fix: 🩹 "++i" statement is not so bad

In some cases, postfix increment may be intentional.

Closes #4

src/main/java/fr/greencodeinitiative/java/checks/IncrementCheck.java

@@ -39,6 +39,8 @@ public List<Kind> nodesToVisit() {
 
     @Override
     public void visitNode(Tree tree) {
-        reportIssue(tree, MESSAGERULE);
+        if (tree.parent().is(Kind.EXPRESSION_STATEMENT)) {
+            reportIssue(tree, MESSAGERULE);
+        }   
     }
 }

src/test/files/IncrementCheck.java

@@ -18,46 +18,71 @@
 class IncrementCheck {
     IncrementCheck(IncrementCheck mc) {
     }
-
+    
     int foo1() {
         int counter = 0;
-        return counter++; // Noncompliant {{Use ++i instead of i++}}
+        return counter++; // Compliant but should raise a java:S2123 and a java:S1854
+    }
+
+    private int j = 0;
+    int foo10() {
+        return this.j++; // Compliant because maybe the use case needs to return j AND increment it
     }
 
     int foo11() {
         int counter = 0;
         return ++counter;
     }
 
-    void foo2(int value) {
+    int foo2() {
         int counter = 0;
         counter++; // Noncompliant {{Use ++i instead of i++}}
+        return counter;
     }
 
-    void foo22(int value) {
+    int foo22() {
         int counter = 0;
         ++counter;
+        return counter;
     }
 
-    void foo3(int value) {
+    int foo3() {
         int counter = 0;
         counter = counter + 197845 ;
+        return counter;
     }
 
-    void foo4(int value) {
-        int counter =0;
+    int foo4() {
+        int counter = 0;
         counter = counter + 35 + 78 ;
+        return counter;
     }
 
-    void foo50(int value) {
+    void foo50() {
         for (int i=0; i < 10; i++) { // Noncompliant {{Use ++i instead of i++}}
-            System.out.println(i);
+            System.out.println(i); //NOSONAR
         }
     }
 
-    void foo51(int value) {
+    void foo51() {
         for (int i=0; i < 10; ++i) {
-            System.out.println(i);
+            System.out.println(i); //NOSONAR
         }
     }
+
+    void bar61(int value) {
+        // For test purpose
+    }
+
+    int foo61() {
+        int i = 0;
+        bar61(i++); // Compliant because maybe bar61 needs the unincremented value
+        return i;
+    }
+
+    int foo62() {
+        int i = 0;
+        bar61(2 + i++); // Compliant because maybe bar61 needs the unincremented value
+        return i;
+    }
 }