diff --git a/.gitea/workflows/test.yaml b/.gitea/workflows/test.yaml
new file mode 100644
index 0000000..aa1aff5
--- /dev/null
+++ b/.gitea/workflows/test.yaml
@@ -0,0 +1,22 @@
+name: Tests C avec Criterion
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    container:
+      image: alpine:latest
+      
+    steps:
+      - name: Récupérer le code
+        uses: actions/checkout@v4
+
+      - name: Installer GCC et Criterion
+        run: apk add --no-cache gcc musl-dev criterion-dev
+
+      - name: Compiler
+        run: gcc -Wall -Wextra -I./Chains_across_the_Island/Fundamentals/basics/ -o tests Chains_across_the_Island/Fundamentals/basics/basics.c tests/tests.c -lcriterion
+      
+      - name: Executer
+        run: ./tests
diff --git a/Chains_across_the_Island/Fundamentals/basics/basics.c b/Chains_across_the_Island/Fundamentals/basics/basics.c
index 7910492..0165a96 100644
--- a/Chains_across_the_Island/Fundamentals/basics/basics.c
+++ b/Chains_across_the_Island/Fundamentals/basics/basics.c
@@ -1,16 +1,16 @@
 #include "basics.h"
 #include <stddef.h>
+#include <stdio.h>
 #include <stdlib.h>
 struct list *list_append(struct list *l, int e)
 {
-    if (!l) return NULL;
-    struct list *tmp = l;
+   struct list *tmp = l;
     
     struct list *new_node = calloc(1, sizeof(struct list));
     if (!new_node) return NULL;
 
     new_node->data = e;
-    if(!tmp) return new_node;
+    if(!l) return new_node;
     
     while (tmp->next) tmp = tmp->next;
     tmp->next = new_node;
@@ -84,17 +84,99 @@ void list_destroy(struct list *l){
     free(l);
 }
 
+struct list *list_find(struct list *l, int e){
+
+    if(!l) return NULL;
+
+    struct list *tmp = l;
+    
+    while (tmp->data != e) tmp = tmp->next;
+
+    return tmp;
+
+}
+
+struct list *list_delete_at(struct list **l, size_t index){
+
+    struct list *old = *l;
+
+    if ( index == 0){
+        *l = old->next;
+        return old;
+    }
+
+    struct list *tmp = *l;
+
+    size_t ind = 0;
+    while(tmp->next != NULL && ind < index - 1){
+        
+        tmp = tmp->next;
+        ind ++;
+    }
+
+    if (ind < index) {
+        old = tmp->next;
+        tmp->next = old->next;
+        return old;
+    }
+    return NULL;
+
+}
+int list_remove(struct list **l, int e){
+
+    struct list *old = *l;
+    struct list *tmp = *l;
+
+    while (tmp->next != NULL && tmp->data != e){
+    
+        tmp = tmp->next;
+    }
+
+    if(tmp->data == e) {
+    
+        old = tmp->next;
+        tmp->next = old->next;
+        return 1;
+    }
+    return 0;
+}
+
+void list_print(struct list *l){
+
+    if(!l) {
+        printf("\n");
+        return ;
+    }
+
+    struct list *tmp = l;
+
+    while (tmp != NULL){
+        
+        printf("%i",tmp->data);
+
+        if (tmp->next != NULL) printf(" -> ");
+
+        tmp = tmp->next;
+
+    }
+    printf("\n");
+}
+
 int main(void)
 {
     struct list *l = NULL;
 
     l = list_append(l, 42);    // l = [42] -> NULL
+    list_print(l);
     l = list_append(l, 7);     // l = [7] -> [42] -> NULL
-    list_count(NULL);               // 0
-    list_count(l);  // 3
+    list_print(l);
 
-    // Here, you should call "list_destroy(l);" when it will be implemented to
-    // prevent any memory leak
+        // l = [1] -> [2] -> [3]
+    list_insert(&l, 1, 99);  // l = [1] -> [99] -> [2] -> [3], and list_insert returns 0
+    list_insert(&l, 9, 99);  // list unchanged, returns 1
+
+
+    list_destroy(l);
 
     return 0;
 }
diff --git a/Chains_across_the_Island/Fundamentals/basics/test b/Chains_across_the_Island/Fundamentals/basics/test
index 9c3ddc3..350dd97 100755
Binary files a/Chains_across_the_Island/Fundamentals/basics/test and b/Chains_across_the_Island/Fundamentals/basics/test differ
diff --git a/tests/tests.c b/tests/tests.c
new file mode 100644
index 0000000..b3ed00e
--- /dev/null
+++ b/tests/tests.c
@@ -0,0 +1,48 @@
+#include <criterion/criterion.h>
+#include "../Chains_across_the_Island/Fundamentals/basics/basics.h"
+
+// Test pour list_append
+Test(basics_suite, test_append) {
+    struct list *l = NULL;
+    
+    l = list_append(l, 42);
+    cr_assert_not_null(l, "La liste ne doit pas être NULL après le premier ajout.");
+    cr_assert_eq(l->data, 42, "La donnée du premier nœud doit être 42.");
+    
+    l = list_append(l, 7);
+    cr_assert_not_null(l->next, "Le deuxième nœud doit exister.");
+    cr_assert_eq(l->next->data, 7, "La donnée du deuxième nœud doit être 7.");
+
+    list_destroy(l);
+}
+
+// Test pour list_count
+Test(basics_suite, test_count) {
+    struct list *l = NULL;
+    
+    cr_assert_eq(list_count(l), 0, "Une liste vide doit avoir une taille de 0.");
+    
+    l = list_append(l, 10);
+    l = list_append(l, 20);
+    l = list_append(l, 30);
+    
+    cr_assert_eq(list_count(l), 3, "La liste doit contenir 3 éléments.");
+
+    list_destroy(l);
+}
+
+// Test pour list_insert
+Test(basics_suite, test_insert) {
+    struct list *l = NULL;
+    
+    // Insertion dans une liste vide
+    int res1 = list_insert(&l, 0, 100);
+    cr_assert_eq(res1, 0, "L'insertion à l'index 0 doit réussir.");
+    cr_assert_eq(l->data, 100, "La valeur insérée doit être 100.");
+    
+    // Insertion hors limite
+    int res2 = list_insert(&l, 5, 200);
+    cr_assert_eq(res2, 1, "L'insertion hors limite doit échouer et renvoyer 1.");
+
+    list_destroy(l);
+}