table';
+    private $query = 'SELECT col1 FROM Table';
     private $otherQuery = 'SELECT name FROM User';
     private $connection;
     public function launchSQLRequest($someCondition)
diff --git a/src/test/resources/checks/AvoidUsingGlobalVariablesCheck.php b/src/test/resources/checks/AvoidUsingGlobalVariablesCheck.php
index 3431ab8..9a1c0b0 100644
--- a/src/test/resources/checks/AvoidUsingGlobalVariablesCheck.php
+++ b/src/test/resources/checks/AvoidUsingGlobalVariablesCheck.php
@@ -2,27 +2,19 @@
 
 $a = 1;
 $b = 2;
-
 function somme() // NOK {{Prefer local variables to globals}}
 {
     $GLOBALS['b'] = $GLOBALS['a'] + $GLOBALS['b'];
 }
 
-somme();
-echo $b;
-
 function somme2() // NOK {{Prefer local variables to globals}}
 {
     global $a, $b;
-    $b = $a + $b;
+    $c = $a + $b;
 }
 
-somme2();
-echo $b;
-
-function somme3($a, $b) // Compliant
+function somme3($c, $d) // Compliant
 {
-    return $a + $b;
+    $e = $c + $d;
+    return ++$e;
 }
-
-echo somme3($a, $b);
diff --git a/src/test/resources/checks/IncrementCheck.php b/src/test/resources/checks/IncrementCheck.php
index 16bfc68..2ea866f 100644
--- a/src/test/resources/checks/IncrementCheck.php
+++ b/src/test/resources/checks/IncrementCheck.php
@@ -3,7 +3,8 @@
 function foo()
 {
     $counter = 0;
-    return $counter++; // NOK {{Remove the usage of $i++. prefer ++$i}}
+    $counter++; // NOK {{Remove the usage of $i++. prefer ++$i}}
+    return $counter;
 }
 
 function bar()
diff --git a/src/test/resources/checks/NoFunctionCallWhenDeclaringForLoop.php b/src/test/resources/checks/NoFunctionCallWhenDeclaringForLoop.php
index 4062cde..1dd5b6f 100644
--- a/src/test/resources/checks/NoFunctionCallWhenDeclaringForLoop.php
+++ b/src/test/resources/checks/NoFunctionCallWhenDeclaringForLoop.php
@@ -2,13 +2,13 @@
 
 /* exemple 1 */
 
-for ($i = 1; $i <= 10; $i++) {
+for ($i = 1; $i <= 10; ++$i) {
     echo $i;
 }
 
 /* exemple 2 */
 
-for ($i = 1; ; $i++) {
+for ($i = 1; ; ++$i) {
     if ($i > 10) {
         break;
     }
@@ -18,30 +18,30 @@
 /* exemple 3 */
 
 $i = 1;
-for (; ;) {
+while (true) {
     if ($i > 10) {
         break;
     }
     echo $i;
-    $i++;
+    ++$i;
 }
 
 /* exemple 4 */
 
-for ($i = 1, $j = 0; $i <= 10; $j += $i, print $i, $i++); // NOK {{Do not call a function in for-type loop declaration}}
+for ($i = 1, $j = 0; $i <= 10; $j += $i, print $i, ++$i); // NOK {{Do not call a function in for-type loop declaration}}
 
 
-function somewhat_calcMax()
+function somewhatCalcMax()
 {
     return 500;
 }
 
 
-for ($i = 0; $i <= somewhat_calcMax(); $i++) { // NOK {{Do not call a function in for-type loop declaration}}
+for ($i = 0; $i <= somewhatCalcMax(); ++$i) { // NOK {{Do not call a function in for-type loop declaration}}
     var_dump($i);
 }
 
-$maxI = somewhat_calcMax();
-for ($i = 0; $i <= $maxI; $i++) { // COMPLIANT
+$maxI = somewhatCalcMax();
+for ($i = 0; $i <= $maxI; ++$i) { // COMPLIANT
     var_dump($i);
 }