diff --git a/raytracing/src/canvas.cpp b/raytracing/src/canvas.cpp
index 0f1ac26..12a7931 100644
--- a/raytracing/src/canvas.cpp
+++ b/raytracing/src/canvas.cpp
@@ -107,7 +107,6 @@ std::string Canvas::to_ppm(void)
             add_color_component(the_result, the_col_number, the_color.blue_to_integer());
         }
         the_result += "\n";
-        the_col_number = 0;
     }
 
     return the_result;
diff --git a/tests/01_tuples.cpp b/tests/01_tuples.cpp
index 1a95824..018dd0c 100644
--- a/tests/01_tuples.cpp
+++ b/tests/01_tuples.cpp
@@ -271,6 +271,10 @@ SCENARIO("Adding two tuples without modify a1", "[features/tuples.feature]")
                 {
                     REQUIRE((a1 + a2) == Tuple(1, 1, 6, 1));
                 }
+                AND_THEN("a3 = a1 + a2")
+                {
+                    REQUIRE((a1 + a2) == a3);
+                }
             }
         }
     }
@@ -312,6 +316,10 @@ SCENARIO("Subtracting two points without modify p1", "[features/tuples.feature]"
                 {
                     REQUIRE((p1 - p2) == Tuple::Vector(-2, -4, -6));
                 }
+                AND_THEN("p3 = p1 - p2")
+                {
+                    REQUIRE((p1 - p2) == p3);
+                }
             }
         }
     }
@@ -414,6 +422,10 @@ SCENARIO("Multiplying a tuple by a scalar without modify a", "[features/tuples.f
             {
                 REQUIRE(a * 3.5 == Tuple(3.5, -7, 10.5, -14));
             }
+            AND_THEN("b = a * 3.5")
+            {
+                REQUIRE((a * 3.5) == b);
+            }
         }
     }
 }
@@ -460,6 +472,10 @@ SCENARIO("Dividing a tuple by a scalar without modify a", "[features/tuples.feat
             {
                 REQUIRE(a / 2 == Tuple(0.5, -1, 1.5, -2));
             }
+            AND_THEN("b = a / 2")
+            {
+                REQUIRE((a / 2) == b);
+            }
         }
     }
 }
diff --git a/tests/02_1_colors.cpp b/tests/02_1_colors.cpp
index abf2ce6..ac8d900 100644
--- a/tests/02_1_colors.cpp
+++ b/tests/02_1_colors.cpp
@@ -119,6 +119,10 @@ SCENARIO("Adding colors without modify c1", "[features/tuples.feature]")
                 {
                     REQUIRE((c1 + c2) == Color(1.6, 0.7, 1.0));
                 }
+                AND_THEN("c3 = c1 + c2")
+                {
+                    REQUIRE(c3 == c1 + c2);
+                }
             }
         }
     }
@@ -160,6 +164,10 @@ SCENARIO("Subtracting colors without modify c1", "[features/tuples.feature]")
                 {
                     REQUIRE((c1 - c2) == Color(0.2, 0.5, 0.5));
                 }
+                AND_THEN("c3 = c1 - c2")
+                {
+                    REQUIRE(c3 == c1 - c2);
+                }
             }
         }
     }
@@ -193,6 +201,10 @@ SCENARIO("Multiplying a color by a scalar without modify c", "[features/tuples.f
             {
                 REQUIRE(c * 2 == Color(0.4, 0.6, 0.8));
             }
+            AND_THEN("c3 = c * 4")
+            {
+                REQUIRE(c3 == c * 4);
+            }
         }
     }
 }
diff --git a/tests/04_transformations.cpp b/tests/04_transformations.cpp
index 2ae9608..5454b7c 100644
--- a/tests/04_transformations.cpp
+++ b/tests/04_transformations.cpp
@@ -252,8 +252,6 @@ SCENARIO("Rotating a point around the z axis", "[features/transformations.featur
             AND_GIVEN("full_quarter <- rotation_z(pi/2)")
             {
                 Matrix full_quarter = Matrix::rotation_z(std::numbers::pi / 2);
-
-                Tuple z = half_quarter * p;
                 THEN("half_quarter * p = point(-sqrt(2) / 2, sqrt(2) / 2, 0)")
                 {
                     REQUIRE(half_quarter * p == Tuple::Point(-sqrt(2) / 2, sqrt(2) / 2, 0));