ajout: Implémentation de Path#isValid

be-graphes-model/src/main/java/org/insa/graphs/model/Path.java

@@ -184,11 +184,29 @@ public class Path {
      * </ul>
      *
      * @return true if the path is valid, false otherwise.
-     * @deprecated Need to be implemented.
      */
     public boolean isValid() {
-        // TODO:
-        return false;
+        // size() == 0 <=> empty
+        // size() == 1 <=> single node (without arcs)
+        boolean result = false;
+        if (this.size() <= 1) {
+            result = true;
+        } else {
+            if (this.arcs.get(0).getOrigin() == this.origin) {
+                Arc prev = null;
+                result = true;
+                for (Arc next : this.arcs) {
+                    if (prev != null) {
+                        if (prev.getDestination() != next.getOrigin()) {
+                            result = false;
+                            break;
+                        }
+                    }
+                    prev = next;
+                }    
+            }
+        }
+        return result;
     }
 
     /**